Objective To investigate the effects of Myelin and lymphocyte protein 2(MAL2)gene silencing on proliferation and drug sensitivity of MDA-MB-231 and MCF-7 in breast cancer cells,in order to explore the mechanism of drug resistance[to Doxorubicin(Dox)and Cisplatin(DDP)].Methods The expression of MAL2 gene in healthy tissues,paracancerous tissues and breast cancer tissues and its correlation with prognosis were analyzed using database.Western blot was used to detect the protein expression of MAL2 in human normal breast epithelial cells MCF-10A and breast cancer cells MDA-MB-231,MCF-7 and MDA-MB-468.MAL2 in MDA-MB-231 and MCF-7 cells was silenced by interference sequence transfection and lentivirus infection.The control group was of the same sequence with siRNA-NC group while the experimental groups belong to the sequence of siRNA-MAL2-1,siRNA-MAL2-2,and siRNA-MAL2-3 groups.The expression of MAL2 of MDA-MB-231 and MCF-7 cells in breast cancer was silenced and divided into sh-NC group(constructed from the sequence of siRNA-NC group)and sh-MAL2 group(constructed from the sequence of siRNA-MAL2-3 group).Western blot was used to detect the expression of MAL2 protein.The proliferative ability of cells was detected by CCK8 assay and cloning formation assay.The effect of breast cancer cells in silencing MAL2 gene expression on the sensitivity of doxorubicin(DOX)and cisplatin(DDP)was detected by CCK8,Flow cytometry(FCM)and Western blot.Western blot was also used to detect the expression of AKT/m-TOR pathway related proteins[phosphorylated protein kinase B(p-AKT),mammalian target of rapamycin(m-TOR),phospho-mammalian target of rapamycin(p-mTOR).Results Bioinformatics analysis showed that MAL2 was highly expressed in breast cancer tissues,and its high expression was closely correlated with poor prognosis of patients with breast cancer(P＜0.05).MAL2 was highly expressed in breast cancer cell lines(P＜0.01).Compared with the siRNA-NC group,the siRNA-MAL2-3 group had better silencing effect of MAL2 protein(P＜0.01).The lentivirus infection showed that MAL2 expression was inhibited in sh-MAL2 group,compared with sh-NC group(P＜0.05).Compared with sh-NC group,the cell proliferation capacity of sh-MAL2 group had no change(P＞0.05),the sensitivity of sh-MAL2 group to DOX and DDP increased(P＜0.05),and the protein expression of P-Akt and P-mtor in sh-MAL2 group was down-regulated(P＜0.05).Conclusion MAL2 silencing has no effect on the proliferation of breast cancer cells,but can promote their sensitivity to DOX and DDP.The mechanism may be associated with the inhibition of AKT/m-TOR pathway related proteins.
breast cancermyelin and lymphocyte protein 2cell proliferationdoxorubicincisplatinAKT/m-TOR
NETL
NSTL
万方数据
