生长抑素对人结肠癌裸鼠移植瘤的作用及机理

THE EFFECT OF SOMATOSTATIN ON THE TRANSPLANTED HUMAN COLONIC CARCINOMA AND ITS MECHANISM IN GYMNOMOUSE BODY

建立人结肠癌细胞株ＳＷ４８０裸鼠移植瘤模型，观察８肽生长抑素（ＳＭＳ２０１９９５，ＳＭＳ）对移植瘤的作用及机理。结果∶ＳＭＳ组及ＳＭＳ＋ＰＧ（５肽胃泌素）组移植瘤的体积、重量、瘤细胞内ｃＡＭＰ、ＤＮＡ、蛋白质含量、Ｓ期和Ｇ２Ｍ期细胞数及增殖指数均显著低于ＰＧ组及对照组，ＰＧ组显著高于对照组；而Ｇ０／Ｇ１期细胞数则显著高于ＰＧ组及对照组，ＰＧ组显著低于对照组。本实验结果提示：生长抑素具有直接抑制人结肠癌细胞株ＳＷ４８０移植瘤生长的作用，又可抑制胃泌素对移植瘤的促增殖作用。这种作用机理是通过抑制瘤细胞内ｃＡＭＰ、ＤＮＡ和蛋白质的合成，从而抑制瘤细胞从Ｇ０／Ｇ１期进入到Ｓ期和Ｇ２Ｍ期。

The model of transplanted colonic SW480 cell line carcinoma in gymnomouse body was set up to observe the effect of octapeptide somatostatin (SMS 201 995,SMS) on the transplanted carcinoma and elucidate its mechanism. Results: the volume, weight, DNA and protein content in carcinoma cell, cell amount and proliferation index of S and G 2M phase in SMS group and SMS+PG (pentagastrin) group were markedly lower than those in PG group and control group, those of PG group were markedly higher than those in control group.The cell amount of G 0/G 1 phase in SMS group and SMS+PG group was markedly higher than that in PG group and control group, and that of PG group was markedly lower than that in control group.All these suggested that somatostatin could not only inhibit the growth of transplanted human colonic SW480 cell line carcinoma directly but also inhibit the growth promoting effect of gastrin on the transplanted carcinoma.The mechanism might be that somatostatin inhibit the synthesis of cAMP, DNA and protein in carcinoma cells, then inhibit the cell growing from G 0/G 1 phase to S and G 2M phases.Our study might provide experimental basis for the homonotherapy with analogue of somatostatin in patients with large intestine carcinoma.