The Expression Of LRIG2 Gene And Protein In Bladder And The Research On The Effect Of BIU-87 Cell Transfected By Recombinated Plasmid PCMV-LRIG2

Purpose: To investigate the expression of LRIG2 gene between bladder cancer and normal bladder tissue, and to identify the different expression in dissimilar grading and staging.Methods: RT-PCR technique was used to detect the expression of LRIG2 mRNA in 31 cases of bladder cancer tissue and 16 cases of normal bladder tissue. Statistics analysis was combined with the staging and grading of the tumor.Results: In the 31 cases of bladder cancer tissue, 34 cases were detected the expression of LRIG2 mRNA, and the average level was 0.39±0.22. All the 16 cases of normal bladder tissue were detected the expression of LRIG2 mRNA, and the average level was 0.54±0.16. There was significant difference between the bladder cancer group and the normal bladder tissue group (P=0.012).The expression of LRIG2 mRNA in bladder cancer was significantly lower than in the normal bladder tissue. In the bladder cancer group, the average expression level of superficial group and invasive group were 0.44±0.16 and 0.21±0.12, and there was significant difference between the two group (P=0.012). The average expression level of lower grading and higher grading were 0.49±0.18 and 0.33±0.16, and there was significant difference between the two group (P=0.033).Conclusion: The expression of LRIG2 gene was significantly down-regulated in bladder cancer, and the expression level was correlated with the grading and staging of the tumor, suggesting that the gene maybe a kind of cancer inhibiting gene and participating the arising and developing of the cancer. Purpose: To investigate the expression of LRIG2 protein between bladder cancer and normal bladder tissue, and to identify the different expression in dissimilar grading and staging.Methods: Western blot technique was used to detect the expression of LRIG2 protein in 31 cases of bladder cancer tissue and 16 cases of normal bladder tissue. Statistics analysis was combined with the staging and grading of the tumor.Results: In the 31 cases of bladder cancer tissue, 33 cases were detected the expression of LRIG2 protein, and the average level was 0.41±0.15. All the 16 cases of normal bladder tissue were detected the expression of LRIG2 protein, and the average level was 0.50±0.08. There was significant difference between the bladder cancer group and the normal bladder tissue group (P=0.038). The expression of LRIG2 protein in bladder cancer was significantly lower than in the normal bladder tissue In the bladder cancer group, the average expression level of superficial group and invasive group were 0.45±0.13 and 0.27±0.13, and there was significant difference between the two group (P=0.027). The average expression level of lower grading and higher grading were 0.49±0.15 and 0.35±0.12, and there was significant difference between the two group (P=0.040).Conclusion: The expression of LRIG2 protein was significantly down-regulated in bladder cancer, and the expression level was correlated with the grading and staging of the tumor, suggesting that the protein maybe a kind of cancer inhibiting protein and participating the arising and developing of the cancer. Purpose: To investigate the effects of recombinated plasmid pCMV-LRIG2 carrying LRIG2 gene on the biological behaviors of human bladder cancer BIU-87.Method: The recombined plasmid pCMV-LRIG2 was transfected into BIU-87 cell by lipofectamine 2000, and G418 was used to screen out the positive clone. Then Western-blot was used to measure the expression of LRIG2 and EGFR protein, MTT assay was used to drawn out the growth curve of the cell, Transwell method and cell-cell adhesion were used to detect the invasion and metastasis ability among transfed cell, non-transfed cell, and pCMV-transfed cell.Result: Among the LRIG2-transfed group, non-transfed group and pCMV-transfed group, the expression of LRIG2 protein was significantly higher in the LRIG2-transfed group than the other two groups, and the expression of EGFR in LRIG2-transfed group was significantly lower. The growth curve of the cells by MTT showed that the LRIG2-transfected group had less proliferation than the other two groups .Contrast to non-transfed gourp and pCMV-group, the invasion ability of transfed group decreased significantly,however, the adhesion ability of transfed group increased significantly.Conclusion: The LRIG2 gene may act as a tumor suppressor gene by participating in construction of negative feedback loop of EGFR, so as to inhibits bladder cancer cells from growth, invasion and metastasis.