Received: 27 May 2020
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
Pharmacological profile and effects of mitotane in adrenocortical carcinoma
Claudia Rita Corso 1,2 Alexandra Acco3 İD İD Camila Bach1,2 | |
Sandro José Ribeiro Bonatto1,2 İD
| Bonald Cavalcante de Figueiredo1,2 (D |
Lauro Mera de Souza1,2 İD
1Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil 2Faculdades Pequeno Príncipe, Curitiba, Brazil 3Pharmacology Department, Federal University of Paraná, Curitiba, Brazil
Correspondence Claudia Rita Corso, Instituto de Pesquisa Pelé Pequeno Príncipe, Silva Jardim, 1632, Água Verde, Curitiba, PR. CEP: 80.250-200, Brazil. Email: claudia_rcorso@hotmail.com
Funding information
Conselho Nacional de Desenvolvimento Científico e Tecnológico, Grant/Award Number: 001; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Fundação Araucária
Mitotane is the only adrenolytic drug approved by the Food and Drug Administration for treating adrenocortical carcinoma (ACC). This drug has cytotoxic effects on tumour tissues; it induces cell death and antisecretory effects on adrenal cells by inhibiting the synthesis of adrenocortical steroids, which are involved in the patho- genesis of ACC. However, high doses of mitotane are usually necessary to reach the therapeutic plasma concentration, which may result in several adverse effects. This suggests that important pharmacological processes, such as first pass metabolism, tissue accumulation and extensive time for drug elimination, are associated with mitotane administration. Few studies have reported the pharmacological aspects and therapeutic effects of mitotane. Therefore, the aim of this review was to summarize the chemistry, pharmacokinetics and pharmacodynamics, and therapeutic and toxic effects of mitotane. This review also discusses new perspectives of mitotane formu- lation that are currently under investigation. Understanding the pharmacological profile of mitotane can improve the monitoring and efficacy of this drug in ACC treatment and can provide useful information for the development of new drugs with specific action against ACC with fewer adverse effects.
KEYWORDS
adrenocortical carcinoma, mechanism of action, mitotane, pharmacokinetics, therapeutic effects
|
1 INTRODUCTION
Adrenocortical carcinoma (ACC) is a rare endocrine malignancy arising from 1 of the 3 cortical layers of the adrenal gland. ACCs can cause an increase in the production of 1 or more steroid hormones, such as cor- tisol, androgens and aldosterone, resulting in clinical manifestations of Cushing’s syndrome, virilization (facial acne, hirsutism, increase in muscle mass) and high blood pressure, respectively. Clinical manifesta- tions are variable, and the prognosis of ACC is often unfavourable, especially in older individuals.1,2 The incidence of ACC is 1.7-2.0 cases/million/year among adults being more common among women and rare among children in most countries (0.2-0.3 cases/million/ year).2-4 One exception is southern Brazil, wherein the incidence of
ACC is higher in children than in adults,5 reaching a rate of 3.4-4.2/ million children versus an estimated worldwide incidence of 0.3/ million children aged younger than 15 years.6
Currently, mitotane is the only approved adrenolytic drug,7 as single or adjuvant treatment, for postoperative or inoperable ACC. The daily dose usually ranges between 2 and 10 g to reach the ideal plasma concentration, with tolerable toxicity of 14-20 mg L-1.8,9 The mean dose is 4 g day-1 for adults and 4 g m-2 day-1 for children with ACC stage 3/4 and recurrence of stage 1/2.10,11 In most patients, the therapeutic plasma concentration is reached only after 3 months of daily treatment,9,12 within which the patients experience several adverse events of the gastrointestinal (diarrhoea, nausea, vomiting and anorexia) and central nervous (confusion, ataxia and dizziness)
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
systems,13 thereby limiting its therapeutic use mainly among paediat- ric ACC patients.
Mitotane (1-chloro-2-[2,2-dichloro-1-{4-chlorophenyl}ethyl] benzene), also known as o,p’-DDD, was isolated in 1940 from the insecticide dichlorodiphenyltrichloroethane (DDT). The adrenolytic effect of mitotane was first reported in dogs, when it induced selec- tive necrosis in the zona fasciculata and zona reticularis of the adrenal cortex.14,15 The first clinical evidence was published in 1959, when the efficacy of mitotane for the treatment of ACC was reported in male patients.16 Thereafter, even though the mechanism of action was unclear, mitotane was approved by the Food and Drug Adminis- tration for ACC treatment and became commercially available in a tablet form as Lysodren.17
Mitotane monotherapy is the first-line of treatment for less pro- gressive ACC after surgery, and mitotane plus chemotherapy with drugs such as etoposide, doxorubicin and cisplatin was used to treat more aggressive forms.18,19 If the first-line therapy fails, mitotane can also be employed in combination with streptozotocin, vincristine, gemcitabine-capecitabine and avelumab.18 A recent meta-analysis revealed that mitotane monotherapy with or without radiotherapy, decreased the recurrence rate and mortality after tumour resection among patients without distant metastasis.2º However, the efficacy of mitotane combined with chemotherapy remains unclear, and few clinical trials have monitored plasma mitotane levels during the mitotane plus chemotherapy regimen (Table 1).
Even after 5 decades of clinical use, only few studies have addressed the pharmacological aspects of mitotane, probably because ACC is a rare disease. Therefore, better understanding of the effects of mitotane on ACC is needed to improve the clinical monitoring of its efficacy. Thus, the aim of this review was to summarize the chemistry, pharmacokinetic and pharmacodynamic features, and therapeutic and toxic effects of mitotane. This review also discusses new formulations containing this drug.
|
2 CHEMISTRY
Unlike DDT, the mitotane molecule exists in 2 configurations depending on the position of the chlorine element in the benzene ring (ortho position in 1 ring and para position in the other). These mitotane configurations are characterized by the presence of an asymmetric chiral carbon atom that gives rise to 2 enantiomeric (R and S) molecules. Considering that mitotane is available as a race- mic mixture, both enantiomers, (S)-(-)-o,p’-DDD and (R)-(+)-o,p’-DDD (Figure 1A) are present in the commercial drug. Furthermore, it has been demonstrated that mitotane metabolism involves 2 reactions via a- and ß-hydroxylation. Alpha-hydroxylation forms the metabolite o,p’-DDE (DDE), whereas ß-hydroxylation forms o,p’-dichlorodiphenyl acyl chloride (DDAC). DDAC has a strong affinity for biological nucle- ophiles and can acylate different cellular molecules, or be rapidly converted to the metabolite o,p’-DDA (DDA) in the presence of water (Figure 1B).
3 PHARMACOLOGICAL ASPECTS |
3.1 Pharmacokinetics |
3.1.1 Absorption |
Mitotane has poor water solubility (0.1 mg mL-1 at 25℃), being more soluble in organic solvents such as ethanol (20 mg mL-1), dimethyl sulfoxide (30 mg mL-1), and dimethyl formamide.27 Generally, in vitro and in vivo assays study mitotane in organic solvents. Additionally, in preclinical studies, mitotane was often dissolved in olive oil or dimethyl sulfoxide followed by aqueous buffer, to reach ideal plasma concentrations.28,29 In clinical tests, mitotane reached the maximum absorption level when administered together with dietary lipids such as high-fat milk, chocolate or oil emulsions, which increased its absorption by 5-fold compared with that of mitotane tablets.30
Data regarding intestinal absorption, gut transport, biodisposition of intravenous administration, and hepatic extraction of mitotane are limited. In addition, high variability in plasma con- centration was observed with different doses among patients. Although the compound (single dose of 2 g) reached a maximal plasma concentration of 0.0016 mg mL-1 (data from 9 ACC patients) 10 hours after administration,30 the time to reach thera- peutic plasma concentration (14-20 mg L-1) was much longer- around 116 days with a cumulative dose of approximately 626 g (data from 53 ACC patients).31 Thus, patients require high daily doses (2-10 g day-1) to reach steady state in about 3 months after treatment initiation.8,9 The bioavailability of the drug is demonstrably low when administered orally, probably due to poor absorption and extensive metabolism.
