生长抑素对人胃癌裸鼠种植瘤生长的影响

Effects of somatostatin on the growth in human gastric cancer transplanted in nude mice

目的 研究生长抑素对裸鼠人胃癌SGC-7901细胞种植瘤生长的影响.方法 构建裸鼠人胃癌SGC-7901细胞种植瘤模型.将24只模型鼠随机分为4组（n=6）,分别尾静脉给予生理盐水（对照组）、奥曲肽（奥曲肽组）、高剂量生长抑素（生长抑素高剂量组）和低剂量生长抑素（生长抑素低剂量组）干预3周后,处死动物并获取肿瘤组织.称取各组种植瘤重量,计算抑瘤率.TUNEL法比较各组瘤体内细胞凋亡情况.Western blot法检测各组种植瘤组织内caspase-3的表达.结果 奥曲肽组、生长抑素高剂量组、生长抑素低剂量组平均瘤体重量较对照组均显著减轻（P＜0.05）,其抑瘤率分别为43.66％、41.55％、28.17％,生长抑素高剂量组和奥曲肽组的抑瘤率明显高于生长抑素低剂量组（P＜0.05）.各用药组细胞凋亡率显著高于对照组（P＜0.05）,生长抑素高、低剂量组细胞凋亡率显著高于奥曲肽组（P＜0.05）,生长抑素高、低剂量组间凋亡率差异无统计学意义（P＞0.05）.生长抑素高、低剂量组caspase-3的表达量显著高于对照组和奥曲肽组（P＜0.05）,生长抑素高、低剂量组间caspase-3的表达量差异无统计学意义（P＞0.05）.结论 生长抑素和奥曲肽均可显著抑制胃癌种植瘤生长、诱导胃癌细胞凋亡,且诱导能力以生长抑素尤为显著.caspase-3的表达上调可能是其诱导胃癌细胞凋亡的相关机制之一。

Objective To observe the effects of somatostatin on the growth in subcutaneous xenografts derived from human gastric carcinoma SGC-7901 cells in nude mice.Methods The animal models of xenotransplanted human gastric cancer were established by implanting human gastric carcinoma SGC-7901 cells subcutaneously in nude mice.Twenty-four nude mice were randomly divided into 4 groups （n =6 each）.After interfering with normal saline,octreotide,high-dose somatostatin and low-dose somatostatin respectively for 3 weeks,the weight of the tumors were observed and the inhibition rates for tumor growth were also calculated.The apoptosis was detected by TUNEL technique and the expression of caspase-3 was examined by Western blot.Results The average weight of tumors in the octreotide group,high-dose somatostatin group and low-dose somatostatin group was significantly reduced compared with the control group （P 〈 0.05）.The inhibition rate for tumor growth in the octreotide group （43.66%） and high-dose somatostatin group （41.55%） was significantly higher than in the low-dose somatostatin group （28.17%） （P 〈0.05）.The apoptosis rate in the octreotide group,high-dose somatostatin group and low-dose somatostatin group was significantly higher than in the control group （P 〈 0.05）.The apoptosis rate in the high-dose somatostatin group and low-dose somatostatin group was significantly higher than in the octreotide group （P 〈 0.05）.The apoptosis rate between the high-dose somatostatin group and low-dose somatostatin group showed no significant statistical difference （P 〉 0.05）.The expression of caspase-3 protein in the two somatostatin groups was significantly higher than in the octreotide group and the control group （P 〈 0.05）.No significant statistical difference in the expression of caspase-3 protein was observed between the high-dose somatostatin group and the low-dose somatostatin group （P 〉 0.05）.Conclusion Somatostatin and octreotide can significantly inhibit the growth of gastric cancer xenografts and induce apoptosis in gastric cancer cells,and somatostatin induced ability is especially significant.One of the mechanisms of inducing gastric cancer cells apoptosis may be related to the upregulation of the expression of caspase-3.