A Study About The Kill Capability Of Tamoxifen Of Estrogen Receptor Negative Breast Cancer Cell In Vitro

bstract Objective Classical drug tamoxifen in breast cancer endocrine therapy, the drug resistance and the existence of the phenomenon of the estrogen receptor negative patients is low; it has been plagued by clinical treatment. In this experiment, through the observation of estrogen receptor positive cell line(MCF-7) in the supernatant can be mediated increase of tamoxifen on estrogen receptor negative cell line (MDA-MB-231) killing effect. To study whether there is other way bypass effect of tamoxifen to promoteapoptosis of breast cancer cells, and the way of tamoxifen resistant mechanismand the existence of increased estrogen receptor negative breast cancer cell killing effect.Methods:CCK-8was used to analyze the difference of killing by tamoxifen between1.0×105/pore MDA-MB-231and MCF-7; CCK-8and FCM was used to analyze the killing of supernatant of MCF-7cell lines to MDB-DA231cell lines and the killing of tamoxifen joint with supernatant of MCF-7cell lines to1.0×105/pore MDA-MB-231cell lines.Results:The survival rate of MCF-7was lower than that of MDA-MB-231culturing with15μmol/L of tamoxifen [(3.03±0.32)%to (45.06±14.29)%, P<0.05]; under the culturing of supernatant of MCF-7cell, MDA-MB-231cells survival rate[(83.79■2.58)%to(99.99+1.07)%, P<0.05); under the culturing of tamoxifen joint with supernatant of MCF-7cell, MDA-MB-231cells survival rate[(1.61±0.15)%to (99.99±1.07)%, P<0.05];.Under culturing with15μmol/L of tamoxifen, the cell cycle of MDA-MB-231was block in G0-G1phase [(59.14±0.39)%to (50.28±0.0.52)%, P<0.05]; under the culturing of supernatant of MCF-7cell, the cell cycle of MDA-MB-231wasn’t block (P>0.05); under the culturing of tamoxifen joint with supernatant of MCF-7cell, the cell cycle of MDA-MB-231was block in G0-G1phase[(60.7910.67)%to (59.1410.39)%, P<0.05].Conclusions:Tamoxifen by supernatant of MCF-7cells is mediated by increased on MDA-MB-231cells killing ability. What components of supernatant MCF-7cells increased the cytotoxic mechanism and effects of tamoxifen and whether it can be obtained by other means in vitro will achieve this effect, still need further experiments and research.