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PubMed1995

Interferon alfa and vinblastine versus medroxyprogesterone acetate in the treatment of metastatic renal cell carcinoma.

OBJECTIVES: Since the beginning of the 1980s, when gene technology provided sufficient amounts of cytokines, numerous Phase II studies in metastatic renal cell carcinoma were carried out mostly with interferon alfa (IFN-alpha) and interleukin-2 (IL-2). So far, no randomized prospective trials including untreated control groups have been reported. We present a prospective study comparing IFN-alpha and vinblastine (VBL) versus medroxyprogesterone acetate (MPA). METHODS: Immunochemotherapy schedule consists of IFN-alpha 8 million U/day subcutaneously for 3 days per week and VBL 0.1 mg/kg body weight intravenously at 3-week intervals. MPA was administrated intramuscularly at a dosage of 500 mg/week. The response rates, toxicities, and actuarial overall survival were analyzed. RESULTS: The overall response rate in 41 patients receiving IFN-alpha and VBL treatment was 20.5% (95% confidence interval, 9% to 33%). Four patients reached a complete and 5 patients reached a partial remission. No remissions were observed in 35 patients of the control group. A statistically significant survival benefit for the IFN-alpha and VBL group could not be demonstrated. Excluding fever, mild to moderate toxicities were observed. About one third of patients refused the proposed schedule due to general malaise and fatigue. CONCLUSIONS: A survival benefit or a favorable outcome of patients with metastatic renal cell carcinoma, treated with IFN-alpha and VBL, could not be demonstrated. As judged from this analysis, IFN-alpha and VBL therapy does not sufficiently meet the requirements of a palliative treatment of renal cell carcinoma.

Actuarial Analysis↗
PubMed2003

Use of medroxyprogesterone acetate (MAP) in lactating Holstein cows within an Ovsynch protocol: follicular growth and hormonal patterns.

To evaluate the effects of incorporating medroxyprogesterone acetate (MAP) in an Ovsynch protocol, cyclic lactating dairy cows were assigned randomly to two groups (control and MAP, n=8 each). Ovsynch treatment (Day 0: GnRH, Day 7: PG, Day 9: GnRH) was initiated at random stages of the estrous cycle (control) and an intravaginal polyurethane sponge impregnated with 300mg of MAP was inserted intravaginally in the MAP group at Day 0 and removed at Day 7 of the Ovsynch protocol (MAP treatment). Ovaries were scanned daily from Day 0 until the second GnRH treatment on Day 9 and from then every 6h for 36 h. Milk samples were collected three times weekly starting 17 days before the initiation of treatment to determine the stage of the cycle at the beginning of the Ovsynch protocol. Blood samples were collected to monitor estradiol (E2), progesterone (P4), LH, and 15-ketodihydro-PGF(2alpha) (PGFM) by RIA. Response to the first GnRH treatment varied with the stage of the cycle at the time of initiation of treatment, as cows in metestrous and late diestrous did not ovulate. In cows ovulating, growth rate of the new follicle was not affected by the addition of MAP. No treatment differences were found in E2 concentrations which reached a maximum at Day 9, consistent with the maximum follicular size. At Day 7, cows with luteal concentrations of P4 had increased concentrations of PGFM, but cows with basal P4 did not show an active release of prostaglandins. There were no treatment differences in the ovulatory response to the second GnRH-induced ovulation, with 11 of the 16 cows ovulating between 16 and 32 h. The addition of MAP to the Ovsynch protocol could not mimic the normal high progesterone levels needed to prevent premature ovulations in those cows with premature CL regression.

Administration, Intravaginal↗
PubMed1977

Injectable contraception (medroxyprogesterone acetate) in rural Bangladesh.

1601 women used the injectable contraceptive agent medroxyprogesterone acetate for up to 3 years. The programme was conducted by a rural health centre with detailed follow-up. While the continuation-rate, 56% after 1 year, compared favourably with that of other contraceptive methods in Bangladesh, at least half the women experienced troublesome menstrual side-effects and there were indications that milk yield was adversely affected in 147 out of the 1020 women who received the first injection while lactating.

