Li Z.-D.,Tongji University |
Yang X.-W.,Municipal Hospital of Shanghai Traditional Chinese Medicine |
Cheng X.-L.,Tongji University |
Zhuang Z.-G.,Tongji University |
Tong X.-W.,Tongji University
Fudan University Journal of Medical Sciences | Year: 2014
Objective: To investigate both the expression of aryl hydrocarbon receptor (AhR) in breast cancer tissues and its association with adriamycin chemotherapy resistance. Methods: AhR expression was observed by immunohistochemical staining in 50 specimens of breast cancer containing 40 cases of metastasis lymph nodes and 10 cases of normal breast tissues. Breast cancer cell line MCF-7/ADR with AhR high expression was transfected by the AhR-siRNA liposome vector. The expression of AhR mRNA and protein was detected by RT-PCR and Western blot after transfection. Adriamycin sensitivity of breast cancer cells before and after transfection was determined by proliferation test, MTT. Results: AhR in immunohistochemical staining was expressed in 82% (46/50) breast cancer tissue, in 92.5% (37/40) metastasis lymph nodes, and in 10% (1/10) normal breast tissue. AhR expression in normal breast tissues was significantly lower than that in breast cancers and metastasis lymph nodes (P<0.05). PCR and Western blot results showed that expression of AhR gene and protein in breast cancer cell line MCF-7/ADR was decreased 24 hours later after AhR gene silencied by liposome transfection. The proliferation of breast cancer cell MCF-7/ADR was significantly inhibited after AhR gene was silenced. MTT showed the inhibition rate of cell proliferation was up to 52% at 48 hours. Median effective concentration (IC50) to adriamycin was decreased from (18.2±0.9) μ mol/L to (8.4±1.1) μ mol/L (P<0.05) before and after AhR-silenced in breast cancer cells. Conclusions: AhR-siRNA can effectively inhibit the expression of AhR gene and reduce the proliferation of breast cancer cell. AhR plays a role in adriamycin resistant process, so that AhR silencing can partly reverse adriamycin resistant in breast cancer.