We have studied the effect of new ligands of progesterone receptors, including pregna-D'-pentaran 6-methoxyimino-16a,17a-cyclohexanopregn-4-en-3,20-dio-ne (K1047), 17a-acetoxy-3b-butanoyloxy-6-methylpregna-4,6-dien-20-one (buterol), progesterone (P4), and medroxyprogesterone acetate on the viability of HeLa cells and expression of estrogen receptor-alpha (Era) mRNA gene in these cells. K1I047 and buterol exhibited high cytostatic activity, which exceeded the activity of reference compounds on the average by 15% (p < 0.05). Both buterol and K-1047 (at 10(-6)M) effectively suppressed ERa mRNA gene expression in HeLa cell culture by 83.4 - 9 8.6%.

Изучено влияние новых лигандов рецепторов прогестерона прегна-D’-пентарана — 6-метоксиимино-16α,17α-циклогексанопрегн-4-ен-3,20-дион (К1047), 17α-ацетокси-3β-бутаноилокси-6-метил-прегна-4,6-диен-20-она (бутерол), прогестерона (P4) и медроксипрогестерона ацетата на жизнеспособность клеток HeLa и экспрессию в них гена эстрогенного рецептора (ERα). Установлена высокая цитостатическая активность К-1047 и бутерола, превосходящая препараты сравнения в среднем на 15 %, p < 0,05. Бутерол и К1047 (10 – 6 М) подавляли экспрессию гена ERα на 83,4 – 98,6 % соответственно.

Phytoestrogen genistein can exhibit cytoprotective and antioxidant properties, providing chemopreventive action, and produce cytotoxic effects on some tu- mors. In this work, the cytotoxic, cytoprotective, and antioxidant properties of genistein have been studied on model tumor cells (human cervical cancer HeLa cells) and normal cells (rat dermal fibroblasts, RDF). For assessing the cytotoxic effect of genistein (spectrophotometric MTT assay), the reference drug was cis-diaminodichloroplatinum (cisplatin); for evaluating antioxidant action, beta-estradiol was the reference drug. It is established that genistein produces a cyto- toxic effect only at high concentrations, IC50 = 20 mM and 14 mM for RDF and HeLa cells, respectively, which is 30 and 10 times higher than IC50 for cisplatin on these cells. Genistein like estradiol, but unlike cisplatin, had no effect on the mitochondrial pore induction from rat liver mitochondria. Thus, genistein at physiological concentrations (up to 200 n) acts as a cytoprotective agent. High antioxidant activity of genistein also suggests the possibility of its use as a chemopreventive drug.

Фитоэстроген генистеин может проявлять как цитопротекторные, антиоксидантные свойства, оказывая как химиопрофилактическое, так и цитотоксическое действие на некоторые опухоли. В данной работе оценивали цитотоксическое, цитопротекторное и антиоксидантное действие субстанции генистеина на моделях опухолевых клеток — рака шейки матки HeLa и культуре фибробластов кожи крыс. При оценке цитотоксического действия генистеина (спектрофотометрический метод МТТ) в качестве препарата сравнения использовали цис-диаминдихлорплатину (цисплатин), а при оценке антиоксидантного действия — 17бета-эстрадиол. Показано, что генистеин проявлял цитотоксический эффект только в высоких концентрациях, IC50 равнялась 20 и 14 мМ на HeLa и культуре фибробластов, соответственно, что в 30 и 10 раз больше, чем у цис-платина. Генистеин, как и эстрадиол, не влиял на индукцию поры и проницаемость мембран изолированных митохондрий из печени крыс, в отличие от цисплатина. Таким образом, генистеин в физиологических концентрациях (до 200 мкл) действует как цитопротектор. Данные о высокой антиоксидантной активности генистеина также свидетельствуют в пользу возможности применения генистеина как химиопрофилактического средства.