Bangladesh↗
PubMed2001

Protective role of medroxyprogesterone acetate on N-methyl-N-nitrosourea-induced lymphomas in BALB/c female mice.

In a previous paper we reported the occurrence of a high incidence of lymphomas in N-methyl-N-nitrosourea (MNU)-treated mice, in the course of an experiment of combined chemical-hormonal carcinogenesis in mammary gland, in which we used medroxyprogesterone acetate (MPA) and MNU in different treatment protocols. In this report we have analyzed the action of MPA in the leukemogenic effects of MNU, by specifically selecting for the analysis experimental groups in which only few mammary carcinomas had developed. A high incidence of lymphomas (65%, median latency: 176 days) was registered in MNU-treated mice, and the administration of MPA was associated with a significant reduction in the incidence of lymphomas (P<0.001) in all protocols.

Animals↗
PubMed2001

Quality of life and costs associated with micronized progesterone and medroxyprogesterone acetate in hormone replacement therapy for nonhysterectomized, postmenopausal women.

BACKGROUND: Because natural progesterone is poorly absorbed and rapidly metabolized, synthetic derivatives of progesterone, such as medroxyprogesterone acetate (MPA), are used in combination with estrogen in hormone replacement therapy. A micronized form of natural progesterone is available that is readily absorbed and reaches peak serum concentrations from 1 to 4 hours after administration. OBJECTIVE: The purpose of this study was to compare the quality of life (QOL), menopausal symptoms, and costs associated with a natural micronized progesterone (MP) formulation versus MPA as add-on therapy to estrogen in hormone replacement for post-menopausal women. METHODS: This prospective, multicenter, randomized, fixed-dose, open-label, parallel-group study enrolled postmenopausal, otherwise healthy, nonhysterectomized women 45 to 65 years of age who had been amenorrheic for > or =6 months and exhibited symptoms of estrogen deficiency. All women received 0.625 mg conjugated equine estrogens on days 1 to 25 of a 30-day cycle; on days 12 to 25, women were randomized to receive either MP 200 mg or MPA 5 mg; patients were followed for 9 months. QOL, the primary end point, was measured at baseline and months 3, 6, and 9 using the 36-Item Short-Form Health Survey (SF-36), the Nottingham Health Profile (NHP), and the condition-specific Women's Health Questionnaire (WHQ). Bleeding pattern, compliance, menopausal symptoms, and cost were evaluated as secondary end points. Costs (in 1997 Canadian dollars) were assessed from the societal perspective and included costs of study medication, hormone therapy monitoring, concomitant medication, outpatient resources, out-of-pocket expenses, and patient and caregiver time loss. RESULTS: A total of 182 women were enrolled; 89 received MP and 93 received MPA. Improvements in climacteric symptoms were observed from baseline to month 9 for both treatments. Mean scores on all domains of the SF-36 at month 9 were greater than scores at baseline in both treatment groups but the increases were not statistically significant. All domains within the NHP and WHQ improved significantly over this period for both groups (P < or = 0.008). Only patients receiving MP showed specific improvements in the menstrual problems and cognitive domains of the WHQ. The difference in average 9-month cost per patient was not statistically significant, at Can 367 dollars +/- 120 dollars and Can 360 dollars +/- 369 dollars for patients receiving MP and MPA, respectively. CONCLUSIONS: MP is a clinically effective, well-tolerated, and cost-comparable alternative to MPA.

Aged↗
PubMed2001

Effect of medroxyprogesterone pretreatment on pentagastrin-induced panic symptoms in females with panic disorder.

Clinical observation, as well as epidemiological and research data, suggest that female gonadal hormones influence the course of panic disorder (PD). Panicogenic agents such as pentagastrin are useful tools with which to study the pathophysiology of panic attacks. Nine women with PD were randomly assigned to receive, in a crossover design, a 3-day pretreatment with medroxyprogesterone acetate (MP) prior to an injection of pentagastrin, and a 3-day pretreatment with a placebo prior to another injection of pentagastrin. The panic response and the anxiety response to pentagastrin were decreased after MP pretreatment. These preliminary results support the use of laboratory models for investigations of the interactions between progestins and anxiety.

