Combined hormonal influence of cyproterone acetate and nomegestrol acetate on meningioma: a case report.

Cyproterone acetate (CPA) is an antiandrogenic drug which has recently been recognized to promote the occurrence and growth of intracranial meningiomas. Nomegestrol acetate (NOMAC) is a widely used progestin-like drug that could be suggested as an alternative for patients taking CPA. We report a case of CPA-related meningioma for which relay from CPA to NOMAC led to further tumor growth and cessation of NOMAC-induced tumor shrinkage. We suggest NOMAC can have a similar effect than CPA on meningiomas. The use of NOMAC as replacement for CPA in the presence of a meningioma should be discouraged until further evidence becomes available on the role of NOMAC in such instances.

Carcinogenicity and chronic rodent toxicity of the selective progesterone receptor modulator ulipristal acetate.

Carcinogenic properties of ulipristal acetate (UPA), a selective progesterone receptor modulator developed for the treatment of benign gynecological conditions such as uterine fibroids, were assessed in a 26-week carcinogenicity study in transgenic TgRasH2 mice and a 104-week study in Sprague Dawley rats. Dose levels used in the mouse study were 15, 45, or 130 mg/kg/day and for the ratstudy the doses used were 1, 3, or 10 mg/kg/day. Vehicle and water controls were part of both studies and a positive control, N-Nitroso-N-methylurea intraperitoneally, was included in the transgenic mouse assay. Survival at all dose levels was similar to vehicle controls in both sexes of both species and there was no evidence of any UPA-induced carcinogenicity in either species. Rats receiving UPA had decreased incidences of fibroadenomas and adenocarcinomas in the mammary gland in all treated groups. UPA exposure [AUC(0-24h)] at the highest dose in rats was 67 times human therapeutic exposure at 10 mg/day. In mice, no tumor of any type increased at UPA exposures up to 313 times of therapeutic exposure. UPA-related findings in mice were limited to organ weight changes in the liver, pituitary, thyroid/parathyroid glands, and epididymis as well as minimal panlobular hepatocellular hypertrophy in male and female mice receiving 130 mg/kg/day. Rats had UPA-related non-neoplastic findings in the reproductive system (mammary gland, ovary, uterus, vagina, seminal vesicle, prostate), endocrine system (adrenal, pituitary), thymus, muscle, liver, pancreas and lungs most of which are considered to be due to exaggerated pharmacological action of the compound.

A 39-week oral toxicity study of ulipristal acetate in cynomolgus monkeys.

Ulipristal acetate (UPA) is a novel Progesterone Receptor Modulator (PRM) and registered for the pre-operative treatment of symptomatic uterine fibroids during 3months. In a study which assessed the potential toxicity of UPA in female cynomolgus monkeys following daily oral administration of 1, 5, or 25mg/kg for 39weeks, UPA was well tolerated with dose-dependent macroscopic and microscopic observations limited to the uterus and oviducts. These findings were considered to be related to the pharmacological action of UPA and showed evidence of partial reversibility. Findings in the endometrium were similar to PRM-associated-endometrial-changes (PAEC) described in PRM-treated women. No adverse effects were found that would raise concerns about potential pre-malignancy. Although the translation of these findings to human is limited by the small study size and species differences, these results from animals chronically exposed to up to 150times the clinical UPA exposure are considered significant and supportive to the chronic administration of UPA for more than 3months in women of reproductive age.

Preclinical pharmacological profile of nomegestrol acetate, a synthetic 19-nor-progesterone derivative.

BACKGROUND: Nomegestrol acetate (NOMAC), a synthetic progestogen derived from 19-nor-progesterone, recently completed clinical trials for use with 17beta-estradiol in a new monophasic combined oral contraceptive. In this review, published as well as previously unpublished preclinical studies that detail the effects of NOMAC on estrogenic, progestogenic, and androgenic systems, as well as mineralocorticoid, glucocorticoid, bone, and metabolic indices are described. METHODS: In vitro assays to determine NOMAC structure-activity relationships used tissue derived from rat uteri. Transactivation profiles were performed using Chinese hamster ovary (CHO) cells transfected with cDNAs encoding human steroid receptors. Estrogenic and anti-estrogenic activities were monitored in vivo in rats as well as in vitro in human breast cancer cells. Standard in vivo techniques were used in rats to determine progestational activity; antigonadotropic, androgenic, mineralocorticoid, and glucocorticoid activities; as well as effects on bone and other metabolic indices. Ovulation inhibition was monitored in rats and primates. NOMAC's effects on cardiovascular systems were determined in dogs and primates. RESULTS: NOMAC was without significant agonistic or antagonistic activity for estrogen receptor alpha or beta in vitro, and inhibited ovulation in rats and monkeys (2.5 mg/kg and 1 mg/kg, respectively). NOMAC lacked androgenic, antimineralocorticoid, glucocorticoid, and metabolic activity and exhibited moderate anti-androgenic activity in rats. NOMAC did not affect bone mineral density (BMD) in rats or hemodynamic and electrophysiologic parameters in dogs and primates. CONCLUSIONS: NOMAC is a selective progestogen structurally similar to progesterone that has modest anti-androgenic activity and does not affect lipid or carbohydrate metabolism, BMD, or many cardiovascular parameters in selected animal models.