|
3.1.2 Distribution
The maximum concentration of mitotane can be detected in the plasma of patients 2-8 hours after a single dose of 2 g.30 The mitotane clearance and volume of distribution in the steady state were determined to be 0.94 + 0.37 L h-1 and 161 + 68 L kg-1 of the lean body mass in 22 patients, respectively.32 Nevertheless, DDA levels were higher than mitotane levels in the plasma, whereas DDE was barely detected after the administration of repeated doses.33 Mitotane concentration in adipose tissue was 200-fold higher than the plasma concentration in patients during chemotherapy.34 In rats, after 80 days of consumption of diet containing 1% mitotane, the compound tended to accumulate mainly in adipose tissues such as brain and adrenal tissue, as well as in the liver and kidney.35 Mitotane labelled with 14℃ was localized mainly in the zona fasciculata and zona reticularis in human adrenocortical tumour and mouse adrenal tissue.36,37
Mitotane is distributed by binding with chylomicrons and lipo- proteins, with most of the compound bound to lipoproteins38; thus, the pharmacological activity of mitotane is exerted by unbound mitotane particles.39 Under normolipidaemic conditions, a
| References | Mean age (y) | Number of patients | Sex | Treatment regimen | Duration of follow-up (mo) | Stage of disease | Mitotane levels (mg L-1) | Overall response rate | Overall survival (mo) | Disease-free survival | Progression-free survival |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 21 | 50 | 50 | Male (n = 24) Female (n = 26) | M+A or A | 16.5 | IV | Not recorded | M+A = 48% ª A = 48% ª | 10.6 | NA | 2.6 mo |
| 10 | 47 | 28 | Male (n = 10) Female (n = 18) | M+E+D+C | NA | II (n = 2) III (n = 6) IV (n = 20) | Not recorded | 53.5%b | NA | NA | NA |
| 22 | 50 | 72 | Male (n = 24) | M+E+D+C | 120 | I (n = 1) II (n = 24) | Not recorded | 48.6% b | Male = 23.6 Female = 38.6 | ≤2 y = 26.4 mo ≥2 y = 51.7 mo | NA |
| Female (n = 48) | III (n = 30) IV (n = 17) | ||||||||||
| 23 | 50 | 304 | Male (n = 121) Female | M+E+D +C->M+Sz c | 78 | III (n = 1) IV (n = 303) | 14-20 | First-line therapy: M+E+D +C = 23.2% ª M+Sz = 9.2% ª | First-line therapy: M+E+D | NA | First-line therapy: M+E+D+C = 5 mo M+Sz = 2.1 mo |
| (n = 183) | M+Sz->M+E +D+C ° | +C = 14.8 M+Sz = 12 | Second-line therapy: M+E+D+C->M +Sz = 5.6 months | ||||||||
| M+Sz->M+E+D +C = 2.2 months | |||||||||||
| 24 | 54 | 37 | Male (n = 19) Female (n = 18) | M+C | NA | IV | Not recorded | 30% d | 11.8 | NA | NA |
| 25 | 46.5 | 45 | Male (n = 23) Female (n = 22) | E+C E+C->M (n = 16) e | NA | III (n = 2) IV (n = 43) | Not recorded | 13% f | 10 | NA | NA |
| 26 | 44.4 | 36 | Male (n = 11) Female (n = 25) | M+E+D+V | 34.8 | IV | 10-15 | 22% g | 13.5 | NA | NA |
A, avelumab; M, mitotane; E, etoposide; D, doxorubicin; C, cisplatin; Sz, streptozotocin; V, vincristine, NA: not available
ª: Complete + partial response until progressive disease or death;
b: Complete + partial response. Complete response was defined as the disappearance of all clinical evidence of the tumour on physical examination or radiography and the complete recalcification of all osteolytic metastases for a minimum of 4 weeks. Partial response required ≥50% decrease in the measurable tumour size and ≥50% recalcification of osteolytic metastases for ≥4 weeks without the appearance of new lesions;
”: first-line therapy: M+E+D+C or M+Sz; second-line therapy: M+E+D+C→M+Sz or M+Sz→M+E+D+C;
d: Complete + partial response. Complete response was defined as the disappearance of all clinical evidence of the tumour for ≥4 weeks. Partial response required ≥50% decrease in the sum of the products of the perpendicular diameters of measured lesions or a decrease ≥30% in the sum of liver measurements below the costal margins in the right, left and xiphoid lines for a minimum of 4 weeks .;
e: Mitotane was employed after disease progression following cisplatin and etoposide treatment in patients who had not received prior mitotane treatment;
f: Complete + partial response. Complete response was defined as the disappearance of all clinical evidence of the tumour on ≥2 successive evaluations. Partial response required a ≥50% decrease in the sum of the products of the perpendicular dimensions of all measurable lesions on ≥2 evaluations;
8: Complete + partial + minor response. Complete response was defined as no evidence of measurable disease for a minimum of 4 weeks. Partial response was defined as a ≥50% decrease in the sum of the products of the dimensions of all measurable lesions for ≥1 month. Minor response was defined as 25-50% decrease in the sum of the products of the dimensions of all measurable lesions for ≥1 month. Symbols: + combination treatment; > change - treatment.
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
substantial amount of mitotane is bound to high-density lipopro- teins and albumin, whereas under hypertriglyceridaemic conditions, mitotane is bound mainly to chylomicrons and to very low-density lipoproteins.40 The distribution of mitotane involves cellular diffu- sion by adhering to low-density lipoprotein. Interestingly, mitotane promotes low-density lipoprotein formation,41 and probably pro- motes its self-uptake into adrenal cells. However, in vitro, lipopro- tein binding inhibited the activity of mitotane, suggesting that lipoprotein-free mitotane is the therapeutically active fraction,38,39 as common for most drugs. Higher antiproliferative and proapoptotic effects of mitotane were shown in H295R cells grown in lipoprotein-free medium, and a higher rate of tumour control was demonstrated in patients with ACC treated with mitotane and statins.39 Under hypertriglyceridaemic conditions, the bound mitotane-very low-density lipoprotein complex does not enter the adrenal cells,40 and the patient may be unresponsive to the effects of mitotane. High concentrations of DDA and DDE were also found bound to chylomicrons. However, DDA is less lipophilic compared to mitotane and DDE due to the presence of the carboxylic acid group.38 High-performance liquid chromatogra- phy methods for mitotane monitoring are not selective for free drug particles, as the denaturation of proteins can also lead to dis- ruption of the mitotane complexes, allowing the mitotane particles to migrate to the organic layer. Thus, it is important to quantify the free circulating mitotane, excluding the lipoprotein-bound mitotane, to estimate its toxicity and efficacy.38
Regarding the enantiomers of mitotane, different elimination ratios were suggested in the exposure of enantiomers to human pla- centas as measured by gas chromatography, despite which the first and the second eluting enantiomer could not be identified.42 The enantiomer S(-)-o,p’-DDD was dominant in the plasma of 2 minipigs, whereas R-(+)-o,p’-DDD was dominant in the plasma of 3 minipigs.43 Although the 2 isomers were equally potent in decreasing H295R cell viability, (S)-(-)-o,p’-DDD affected hormone secretion (dehydroepian- drosterone and cortisol) slightly less than (R)-(+)-o,p’-DDD and the racemic mixture.44 Thus, it is also suggested that a racemic mixture is important for the therapeutic effects of mitotane. However, the phar- macological features of each enantiomer in ACC treatment are unclear. As it is known that some chiral drugs have differences in pharmacokinetic and/or pharmacodynamic properties,45,46 further studies with mitotane’s enantiomers are encouraged to elucidate their pharmacokinetics and mechanism of action.
3.1.3 Metabolism |
The metabolism of mitotane was previously described as occurring primarily in adrenal cells.47 This drug is metabolized in the mito- chondria of adrenal cells through a-hydroxylation, which yields the end-product DDE, and ß-hydroxylation, which yields the end- product DDA (Figure 1B). Although measurements of plasma DDA for estimating the effects of mitotane suggested that it was an
(A)
CI
CI
CI
CI
H.
CI
CI
H
CI
CI
(R)-(+)-o,p’-DDD
(S)-(-)-o,p’-DDD
(B)
CI
CI
CI
a-OH
CI
CI
CI
CI
o,p’-DDE
+ O2
Acyllation of cellular molecules
CI
o,p’-DDD
CI
CI
HO
0
CI
0
B-OH
CI
OH
- HCI
ÇI
CI
+ H2O
CI
CI
CI
o,p’-DDAC
o,p’-DDA
active metabolite,33 other authors claimed that DDA was an inactive metabolite.48 In fact, DDA is less lipophilic; further, its presence in the urine (see section 3.1.4) suggests that it is an end- product of the mitotane deactivation pathway. In contrast, it has been speculated that DDE could be an active metabolite as it was not extensively found in plasma, urine or faeces (see section 3.1.4) and had a cytotoxic effect on the H295R adrenocortical cell line.49 However, no studies have been conducted yet to confirm this hypothesis.
Mitotane metabolism also produces reactive metabolites, such as DDAC, via ß-hydroxylation through cytochrome P540 (CYP450), which could covalently bind to mitochondrial macromolecules of adre- nal cells.5º The covalent bond is not permanent and can be reversed by the addition of glutathione reductase, suggesting that glutathione reductase can inactivate mitotane.51 The reaction for the covalent bond is mediated through a specific CYP450 responsible for steroido- genesis in adrenal cells, such as CYP11A1 (see section 3.2).52 The binding was also partially reversed by metyrapone, a known inhibitor of CYP11B1,36,37 suggesting that both CYP11A1 and CYP11B1 are involved in the formation of the DDAC.
