Glucagon-like peptide 2 stimulates intestinal epithelial proliferation in vitro

Glucagon-like peptide 2 (GLP-2) is a potent intestine-specific growth factor. To determine whether GLP-2 has a direct effect on cellular proliferation, we examined the effects of GLP-2 on three different intestinal epithelial cell lines: Caco-2, T84, and IEC-6. Proliferation was assessed by measuring [³H]thymidine incorporation into cellular DNA. The expression of the cell cycle regulators cyclins D1, E, and A was determined by western blotting. GLP-2 stimulated [³H]thymidine incorporation in Caco-2 and T84 cells but not in IEC-6 cells. In Caco-2 cells, increased [³H]thymidine incorporation was detectable by day 1 and was maximal at day 5 following initiation of daily GLP-2 administration. Increased [³H]thymidine incorporation persisted for three days following treatment with a single dose of GLP-2. GLP-2 administration resulted in the induction of cyclins D1, E, and A in Caco-2 cells. These results suggest that GLP-2 acts directly on human intestinal epithelial cells to stimulate their proliferation.     

细胞周期蛋白G2在结直肠癌中表达水平与临床意义

目的探讨细胞周期蛋白G2(cyclin G2,CCNG2)在结直肠癌中的表达意义。方法采用免疫组织化学方法、蛋白印迹法(Western blot)检测57例结直肠癌组织及距其癌组织边缘2cm以上的镜下未见癌浸润的正常组织中蛋白的表达情况。结果免疫组织化学结果表明,CCNG2蛋白在结直肠癌组织中的表达较正常结直肠组织明显降低,分别为38.6%(22/57)、91.3%(31/33)(P0.05)。Western blot结果表明,CCNG2的蛋白在结直肠癌组织的表达相对量较正常结直肠组织的表达相对量明显降低(P0.05)。CCNG2蛋白表达与结直肠癌T分期、淋巴结转移、肿瘤临床分期及肿瘤分化有关(P0.05)。结论结直肠癌组织中CCNG2蛋白表达明显减低,且与结直肠癌T分期、淋巴结转移、临床分期及肿瘤分化有关。