Progesterone receptor antagonist CDB-4124 increases depression-like behavior in mice without affecting locomotor ability.

Progesterone withdrawal has been proposed as an underlying factor in premenstrual syndrome and postpartum depression. Progesterone withdrawal induces forced swim test (FST) immobility in mice, a depression-like behavior, but the contribution of specific receptors to this effect is unclear. The role of progesterone's GABA(A) receptor-modulating metabolite allopregnanolone in depression- and anxiety-related behaviors has been extensively documented, but little attention has been paid to the role of progesterone receptors. We administered the classic progesterone receptor antagonist mifepristone (RU-38486) and the specific progesterone receptor antagonist CDB-4124 to mice that had been primed with progesterone for five days, and found that both compounds induced FST immobility reliably, robustly, and in a dose-dependent fashion. Although CDB-4124 increased FST immobility, it did not suppress initial activity in a locomotor test. These findings suggest that decreased progesterone receptor activity contributes to depression-like behavior in mice, consistent with the hypothesis that progesterone withdrawal may contribute to the symptoms of premenstrual syndrome or postpartum depression.

[The central effects of a steroid alkaloid, Buxaminol-E, in conscious cats]. / Centrálne úcinky stereoidného alkaloidu Buxaminolu-E u bdelých maciek.

Buxaminol-E injected i.v. to conscious cats evoked hypothermia, tachypnoe, anorexia, salivation, defecation, decrease of spontaneous activity and sensitivity to painful stimulus and agitation during its administration. The above mentioned effects of B--E, with the exception of the antinociceptive action which was not examined and of the initial excitation, were observed also after intracerebroventricular (i.c.v.) administration of B--E, and they were depressed by atropine administered i.c.v. Our findings suggest a central cholinergic action of B--E in conscious cats. Paroxysmal tonic-clonic convulsions and circling observed only after i.c.v. administration of B--E and piloerection, ataxia and urination were not inhibited by atropine administered i.c.v.

The morphologic effects of synthetic reproductive steroids on the mammary gland of rhesus monkeys. Mestranol, ethynerone, mestranol-ethynerone, chloroethynyl norgestrel-mestranol, and anagestone acetate-mestranol combinations.

A total of 213 treated and 16 control monkeys comprising 12 experimental groups was evaluated for determination of the long-term (10 years) effects of various dosages of a variety of synthetic oral contraceptive steroids on the mammary glands of rhesus monkeys. The steroid hormones included mestranol, ethynerone, a combination of mestranol and ethynerone, chlorethynyl norgestrel plus mestranol, and anagestone acetate plus mestranol. Various degrees of physiologic lobular hyperplasia and lactational changes were observed in association with all of these steroid hormones; these changes appeared dose-dependent. Mestranol caused a proliferative atypia ranging from a minimal to a moderate degree in 8 of 34 (23%) animals, but it was not dose-related. Eleven of 15 monkeys (73%) administered ethynerone developed proliferative atypia, ranging in degree from minimal to severe, including one invasive carcinoma and 2 lesions resembling intraductal carcinoma in the human. The mestranol and ethynerone combination produced a proliferative atypia in 22 of 52 animals (42%), including five identical to intraductal carcinoma in the human and one identical to lobular neoplasia. Of the 40 monkeys administered anagestone acetate and mestranol, 20 (50%) developed proliferative atypias; the atypias ranged from mild to severe and included five resembling intraductal carcinoma in human breast. The chloroethynyl norgestrel and mestranol combination induced proliferative atypia in 25 of 52 monkeys (49%); six of these atypias were severe and indistinguishable from intraductal carcinoma of the human breast; and one, if in the human breast, would reflect a solid variant of an invasive carcinoma. Only 2 of the 16 control monkeys (12%) developed proliferative atypias, and these were of minimal to mild degree. The occurrence of severe degrees of atypia identical to intraductal carcinoma in the human breast and invasive carcinoma associated with hormone administration suggests a carcinogenic effect.

Growth inhibition by progestins in a human endometrial cancer cell line with estrogen-independent progesterone receptors.