In order to determine the cytotoxic or cytoprotective effect of the synthetic isoflavonoid genistein, we studied its effect on HeLa tumor cells, which contain estrogen alpha receptors and do not contain estrogen beta receptors. It was shown that the genistein concentration (IC 50 = 0.2 mM) at which the half maximal inhibition of the HeLa cell viability is achieved is ten times higher than the concentrations of tamoxifen and cisplatin, which are reference agents with a cytotoxic effect. At micromolar concentrations (0.1–10 µM) genistein decreased the cytotoxic effects of cisplatin and tamoxifen. We found the reduced Bax mRNA expression and increased Bcl-2 mRNA expression during incubation of the cells with genistein, which also indicates its cytoprotective anti-apoptotic effect. Genistein, even in high concentrations, had no effect on the membrane potential and calcium capacity of isolated mitochondria and did not activate the opening of the Ca2+-induced mitochondrial pore. Thus, the data show a protective effect of the isoflavonoid genistein on tumor cells.

In this paper we study the effect of synthetic isoflavonoid genistein against cancer HeLa cells, which contain estrogen receptors alpha but not beta, with the aim to determine the cytotoxic or cytoprotective effect of genistein. It is shown that the half maximal inhibitory concentration (IC50) value of genistein (0.2 mM) for the growth inhibition of HeLa cells is at least ten times higher than that one of tamoxifen and cisplatin--drugs, used in cervical cancer treatment. In micromolar concentrations (0.1-10 μM) genistein decreased the cytotoxic effects of cisplatin and tamoxifen. The decreased Bax mRNA expression and increased Bcl-2 mRNA expression after incubation .of the cells with genistein also demonstrate the cytoprotective, anti-apoptotic effect of genistein. Genistein, even in high concentrations, had no effect on membrane potential and calcium capacity of isolated mitochondria, without activating the opening of Ca(2+)-induced mitochondrial pore. Thus, these data demonstrate a cytoprotective effect of isoflavonoid genistein against this type of cancer cells.

Cytestrole acetate (CA), in the structure of which the steroidal antiestrogen component is associated with bis-β-cloroethylamino group, exhibits a strong cytotoxic activity against hormone-dependent cancer cell lines (CaOV, HeLa, MCF-7). In doxorubicin-resistant MCF-7 cells, CA potentiates the cytotoxic effect of etoposide and doxorubicin, and the IC50 for CA in these cells is 40 times lower than that for tamoxifen (TAM). In transplantable mice breast adenocarcinoma Ca-755, the therapeutic CA dose is 25 mg/kg when administered subcutaneously in oil solution for 5 days. On the DMBA-induced mammary tumors in rats, CA injected subcutaneously led to partial regressions 4 weeks after treatment in 75% of test rats, whereas TAM produced this effect in 43% of rats. Among various drug forms of CA, the most active were oil solution of CA in gelatin capsules for oral use and liposomal emulsion for intravenous administration, since these forms exhibited the highest values of Ca-755 tumor growth inhibition index (TGI = 97 – 98%).

Cytestrole acetate (CA), in the structure of which the steroidal antiestrogen component is associated with bis-β-cloroethylamino group, exhibits a strong cytotoxic activity against hormone-dependent cancer cell lines (CaOV, HeLa, MCF-7). In doxorubicin-resistant MCF-7 cells, CA potentiates the cytotoxic effect of etoposide and doxorubicin, and the IC50 for CA in these cells is 40 times lower than that for tamoxifen (TAM). In transplantable mice breast adenocarcinoma Ca-755, the therapeutic CA dose is 25 mg/kg when administered subcutaneously in oil solution for 5 days. On the DMBA-induced mammary tumors in rats, CA injected subcutaneously led to partial regressions 4 weeks after treatment in 75% of test rats, whereas TAM produced this effect in 43% of rats. Among various drug forms of CA, the most active were oil solution of CA in gelatin capsules for oral use and liposomal emulsion for intravenous administration, since these forms exhibited the highest values of Ca-755 tumor growth inhibition index (TGI = 97 - 98%).

