Cytotoxicity of Synthetic Estrogen and Related Compounds in Various Tumor-Derived Cells.

Abstract

Various activities of estrogen, other than its primary activity as a hormone, have recently been revealed. [1][2][3][4][5][6][7][8][9] Among them, an involvement in carcinogenesis is of particular interest. [10][11][12] Consequently, the environmental effects of a synthetic estrogen, diethylstilbestrol (DES), large amounts of which have been used in stock-farming, have become a serious concern.We have shown that natural and synthetic estrogens and their related compounds have inhibitory activities on the in vitro polymerization of microtubule proteins, which play important roles in the cytoskeleton and cell division in addition to having hormonal activity. [13][14][15][16][17][18] We have also clarified that indenestrol A (IA), which is a metabolite of DES, has the highest antioxidant action among its related compounds. 19) Because the cytotoxicity of IA on colony formation by Chinese hamster V79 cells is similar to the effects of IA on microtubule proteins, the cytotoxicity is considered to be due partially to these effects on microtubule proteins. 16) We have also found that indenestrol B (IB), an isomer of IA, is highly cytotoxic to Chinese hamster V79 cells. 16) Taxol, which has the opposite effect of the well-known microtubule inhibitor colchicine, has drawn attention as a carcinostatic. However, the compounds related to synthetic estrogens mentioned in this study are more promising as carcinostatics, because their inhibitory activity against microtubule proteins is weaker than that of colchicine. In this study, cell growth inhibition by DES and its related compounds was examined by the MTT method using L1210, KB, and NIH-3T3 cells transformed with oncogenes, which are commonly used as screening systems for carcinostatics. MATERIALS AND METHODSMaterials DES and EE-dienestrol were obtained from Sigma Chemical Co. Other test compounds were synthesized as described previously. [12][13][14] Assay of in Vitro Antitumor Activity The assay of in vitro antitumor activity was performed using murine leukemia L1210 cells and human epidermoid carcinoma KB cells. NIH-3T3 cells transformed with oncogenes such as Ha-ras, Ki-ras, sis, abl, and src were obtained from the Virus Department of Kanazawa University. Roswell Park Memorial Institute medium 1640 supplemented with 10% heat-inactivated fetal bovine serum and kanamycin 50 mg/ml was used as the cell culture medium. The test compounds were dissolved in DMSO and added to the culture plates at 1% as the final volume. The DMSO concentration had no effect on the cytotoxicity. Tumor cells (2ϫ10 3 cells/ml) were cultured in 1 ml of the medium containing various concentrations of test compounds in a CO 2 gas incubator at 37°C for 72 h. Their viability, estimated by a modification of the colorimetric (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) MTT assay, 20) was compared to that of control cells incubated in the same medium without the test compounds. The antitumor activity was evaluated as the IC 50 (the concentration [mM] of the compounds required for 50% ...

Biocompatibility of components of a female controlled drug delivery system

“…Therefore, it was concluded that the effects of EDTA on the model cell lines were more likely antiproliferative than acutely toxic. This is in accordance with previous in vivo results, in which no toxicity of EDTA at a concentration range was demonstrated 16, 23…”

Cytotoxic effects of the synthetic oestrogens and androgens on Balb/c 3T3 and HepG2 cells

“…The mean cytotoxic concentration (IC50-MTT-72h) of DES against prostate cancer cell lines (I-LN, DU145, PC-3, and LNCaP) was approximately 21 µM (5.6 µg/mL) (23). In murine leukaemia (L1210) and human epithelial carcinoma (KB) lines exposed to DES, 50% inhibition of cell viability was 5.6 µM (1.5 µg/mL) and 9.7 µM (2.6 µg/mL) respectively (18). Konac et al (14) investigated the relationship among the viability, necrosis, and apoptosis rates on human lymphocytes, which were treated with different DES concentrations ranging from 1 to 20 µM (0.26-5.2 µg/mL) for 24, 48, and 72 h. A drastic decrease in the viability rates of the cells for all times of exposure was recorded at the concentration of 5 µM (1.3 µg/mL).…”