Expression And Significance Of LRIG1 In Gastric Adenocarcinoma Tissues And Cell Lines

ObjectiveTo investigate the possible role of LRIG1 in the genesis and the development of gastric adenocarcinoma by detecting LRIG1 protein and m RNA in gastric adenocarcinoma tissues and in GES-1,MGC-803,SGC-7901,HGC-27 cell lines.Methods1.The immunohistochemical En Vision methodTo detect the expression of LRIG1 protein in 116 cases of gastric adenocarcinoma tissues and adjacent normal gastric tissues.The relationship between LRIG1 expression and clinicopathological parameter was analyzed.2.RT-PCRTo detect LRIG1 m RNA expression in 40 cases of fresh gastric adenocarcinoma tissues(well-moderate and poorly differentiation with 20 cases each)and adjacent normal gastric tissues,and compared the differences.To detect the expression of LRIG1 m RNA in GES-1,MGC-803,SGC-7901 and HGC-27 cell lines,and compared the differences between groups.3.Western blotTo detect LRIG1 protein expression in 40 cases of fresh gastric adenocarcinoma tissues(well-moderate and poorly differentiation with 20 cases each)and adjacent normal gastric tissues,and compared the differences.To detect the expression of LRIG1 protein in GES-1,MGC-803,SGC-7901 and HGC-27 cell lines,and compared the differences between groups.4.Statistical methodsStatistical software SPSS17.0 was used to analyze the experimental data,immunohistochemical results were analyzed by chi square test of fourfold table,one-way analysis of variance was used to analyze RT-PCR and Western blot results,SNK method was used to compare differences between two groups,experimental data were presented by mean ± standard deviation(x ± s),and the results were considered to be statistically significant with P<0.05.Results1.Immunohistochemical results: Compared with adjacent normal gastric tissues,the expression of LRIG1 in gastric adenocarcinoma tissues was decreased.The positive rates of LRIG1 were 81.9%(95/116)and 63.8%(74/116),respectively,the difference was statistically significant(P<0.05).The expression of LRIG1 in gastric adenocarcinoma tissues was closely related to tumor differentiation,depth of invasion,lymph node metastasis,distant metastasis and TNM staging(P<0.05),but not to age,gender or tumor size(P>0.05).2.RT-PCR results: Compared with adjacent normal gastric tissues,the expression of LRIG1 m RNA in well-moderate and poorly differentiated gastric adenocarcinoma tissues were both reduced,and the differences were statistically significant(P<0.01).Compared with GES-1,the expression of LRIG1 m RNA in MGC-803,SGC-7901 and HGC-27 cell lines were decreased in a descending order,the differences were statistically significant(P<0.01).3.Western blot results: Compared with adjacent normal gastric tissues,the expression of LRIG1 protein in well-moderate and poorly differentiated gastric adenocarcinoma tissues were both reduced,the differences were statistically significant(P<0.01).Compared with GES-1,the expression of LRIG1 protein in MGC-803,SGC-7901 and HGC-27 cell lines were decreased,the differences were statistically significant(P<0.01).Conclusion1.The expression of LRIG1 in gastric adenocarcinoma tissues was significantly lower than that of adjacent normal gastric tissues;The expression of LRIG1 in MGC-803,SGC-7901 and HGC-27 cell lines was lower than that of GES-1.2.LRIG1 may be involved in the tumorigenesis of gastric adenocarcinoma as a suppressor.