Other CYPs are also related to the effects of mitotane. Recently, Murtha and colleagues demonstrated that silencing of CYP2A6 mRNA in H295R cells promoted higher sensitivity of this cell line to the effects of mitotane.53 This enzyme is a known metabolizer of some xenobiotics; however, the exact function of CYP2A6 in ACC is still unclear. D’Avolio et al. (2013)31 demonstrated that the polymorphism of CYP2B6 was positively correlated with higher plasma mitotane concentration. Mitotane can be metabolized by CYP2B6 in the liver or intestine, reducing its bioavailability. It is documented that mitotane is a CYP2B inducer (see below); therefore, its polymorphism can increase mitotane bioavailability. A high level of CYP2W1 mRNA expression was observed in both normal and neoplastic adrenal glands and was related to a better response to mitotane treatment among patients.54 In patients with any stage of ACC treated with mitotane monotherapy, the polymorphism of CYP2W1 was associated with reduced probability of reaching the mitotane therapeutic range and with lower response rates.55 It has been suggested that this polymor- phism could have a different catalytic metabolism on mitotane that influences in a lower mitotane bioavailability.55 Nonetheless, the exact role of CYP2W1 on mitotane metabolism and the influence on its bio- availability are unclear.
Mitotane administered to mice via the intraperitoneal route had antitumour effects for 34 days, whereas the oral administration yielded antitumour effects for only 13 days. However, the plasma concentration of mitotane, within the therapeutic range for humans, was observed more in mice treated orally than in those treated intra- peritoneally.29 This suggests that oral mitotane could be metabolized to its active metabolite form in the stomach or gut faster, resulting in better antitumour effects than intraperitoneal mitotane. We hypothe- size that a higher mitotane concentration after oral administration could result, in this particular case, in a faster distribution of mitotane to fatty tissues than after intraperitoneal administration, reducing its plasma concentration, and the time of treatment (about 1.5 mo) is
lower than the expected time to reach the mitotane steady state (about 3 mo).9,12 Further studies are necessary to confirm this hypothesis.
The role of the intestinal microbiome in mitotane metabolism is not known, but it should be considered as the gut microbiota plays a role in drug metabolism prior to absorption or during enterohepatic circulation, via various microbial enzymatic reactions in the intes- tine.56 The hypothesis of intestinal mitotane metabolism is supported by high concentrations of DDA and DDE found in chyle. DDE might be metabolized further in the liver, which would also explain why this compound was barely detected in the plasma.33,38 This indicates that mitotane might be metabolized in the liver via enzymatic (i.e., CYP450) and nonenzymatic (i.e., glutathione reductase) reactions as DDT is metabolized in the liver in a same manner.57 However, no preclinical studies have investigated the metabolism of mitotane, DDA and DDE in the liver. Therefore, understanding the effects of liver and gut microbiota on mitotane metabolism is crucial to explaining the changes in its pharmacokinetics.
Mitotane has a narrow therapeutic index; thus, the possibility of pharmacokinetic drug-drug interactions needs to be considered. This drug has a long-lasting inductive effect on CYP3A4 and CYP2B and a potent inhibitory effect on CYP2C19, which result in clinical interactions with many drugs metabolized by these enzymes.58-60 The induction of CYP3A4 by mitotane was demon- strated to occur via activation of pregnane X receptor, leading to enzyme autoinduction as pregnane X receptor ligands accelerate its metabolism. Enzyme autoinduction may contribute to different effects of mitotane in patients. Accordingly, Arshad and col- leagues61 proposed a pharmacokinetic model to predict enzyme autoinduction, contributing to the optimization of mitotane dosage schedules and improve the therapeutic drug monitoring.61 When associative treatment of mitotane in combination with drugs that interact with CYPs mentioned above (e.g. doxorubicin, etoposide, hydrocortisone, cyclophosphamide, omeprazole and clopidogrel) is necessary, the therapeutic effects and toxicity of these drugs need to be monitored closely.
3.1.4 | Elimination
After an oral intake of a single mitotane dose in tablet form (2 g), around 40% of unchanged mitotane could be detected in the faeces after 12 hours, whereas when mitotane was formulated in milk or emulsion, only less than 10% of the drug was excreted.3º In oral mitotane administration in rats, 7.1% was excreted in the urine and 87.8% was found in the faeces within 8 days.62 Unchanged mitotane appears to be eliminated largely through biliary excretion.63 Mitotane, DDA and DDE can also undergo enterohepatic circulation; chyle could be enriched with these compounds due to hepatic transformation.38 DDA was also found in the urine of mice treated with mitotane for a total of 96 hours,28 as well as in the faeces.64 Although renal elimina- tion also plays an important role in mitotane clearance, the rate is lower than that of biliary elimination. In a study of 19 patients who
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
received mitotane at 3-6 g day-1 for a period of 30-60 days, the half- life was found to be between 18 and 159 days after mitotane was withdrawn.30 Long-term mitotane elimination observed was probably due to its accumulation in fat tissue, attributable to its lipophilic char- acteristics and gradual return to plasma.
3.2 | Pharmacodynamics and pharmacological effects
The main effects of mitotane in ACC is the induction of tumour cell death and reduction of steroid production, such as androgens, dehy- droepiandrosterone, and cortisol.9,13 The current recommendation is to maintain the plasma level higher than 7 mg L-1 (>21.8 uM) to pro- duce anti-steroidogenic effects and between 14-20 mg L-1 (43.7-62.5 µM) for antitumour effects.33,65 The major findings on the mechanism of action of mitotane were firstly reported in dogs and mice, besides reports suggesting that rodents were more insensitive to antisecretory mitotane effects.29,50,51 The mechanism of action of mitotane in adrenal cells mainly occurs in the adrenal mitochondria and can be divided into 4 major categories: (i) inhibition of steroido- genesis, (ii) endoplasmic reticulum (ER) stress, (iii) cell death, and (iv) others (Figure 2).
3.2.1 Inhibition of steroidogenesis |
The rate-limiting step in steroidogenesis is the transport of cholesterol from the outer to the inner mitochondrial membrane through the enzyme CYP11A1 (Figure 3). Cholesterol reaches CYP11A1 via the transduceosome complex, a multiple protein complex in the mito- chondrial membrane that contains the translocator protein, steroido- genic acute regulatory protein, ATPase family AAA domain-containing protein 3A, and voltage-dependent anion channel.66 Interestingly, incubation with translocator protein inhibitor in combination with mitotane significantly potentiated the antitumour and antisecretory actions of mitotane in H295R cells.67 The expression of protein kinase cAMP-dependent type I regulatory subunit «, which is involved in the activation of steroidogenesis, was also reduced follow- ing 24 hours of treatment with mitotane.53 This confirms that mitotane binds specifically to CYP11A1.
The binding of mitotane to mitochondrial adrenal cells was par- tially reversed by metyrapone, a known inhibitor of CYP11B1.36,37 These data suggest that CYP11B1 activity on mitotane binding also results in the formation of reactive species or molecules such as DDAC. CYP11B1 is localized in the mitochondrial inner membrane and is involved in the conversion of progesterone to cortisol in the adrenal cortex.68 CYP21A2, CYP17A1, and hydroxy-8-5-steroid dehydrogenase 3 B- and steroid 8-isomerase type 2 and type 1 were also found to be decreased in cells after incubation with mitotane.52,69 The inhibition of these enzymes results in reduction in aldosterone, cortisol, dehydroepiandrosterone, testosterone and oestradiol produc- tion, reducing ACC symptoms.
Considering that the aforementioned CYPs are steroidogenic enzymes localized mainly in the adrenals, this may partially explain the localized effect of mitotane on adrenal tissue. There are no studies that have assessed the DDAC bound to macromolecules in human adrenal and liver cells to support this hypothesis. The involvement of other reactive intermediates such as epoxides and free radicals should also be considered in elucidating the mechanisms of mitotane action.51
The adrenocortical cell lines (NCI-H295 and NCI-H295R) are more sensitive to mitotane (50% effective concentration = 18.1 µM) than the nonadrenocortical cell lines (HeLa, HepG2, HEK293, and IMR32 cells).70 This supports the idea that mitotane specifically affects the steroidogenesis pathways in adrenocortical cells. However, it is still unclear whether mitotane inhibits a key enzyme, such as CYP11A1, resulting in reductions in several steroidogenic enzymes; inhibits a steroidogenic regulatory gene, such as sterol regulatory element-binding transcription factor 1 (SREBF; see below); or affects all the steroidogenic enzymes simultaneously. Additional studies eval- uating the chemical reaction between the intermediate metabolite DDAC and adrenal mitochondrial compounds are warranted.
|
3.2.2 ER stress
Mitotane inhibited the function of sterol-O-acyl transferase 1 (SOAT1) in H295R cells that highly express this enzyme.7º SOAT1 is an intra- cellular protein located in the ER that promotes the formation of fatty acid-cholesterol esters.71 The suppression of SOAT1 by mitotane led to accumulation of free cholesterol and fatty acids, which explains why patients had an increase in cholesterol level throughout mitotane treatment. This may be attributed to the blocking of ATP-binding cas- sette subfamily G member 1 by mitotane in adrenal cells, reducing the transport of cholesterol to outside the cells.72-74 The increase in free cholesterol ester and fatty acid levels induced ER stress promoting the downregulation of SREBF.7º SREBF stimulates the transcription of steroid-regulated genes70; thus, the inhibition of steroid production induced by mitotane may be due to the downregulation of SREBF. As ER stress persists, it induces the expression of eukaryotic translation initiation factor 2 « kinase 3, which phosphorylates the eukaryotic initiation factor 2 subunit & and activates the CCAAT-enhancer- binding protein homologous protein expression, the upregulation of which activated the intrinsic apoptosis pathway, leading to cellular death.7º Therefore, the inhibition of SREBF through ER stress may underlie 1 of the mechanisms by which mitotane induces the activity of caspases and reduces steroid production in ACC.
