目的：探讨奥曲肽诱导人结肠癌细胞凋亡与细胞周期的影响及机制。 方法：奥曲肽、GSK-3β 抑制剂LiCl 单独或联合作用于人结肠癌SW480 细胞后，用流式细胞术检测 SW480 细胞的凋亡与细胞周期，以及用DNA 凝胶电泳实验进一步验证细胞凋亡；Western blot 检测 SW480 细胞中GSK-3β、p-GSK3-β（Tyr216）及p-GSK-3β（Ser9）蛋白表达。 结果：与未处理的空白对照组SW480 比较，奥曲肽处理SW480 细胞后，细胞凋亡率与G0/G1 细胞明显 升高，凝胶电泳出现典型的“梯形”DNA 条带，总GSK-3β 蛋白与p-GSK3β（Tyr216）表达明显上调， 而p-GSK3β（Ser9）蛋白表达明显下降（均P<0.05）；LiCl 单独作用对SW480 细胞的凋亡与细胞周 期无明显影响（均P>0.05），但与奥曲肽联合作用能明显削弱奥曲肽对SW480 的促凋亡与细胞周期阻 滞作用（均P<0.05）。 结论：奥曲肽能有效诱导SW480 细胞凋亡与细胞周期阻滞，该作用可能与其上调GSK-3β 蛋白的表达， 并调节GSK-3β 蛋白的磷酸化水平有关。
Influence of octreotide on apoptosis and cell cycle in human colon cancer cells and the mechanism
Objective: To investigate the influence of octreotide on apoptosis and cell cycle in human colon cancer cells and the mechanism. Methods: Human colon cancer SW480 cells were exposed to octreotide or GSK-3β inhibitor LiCl alone or in combination; the apoptosis and cell cycle in SW480 were analyzed by flow cytometry, and the apoptosis was also verified by DNA agarose gel electrophoresis. In addition, the expressions of GSK-3β, p-GSK3β (Tyr216) and p-GSK3β (Ser9) in SW480 cells were determined by Western blot analysis. Results: Compared with the blank control group of untreated SW480 cells, in SW480 cells after octreotide treatment, the apoptosis and ratio of G0/G1 phase cells were significantly increased, typical DNA ladders were present in the agarose gel electrophoresis, and the total GSK-3β protein and p-GSK3β (Tyr216) protein expressions were significantly increased, while the p-GSK3β (Ser9) protein expression was significantly decreased (all P<0.05); LiCl treatment alone exerted no influence on apoptosis and cell cycle in SW480 cells (both P>0.05), but it significantly weakened the apoptosis-inducing and cell cycle arrest effect of octreotide in SW480 cells in combination with octreotide (both P<0.05). Conclusion: Octreotide can effectively induce apoptosis and cell cycle arrest in SW480 cells, which may be related to its increasing GSK-3β protein expression and regulating phosphorylation level of GSK-3β.