[LRIG1 promotes the apoptosis of pituitary tumor cells induced by cisplatin].

Objective To investigate the expression of leucine rich repeats and immunoglobulin like domains 1 (LRIG1) in the tumor tissues of human pituitary tumor, and the effects of LRIG1 over-expression on the proliferation and apoptosis of human pituitary tumor cells induced by cisplatin (DDP). Methods The expression of LRIG1 in the tumor tissues and adjacent tissues of 45 cases with pituitary tumor was detected by immunohistochemistry, and the correlations between the positive expression of LRIG1 and the clinicopathological data of the patients were analyzed. In addition, the isolated human pituitary tumor cells were selected. The LRIG1 gene over-expression plasmid pEGFP-N1-LRIG1 was transfected into the cells by liposome-mediated gene transfection. The cells transfected with LRIG1 were screened, and meanwhile, the cells transfected with empty plasmid pEGFP-N1 were selected as a control group. The cells of the two groups were induced by 20 g/mL DDP, and 48 hours later, the cell apoptosis was detected by flow cytometry; the proliferation capacity was tested by plate cloning experiment; and the relative expressions of apoptosis-related proteins Bax, caspase-3 and Bcl2 in the cells were examined by Western blot analysis. Results LRIG1 in the tumor tissues of pituitary tumor was obviously lower than that of the adjacent tissues, and LRIG1 was significantly reduced in the invasive tumor tissues. Compared with the control group, after LRIG1 was over-expressed, the cell apoptosis rate significantly increased, the cell proliferation significantly decreased, and the levels of Bax and caspase-3 increased as well, while the level of Bcl2 decreased remarkably. Conclusion Over-expression of LRIG1 increases the apoptosis and inhibits the proliferation of human pituitary tumor cells induced by DDP.