抑癌基因LRIG1对膀胱癌细胞BIU87生物学特性的影响

质粒转染人膀胱癌BIU87细胞，用G418（800mg／L）筛选出抗性克隆。Western blot检测转染前后LRIG1和EGFR蛋白水平的变化；MTT法绘制转染前后细胞的生长曲线；Boyden小室和同质黏附实验观察转染前后细胞侵袭和黏附能力的变化。结果转染pLRIG1-GFP组LRIG1蛋白表达水平较对照组和转染空载体组明显升高，而EGFR蛋白表达水平较对照组和转染空载体组显著降低；转染pLRIG1-GFP组细胞的生长速度较对照组和转染空载体组明显减慢；转染pLRIG1-GFP后的BIU87细胞侵袭目的研究抑癌基因LRIG1对膀胱癌细胞BIU87生物学特性的影响。方法用脂质体介导的基因转染技术，将pLRIG1-GFP和黏附能力显著降低（P〈0．05）。结论LRIG1是一种抑癌基因，通过参与形成EGFR的负反馈环路，对膀胱癌细胞BIU87的生长、侵袭和转移有显著的抑制作用。

Effects of tumor suppressor gene LRIG1 on the biological behaviors of human bladder cancer cell BIU87

Objective To investigate whether the expression of tumor suppressor gene LRIG1 can suppress the invasive or metastatic ability of bladder cancer cells. Methods Plasmid pLRIG1-GFP was transfected into bladder cancer cell (BIU8) by Lipofectamine2000, and cells that can express LRIG1 stably was screened out by G418 (800 mg/L). Changes of LRIG1 and EGFR protein levels were measured by Western blot;Growth curve of the LRIG1 gene transfected bladder cancer cells was drawn with the results of MTT assay; Then Boyden chamber and cell-cell adhesion were used to detect the difference of invasion and metastases between transfected and non-transfected cells. Results LRIG1 protein level in pLRIG1-GFP transfected BIU87 cells was significantly higher than that in control BIU87 cells and pEGFP-N1 transfected BIU87 cells. EGFR protein level in pLRIG1-GFP transfected BIU87 cells was significantly lower than that in control BIU87 cells and pEGFP-N1 transfected BIU87 cells. The growth curve of the LRIG1 gene transfected cells by MTT revealed that the LRIG1 gene transfected cells had less proliferation than control cells and pEGFP-N1 transfected BIU87 cells. As compared with control cells and pEGFP-N1 transfected BIU87, the invasion and adhesion ability of pLRIG1-GFP transfected cells was decreased obviously ( P < 0.05). Conclusion LRIG1, as a tumor suppressor gene, participates in construction of negative feedback loop of EGFR to inhibit bladder cancer cells from growth, invasion and metastasis.