Silencing Of The EGFR Gene By SiRNA Effects On Sensitivity Of Chemotherapy In MDA-MB-231 Cell Line

Objective Studying the expression level of EGFR in Triple negative breast cancer affecting on sensitivity of chemotherapy in vitro, so as to provide a more effective predictor for the choice of chemotherapy drugs and to supply a more rational basis for the individual treatment for breast cancer.Method Since human breast cancer cell line MDA-MB-231 confirmed amplification of EGFR, we have used siRNA to interfere in the expression of EGFR in MDA-MB-231 cell line. And the effect of silence has been tested in the two levels of gene and protein by Real-time PCR and Western-blot. The influence of different EGFR expression after gene silencing made on sensitivity of doxorubicin,docetaxel and 5-Fu was tested by CCK-8 separately.Result For MDA-MB-231 cell line, the inhibition of EGFR gene was 40% by siRNA. Compare the high expression of EGFR group with the low expression of EGFR group about the sensitivity of chemotherapy in MDA-MB-231, and the IC50 of doxorubicin was 0.52±0.13vs0.22±0.06μg/ml, of docetaxel was 2.41±0.78vs2.05±0.55μg/ml and of 5-Fu was 18.9±4.05vs19.3±4.21μg/ml.Conclusion For MDA-MB-231 cell line, silencing of EGFR gene can improve chemotherapy sensitivity of anthracycline significantly, but docetaxel and 5-Fu were not significantly improved.