RESUMO
Objective To investigate whether TG2 promotes drug resistance to epirubicin through AKT signal pathway in breast cancer. Methods MCF-7 cells with constant expression of TGM2 gene(TGM2-LV)were established via the lentiviral vector. The breast cancer cells were divided into five groups,including the NC group, TG2 group and MK2206 group. The MCF-7/adr cells were divided into ADR group and MKadr group. The expres-sion of TG2 ,AKT ,Bcl-2 and P53 was detected by Western blot assay. Cells were treated with epirubicin. MTT assay was performed to assess cell proliferation. The inhibition ratio of cancer cell proliferation was evaluated. TUNEL analysis was performed to identify the apoptosis of the breast cancer cells. Results Lvels of TG2,p-AKT and Bcl-2 in NC group were significantly lower than those in TG2 group,while the expression of P53 in NC group was much higher. In MK2206(or MK/adr )group,p-AKT and Bcl-2 were down-regulated,while P53 was markedly up-regulated compared with TG2(or ADR)group(P<0.05). The results of the MTT assay showed a strong inhibi-tion in cell proliferation rate in MK2206(or MKadr )group. Compared with the NC group,TG2 promoted prolifera-tion of MCF-7 cells in TG2 group. The cell apoptosis rate in MK2206(or MKadr )group was significantly higher than that in TG2(or ADR)group(P<0.05). TG2 significantly inhibit the apoptosis of breast cancer cells ,com-pared to the control group. Conclusion TG2 might promote drug resistance to epirubicin through AKT signal path-way in breast cancer
RESUMO
Objective To investigate whether TG2 promotes drug resistance to epirubicin through AKT signal pathway in breast cancer. Methods MCF-7 cells with constant expression of TGM2 gene(TGM2-LV)were established via the lentiviral vector. The breast cancer cells were divided into five groups,including the NC group, TG2 group and MK2206 group. The MCF-7/adr cells were divided into ADR group and MKadr group. The expres-sion of TG2 ,AKT ,Bcl-2 and P53 was detected by Western blot assay. Cells were treated with epirubicin. MTT assay was performed to assess cell proliferation. The inhibition ratio of cancer cell proliferation was evaluated. TUNEL analysis was performed to identify the apoptosis of the breast cancer cells. Results Lvels of TG2,p-AKT and Bcl-2 in NC group were significantly lower than those in TG2 group,while the expression of P53 in NC group was much higher. In MK2206(or MK/adr )group,p-AKT and Bcl-2 were down-regulated,while P53 was markedly up-regulated compared with TG2(or ADR)group(P<0.05). The results of the MTT assay showed a strong inhibi-tion in cell proliferation rate in MK2206(or MKadr )group. Compared with the NC group,TG2 promoted prolifera-tion of MCF-7 cells in TG2 group. The cell apoptosis rate in MK2206(or MKadr )group was significantly higher than that in TG2(or ADR)group(P<0.05). TG2 significantly inhibit the apoptosis of breast cancer cells ,com-pared to the control group. Conclusion TG2 might promote drug resistance to epirubicin through AKT signal path-way in breast cancer
RESUMO
Objective To investigate the effect of STAT3 knockdown on the sensitivity of breast cancer cells with drug-resistant to adriamycin (MCF-7/ADR). Methods Levels of STAT3 and p-STAT3 in MCF-7/ADR and MCF-7 cells were detected by Western Blot. The MCF-7/ADR cells were infected with lentivirus expressing STAT3-shRNA and the negative control vectors in the STAT3-RNAi group and NC group, respectively, wihle the cells in the blank group received no treatment. The transfection efficiency was observed with fluorescence microscope, the mRNA level of STAT3, protein levels of STAT3 and p-STAT3 were detected by qRT-PCR and Western Blot, respectively. MCF-7/ADR cells were treated with different concentrations of adriamycin for 48 hours, cell proliferation was detected by MTT assay and cell apoptosis was detected by flow cytometry. Results Levels of STAT3 and p-STAT3 in MCF-7/ADR cells were significantly higher than those in the MCF-7 cells (P < 0.05). The levels of STAT3 mRNA, STAT3 and p-STAT3 in the STAT3-RNAi group were significantly lower than those in the Con group and the NC group (P<0.05, respectively). The Adriamycin IC50 in the Con group, NC group and STAT3-RNAi group was (56.1 ± 3.00)ug/mL,(54.9 ± 11.9)ug/mL and (7.6 ± 0.2)ug/mL, respectively. The flow cytometry results showed that the cell apoptosis in the Con group, the NC group and the STAT3-RNAi group was (10.5+0.7)%, (11.7+0.7)%and (34+3.1)%, respectively. Conclusion LV-shRNA-STAT3 can significantly inhibit STAT3 expression and enhance the sensitivity of breast cancer cells to adriamycin, and the underlying mechanism may be related to cell apoptosis.