奥曲肽上调Smad4表达抑制肝癌细胞生长

目的观察奥曲肽（octreotide，OCT）对Bel7402人肝癌细胞内Smad4调节及其对肝癌细胞的抑制作用。方法以MTr法测量OCT对Bel7402细胞增殖的影响，光镜下观察细胞形态的变化。以细胞迁移实验和粘附实验观察细胞侵袭和粘附能力的影响。以流式细胞仪检测细胞周期和Smad4蛋白的变化。以裸鼠人肝癌种植模型，观察OCT对种植瘤生长的影响，以免疫组化观察种植瘤内Smad4蛋白的表达。以半定量RT—PCR观察体内外Smad4mRNA的表达。结果OCT处理的Bel7402细胞增殖能力和细胞形态无明显改变，细胞的侵袭和粘附能力明显下降，细胞生长静止期（G0／G1）的比例显著增加（48．0％±3．2％vs57．7％±0．9％），OCT明显抑制裸鼠人肝癌种植瘤的生长，抑瘤率达到67．9％。体外OCT流式细胞仪检测治疗组种植瘤内Smad4蛋白（6．36±1．22）的表达显著高于对照组（3．22±1．20）。体内外Smad4 mRNA的表达，治疗组（0．701±0．035，1．091±0．131）也明显高于对照组（O．531±O．073，0．634±0．222）。结论OCT能显著抑制体内外肝癌细胞的生长，上调肝癌细胞内Smad4的表达可能是其抑瘤的重要机制。

Octreotide in inhibiting hepatocellular carcinoma through Up-regulating Smad4 expression

Objective To observe the regulation of octreotide （OCT） on the expression of Smad4 in Bel7402 hepatocellular carcinoma （HCC） cell, and it＇s inhibiting effect on the growth of HCC. Methods The effects of OCT on proliferative ability of Bel 7402 cells were determined by MTT assay. The cellular morphologic changes were observed by light microscope. The cellular adhesive and invasive ability were observed by cellular adhesion and migration experiments. Changes of the cellular cycle and Smad 4 protein by immunofluorescence flow cytometry. With human liver cancer planted mode of nude mice, effects of OCT on planted tumor growth and planted tumor Smad4 RNA expression were observed by immunohistochemical method. Smad4 RNA expression of in vivo and in vitro were observed by semi-quantitative RT-PCR. Results After OCT management, Bel 7402 cellular proliferative ability and cellular morphology were no changes significantly. The cellular invasive and adhesive ability were declined obviously. The ratio of cellular growth resting stage （G0/Gl）was increased obviously （48.0%±3.2% vs 57.7%±0.9%）. Human liver cancer planted tumor growth of nude mice was signifrcantly inbibited by OCT（0.17±0.144 g vs 0.532±0.60 g） and tumor inhibiting rate was 67.9%. In the detection of corporeal OCT group with flow cytometry,the therapeutic group expression of planted tumor Smad4 protein was higher than that control group significantly. In vivo and vitro Smad 4 mRNA expression, therapeutic group was also higher than that control group significantly. Conclusion OCT would signifieantly inhibit growth of hepatic carcinoma cells in the vivo and in vitro. Up-regulation of Smad 4 expression of hepatic carcinoma cells may be an important organism for inhibiting tumor.