生长抑素受体SSTR3基因对胃癌细胞生长的影响

Effect of Human SSTR 3 Gene on Growth of Gastric Cancer Cells

目的克隆生长抑素受体SSTR3基因,构建其真核表达载体,并进行转染研究,探讨SSTR3基因在胃癌细胞中的作用。方法从永生化的胃上皮细胞系GES中提取总RNA,经RTPCR扩增出SSTR3基因,并构建真核表达载体pcDNA3.1(+)SSTR3,转染胃癌细胞系MKN45,以MTT法和流式细胞仪观察转染SSTR3基因前后使用奥曲肽对胃癌细胞增殖和凋亡的影响。结果克隆的SSTR3基因测序正确;构建的真核表达载体pcDNA3.1(+)SSTR3能高表达SSTR3蛋白;转染SSTR3基因的胃癌细胞系MKN45加用奥曲肽后,出现明显的增殖抑制和凋亡发生。结论SSSTR3基因介导了生长抑素类似物引起的胃癌细胞的增殖抑制和凋亡发生。通过基因转移使原来不表达SSTR3基因的胃癌细胞再表达,为生长抑素和SSTR3基因治疗胃癌提供了又一有效途径。

Objective We cloned human gene somatostatin recptor subtype SSTR 3 from eternal gastric epithelial cell line GES, constructed its recombinat eukaryotic expression vector and transfected into MKN 45 cells to examine the effect of somatostatin and SSTR 3 on the proliferation and apoptosis of gastric cancer cells. Methods Human SSTR 3 gene fragment was extreted and amplified from eternal gastric epithelial cell line GES by RT-PCR . Recombinant plasmid pcDNA 3.1 （ ＋ ） -SSTR 3 was constructed and transfected into gastric cancer cell line MKN 45 by lipofectamine . The change of pruliferation and apoptosis of MKN 45 were examined by MTT, flow cytometry. Results After transfection ,SSTR 3 was reexpressed in SSTR 3 transfectants stably. Somatostatin analogue octreotide could inhibit the proliferation and induce the apoptosis of SSTR 3 transfectants , but didn＇ t affect MKN 4,5 cells and empty vector control cells with no expression of SSTR 3. Conclusion The preliminary study indicates that octreotide is effective in inhibiting the proliferation and inducing apoptosis of SSTR 3 transfected gastric cancer cells through mediation of SSTR 3 , Transfer of SSTR 3 gene is a potential clinical utility in gene therpy for gastric cancers.