3.2.3 Cell death
|
The attachment of the DDAC to adrenal cells can induce oxidative stress and cellular death by apoptosis and/or necroptosis. It was also found that the decrease in adrenal cell viability was due to increase in caspase 3/7 activity, which induced cellular apoptosis.52
ABCG1
H+
H+
H+
Intermembrane space
+
DDD
Cyt c
Q
XX
Matrix
NADH
FADH2
1/2 O2
H2O
NAD+
FAD
H+
Free cholesterol and fatty acids
SOAT1
Cholesterol ester
ADP
ATP
Complex I
Complex II
Complex III
Complex IV
Complex V
ER stress
PERK
CYP11A1 CYP11B1 CYP17A1 CYP21A2
DDD
Endoplasmatic reticulus
elF2a P
Mitochondria respiration
(Steroidogenesis)
Bax
Bcl-2
CHOP
SREBF
Caspase 3/7
Mitochondria
Nucleus
Apoptosis
Adrenal cells
The apoptosis was also due to the inhibition of mitochondrial respiratory chain complexes I and IV (Complex I, ubiquinone oxido- reductase; complex IV, cytochrome c oxidase) in H295R cells by inducing cytochrome c oxidase defect.75 It has been observed that mitotane (30 and 50 µM) induced mitochondrial morphological alterations in human tumour adrenocortical cells (H295R and SW13), including membrane disruption, affecting respiratory chain enzymes, such as succinate dehydrogenase and the voltage- dependent anion channel, resulting in the inhibition of tumour cell proliferation and induction of cellular apoptosis.75,76 Although adrenal cortical cells were also susceptible to ferroptosis dependent on steroid pathways, mitotane did not induce this form of cell death in ACC cells.77
3.2.4 Other mechanisms |
In addition to the inhibition of steroidogenesis, ER stres, and apopto- sis, mitotane also alters other pathways that need further investiga- tions. Mitotane modulates proteins involved in cellular metabolism, such as the reduced nicotinamide adenine dinucleotide phosphate, stress response (peroxiredoxins I, II and VI and heat shock protein 27), cytoskeleton structure (tubulin-b isoform II and profilin-1), and tumourigenesis (prohibitin, heterogenous nuclear ribonucleoprotein A2/B1 and cathepsin D).78 Mitotane has been found to inhibit the
expression of transforming growth factor $1 gene, encoding a potent inhibitor of cell proliferation and steroidogenesis.52 Nonetheless, studies involving the aforementioned proteins are preliminary and the topic requires further investigation.
These mechanisms are relevant to understand the effects of mitotane on the body as a whole for the development of strategies that can directly inhibit ACC growth78 and for repurposing of drugs that target those proteins and factors to treat ACC. For instance, drugs affecting the cytoskeleton, such as vincristine, have been used as second-line treatment in chemotherapy combination protocols (vincristine, cisplatin, teniposide and cyclophosphamide, or cyclophos- phamide, doxorubicin, vincristine and prednisone) for adrenal tumours.79,80
Despite the evidence that mitotane affects the aforementioned pathways, the molecular mechanisms of acquired mitotane resistance are currently unknown. A recent study established an in vitro model of mitotane resistance in ACC using the HAC-15 cell line. The findings showed an absence of mitochondrial damage and increase in intracel- lular free cholesterol levels, downregulation of adrenal steroids pro- duction, and regulation of mitogen-activated protein kinase, apoptotic cell clearance, and response to xenobiotics in mitotane-treated resis- tant cells compared to those in nonresistant controls. The study rev- ealed changes in lipoprotein and lipid homeostasis, which may collectively contribute to the characteristics of the resistant pheno- type. Because this model evaluated mitotane resistance only in vitro,
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
Cholesterol
DDD
StAR
Cholesterol
DDD
CYP11A1
CYP17A1
17-
CYP17A1
DHEA (dehydroepiandrosterone)
17ß-OH
Pregnenolone
hydroxypregnenolone
Androstenediol
DDD
HSD3B2
DDD
HSD3B2
DDD
HSD3B2
3ß-OH
CYP17A1
17-OH
SRD5A2
Progesterone
17-
hydroxyprogesterone
Androstenedione
Testosterone
Dihidrotestosterone
DDD
CYP17A1
CYP21A2
CYP21A2
CYP19A1
CYP19A1
11-
HSD173B
Deoxycorticosterone
11-deoxycortisol
Estrone
Estradiol
DDD
CYP11B1
DDD
CYP11B1
Corticosterone
Cortisol
CYP11B2
Zona fasciculata
Zona reticularis
Aldosterone
Zona glomerulosa
Mitochondria
further studies should be performed using in vivo models.81 This might explain recurrence during and after ACC therapy.
Considering the pathways mentioned above, mitotane may have multiple mechanisms of action on adrenal tumour cells. It is unknown whether mitotane has distinct mechanisms of action in normal and tumour adrenal tissues. Therefore, further in vivo studies are encour- aged to verify the specificity of mitotane in tumour adrenal cells.
|
4 TOXICITY
Mitotane concentrations above 20 mg L-1 are highly toxic. The oral lethal dose 50 of mitotane were reported to be 17, 5, 4 and 5 g in humans, guinea pigs, mice and rats, respectively.27 Even though plasma mitotane levels are maintained below 20 mg L-1 for ACC treatment, patients with plasma levels <15 mg L-1 can experience several toxic effects, probably due to the variability in CYP activity among patients.
Mitotane has several side effects that may involve the gastroin- testinal, nervous and endocrine systems, and can vary among patients. Gastrointestinal symptoms include diarrhoea, nausea, vomiting and anorexia, which can evolve to mucositis.13,22,82 These symptoms were reported in 78% of patients who received daily doses of 2 g or more.83 At higher doses, mitotane affected the central nervous sys- tem and produced neuromuscular manifestations, including ataxia, speech disturbance, confusion, somnolence, depression, decreased memory, muscle tremors, polyneuropathy and dizziness.83 Mitotane increased the hepatic production of steroid and hormone-binding
globulins (i.e. corticosteroid-binding globulin or transcortin, sex hormone-binding globulin, thyroxine-binding globulin, cortisol-binding globulin and vitamin D-binding protein), which increased total serum levels of gonadal steroids and cortisol. Thus, the androgen synthesis-reducing effect of mitotane and a relative increase in sex hormone-binding globulin may cause gynaecomastia and primary hyp- ogonadism.2,22,82 Changes in these binding proteins also potentially induce hypoadrenalism and hypothyroidism.84,85 Hypoadrenalism may occur even when mitotane is used as adjuvant therapy combined with cortisol replacement for ACC treatment.86 Mitotane treatment may also increase bilirubin levels and induce skin rashes.82,83
An increase in cholesterol levels was also documented during mitotane administration. Mitotane’s inhibition of CYP450, an enzyme involved in cholesterol metabolite formation, may result in an increase in mevalonic acid and oxysterols responsible for downregulating hepatic cholesterol synthesis.41 However, the exact effect of the increase in the activity of the mevalonate pathway during mitotane treatment is not well explored. Mitotane also influenced the produc- tion of thyroid hormones, leading to a decrease in the levels of thyroid-stimulating hormone and free thyroxine, which must be moni- tored and replaced if necessary.82 Other manifestations included impotence, thrombocytopenia, anaemia and increases in hepatic enzyme levels.22,82 Adverse events were reversible after the cessation of mitotane treatment.82 It is mandatory that clinicians consider the need to prescribe glucocorticoid and mineralocorticoid replacements because mitotane may effectively decrease the synthesis of all ste- roids. This concern is more urgent in tumours presenting with high levels of glucocorticoids, suppression of the hypothalamus-pituitary-
BJCP
adrenal axis, and potential acute or chronic adrenal insufficiency. Mitotane may aggravate adrenal cortex suppression. Taken together, mitotane toxicity may limit tolerability, thereby necessitating the dis- continuation of treatment.
5 NEW PERSPECTIVES FOR MITOTANE TREATMENT |
To improve the current therapeutic options for ACC with less toxic effects, the development of new formulations containing mitotane or new compounds containing its metabolites should be considered. Below we discuss 2 potential options for ACC treatment.
