Effects of N6-methyladenosine-induced LncRNA PVT1 targeting MYC on the stemness of ketamine-treated breast cancer cells / 中华内分泌外科杂志

ABSTRACT

Objective:To investigate the effect of ketamine on dryness maintenance of breast cancer (BC) cells by regulating LncRNA PVT1/MYC axis.Methods:BC cell line MCF-7 was treated with different concentration of ketamine (0, 5, 10 or 20 g/ml) or treated with 20g/ml ketamine for different periods (0, 24, 48 or 72h) . Furthermore, the expression of METTL3, PVT1 and MYC in MCF-7 cells was interfered and MCF-7 cells were divided into different groups.Western blot was used to detect the expression levels of stem cell characteristic related molecules (OCT4 and SOX2) . The expression level of PVT1/MYC in each group was detected by qRT-PCR. MeRIP analysis was used to detect THE m6A methylation level of PVT1.Results:Ketamine treatment significantly reduced the number of BC globules and inhibited the protein expression of OCT4 and SOX2 in a dose-and time-dependent manner (all P<0.05) . Ketamine regulated m6A level of METTL3-mediated PVT1. Compared with ketamine+pcDNA3.1 group (207±11) , the number of globules formed in ketamine+PVT1 group (311±15) was significantly increased ( t=12.06, P<0.001) , and the protein expression levels of OCT4 and SOX2 were increased ( t=9.68, P<0.001; t=11.50, P<0.001) . MYC was a downstream regulatory gene of PVT1. Compared with ketamine+PVT1+ Si-NC group, ketamine+PVT1+si-MYC group significantly reduced the number of spheroid formation ( t=0.54, P=0.005) and the expression levels of OCT4 and SOX2 proteins ( t=5.98, P=0.004) ( t=7.33, P=0.002) . Conclusion:Ketamine mediates the expression of PVT1 and its downstream gene MYC by inhibiting THE m6A level of PVT1, thus inhibiting the stem cell-like characteristics of BC cells.