Effects of GRHL2 gene silencing on proliferation and cell cycle of human colorectal cancer / 肿瘤

ABSTRACT

Objective: To investigate the expression of grainyhead like 2 (GRHL 2) gene in human colorectal cancer (CRC) tissues and cells, and to explore the effects of GRHL 2 gene silence on the proliferation and cell cycle of CRC cells. Methods: The expression level of GRHL2 mRNA in CRC tissues and their para-cancerous normal tissues as well as CRC cells (HT29, SW480, SW1116, SW620, HCT116, Caco2 and LoVo cells) was detected by real-time fluorescent quantitative PCR. After the recombinant lentivirus carrying GRHL2-shRNA was infected into HT29 and HCT116 cells, the cell proliferation was determined by CCK-8 method and cloning formation assay, the cell cycle distribution was detected by FCM, and the expressions of cell cycle-related proteins (cyclin A, cyclin D1, p21 and p27) were determined by Western blotting. Furthermore, the subcutaneous transplantation models of CRC HT29 and HCT116 cells were established in nude mice, then the effect of GRHL 2 gene silencing on the growth of colorectal cancer xenografts was observed. Results: The expression level of GRHL2 mRNA in CRC tissues was higher than that in paracancerous normal tissues (2.8 times, P < 0.001). GRHL2 mRNA was highly expressed in most CRC cells (HT29, SW480, HCT116, Caco2 and LoVo cells). The expression levels of GRHL2 mRNA and protein in HT29 and HCT116 cells were down-regulated after transfection of GRHL2-shRNA (both P < 0.001). Silencing GRHL 2 gene significantly suppressed cell proliferation (both P < 0.05), produced the cell cycle arrest in G1 phase (both P < 0.01), down-regulated the expressions of cyclin A and cyclin D1 (P < 0.05, P < 0.01), and upregulated the expressions of p21 and p27 (P < 0.01, P < 0.05). Meanwhile, GRHL 2 gene silencing significantly promoted the growth of colorectal cancer xenografts in nude mice. Conclusion: GRHL2 maybe promote the proliferation of CRC cells by regulating the expression of cell cycle-related proteins.