生长激素对胰腺癌IGF-Ⅰ,Ⅱ-IGFBP3通路动态影响的实验研究

Effect of growth hormone on features of IGF-Ⅰ-Ⅱ-IGFBP3 pathway in pancreatic cancer

目的 观察生长激素（GH）对胰腺癌细胞增殖及对肿瘤宿主胰岛素样生长因子Ⅰ,Ⅱ（IGF-Ⅰ,Ⅱ）-胰岛素样生长因子结合蛋白3（IGFBP3）通路的影响,初步探讨体内外实验差异的原因.方法 体外应用GH（50 ng/ml）24 h,48 h,72 h后计数胰腺癌细胞SW-1990,PANC-1及P3;选用BALB/C雌性裸小鼠35只,以SW-1990成瘤,测量瘤体积,成瘤裸鼠随机分为注射GH的实验组（GH组）及对照组（NS组）,荷瘤裸鼠在最后依次注射GH后第1小时、2小时、6小时及24小时处死动物,心室穿刺抽血,切除肝脏,酶联免疫吸附法（ELISA）检测血清IGF-Ⅰ,-Ⅱ水平（P＜0.05）,蛋白印记（Western Blot）方法观察肝脏IGFBP3的相对光密度（ROD）变化.结果 GH在体外可加速胰腺癌细胞增殖但在体内不促进肿瘤生长;GH上调荷瘤宿主血清IGF-Ⅰ、Ⅱ水平;与GH刺激前（NS）相比,肝脏IGFBP3表达在GH刺激后1 h、2 h、6 h有显著提高（P＜0.05）,24 h有所减弱.结论 GH对胰腺癌细胞的作用存在一定的体内外差异;GH在体内通过提高IGF-Ⅰ、Ⅱ水平发挥效应,GH不刺激在体肿瘤生长可能与IGFBP3上调有关.

Objective To investigate the effect of GH on proliferation of pancreatic cancer cells and observe the features of IGF-IGFBP3 pathway in the host after GH administration. Methods Pancreatic cancer cells （SW-1990,PANC-1 and P3） during exponential growth stage were harvested and cultured in medium containing growth hormone （50 ng/ml）. After 24, 48 and 72 hours, cells were counted using a Coulter Counter. Thirty-five Athymic nude Balb/c mice were inoculated with SW-1990cells. When tumors became palpable after inoculation, animals were randomized to receive GH points （1 h, 2 h, 6 h, 24 after the last injection）, plasma samples were gathered for subsequent ELISA determination and liver was rapidly incised for immune blotting analysis. Results The results revealed that GH stimulated cell growth in vitro. GH elevated levels of IGF-Ⅰ , Ⅱ at the 1st , 2nd , 6th hour after the last injection. GH augmented the expression of IGFBP3 in the liver of the host in vivo （1 h, 2 h, 6 h, 24 h, respectively）. Conclusion Such proteins as IGF- Ⅰ and Ⅱ might be associated with mechanism of last effect of GH on tumor host. The up-regulation of IGFBP3 by GH administration in the host may help to explain the phenomena that GH doesn＇t accelerate growth of pancreatic tumor in vivo.