Among the targets of steroid hormones are mitochondria, which as the main source of reactive oxygen species (ROS) in the cell play a central role in the development of various pathologies. We studied the effect of progesterone and its synthetic analogs on mitochondrial ROS production. It was found that progesterone promoted formation of superoxide anion and hydrogen peroxide in mitochondria oxidizing the substrates of complex I of the respiratory chain but did not influence the production of ROS during oxidation of succinate, respiratory chain complex II substrate. Progesterone derivatives—Medroxyprogesterone acetate, Buterol, Acetomepregenol, Megestrol acetate—had different effects on ROS production, depending on their chemical structure. By the stimulation of ROS production in mitochondria (during oxidation of pyruvate + malate), the tested steroids can be arranged in decreasing order as follows: progesterone > Buterol ≈ Acetomepregenol > Medroxyprogesterone acetate = Megestrol acetate. Activation of ROS production by progesterone and by Buterol involves different mechanisms: progesterone acts as an inhibitor of NAD-dependent respiration, while Buterol and Acetomepregenol perhaps form noncovalent complexes by hydrogen bonding of the ester carbonyl at C3 to the SH groups of the respective targets.

It was shown that carrying out the reaction of cholesterol photosensitized oxidation in the presence of porphyrins immobilized on the hydrolyzed copolymer of tetrafluorethylene and H + form of perfluoro-3,6-dioxo-5-methyl-6-sulfonylfluorideoctene-1 leads to the formation of not previously described new products: 6β-phormyl-B-norcholestan-3β,5β-diol, 6β-chlorocholestan-3β,5α-diol, cholestan-3β,5α,6β-triol, and 5α-chlorocholestan-3β,6β-diol.

Five new 1,4-dihydropyridines containing 3-dialkylamino-2,2-dimethylpropyl fragments were synthesized. The hypotensive activity of the resulting compounds was studied.

11α-Nitroxy group was introduced into 17α-ethynylestradiol-3,17-diacetate using a scheme of synthesis involving the oxidative nitration by cerium ammonium nitrate and the inversion of the configuration at C11 by the reduction of 11-nitrated 9α,11β-dihydroxy derivative of the initial steroid with sodium borohydride. The obtained 11α-nitroxy analog of ethynylestradiol exhibits antiestgrogen activity.

An 11α-nitroxy group was introduced into 17α-ethynylestradiol-3,17-diacetate using a synthetic scheme involving oxidative nitration by cerium ammonium nitrate and configuration inversion at C11 by sodium-borohydride reduction of the 11-nitrate 9α,11β-dihydroxy derivative of the starting steroid. The 11α-nitroxy-containing ethynylestradiol exhibits antiestrogen activity.

Molecular mechanisms of sex hormones (progesterone, medroxyprogesterone acetate (MPA), and new synthetic gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methylpregna-4,6-dien-20-on (ABMP) with human serum albumin, globulins, and calf embryo serum were studied. The binding of ABMP to albumin and progesterone-binding proteins were investigated using spectroscopic techniques (with the use of 1-anilino-8-naphthalenesulfonate as fluorescent probe) and radiolabeled progesterone, (either progesteron or MPA as comparative progestines). There is no difference between the non-specific binding of ABMP, progesterone, and MPA, but the ABMP binding is much smaller as compared to the binding of progestines, so that the new progestine ABMP will produce a more effective action on the target tissue than comparative progestines.

The sensitivity of normal (MCF-7/WT) and doxorubicin-resistant (MCF-7/R) breast cancer cells to the antiproliferative effect of ethynylestradiol 11α-derivatives with the cytostatic residue in the 3-position of the steroid ring (antiestrogen cytostatics) was studied by evaluating cell viability using methylthiazole tetrazolium staining. The antiproliferative effects of these agents on cell lines in the presence of doxorubicin were compared. Antiestrogen cytostatics produced weaker cytostatic effect on MCF-7/WT cells, but more potent cytostatic effect on MCF-7/WT cells compared to those of doxorubicin. Moreover, administration of these agents in combination with doxorubicin more significantly suppressed proliferation of tumor cells. Accumulation and efflux of cytostatic doxorubicin in MCF-7/R cells were studied in the presence and absence of antiestrogen cytostatic Po716. Confocal laser microscopy showed that doxorubicin accumulation in MCF-7/R cells in the absence of Po716 took 20 min, while in the presence of antiestrogen cytostatic this process took 5 min. The rate of doxorubicin transport from tumor cells was much lower in the presence of the test antiestrogen cytostatic. Our results suggest that antiestrogen cytostatics increase the sensitivity of resistant MCF-7/R cells to doxorubicin by modulating the mechanisms of multidrug resistance of tumor cells.