The presence of estrogen-independent progesterone receptors (PgR) was demonstrated in a subline of a human endometrial cancer cell line, Ishikawa cells, although the original Ishikawa cells contained estrogen-inducible PgR. Scatchard plot analysis of cytoplasmic binding data in our subline (IK-90) revealed a high affinity binding site for R5020 (Kd, 1.0 nM) with maximum binding sites of 158 fmol/mg protein. Competition experiments showed a binding specificity similar to that of typical PgR. By low-salt sucrose gradient centrifugation, radioactive 8S and 4S peaks were found. The addition of 1 microM progesterone in culture medium resulted in a rapid nuclear translocation of cytoplasmic PgR. In contrast to the original cells, estrogen receptors could not be detected in IK-90 cells, and an addition of 17 beta-estradiol (10 nM) to culture medium failed to increase PgR. Accumulation of glycogen in cytoplasm of IK-90 cells in response to R5020 (0.1-1 microM) was observed by periodic acid-Schiff staining. The addition of R5020 to culture medium (0.1-1 microM) also caused a marked decrease in the growth of IK-90 cells, whereas the other steroids including 17 beta-estradiol, tamoxifen, testosterone, and cortisol had no significant effects. These results demonstrate for the first time the presence of a progestin-responsive human endometrial cancer cell line that contains estrogen-independent functional PgR. IK-90 cells appear to be an ideal model for studying the mechanism of the antiproliferative effect of progestin on endometrial cancer cells.

Effect of potent antiglucocorticoids on dexamethasone induced enzymes in cultured hepatoma and rat liver cells.

The antagonism by 3 synthetic steroids of the induction of tyrosine aminotransferase and tryptophan dioxygenase by dexamethasone were compared in HTC and FAZA hepatoma cells and in isolated liver cells. It was observed: (i) the sensitivity of liver cells to glucocorticoid agonists and antagonists changed in relation to time of culture; (ii) the extent of the inhibitory effect on enzyme induction depends on the nature of the antagonist; (iii) hepatoma cells, especially HTC cells, appeared more sensitive to glucocorticoid antagonism than liver cells.

Malignant mammary tumors in beagle dogs dosed with investigational oral contraceptive steroids.

Of 172 beagle dogs administered investigational oral contraceptive steroids for 2.4-5.2 years, 9 developed malignant mammary tumors. At necropsy their ages varied from 41 to 70 months, with a mean age of 4.9 years. The malignant tumors were observed in 1 dog that received ethynerone plus mestranol at 1.05 mg/kg/day and in 4 dogs that received chlorethynyl norgestrel plus mestranol at 1.05 mg/kg/day. Also, 4 dogs that received anagestone acetate plus mestranol at either 0.44 or 1.10 mg/kg/day developed malignant mammary tumors. Malignant tumors were not seen in 33 dogs administered mestranol at 0.02 and 0.05 mg/kg/day for 7 years or in 18 dogs given ethynerone without mestranol at 1.00 mg/kg/day for 5 years. No malignant tumors were observed in 18 control dogs maintained for 7 years without treatment. Three dogs had single malignant mammary nodules, 3 dogs had 2 malignant nodules, 2 dogs had 4-6 malignant nodules, and 1 dog in the treatment group given high dosages of ethynerone plus mestranol had 14 mammary nodules composed of fibrosarcoma. The malignant tumors were histologically classified as 5 anaplastic carcinomas, 2 solid carcinomas, 1 tubular adenocarcinoma, 1 squamous cell carcinoma, and 1 fibrosarcoma. Most dogs had only 1 histologic type of cancer (8/9 dogs); however, 1 dog had carcinomas of both solid and anaplastic types involving different glands. Metastases were present in 5 dogs and most often involved regional lymph nodes and lung.

Mammary nodules in beagle dogs administered investigational oral contraceptive steroids.

Of 172 beagle dogs administered oral contraceptive steroids for 5-7 years, 114 developed 1,156 nodules in the mammary gland region. Most of these nodules arose 2.5-3.5 years after initiation of treatment. Approximately 16% of the nodules were transient and disappeared spontaneously from the mammary gland during the study. A total of 925 nodules were present in 99 dogs at the time of death or necropsy. These nodules were classified as benign mammary dysplasias (7.0%), lobular or intraductal hyperplasias (31.4%), simple adenomas (20.8%), complex adenomas (25.4%), benign mixed tumors (5.3%), malignant tumors (3.6%), or nonmammary lesions (6.5%). Histologically, the mammary nodules were representative primarily of the hyperplasias and tumors that occur spontaneously in the mammary glands of the dog. The only major exception was the presence of 82 simple adenomas that had basaloid features. Most of the contraceptive-related mammary nodules developed in dogs receiving the combination of progestion and mestranol at 10 or 25 times the proposed human dosage. Control dogs and dogs receiving mestrenol alone had few mammary nodules. Combinations of anagestone acetate and mestranol and chloroethynyl norgestrel (WY-4355) and mestranol produced large numbers of nodules at 10 and 25 times the proposed human dosage, whereas ethynerone plus mestranol produced large numbers of nodules only at 25 times the proposed human dosage. Ethynerone, when given alone at 25 times the proposed human dosage, was associated with fewer mammary nodules. Malignant neoplasms were seen in dogs given 10 and 25 times the proposed human dosage of anagestone acetate plus mestranol and 25 times the proposed human dosage of WY-4355 plus mestranol and ethynerone plus mestranol. This study strongly associates certain combinations of progestin and mestranol with mammary neoplasia in dogs.