Effect of miR-144-3p targeting Nrf2 on cisplatin sensitivity in bladder cancer / 中国医师杂志

ABSTRACT

Objective:To investigate the role of miR-144-3p in cisplatin resistance of bladder cancer.Methods:Bladder cancer T24 cells were cultured in vitro and divided into blank group (untreated), mimetic control group, miR-144-3p mimetic transfection group, inhibitor control group, and miR-144-3p inhibitor transfection group. Real time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to verify the transfection effect, methyl thiazolyl tetrazolium (MTT) method was used to detect the survival rate of cells treated with cisplatin in each group, and Western blot was used to detect the expression of the target protein. The targeting relationship between miR-144-3p and nuclear factor E2 related factor 2 (Nrf2) was validated using dual fluorescence reporter gene experiments. Furthermore, Nrf2 was knocked out in each group of cells, and the mRNA and protein expression levels of HO-1, Bcl-2, and Caspase-3 were detected by qRT-PCR and Western blot in each group of cells.Results:Compared with the control group, bladder cancer cells in the miR-144-3p mimetic transfection group were more sensitive to cisplatin, while the miR-144-3p inhibitor transfection group had the opposite effect; The miR-144-3p simulant transfection group can effectively inhibit the mRNA and protein expression level of Nrf2 in bladder cancer cells (all P<0.05), while the miR-144-3p inhibitor transfection group can up regulate the mRNA and protein level of Nrf2 (all P<0.05). The miR-144-3p mimetic transfection group showed significant downregulation of mRNA and protein expression of HO-1 and Bcl-2, while the expression of Caspase-3 was upregulated (all P<0.05), while the miR-144-3p inhibitor transfection group showed the opposite results. The luciferase results confirmed that miR 144 3p can directly bind to the 3′- UTR region of Nrf2, reducing the mRNA level of Nrf2. When Nrf2 was knocked out, whether miR-144-3p mimetic transfection group or miR-144-3p inhibitor transfection group, the mRNA and protein expression levels of HO-1, Bcl-2 and Caspase-3 did not change significantly, and miR-144-3p lost the ability to regulate the cisplatin sensitivity of bladder cancer cells. Conclusions:miR-144-3p targets to regulate the sensitivity of Nrf2 to cisplatin in bladder cancer, and miR-144-3p is expected to become a new target for the treatment of cisplatin resistant or refractory bladder cancer.