The Effects Of Overepression Of TG2 On The Resistance Of Breast Cancer To Adriamycin And Its Related Mechanism

Objiective:To observe the effects of overexpression of TG2 on Adriamycin resistance of hunman breast cancer and explore its related mechanism.Methods:1、The cells were divided into 3 groups:the interference group-TG2 group、the negative control group-NC group and the blank group-CON group. For the TG2 group, MCF-7 cells were transffected by lentiviral particles targeting TG2 gene, while the NC group with the negative control lentiviral particles targeting the no sense sequence, the CON group with no treatment.After 72 hours, these cells were screened for five days with 1ug/ml puromycin, and the infection efficiency of lentiviral was observed with fluorescence microscope. The expression of TG2 mRNA and protein in each group were delected by Q-PCR and Western blot.2、After being treated with Adriamycin,the IC50 of each groups were detected by MTT assay. Apoptosis rate and cell cycle of every group cells were detected by flow cytometry assay.3、These proteins BCL-2、Capase-3 and AKT/PAKT which are related to apoptosis and survival were further detected by Western blotting teachnology.4、The TG2 group was treated with MDC (an inhibitor of TG2) then detected its IC50、Apoptosis rate cell cycle and the expression of TG2.Results:1、The infection efficiency of the TG2 group and NC group cells were more than 95%.Compaired with the CON group and NC group,the expression of TG2 mRNA and TG2 protein in TG2 group were significantly higher(P<0.05)2、MTT assay results showed that, the IC50 of TG2 group was (40.7±3.56) ug/ml, CON group was (17.4±1.45) ug/ml and NC group was (22.7±2.0) ug/ml (P<0.05).FCM results showed that the apoptosis rate of the TG2 group、NC group and con group was respetively (38.50±5.50)%、(53.1±4.7)%% and(87.4±12.5)%.3、Western bolt results showed that the expression of Capase-3 in TG2 group were lower, BCL-2 and AKT/PAKT were higher than CON group (P< 0.05), while there was no statistically significant difference compared with NC group (P>0.05).4、With the treatment of MDC,the expression of AKT in TG2 group was respective significantly(P< 0.05),but the expression of BCL-2 and Capase-3 there were no statistically significant difference (P> 0.05),the the decrease of IC50 was significantly (P<0.05)Conclutions:1、The overexpression of TG2 in breast cancer can promote the resistance of Adriamycin, while this function of TG2 can be restrain by MDC.2、The mechanism of overexpressing of TG2 can enhance the resistance of Adriamycin in breast cancer may be related to the down-regulation of Capase-3 protein and the up-regulation of AKT and Bcl-2 protein.