Adult↗
PubMed1999

Androgen receptor agonist activity of the synthetic progestin, medroxyprogesterone acetate, in human breast cancer cells.

Medroxyprogesterone acetate (MPA), which is frequently used as second line hormonal therapy for the treatment of metastatic breast cancer, binds with high affinity to the progesterone receptor (PR). However, the androgenic side-effects of MPA suggest that it may also activate androgen receptor (AR) regulated pathways. Treatment of the human breast cancer cell lines MDA-MB-453, ZR-75-1 and T47-D with high dose (100 nM) MPA resulted in 26-30% inhibition of cell growth, which was partially reversed by co-treatment with a 10-fold excess of the synthetic antiandrogen, anandron. Scatchard analysis demonstrated specific, high affinity (non-PR) binding of [3H]MPA to cytosols prepared from the PR-/AR+ MDA-MB-453 and PR+/AR+ ZR-75-1, but not the PR-/AR- BT-20 breast cancer cell lines. Competition of [3H]MPA binding to MDA-MB-453 cytosols by equimolar concentrations of androgens (5alpha-dihydrotestosterone (DHT), R1881) and the antiandrogen, anandron was consistent with binding of MPA to the AR. In ZR-75-1 cell cytosol fractions, DHT, R1881 and anandron only partially competed out [3H]MPA binding, suggesting that androgens displace [3H]MPA binding to AR but not to PR. Induction by MPA of AR transactivation was demonstrated in MDA-MB-453 and ZR-75-1 cells, and in the CV-1 cell line transfected with a full-length AR. In these cell lines the increased activity of the androgen responsive reporter gene (MMTV-CAT) by 1 nM MPA was fully (MDA-MB-453, CV-1) or partially (ZR-75-1) inhibited by co-culture with 1 microM anandron. These findings indicate that MPA is an AR agonist and suggest that the in vivo effects of MPA in breast cancer patients may in part be mediated by the AR.

Androgen Antagonists↗
PubMed2000

Inhibition by 9alpha-fluoromedoroxyprogesterone acetate (FMPA) against mammary carcinoma induced by dimethylbenz[a]anthracene in rats and angiogenesis in the rabbit cornea - comparison with medroxyprogesterone acetate (MPA).

Medroxyprogesterone acetate (MPA) is currently used therapeutically in the treatment of mammary and endometrial carcinomas. In order to develop a more potent and useful drug, we synthesized the novel compound, 9alpha-fluoromedoroxyprogesterone acetate (FMPA), by fluorinating MPA, and we also previously reported that FMPA displays more potent anti-angiogenic activity in the chorioallantoic membrane assay than MPA. In the present study, we investigated (1) the effects of FMPA on rat mammary carcinomas induced by dimethylbenz[a]anthracene (DMBA) to determine the anti-tumor activity, (2) the effect on angiogenesis in rabbit corneal assays, and (3) compared these results with those for MPA. FMPA inhibited the growth of mammary carcinomas in a dose-dependent manner (7.5, 30 and 120 mg/kg). Almost complete involution of the carcinomas was observed at doses of 30 and 120 mg/kg. MPA also inhibited the growth of carcinomas at doses of 30 and 120 mg/kg, but no involution of carcinomas was observed even at 120 mg/kg. FMPA significantly and MPA to a lesser degree inhibited carcinogenesis at 120 mg/kg within their treatments. In rabbit corneal assays, FMPA significantly inhibited angiogenesis (IC50 value=0.085 microg/pellet). MPA also significantly inhibited angiogenesis (IC50 value=0.60 microg/pellet). From these results, we conclude that FMPA is potentially more effective in the treatment of mammary carcinomas than MPA.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

The comparison of effects of tibolone and conjugated estrogen-medroxyprogesterone acetate therapy on sexual performance in postmenopausal women.

