Effects of PinX1 gene on migration and invasion of colon cancer cells and the molecular mechanisms

Abstract

Objective To observe the function of telomerase inhibitor 1 (PinX1) gene in cell migration and invasion and its possible molecular mechanisms in the colon cancer cell lines. Methods The PinX1 interfering lentivirus (sh-PinX1) and its negative control (sh-con) were transfected into HCT116 and SW480 colon cancer cells. The protein expression levels of PinX1, matrix metalloproteinase (MMP)-2 and MMP-9 were detected by Western blotting. The alterations in the ability of the migration and invasion of colorectal cancer cells (HCT116 and SW480) were investigated by Transwell migration and invasion assays. The MMPs activities in the two colon cancer cell lines were examined by gelatin zymography. Results Western blotting showed that PinX1 protein level was decreased by interference of PinX1 gene in colon cancer cell lines: for HCT116 [(40 459±154) vs. (3 135±24), P=0.001]; for SW480 (54 709±202) vs. (6 537±55), (P=0.000). Migration assay showed that the decreased PinX1 increased the ability of migration in colon cancer cells [116-sh-con group (100.0±5.8) vs. 116-sh-PinX1 group (217.3±11.6), P=0.000; 480-sh-con group (193.0±6.6) vs. 480-sh-PinX1 group (407.0±6.6), P=0.004]. Invasion assay showed that decreased PinX1 increased the invasive ability in colon cells [116-sh-con group (71.7±3.3) vs. 116-sh-PinX1 group (170.0±5.8), P=0.000; 480-sh-con group (58.3±4.4) vs. 480-sh-PinX1 (130.0±5.8), P=0.001]. Western blotting showed that MMP-2 protein level was increased by interference of PinX1 gene in colon cancer cells [116-sh-PinX1 group (58 549±220) vs. 116-sh-con group (3 819±31), P=0.000); 480-sh-PinX1 group (56 540±207) vs. 480-sh-con group (2 909±33), P=0.001]. Western blotting showed that PinX1 did not affect the MMP-9 expression [116-sh-PinX1 group (8 499±769) vs. 116-sh-con group (8 499±769, P=0.390); 480-sh-PinX1 group (4 008±290) vs. 480-sh-con group (3 907±256), P=0.808]. Gelatin zymography assay showed that low expression PinX1 suppressed the activity of MMP-9 [116-sh-PinX1 group (12 699±284) vs. 116-sh-con group (5 571±91, P=0.000); 480-sh-PinX1 group (14 418±296) vs. 480-sh-con group (8 704±55), P=0.000]. Conclusion PinX1 could increase the ability of migration and invasion by activating MMP-2 signaling pathway in colon cancer cells. Key words: PinX1; Colon cancer; Migration; Invasion; Matrix metalloproteinase-2