Growth inhibition of colorectal cancer HCT116 cells by lincRNA-p21 through STAT3 signaling pathway

AIM: To study the effect of long intergenic non-coding RNA-p21 (lincRNA-p21) on the growth inhibition of colorectal cancer HCT116 cells via STAT3 signaling pathway. METHODS: The human colorectal cancer cell line HCT116 was used to construct the cells with over-expression of lincRNA-p21 by transfection of pcDNA-lincRNA-p21, and negative control cells were also set up. After transfection, the expression level of lincRNA-p21 was detected by RT-qPCR. The cell viability and proliferation were examined by MTT assay and plate colony formation assay, respectively. The protein levels of STAT3 and phosphorylated STAT3 (p-STAT3) were determined by Western blot. After STAT3 signaling pathway activator SD19 was used to treat the colorectal cancer HCT116 cells with over-expression of lincRNA-p21, Western blot was used to detect the protein levels of STAT3 and p-STAT3, MTT assay was used to measure the viability of the cells, and flow cytometry analysis was used to determine the cell apoptosis. RESULTS: Compared with control group and pcDNA group, the expression of lincRNA-p21 in pcDNA-lincRNA-p21 group was significantly up-regulated, the cell proliferation was inhibited, and the protein levels of STAT3 and p-STAT3 were significantly decreased (P<0.05). After treatment with STAT3 activator SD19, the protein levels of STAT3 and p-STAT3 in pcDNA-lincRNA-p21+SD19 group were higher than those in pcDNA-lincRNA-p21 group, the cell viability was increased, and the apoptotic rate was decreased significantly (P<0.05). CONCLUSION: Over-expression of lincRNA-p21 inhibits the growth of colorectal cancer HCT116 cells. STAT3 signaling pathway activator abolishes the growth inhibitory effect of lincRNA-p21 over-expression. lincRNA-p21 inhibits the growth of colorectal cancer cells by inhibiting the activation of STAT3 signaling.