5.1 MeSO2-DDE (3-methylsulfonyl-2,2-bis (4-chloro-[14C]phenyl)-1,1-dichloroethene MeSO2- [14C]DDE) |
MeSO2-DDE is a synthetic compound derived from DDE and aryl methyl sulfones. MeSO2-DDE is selectively taken up and covalently bound in the zona fasciculata in adrenal cortex in mice.87 MeSO2-DDE has adrenocorticolytic effects at lower doses than mitotane in humans.37 Similar to mitotane, MeSO2-DDE generated a reactive intermediate metabolite by binding to CYP11B1, inducing mitochon- drial degeneration and cell death in the murine adrenal cortex.37 In murine adrenocortical Y-1 tumour cells, both mitotane and MeSO2- DDE inhibited corticosterone production, but only MeSO2-DDE was cytotoxic. The cytotoxicity was inhibited by the CYP11B1 inhibitor etomidate, suggesting that CYP11B1 plays a role in this effect of MeSO2-DDE.88,89 MeSO2-DDE also inhibited cortisol production in H295R cells but did not affect aldosterone secretion.9º By contrast, in H295R cells (5-15 µM) and a nude mice xenograft model (50 mg kg-1, i.p.), mitotane was more cytotoxic than MeSO2-DDE.91 The concen- tration and dose of MeSO2-DDE are important factors since at low concentrations it can stimulate steroid production and CYP11B1 expression, and at higher concentrations it has the opposite effect.92 We hypothesized that this biphasic response is caused by the reactive intermediate metabolite that is generated in high MeSO2-DDE concentrations. Investigation using minipigs showed that the plasma, fat, and liver concentrations of MeSO2-DDE were 2-, 25-, and 18-fold higher than those of mitotane, respectively. Likewise, its rate of elimination was slow, which might pose a challenge while formulating appropriate dosages for patients.89 Overall, MeSO2-DDE may repre- sent a potential alternative for the treatment of ACC, and further clinical studies are encouraged.
|
5.2 Nanoformulations
Nanoformulations have emerged as an attractive strategy for incorpo- ration of molecules that have poor water solubility, such as mitotane. Mitotane nanoformulations are expected to improve the therapeutic
effect, enhance bioavailability, and reduce the toxic effects of mitotane.93 Three formulations are being developed: (i) self- microemulsifying drug delivery system (SMEDDS); (ii) lipid-based nanocarriers; and (iii) micelles.
i. SMEDDS: SMEDDS is an approach to incorporating lipid mole- cules. Preconcentrated microemulsion is useful for enhancing the dissolution rate of poorly water-soluble drugs and increasing bio- availability.94 The formulation mitotane-SMEDDS contains Capryol, Tween, and Cremophor at the same concentrations. SMEDDS was found to cross the intestinal barrier much faster than a solution of mitotane, with a bioavailability of 3.4%.95 Nonetheless, no studies have been performed to evaluate if SMEDDS can prevent gastrointestinal toxicity, which occurs due to the poor solubility of mitotane in the gastrointestinal system yet. Moreover, there is a lack of preclinical studies, including in vitro and in vivo observations, on whether SMEDDS could enhance the antisecretory and antitumour effects in ACC. Never- theless, SMEDDS can be considered as a new tool for optimizing the administration of mitotane and additional studies should be performed in this regard.
ii. Lipid-based nanocarriers: solid lipid nanoparticles or nanostruc- tured lipid carriers (NLCs) consist of either solid or lipid nanoparticles. NLCs are a novel type of lipid nanoparticles that use a solid matrix.93 In fact, mitotane was efficiently loaded in solid lipid nanoparticles and in NLCs, as potential delivery sys- tems for enhancing the therapeutic effects of mitotane, improv- ing bioavailability, and controlling drug release.96 So far, no additional studies have been carried out to evaluate the efficacy of nanoformulations in ACC.
iii. Micelles: micelles are promising nanocarrier systems for drug deliv- ery, especially for antitumour agents.97 Polymeric micelles are structures formed by an arrangement of amphiphilic copolymers in aqueous solutions.98 The advantages of this nanoformulation are control of drug release, tissue-penetrating ability and reduced tox- icity.97 As mitotane has poor solubility in water and consequently in plasma, Haider and colleagues99 developed a micelle poly (2-methyl-2-oxazoline)-block-poly(2-butyl-2-oxazoline)-block-poly (2-methyl-2-oxazoline)-based mitotane nanoformulation with high drug loading. Micellar mitotane exhibits comparable efficacy with its ethanol equivalent, suggesting that this nanoformulation is suit- able for intravenous administration and may improve mitotane plasma concentration and consequently the efficacy. Additional studies about the safety and tolerability of this injectable formula- tion are warranted.99
6 CONCLUSION AND FUTURE DIRECTIONS |
Mitotane is the only drug approved by the Food and Drug Administra- tion for ACC treatment as there is a lack of new compounds with
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
specific antisecretory and antitumour effects. However, its pharmacoki- netic features do not make it an ideal drug for ACC because of its very poor absorption and absorption into fat acting as a reservoir. The poly- morphism of CYPs may also be involved in the variability of the thera- peutic effect of mitotane among patients. Consequently, high doses are employed, inducing several side effects. Although the mechanism of action is not well elucidated, there is evidence that mitotane might con- trol steroid production and induce apoptosis through ER stress and inhibition of mitochondrial respiration in tumour cells. The formation of reactive species during ß-hydroxylation, such as DDAC, should also be considered in the mechanism of mitotane action, as this can lead to the acylation of cellular molecules and induce cell death. The ability of mitotane to bind to adrenal mitochondria via steroidogenic enzymes (i.e. CYP11B1 and CYP11A1) suggests that mitotane is metabolized in the adrenals first. However, the pharmacokinetics and exact mecha- nisms of action of mitotane still need to be thoroughly clarified. Nanoformulations containing mitotane are currently the most studied options to improve the therapy, as they seem to be able to enhance bioavailability, adrenal drug delivery, and decrease side effects, mainly in the gastrointestinal system. Therefore, further studies are warranted in this regard to improve ACC treatment.
6.1 | Nomenclature of targets and ligands
Key protein targets and ligands in this article are hyperlinked to corresponding entries in http://www.guidetopharmacology.org, and are permanently archived in the Concise Guide to PHARMACOLOGY 2019/20.100
ACKNOWLEDGEMENTS
The authors thank the Pele Pequeno Príncipe Research Institute, Curitiba-PR, and the Brazilian funding agencies: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação Arau- cária-PR; and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) [finance code 001].
COMPETING INTERESTS
There are no competing interests to declare.
CONTRIBUTORS
C.R.C. conceptualized the manuscript, performed the literature search, wrote the first draft and edited the manuscript. A.A. performed the lit- erature search and edited the first draft. C.B. edited the first draft. S.J.R.B. performed the literature search, and edited the first draft and manuscript. B.C.F. edited the manuscript. L.M.S. conceptualized the manuscript and edited the manuscript. All authors have read the final manuscript and agree to its publication.
ORCID
Claudia Rita Corso (D https://orcid.org/0000-0001-6594-3542 Alexandra Acco D https://orcid.org/0000-0003-3977-687X Camila Bach ID https://orcid.org/0000-0003-2910-2679
Sandro José Ribeiro Bonatto ID https://orcid.org/0000-0001-7262- 3766
Bonald Cavalcante de Figueiredo D https://orcid.org/0000-0002- 1051-2056
Lauro Mera de Souza D https://orcid.org/0000-0001-9166-2146
REFERENCES
1. Michalkiewicz E, Sandrini R, Figueiredo B, et al. Clinical and outcome characteristics of children with adrenocortical tumors: A report from the International Pediatric Adrenocortical Tumor Registry. J Clin Oncol. 2004;22(5):838-845. https://doi.org/10.1200/JCO.2004. 08.085
2. Else T, Kim AC, Sabolch A, et al. Adrenocortical carcinoma. Endocr Rev. 2014;35(2):282-326. https://doi.org/10.1210/er.2013-1029
3. Sharma E, Dahal S, Sharma P, et al. Characteristics and Trends in Adrenocortical Carcinoma: A United States Population Based Study. J Clin Med Res. 2018;10(8):636-640. https://doi.org/10.14740/ jocmr3503w
4. Kebebew E, Reiff E, Duh QY, Clark OH, McMillan A. Extent of dis- ease at presentation and outcome for adrenocortical carcinoma: have we made progress? World J Surg. 2006;30(5):872-878. https:// doi.org/10.1007/s00268-005-0329-x
5. Custódio G, Parise GA, Kiesel Filho N, et al. Impact of Neonatal Screening and Surveillance for the TP53 R337H Mutation on Early Detection of Childhood Adrenocortical Tumors. J Clin Oncol. 2013; 31(20):2619-2626. https://doi.org/10.1200/JCO.2012.46.3711
6. Allolio B, Fassnacht M. Adrenocortical carcinoma. In: Grossman AP, ed. Endocrinology Adult and pediatric, The adrenal gland. sixth ed. Philadelphia: Elsevier; 2010:e168.