OBJECTIVE: To compare the effects of two different postmenopausal regimens on sexual performance. METHODS: A single blind prospective clinical study was planned on fifty natural postmenopausal women with no absolute contraindication for hormone replacement therapy (HRT). A total of 25 women were randomized for tibolone therapy (group T) and the rest 25 for continuous conjugated estrogen (CE) 0. 625 mg plus medroxyprogesterone acetate (MPA) 2.5 mg (group E) for a year. Two women in group T and four women in group E were excluded from the study as they didn't attend the control visit. At baseline and after a year, sexual performance parameters (sexual desire, coital frequency, orgasm frequency, vaginal dryness/dyspareunia) and after therapy subjective well-being, vasomotor symptoms, and side effects were assessed by score method designed by us. RESULTS: Treatment with either preparation significantly improved subjective well-being, vasomotor symptoms and vaginal dryness. The rates of overall side effects between two groups were not found statistically different (P=0.84). Tibolone therapy increased sexual desire and coital frequency (P=0.001, P=0.014). CONCLUSIONS: Both tibolone and continuous combined CE/MPA effectively improve the findings of hypoestrogenism and subjective well being. Moreover, tibolone effectively increases sexual performance. It is seen that tibolone with acceptable androgenic side effects can be an appropriate selection for HRT in postmenopausal women with decreased sexual desire.

Anabolic Agents↗
PubMed2001

Anti-ischemic effect of chronic oestrogen replacement therapy alone or in combination with medroxyprogesterone acetate in different replacement schemes.

BACKGROUND: Oestrogen replacement therapy in postmenopausal women has a protective effect upon the cardiovascular system and improves exercise-induced myocardial ischemia. Although in hormone replacement schemes progestins are required to reduce the likelihood of uterine malignancies, little is known on the cardiovascular effect of progestins. The purpose of this study was to evaluate the effect of oestrogen replacement alone and two different estrogen-progestin replacement therapy schemes upon exercise induced myocardial ischemia. MATERIAL AND METHOD: The study population included 18 female menopausal patients with coronary artery disease. After a baseline exercise test patients received conjugated equine estrogens (CEE) 0.625 mg alone for 30 days when they underwent a second exercise test and were randomized to receive in a cross-over design medroxyprogesterone acetate (MPA) either in continuous combined therapy (2.5 mg/daily) for 28 days or in cyclical therapy (10 mg o.d. from day 16 to day 28). RESULTS: After CEE alone two patients with a previously positive exercise test showed a negative exercise test. CEE increased time to 1 mm ST compared to baseline (352+/-185 vs 265+/-133 s, P<0.01). In the 2 pts in whom the exercise test was negative after CEE the test remained negative during continuous combined MPA therapy while become positive during cyclical MPA. CEE+continuous combined MPA increased both time to 1 mm ST and exercise time compared to baseline (386+/-165 vs 265+/-133 s, P<0.01 and 545+/-198 vs 465+/-186 s, P<0.05, respectively). No difference was found between baseline and CEE+cyclical MPA in either time to 1 mm ST or exercise time (268+/-164 vs 265+/-133 s, P=NS and 455+/-223 vs 465+/-186 s, P=NS, respectively). CONCLUSION: Continuous combined therapy with CEE+MPA improves exercise-induced myocardial ischemia in female patients with coronary artery disease while the beneficial effect of CEE is reduced by cyclical therapy.

Aged↗
PubMed2000

A double-blind, randomized, comparative study evaluating clinical effects of two sequential estradiol-progestogen combinations containing either desogestrel or medroxyprogesterone acetate in climacteric women.

