The effect and mechanism of LMO1 on the invasion and metastasis of gastric cancer

Abstract

Objective To investigate the expression level of LMO1 in gastric cancer tissues and human gastric cancer cell lines, and explore the invasive and metastatic potential of LMO1 gene silencing by small interfering RNA on the human gastric cancer cell line MKN28. Methods Immunohistochemical technique was applied to detect the expression of LOM1 protein in gastric cancer tissues and tumor adjacent tissues of paraffin specimens in 30 cases. The expression levels of LMO1 in human gastric cancer cell lines AGS, BGC-823, SGC-7901, MKN28 and human gastric mucosal epithelial cells GES were detected by real time-PCR and Western blot. Using Lipofectamine™ 2000, LMO1 siRNA was transfected into MKN28 cells in vitro (siRNA transfect group). Negative control was established.Real time-PCR and Western blot was used to examine the difference of LMO1 expression. Transwell assays were performed to identify the differences and changes of invasive and metastatic ability in gastric cancer cell line MKN28. Western blot was used to examine the expression levels of E-cadherin, MMP-9 and VEGF. Results Positive rate of LOM1 protein in gastric cancer tissues(77%)was higher than that in tumor adjacent tissues (17%)(χ2=21.70, P<0.01). Positive rate of Vav1 protein was higher in lymphatic metastasis group than in non-lymphatic metastasis group(χ2=5.83, P=0.02). Compared with GES, the expression level of LMO1 increased significantly in gastric cancer cell lines, especially in MKN28 (P<0.01). The expression levels of LMO1 mRNA and protein in LMO1-siRNA transfected MKN28 cells were lower than the matched negative control cells (P<0.01). The invasive and metastatic potentials of LMO1-siRNA transfected MKN28 cells significantly decreased (t=-11.53, P<0.01; t=-10.68, P<0.01). The expression levels of E-cadherin were higher than the matched negative control cells; and MMP-9, VEGF protein in LMO1-siRNA transfected MKN28 cells were lower than the matched negative control cells (P<0.01). Conclusions LMO1 has higher expression level in gastric cancer tissues and some gastric cancer cell lines, and down-regulation of LMO1 can inhibit the invasion and metastasis ability of gastric cancer. Key words: Stomach neoplasms; Neoplasm invasiveness; Neoplasm metastasis