7. Fassnacht M, Dekkers O, Else T, et al. European Society of endocri- nology clinical practice guidelines on the management of adrenocor- tical carcinoma in adults, in collaboration with the European network for the study of adrenal tumors. Eur J Endocrinol. 2018;179(4):G1- G46. https://doi.org/10.1530/EJE-18-0608
8. Mauclère-Denost S, Leboulleux S, Borget I, et al. High-dose mitotane strategy in adrenocortical carcinoma: prospective analysis of plasma mitotane measurement during the first 3 months of follow-up. Eur J Endocrinol. 2012;166(2):261-268. https://doi.org/10.1530/EJE-11- 0557
9. Zancanella P, Pianovski MA, Oliveira BH, et al. Mitotane Associ- ated with cisplatin, etoposide, and doxorubicin in advanced childhood adrenocortical carcinoma. J Pediatr Hematol Oncol. 2006; 28(8):513-524. https://doi.org/10.1097/01.mph.0000212965. 52759.1c
10. Berruti A, Terzolo M, Pia A, et al. Mitotane associated with etoposide, doxorubicin, and cisplatin in the treatment of advanced adrenocortical carcinoma. Italian Group for the Study of Adrenal Cancer. Cancer. 1998;83:2000-2194. https://doi.org/10. 1002/(SICI)1097-0142(19981115)83:10<2194:AID-CNCR19>3.0. CO;2-3
11. Pereira RM, Michalkiewicz E, Sandrini F, et al. Childhood Adrenocor- tical Tumors: A Review. Arq Bras Endocrinol Metabol. 2004;48(2): 651-658. https://doi.org/10.1186/1897-4287-4-2-81
12. Terzolo M, Pia A, Berruti A, et al. Low-dose monitored mitotane treatment achieves the therapeutic range with manageable side effects in patients with adrenocortical cancer. J Clin Endocrinol Metab. 2000;85(6):2234-2238. https://doi.org/10.1210/jcem.85.6. 6619
13. Daffara F, De Francia S, Reimondo G, et al. Prospective evaluation of mitotane toxicity in adrenocortical cancer patients treated adjuvantly. Endocr Relat Cancer. 2008;15(4):1043-1053. https://doi. org/10.1677/ERC-08-0103
14. Nelson AA, Woodard G. Severe adrenal cortical atrophy (cytotoxic) and hepatic damage produced in dogs by feeding 2,2-bis
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
(parachlorophenyl)-1,1-dichloroethane DDD or TDE. Arch Pathol (Chic). 1949;48(5):387-394.
15. Nichols J, Green HD. Effect of DDD Treatment on Metabolic Response of Dogs to ACTH Injection. Am J Physiol. 1954;176(3): 374-376. https://doi.org/10.1152/ajplegacy.1954.176.3.374
16. Bergenstal DM, Lipsett MB, Moy RH, et al. Regression of adrenal cancer and suppression of adrenal function in men by o,p’-DDD. Trans Assoc Am Physicians. 1959;72:341-350. https://doi.org/10. 1016/B978-1-4832-2866-2.50035-0
17. Waszut U, Szyszka P, Dworakowska D. Understanding mitotane mode of action. J Physiol Pharmacol. 2017;68(10):13-26. https://doi. org/10.1590/S0100-879X2000001000009
18. Megerle F, Kroiss M, Hahner S, Fassnacht M. Advanced Adrenocor- tical Carcinoma - What to do when First-Line Therapy Fails? Exp Clin Endocrinol Diabetes. 2018;127(02/03):109-116. https://doi.org/ 10.1055/a-0715-1946
19. Puglisi S, Calabrese A, Basile V, et al. New perspectives for mitotane treatment of adrenocortical carcinoma. Best Pract Res Clin Endocrinol Metab. 2020;34(3):101415. https://doi.org/10.1016/j.beem.2020. 101415
20. Tang Y, Liu Z, Zou Z, Liang J, Lu Y, Zhu Y. Benefits of Adjuvant Mitotane after Resection of Adrenocortical Carcinoma: A Systematic Review and Meta-Analysis. Biomed Res Int. 2018;2018:1-8. https:// doi.org/10.1155/2018/9362108
21. Le Tourneau C, Hoimes C, Zarwan C, et al. Avelumab in patients with previously treated metastatic adrenocortical carcinoma: Phase 1b results from the JAVELIN solid tumor trial. J Immunother Cancer. 2018;6(1):111. https://doi.org/10.1186/s40425-018-0424-9
22. Berruti A, Terzolo M, Sperone P, et al. Etoposide, doxorubicin and cisplatin plus mitotane in the treatment of advanced adrenocortical carcinoma: A large prospective phase II trial. Endocr Relat Cancer. 2005;12(3):657-666. https://doi.org/10. 1677/erc.1.01025
23. Fassnacht M, Terzolo M, Allolio B, et al. Combination chemotherapy in advanced adrenocortical carcinoma. N Engl J Med. 2012;366(23): 189-197. https://doi.org/10.1056/NEJMoa1200966
24. Bukowski RM, Wolfe M, Levine HS, et al. Phase II Trial of Mitotane and Cisplatin in Patients With Adrenal Carcinoma: A Southwest Oncology Group Study. J Clin Oncol. 1993;11(1):161-165. https:// doi.org/10.1200/JCO.1993.11.1.161
25. Williamson SK, Lew D, Miller GJ, et al. Phase II Evaluation of Cis- platin and Etoposide Followed by Mitotane at Disease Progression in Patients with Locally Advanced or Metastatic Adrenocortical Car- cinoma: a Southwest Oncology Group Study. Cancer. 2000;88: 1159-1165. https://doi.org/10.1002/(SICI)1097-0142(20000301) 88:5<1159:AID-CNCR28>3.0.CO;2-R
26. Abraham J, Bakke S, Rutt A, et al. A phase II trial of combination che- motherapy and surgical resection for the treatment of metastatic adrenocortical carcinoma: continuous infusion doxorubicin, vincris- tine, and etoposide with daily mitotane as a P-glycoprotein antagonist. Cancer. 2002;94(9):2333-2343. https://doi.org/10. 1002/cncr.10487
27. PubChem. National Library of Medicine. https://pubchem.ncbi.nlm. nih.gov/compound/4211. Accessed in October 20, 2020.
28. Gold B, Brunk G. A mechanistic study of the metabolism of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD) to 2,2-bis(p- chlorophenyl)acetic acid (DDA). Biochem Pharmacol. 1984;33(7):979- 982. https://doi.org/10.1016/0006-2952(84)90503-3
29. Doghman M, Lalli E. Lack of long-lasting effects of mitotane adju- vant therapy in a mouse xenograft model of adrenocortical carci- noma. Mol Cell Endocrinol. 2013;381(1-2):66-69. https://doi.org/10. 1016/j.mce.2013.07.023
30. Moolenaar AJ, van Slooten H, van Seters AP, Smeenk D. Blood Levels of o,p’-DDD Following Administration in Various Vehicles After a Single Dose and During Long-term Treatment. Cancer
Chemother Pharmacol. 1981;7(1):51-54. https://doi.org/10.1007/ bf00258213
31. D’Avolio A, De Francia S, Basile V, et al. Influence of the CYP2B6 polymorphism on the pharmacokinetics of mitotane. Pharmacogenet Genomics. 2013;23(6):293-300. https://doi.org/10.1097/FPC. 0b013e3283606cb2
32. Kerkhofs TM, Derijks LJ, Ettaieb H, et al. Development of a Pharma- cokinetic Model of Mitotane: Toward Personalized Dosing in Adre- nocortical Carcinoma. Ther Drug Monit. 2015;37(1):58-65. https:// doi.org/10.1097/FTD.0000000000000102
33. Hermsen IG, Fassnacht M, Terzolo M, et al. Plasma Concentrations of o’,p’DDD, o’,p’DDA, and o’,p’DDE as Predictors of Tumor Response to Mitotane in Adrenocortical Carcinoma: Results of a Retrospective ENS@T Multicenter Study. J Clin Endocrinol Metab. 2011;96(6):1844-1851. https://doi.org/10.1210/jc.2010-2676
34. von Slooten H, van Seters AP, Smeenk D, et al. O,p’-DDD (mitotane) levels in plasma and tissues during chemotherapy and at autopsy. Cancer Chemother Pharmacol. 1982;9(2):85-88. https://doi.org/10. 1007/bf00265384