OBJECTIVES: The aim of this study was to compare a new sequential estradiol-desogestrel (E2-DSG) hormone replacement regimen (Liseta) with one of the standard treatments i.e. estradiol valerate-medroxyprogesterone acetate (E2V-MPA) combination (Klimalet) regarding the alleviation of climacteric symptoms, vaginal bleeding pattern and the occurrence of adverse experiences. METHODS: In a multicenter study performed in Denmark, a total of 376 perimenopausal women with climacteric symptoms were randomly allocated to oral sequential treatment with either E2-DSG (1.5 mg E2 for 24 days with 0.15 mg DSG for the last 12 days followed by a placebo tablet for 4 days) (n = 186) or with E2V-MPA (2 mg E2V for 21 days with 10 mg MPA for the last 10 days) (n = 190). Treatments were administered, using a double-blind, double-dummy technique for 6 cycles of 28 days. RESULTS: Three hundred and seventeen women, 158 in the E2-DSG and 159 in the E2V-MPA group, completed six treatment cycles. Both treatments reduced menopausal symptoms rapidly and to a similar extent. Hot flushes were present in 88% of the women in both groups. After six treatment cycles, hot flushes were no longer present in 71 and 62% of the women in the E2-DSG and E2V-MPA group, respectively. Perspiration decreased from 80 to 65% in the E2-DSG group and from 82 to 63% in the E2V-MPA group. Mood disturbances were present in 82% of the women in the E2-DSG at baseline, and in 52% after six cycles. In the E2V-MPA group the corresponding figures were 68 and 42%, respectively. The bleeding pattern was comparable in both treatment groups. Regular withdrawal (expected) bleeding appeared in 90-92% and in 85-90% of the women in cycles 1-5 with E2-DSG and E2V-MPA, respectively. Irregular bleeding (including spotting) occurred in 15.2% of the women receiving E2-DSG and in 20.1% of the women treated with E2V-MPA in cycle 6. In both treatment groups there was a tendency of a slight decrease in blood pressure. Adverse events were in less than 10% in each group the reason to discontinue treatment. CONCLUSIONS: Both treatments effectively alleviated menopausal complaints and presented good cycle control. Bleeding pattern and mood disturbances appeared to be more favorable influenced by E2-DSG.

Administration, Oral↗
PubMed1999

Development and validation of a reversed-phase liquid chromatographic method for analysis of estradiol valerate and medroxyprogesterone acetate in a tablet formulation.

A simple and accurate liquid chromatographic method was developed for estimation of estradiol valerate and medroxyprogesterone acetate in pharmaceuticals. Drugs were chromatographed on a reverse phase C18 column, using a mixture (30:70) of ammonium nitrate buffer and acetonitrile and eluants monitored at a wavelength of 280 nm. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The method was statistically validated for its linearity, accuracy, precision and selectivity. Due to its simplicity and accuracy, the authors believe that the method may be used for routine quality control analysis. It does not require any specific sample preparation except the use of a column guard before the analytical column and suitable prefilter attached to the syringe prior to injection.

Calibration↗
PubMed1995

A prospective randomized trial to evaluate different oral dose regimens of medroxyprogesterone acetate in women with advanced breast cancer.

A prospective randomized study was conducted to try to answer two questions: is a loading dose of medroxyprogesterone acetate (1000 mg p.o. q.d.s. for 48 h) superior to conventional dosing; and does an oral maintenance dose of 1000 mg daily offer any advantage over 500 mg daily in women with advanced breast cancer who have failed to respond to, or have relapsed after, tamoxifen? Of 211 patients randomized, 207 were evaluable. There was no improvement in response rates, time to response, response duration or overall survival as a result of the loading dose. When comparing high and low maintenance doses, there was a significant difference in response rates (48% versus 32%; chi 2 = 10.09, df = 2, P = 0.006) and survival (66% versus 41% alive at 12 months; chi 2 = 9.06, df = 1, P = 0.003) in favour of the higher dose regimen, although there was no significant difference in the duration of response. There was no additional toxicity attributable to the loading dose regimen, but side effects were more frequent with the high dose maintenance schedule (141 of 201 adverse effects occurring in these two groups) although the incidence of severe toxicity was similar with both high dose and low dose treatments.

Administration, Oral↗
PubMed2002

Adjuvant endocrine treatment with medroxyprogesterone acetate or tamoxifen in stage I and II endometrial cancer--a multicentre, open, controlled, prospectively randomised trial.

