奥曲肽抑制肝癌生长的实验研究

目的研究生长抑素类似物奥曲肽在体外、体内对肝癌生长及凋亡的影响.方法采用3H-胸腺嘧啶核苷(3H-TdR)掺入法、DNA末端原位标记染色(TUNEL)及流式细胞技术检测奥曲肽对体外培养的肝癌细胞生长影响及凋亡的诱导作用.利用SMMC-7721肝癌细胞株建立裸鼠肝癌原位种植瘤模型,实验组皮下注射奥曲肽100μg@kg-1@d-1;对照组予生理盐水20μg@d-1;共给药8周.结果培养细胞经不同浓度的奥曲肽作用48h后,对肝癌细胞的生长具有明显的抑制作用,且肝癌细胞3H-TdR掺入值与奥曲肽的浓度呈负相关(r=-0.97,P<0.01).TUNUL显示,1×10-6mol/L的奥曲肽作用24h后,肝癌细胞凋亡率为15.2%±2.4%;流式细胞检测可见明显的凋亡峰.奥曲肽治疗组裸鼠肝癌原位种植瘤重量明显低于对照组(0.27±0.05vs0.85±0.37,P<0.01).结论体内及体外实验表明,奥曲肽能有效抑制肝癌生长,其机制可能与抑制肝癌细胞DNA合成及诱导肝癌细胞凋亡有关.

Inhibition effects of octreotide on the growth of hepatocellular carcinoma in vitro and in vivo

OBJECTIVE: To investigate the effects of somatostatin analogue octreotide on the proliferation and apoptosis of human hepatocellular carcinoma (HCC) cell line as well as the growth of HCC xenografts in nude mice. METHODS: The effects of octreotide on the proliferation and apoptosis of SMMC-7721 HCC cells was measured by 3H-thymidine incorporation into DNA and the TdT-mediated dUTP nick end labeling assay (TUNEL) or flow cytometric assay separately. Nude mice bearing xenografts of the cell line were treated with octreotide or saline as a control daily until eight weeks after tumor implantation. RESULTS: Incubation with octreotide decreased 3H-thymidine incorporation into DNA of SMMC-7721 cells by approximately 50% at a concentration of 1 mumol/L. The inhibit effect of octreotide showed a concentration dependence. After 96 h incubation, total cell count was decreased 52.2% compared with control. When cells were treated by octreotide at 1 x 10(-6) mol/L for 24 hours, the apoptosis rates was (15.2 +/- 2.4)%. At necropsy, in mice given octreotide, the mean tumor weight were significantly lower than that of control group (0.27 +/- 0.05 vs 0.85 +/- 0.37, P < 0.01). The inhibition rate of tumor in vivo at 2 months was 68.2%. CONCLUSION: Octreotide is effective in inhibiting growth of HCC both in vivo and in vitro significantly. The mechanisms of antineoplastic effect action may involved in inhibiting DNA synthesize and inducing apoptosis of tumor cells.