[The effects of three plastic additives on the proliferation of MCF-7 cell].

Objective: To explore the effect of environmental estrogens on the proliferation of breast cancer cell line MCF-7.

Methods: The tested compounds were n-4-nonyphenol, Bisphenol A and dibutylphthalate. Human estradiol-dependent MCF-7 breast cancer cells were grown in DMEM medium containing 10% bovine serum. Five days before the addition of the test compounds, the cells were washed by phosphate-buffered saline, and the medium was substituted with a phenol red-free DMEM medium containing 5% dextral charcoal-stripped FBS. The respective test compound was added in fresh medium and the control cell received only the vehicle (ethanol). The proliferation of MCF-7 was analyzed by the MTT assay, (3)H-TdR incorporation assay and flow cytometry.

Results: Compared with the ethanol control, the proliferation and DNA synthesis of the test cells treated with n-4-nonyphenol (8 x 10(-7) mol/L, 96 h), Bisphenol A (8 x 10(-7) mol/L, 96 h) or dibutylphthalate (32 x 10(-6) mol/L, 96 h) treatment was markedly enhanced in a time-dependent and dose-dependent manner.

Conclusion: n-4-Nonyphenol, Bisphenol A and dibutylphthalate enhanced the proliferation of human breast cancer cell in vitro, which may demonstrate an estrogenic activity.