Endometrial cancer is a hormone-dependent disease and therefore an adjuvant hormonal therapy might improve the outcome in the early stages of the disease. Between 1983 and 1989, we conducted a randomised trial of 388 patients who received either medroxyprogesterone acetate (MPA) (n=133) or tamoxifen (n=121) orally for 2 years, or were observed only (n=134) after surgical therapy. The aim was to evaluate whether an adjuvant treatment can improve disease-free and overall survival rates. After a median follow-up period of 56 months (range 3-199 months), we observed no differences in the disease-free and overall survival rates for the tamoxifen group compared with the control or the MPA group. Side-effects were more frequent and severe in the MPA-group than in the tamoxifen group. In patients with early endometrial cancer, adjuvant endocrine treatment did not significantly improve the outcome. However, tamoxifen did have some beneficial effects on coexisting morbidity.

Adult↗
PubMed1997

Medroxyprogesterone acetate reduces the in vitro production of cytokines and serotonin involved in anorexia/cachexia and emesis by peripheral blood mononuclear cells of cancer patients.

Medroxyprogesterone acetate (MPA) is widely used in oncology both in the treatment of hormone-related cancers and as supportive therapy in anorexia/cachexia syndrome (ACS), but conclusive data are not yet available to explain its anticachectic effect. ACS is characterised by weight loss, changes in metabolism, reduction of appetite, nausea and vomiting. Several cytokines, mainly interleukin (IL)-1, IL-2, IL-6 and tumour necrosis factor alpha (TNF alpha), are involved in the pathogenesis of ACS. Additionally, nausea and vomiting can be mediated by factors inducing serotonin (5-HT) production and/or release by pleiotropic cells including activated T lymphocytes. In the present study, we report the effect of MPA on peripheral blood mononuclear cells (PBMC) from 10 cancer patients in advanced stage of disease (6 head and neck, 2 colon, 1 lung and 1 ovary). The proliferative response of PBMC to PHA, anti-CD3 monoclonal antibody (MAb) or recombinant IL-2 (rIL-2), the production of IL-1 beta, IL-2, IL-6, TNF alpha and 5-HT by PHA-stimulated PBMC and the expression of lymphocyte membrane-bound IL-2 receptor (IL-2R) subunities (CD25 and CD122) were studied. The addition of MPA significantly reduced the PBMC proliferative response to PHA and anti-CD3 MAb but not to rIL-2. MPA 0.2 microgram/ml was also capable of reducing the levels of IL-1 beta, IL-6, TNF alpha and 5-HT produced in culture by PHA-stimulated PBMC, whereas it did not induce any change in the percentage of PBMC expressing either CD25 or CD122 or both molecules after stimulation with PHA or anti-CD3 mAb.

Aged↗
PubMed1997

Predictive value of serum medroxyprogesterone acetate concentration for response in advanced or recurrent breast cancer.

Medroxyprogesterone acetate (MPA) is one of the most commonly prescribed drugs for endocrine therapy of metastatic breast cancer. In this study, the serum MPA concentration was measured by high-performance liquid chromatography (HPLC) and evaluated for its usefulness in predicting the response in 79 cases of advanced or recurrent breast cancers. Overall, 29 patients (37%) achieved an objective response. The response rate correlated significantly with the oestrogen receptor (ER) status (P = 0.03), proliferative activity determined by DNA polymerase alpha (P = 0.04), the disease-free interval (DFI) (P = 0.05) and the serum MPA concentration (P < 0.001). Patients with ER-positive tumours, lower proliferative activity, a longer (DFI) or a higher serum MPA concentration responded more frequently. The mean serum MPA concentration in the responders with ER-positive tumours (P = 0.01) or tumours with a lower proliferative activity (P = 0.008) were significantly lower than in cases with ER-negative tumours or tumours with a higher proliferative activity, respectively. Cases with soft tissue metastases showed responses at significantly lower MPA concentrations (P = 0.003) than those with bone or visceral metastases. Furthermore, there was a dramatic decrease in the MPA concentration when a responder with a high concentration became unresponsive to the therapy. Thus, the serum MPA concentration is a determining factor for the response to treatment.

Adult↗
PubMed2003

Norelgestromin as selective estrogen enzyme modulator in human breast cancer cell lines. Effect on sulfatase activity in comparison to medroxyprogesterone acetate.