35. De Francia S, Pirro E, Zappia F, et al. A new simple HPLC method for measuring mitotane and its two principal metabolites Tests in ani- mals and mitotane-treated patients. J Chromatogr B Analyt Technol Biomed Life Sci. 2006;837(1-2):69-75. https://doi.org/10.1016/j. jchromb.2006.04.005
36. Lindhe Ö, Lund BO, Bergman Å, Brandt I. Irreversible Binding and Adrenocorticolytic Activity of the DDT Metabolite 3-Methylsulfonyl-DDE Examined in Tissue-Slice Culture. Environ Health Perspect. 2001;109(2):105-110. https://doi.org/10.1289/ ehp.109-1240628
37. Lindhe Ö, Skogseid B, Brandt I. Cytochrome P450-Catalyzed Binding of 3-Methylsulfonyl-DDE and o,p’-DDD in Human Adrenal Zona fasciculata/Reticularis. J Clin Endocrinol Metab. 2002;87(3):1319- 1326. https://doi.org/10.1210/jcem.87.3.8281
38. Kroiss M, Plonné D, Kendl S, et al. Association of mitotane with chy- lomicrons and serum lipoproteins: practical implications for treat- ment of adrenocortical carcinoma. Eur J Endocrinol. 2016;174(3): 343-353. https://doi.org/10.1530/EJE-15-0946
39. Hescot S, Seck A, Guerin M, et al. Lipoprotein-Free Mitotane Exerts High Cytotoxic Activity in Adrenocortical Carcinoma. Clin Endocrinol Metab. 2015;100(8):2890-2898. https://doi.org/10.1210/JC.2015- 2080
40. Gebhardt DO, Moolenaar AJ, van Seters AP, et al. The distribution of o,p’-DDD (Mitotane) among serum lipoproteins in normo- and hypertriglyceridemia. Cancer Chemother Pharmacol. 1992;29(4): 331-334. https://doi.org/10.1007/bf00685956
41. Maher VM, Trainer PJ, Scoppola A, et al. Possible mechanism and treatment of o,p’DDD-induced hypercholesterolaemia. Q J Med. 1992;84:671-679. https://doi.org/10.1093/oxfordjournals.qjmed. a068705
42. Shen H, Virtanen HE, Main KM, et al. Enantiomeric ratios as an indi- cator of exposure processes for persistent pollutants in human pla- centas. Chemosphere. 2006;62(3):390-395. https://doi.org/10.1016/ j.chemosphere.2005.04.100
43. Cantillana T, Lindström V, Eriksson L, Brandt I, Bergman Å. Inter- individual differences in o,p’-DDD enantiomer kinetics examined in Göttingen minipigs. Chemosphere. 2009;76(2):167-172. https://doi. org/10.1016/j.chemosphere.2009.03.050
44. Asp V, Cantillana T, Bergman Å, Brandt I. Chiral effects in adrenocorticolytic action of o,p’-DDD (mitotane) in human adrenal cells. Xenobiotica. 2010;40(3):177-183. https://doi.org/10.3109/ 00498250903470230
45. Calcaterra A, D’Acquarica I. The market of chiral drugs: chiral switches versus de novo enantiomerically pure compounds. J Pharm Biomed Anal. 2018;147:323-340. https://doi.org/10.1016/j.jpba. 2017.07.008
BJCP
BRITISH PHARMACOLOGICAL SOCIETY
46. Alkadi H, Jbeily R. Role of Chirality in Drugs: An Overview. Infect Disord Drug Targets. 2018;18(3):88-95. https://doi.org/10.19080/ OMCIJ.2018.05.555661
47. Martz F, Straw JA. Metabolism and covalent bin- ding of 1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloroethane (o,p’-DDD). Correlation between adrenocorticolytic activity and metabolic activation by adrenocortical mitochondria. Drug Metab Dispos. 1980;8(3):127-130. https://doi.org/10.1124/dmd.8.3.127
48. Hescot S, Paci A, Seck A, et al. The Lack of Antitumor Effects of o,p’-DDA Excludes Its Role as an Active Metabolite of Mitotane for Adrenocortical Carcinoma Treatment. Horm Cancer. 2014;5(5):312- 323. https://doi.org/10.1007/s12672-014-0189-7
49. Germano A, Rapa I, Volante M, et al. RRM1 modulates mitotane activity in adrenal cancer cells interfering with its metabolization. Mol Cell Endocrinol. 2015;401:105-110. https://doi.org/10.1016/j. mce.2014.11.027
50. Martz F, Straw JA. The in vitro metabolism of 1-(o-chlorophenyl)- 1-(p-chlorophenyl)-2,2-dichloroethane (o,p’-DDD) by dog adrenal mitochondria and metabolite covalent binding to mitochondrial mac- romolecules: a possible mechanism for the adrenocorticolytic effect. Drug Metab Dispos. 1977;5(5):482-486.
51. Lund BO, Bergman A, Brandt I. In vitro macromolecular binding of 2-{2-chlorophenyl}-2-{4-chlorophenyl}-i,i-dichloroethane (o,p’-DDD) in the mouse lung and liver. Chem Biol Interact. 1989;70(1-2):63-72. https://doi.org/10.1016/0009-2797(89)90063-x
52. Lehmann TP, Wrzesiński T, Jagodziński PP. The effect of mitotane on viability, steroidogenesis and gene expression in NCI-H295R adrenocortical cells. Mol Med Rep. 2013;7(3):893-900. https://doi. org/10.3892/mmr.2012.1244
53. Murtha TD, Brown TC, Rubinstein JC, et al. Overexpression of cyto- chrome P450 2A6 in adrenocortical carcinoma. Surgery. 2017;161 (6):1667-1674. https://doi.org/10.1016/j.surg.2016.11.036
54. Ronchi CL, Sbiera S, Volante M, et al. CYP2W1 Is Highly Expressed in Adrenal Glands and Is Positively Associated with the Response to Mitotane in Adrenocortical Carcinoma. PLoS ONE. 2014;9(8): e105855. https://doi.org/10.1371/journal.pone.0105855
55. Altieri B, Sbiera S, Herterich S, et al. Effects of Germline CYP2W1*6 and CYP2B6*6 Single Nucleotide Polymorphisms on Mitotane Treatment in Adrenocortical Carcinoma: A Multicenter ENSAT Study. Cancers (Basel). 2020;12(2):359. https://doi.org/10.3390/ cancers12020359
56. Noh K, Kang YR, Nepal NR, et al. Impact of gut microbiota on drug metabolism: an update for safe and effective use of drugs. Arch Pharm Res. 2017;40(12):1345-1355. https://doi.org/10.1007/ s12272-017-0986-y
57. Kitamura S, Shimizu Y, Shiraga Y, Yoshida M, Sugihara K, Ohta S. Reductive metabolism of p, p-DDT and o, p-DDT by rat liver cyto- chrome p450. Drug Metab Dispos. 2002;30(2):113-118. https://doi. org/10.1124/dmd.30.2.113
58. van Erp NP, Guchelaar HJ, Ploeger BA, Romijn JA, Hartigh, Gelderblom H. Mitotane has a strong and a durable inducing effect on CYP3A4 activity. Eur J Endocrinol. 2011;164(4):621-626. https:// doi.org/10.1530/EJE-10-0956
59. Theile D, Haefeli WE, Weiss J. Effects of adrenolytic mitotane on drug elimination pathways assessed in vitro. Endocrine. 2015;49(3): 842-853. https://doi.org/10.1007/s12020-014-0517-2
60. Nims RW, Lubet RA, Fox SD, et al. Comparative pharmacodynamics of CYP2B induction by DDT, DDE, and DDD in male rat liver and cultured rat hepatocytes. J Toxicol Environ Health. 1998;53(6):455- 477. https://doi.org/10.1080/009841098159187
61. Arshad U, Taubert M, Kurlbaum M, et al. Enzyme autoinduction by mitotane supported by population pharmacokinetic modeling in a large cohort of adrenocortical carcinoma patients. Eur J Endocrinol. 2018;179(5):287-297. http://doi.org/10.1530/EJE- 18-0342
62. Reif VD, Sinsheimer JE. Metabolism of 1-(0-chlorophenyl)- 1-(p-chlorophenyl)-2,2-dichloroethane (o,p’-DDD) in rats. Drug Metab Dispos. 1975;3(1):15-25.
63. Sieber SM. The Lymphatic Absorption of p,p’-DDT and Some Structurally-Related Compounds in the Rat. Pharmacology. 1976;14 (5):443-454. https://doi.org/10.1159/000136627
64. Touitou Y, Bogdan A, Legrand JC, Desgrez P. Metabolism of o,p’- DDD (mitotane) in human and animals. Actual notions and practical deductions. Ann Endocrinol (Paris). 1977;38(1):13-25.
