抑制STAT5a、STAT5b对大肠癌细胞增殖、周期和凋亡的影响

PURPOSE: To investigate the role of two isoforms of STAT5 in the progression of colorectal cancer (CRC). METHODS: We studied cell viability using Cell Counting Kit 8 with depletion of each STAT5a/5b, which was induced by treating CRC cells with the respective small interfering RNA (siRNA). Cell cycle and apoptosis was determined by flow cytometry analysis with RNAi-induced deficiency of STAT5a/5b. Besides, the expression of cell-cycle-regulatory and apoptosis proteins that are known to be downstream targets of the STATs pathway was examined. RESULTS: Our results showed that both STAT5a and STAT5b are involved in the cell growth, cell-cycle progression, and apoptosis of CRC cells. Upregulation of p16ink4a and p27kip1 expression and downregulation of Bcl-2 and survivin expression exerted their effects after targets of the STAT5 isoforms. We found that STAT5b induced cell apoptosis to greater extent than STAT5a and STAT5a/b played more important roles in LoVo cells than in SW1116 cells. CONCLUTIONS: Both the isoforms of STAT5 are involved in the growth and cell-cycle progression of CRC cells via downstream targets of the STATs pathway, and they could play a more important role in the progression of metastatic adenocarcinoma.