Human breast cancer tissue contains enzymes (estrone sulfatase, 17beta-hydroxysteroid dehydrogenase, aromatase) involved in the last steps of estradiol (E(2)) formation. In this tissue, E(2) can be synthesized by two main pathways: (1) sulfatase-transforms estrogen sulfates into bioactive E(2), and the (2) aromatase-converts androgens into estrogens. Quantitative assessment of E(2) formation in human breast tumors indicates that metabolism of estrone sulfate (E(1)S) via the sulfatase pathway produces 100-500 times more E(2) than androgen aromatization. In the present study, we demonstrated in T-47D and MCF-7 human breast cancer cells that norelgestromin (NGMN) (a metabolite of norgestimate) is a potent inhibitory agent of the estrone sulfatase activity. After 24h incubation of physiological concentrations of E(1)S (5 x 10(-9)mol/l) the inhibitory effect of NGMN at concentrations of 5 x 10(-9), 5 x 10(-7) and 5 x 10(-5)mol/l was 43+/-7, 74+/-4 and 97+/-2%, respectively, in T-47D cells; 25+/-4, 57+/-5 and 96+/-2% respectively, in MCF-7 cells. Comparative studies using medroxyprogesterone acetate (MPA) showed that this progestin also has an inhibitory effect on sulfatase activity, but significantly less intense than that of NGMN. The inhibition for MPA at concentrations of 5 x 10(-9), 5 x 10(-7) and 5 x 10(-5)mol/l was 31+/-5, 47+/-3 and 61+/-3%, respectively, for T-47D cells; 6+/-3, 20+/-3 and 63+/-4%, respectively, for MCF-7 cells. In conclusion, the present data show that NGMN is a very potent inhibitory agent for sulfatase activity in the hormone-dependent breast cancer cells, resulting in decreased tissue concentration of E(2). The clinical significance of this finding remains to be elucidated.

Antineoplastic Agents, Hormonal↗
PubMed1998

Involvement of insulin-like growth factors-I and -II and their receptors in medroxyprogesterone acetate-induced growth of mouse mammary adenocarcinomas.

The role of the insulin-like growth factors (IGFs) system was investigated in hormone-dependent (HD) and -independent (HI) in vivo lines of the medroxyprogesterone acetate (MPA)-induced mammary tumor model in Balb/c mice. IGF-II protein and message showed a three- to four-fold increase in HD lines growing in MPA-treated mice, as compared with HD tumors growing in untreated mice. Progression to a hormone-independent phenotype in all these lines was accompanied by a high constitutive expression of IGF-II. Similar IGF-I mRNA levels were detected in HD and HI lines. Both IGF-I and -II messages arose from the malignant epithelial cells, as shown by in situ hybridization studies. A significant decrease in Man-6P/type II IGF-R content was detected in HD tumors growing in MPA-treated mice as compared with HD lines growing in untreated mice. On the other hand, in HI tumors, notwithstanding high IGF-II synthesis, the levels of Man-6P/type II IGF-R remain high. Competitive inhibition and affinity labeling studies showed an almost exclusive binding of IGF-II to Man-6P/type II IGF-R on tumor membranes. The involvement of IGFs in the growth of epithelial primary cultures of the C4-HD line was evaluated. Exogenous IGF-I potentiated MPA stimulatory effect at concentrations of 50-100 ng/ml. Treatment of C4-HD cells with antisense oligodeoxynucleotides (ASODNs) to type I IGF-R and to IGF-II RNA resulted in a dose-dependent inhibition of MPA-mediated cell proliferation. The inhibition caused by IGF-II ASODNs could not be overcome by the addition of IGF-II up to 150 ng/ml. ASODNs to type I IGF-R at 40 microg/ml reduced by 75% the number of type I IGF-R; ASODNs to IGF-II at 1 microM decreased by 83% the levels of IGF-II protein. Our results provide support for the involvement of IGF-I and -II in MPA-induced mammary tumor growth by autocrine pathways.

Adenocarcinoma↗