65. Lin CW, Chang YH, Pu HF. Mitotane exhibits dual effects on ste- roidogenic enzymes gene transcription under basal and cAMP- stimulating microenvironments in NCI-H295 cells. Toxicology. 2012; 298(1-3):14-23. https://doi.org/10.1016/j.tox.2012.04.007
66. Rone MB, Midzak AS, Issop L, et al. Identification of a dynamic mito- chondrial protein complex driving cholesterol import, trafficking, and metabolism to steroid hormones. Mol Endocrinol. 2012;26(11):1868- 1882. https://doi.org/10.1210/me.2012-1159
67. Hescot S, Amazit L, Lhomme M, et al. Identifying mitotane-induced mitochondria-associated membranes dysfunctions: metabolomic and lipidomic approaches. Oncotarget. 2017;8(66):109924-109940. https://doi.org/10.18632/oncotarget.18968
68. Germano A, Saba L, De Francia S, et al. CYP11B1 has no role in mitotane action and metabolism in adrenocortical carcinoma cells. PLoS ONE. 2018;13(5):e0196931. https://doi.org/10.1371/journal. pone.0196931
69. Zsippai A, Szabó DR, Tömböl Z, et al. Effects of mitotane on gene expression in the adrenocortical cell line NCI-H295R: a microarray study. Pharmacogenomics. 2012;13(12):1351-1361. https://doi.org/ 10.2217/pgs.12.116
70. Sbiera S, Leich E, Liebisch G, et al. Mitotane Inhibits Sterol-O-Acyl Transferase 1 Triggering Lipid-Mediated Endoplasmic Reticulum Stress and Apoptosis in Adrenocortical Carcinoma Cells. Endocrinology. 2015;156(11):3895-3908. https://doi.org/10.1210/en.2015-1367
71. Rogers MA, Liu J, Song B, et al. Acyl-CoA:cholesterol acyltransferases (ACATs/SOATs): Enzymes with multiple sterols as substrates and as activators. J Steroid Biochem Mol Biol. 2015;151: 102-107. https://doi.org/10.1016/j.jsbmb.2014.09.008
72. Shawa H, Deniz F, Bazerbashi H, et al. Mitotane-Induced Hyperlipid- emia: A Retrospective Cohort Study. Int J Endocrinol. 2013;2013: 624962-624967. https://doi.org/10.1155/2013/624962
73. LaPensee CR, Mann JE, Rainey WE, et al. ATR-101, a Selective and Potent Inhibitor of Acyl-CoA Acyltransferase 1, Induces Apoptosis in H295R Adrenocortical Cells and in the Adrenal Cortex of Dogs. End- ocrinologie. 2016;157(5):1775-1788. https://doi.org/10.1210/en. 2015-2052
74. Kerr ID, Haider AJ, Gelissen IC. The ABCG Family of membrane- associated transportes: you donn’t have to be big to be mighty. Br J Pharmacol. 2011;164(7):1767-1779. https://doi.org/10.1111/j. 1476-5381.2010.01177.x
75. Hescot S, Slama A, Lombès A, et al. Mitotane alters mitochondrial respiratory chain activity by inducing cytochrome c oxidase defect in human adrenocortical cells. Endocr Relat Cancer. 2013;20(3):371- 381. https://doi.org/10.1530/ERC-12-0368
76. Poli G, Guasti D, Rapizzi E, et al. Morphofunctional effects of mitotane on mitochondria in human adrenocortical cancer cells. Endocr Relat Cancer. 2013;20(4):537-550. https://doi.org/10.1530/ ERC-13-0150
77. Weigand I, Schreiner J, Röhrig F, et al. Active steroid hormone syn- thesis renders adrenocortical cells highly susceptible to type II fer- roptosis induction. Cell Death Dis. 2020;11(3):192. https://doi.org/ 10.1038/s41419-020-2385-4
78. Stigliano A, Cerquetti L, Borro M, et al. Modulation of proteomic profile in H295R adrenocortical cell line induced by mitotane. Endocr Relat Cancer. 2008;15(1):1-10, https://doi.org/10.1677/ERC- 07-0003
BRITISH PHARMACOLOGICAL SOCIETY
79. Khan TS, Sundin A, Juhlin C, Wilander E, Öberg K, Eriksson B. Vin- cristine, cisplatin, teniposide, and cyclophosphamide combination in the treatment of recurrent or metastatic adrenocortical cancer. Med Oncol. 2004;21(2):167-177. https://doi.org/10.1385/MO:21: 2:167
80. Harada K, Kimura K, Iwamuro M, et al. The Clinical and Hormonal Characteristics of Primary Adrenal Lymphomas: The Necessity of Early Detection of Adrenal Insufficiency. Intern Med. 2017;56 (17):2261-2269. https://doi.org/10.2169/internalmedicine. 8216-16
81. Seidel E, Walenda G, Messerschmidt C, et al. Generation and charac- terization of a mitotane-resistant adrenocortical cell line. Endocr Connect. 2020;9(2):122-134. https://doi.org/10.1530/EC-19-0510
82. Allolio B, Fassnacht M. CLINICAL REVIEW: Adrenocortical Carci- noma: Clinical Update. J Clin Endocrinol Metab. 2006;91(6):2027- 2037. https://doi.org/10.1210/jc.2005-2639
83. Veytsman I, Nieman L, Fojo T. Management of Endocrine Manifesta- tions and the Use of Mitotane As a Chemotherapeutic Agent for Adrenocortical Carcinoma. J Clin Oncol. 2009;27(27):4619-4629. https://doi.org/10.1200/JCO.2008.17.2775
84. Hampl R, Kancheva R, Hill M, Bičíková M, Vondra K. Interpretation of Sex Hormone-Binding Globulin Levels in Thyroid Disorders. Thyroid. 2003;13(8):755-760. https://doi.org/10.1089/ 105072503768499644
85. Henley DE, Lightam SL. New insights into corticosteroid-binding globulin and glucocorticoid delivery. Neuroscience. 2011;28:1-8. https://doi.org/10.1016/j.neuroscience.2011.02.053
86. Reimondo G, Puglisi S, Zaggia B, et al. Effects of mitotane on the hypothalamic-pituitary-adrenal ax is in patients with adrenocortical carcinoma. Eur J Endocrinol. 2017;177(4):361-367. https://doi.org/ 10.1530/EJE-17-0452
87. Lund B, Bergman Â, Brandt I. Metabolic activation and toxicity of a ddt metabolite, 3-methylsulphonyl-dde, in the adrenal zona fascicula ta in mice. Chem Biol Interact. 1988;65(1):25-40. https://doi.org/10. 1016/0009-2797(88)90028-2
88. Asp V, Lindström V, Olsson JA, Bergström U, Brandt I. Cytotoxicity and decreased corticosterone production in adrenocortical Y-1 cells by 3-methylsulfonyl-DDE and structurally related molecules. Arch Toxicol. 2009;83(4):389-396. https://doi.org/10.1007/s00204-008- 0342-6
89. Hermansson V, Asp V, Bergman A, Bergström U, Brandt I. Compara- tive CYP-dependent binding of the adrenocortical toxicants 3-methylsulfonyl-DDE and o,p’-DDD in Y-1 adrenal cells. Arch Toxicol. 2007;81(11):793-801. https://doi.org/10.1007/s00204- 007-0206-5
90. Ulleras E, Ohlsson A, Oskarsson A. Secretion of cortisol and aldoste- rone as a vulnerable target for adrenal endocrine disruption - screening of 30 selected chemicals in the human H295R cell model. J Appl Toxicol. 2008;28(8):1045-1053. https://doi.org/10.1002/ jat.1371
91. Lindhe Ö, Skogseid B. Mitotane Effects in a H295R Xenograft Model of Adjuvant Treatment of Adrenocortical Cancer. Horm Metab Res. 2010;42(10):725-730. https://doi.org/10.1055/s-0030- 1261923
92. Asp V, Ullerås E, Lindström V, Bergström U, Oskarsson A, Brandt I. Biphasic hormonal responses to the adrenocorticolytic DDT metab- olite 3-methylsulfonyl-DDE in human cells. Toxicol Appl Pharmacol. 2010;242(3):281-289. https://doi.org/10.1016/j.taap.2009.10.018
93. Menaa F, Menaa B. Development of Mitotane Lipid Nanocarriers and Enantiomers: Two-in-One Solution to Efficiently Treat Adreno- Cortical Carcinoma. Curr Med Chem. 2012;19(34):5854-5862. https://doi.org/10.2174/092986712804143376
94. Lin Y, Chen Y, Wu T, et al. Enhancement of dissolution rate of mitotane and warfarin prepared by using microemulsion systems. Colloids Surf B Biointerfaces. 2011;85(2):366-372. https://doi.org/10. 1016/j.colsurfb.2011.03.015
95. Attivi D, Ajana I, Astier A, Demoré B, Gibaud S. Development of microemulsion of mitotane for improvement of oral bioavailability. Drug Dev Ind Pharm. 2010;36(4):421-427. https://doi.org/10.3109/ 03639040903225083
96. Severino P, Souto EB, Pinho SC, Santana MHA. Hydrophilic coating of mitotane-loaded lipid nanoparticles: Preliminary studies for muco- sal adhesion. Pharm Dev Technol. 2013;18(3):577-581. https://doi. org/10.3109/10837450.2011.614250
97. Nishiyama N, Kataoka K. Current state, achievements, and future prospects of polymeric micelles as nanocarriers for drug and gene delivery. Pharmacol Ther. 2006;112(3):630-648. https://doi.org/10. 1016/j.pharmthera.2006.05.006
98. Yadav HKS, Almokdad AA, Shaluf SIM, et al. Nanocarriers for Drug Delivery: Nanoscience and Nanotechnology in Drug Delivery. Amsterdam: Elsevier; 2019:531-556.
99. Haider MS, Schreiner J, Kendl S, Kroiss M, Luxenhofer R. A Micellar Mitotane Formulation with High Drug Loading and Solubility: Physico-Chemical Characterization and Cytotoxicity Studies in 2D and 3D in vitro Tumor Models. Macromol Biosci. 2020;20(1): e1900178. https://doi.org/10.1002/mabi.201900178
100. Alexander SPH, Kelly E, Mathie A, et al. The Concise Guide to PHARMACOLOGY 2019/20. Br J Pharmacol. 2019;176:S247-S296. https://doi.org/10.1111/bph.14747
How to cite this article: Corso CR, Acco A, Bach C, Bonatto SJR, de Figueiredo BC, de Souza LM. Pharmacological profile and effects of mitotane in adrenocortical carcinoma. Br J Clin Pharmacol. 2021;1-13. https://doi.org/10.1111/bcp. 14721