下调胰岛素样生长因子-1表达对人胃癌细胞增殖和侵袭及迁移的影响

目的 胰岛素样生长因子1(insulin like growth factor-1,IGF-1)作为体内重要的促有丝分裂原分子,可能与恶性肿瘤的转化及转移相关,但是目前有关IGF-1的表达与胃癌细胞迁移、侵袭的研究较少.本研究旨在研究IGF-1在胃癌组织中的表达,并探讨其表达对人胃癌HGC-27细胞体外增殖及侵袭、迁移能力的影响.方法 检测承德医学院附属医院2014-05-10-2016-05-10胃癌手术切除78例胃癌组织、30例癌旁正常组织及体外不同胃癌细胞系中IGF-1的表达情况.针对IGF-1基因序列,设计发夹RNA(short-hairpin RNA,shRNA)干扰序列并构建干扰载体,转染胃癌HGC-27细胞.荧光实时定量PCR及蛋白质印迹技术分别检测转染干扰载体后HGC-27细胞中IGF-1的表达情况.细胞增殖-毒性检测试剂盒(cell counting kit 8,CCK-8)、划痕实验及Transwell侵袭实验分别检测下调IGF-1对体外细胞HGC-27增殖及迁移、侵袭能力的影响.结果 免疫组织化学法检测显示,低分化胃癌组织中IGF-1阳性表达率为76％(29/38),高、中分化为53％(21/40),癌旁正常组织为27％(8/30).不同胃癌组织与癌旁组织中IGF-1的表达差异有统计学意义,x2=16.66,P＜0.01.并且其表达与胃癌的病理分期(x2=7.430,P=0.007)、组织分化(x2=4.618,P=0.032)等病理因素相关.体外不同胃癌细胞系中IGF-1均呈现高表达,但差异无统计学意义.利用干扰载体能够有效下调胃癌细胞HGC-27中IGF-1在mRNA及蛋白质水平的表达.与空载体转染对照组和野生型HGC-27细胞比较,IGF-1表达下调明显抑制胃癌细胞的体外增殖和侵袭、迁移能力.结论 IGF 1在体内胃癌组织及体外胃癌细胞中高表达,下调IGF-1的表达能够抑制人胃癌细胞HGC-27的增殖及体外侵袭、迁移能力.

Effects of IGF-1 down-regulation on proliferation,migration and invasion of human gastric cancer cells

OBJECTIVE As an important mitogen molecule,insulin like growth factor-1 (IGF-1) may be related with transformation and metastasis of malignant tumor cells.However,the relationship between the IGF-1 expression and gastric cancer cell migration andinvasion were rarely studied recently.This study aimed to investigate the expression of IGF-1 in gastric cancer and study the effects of IGF-1 expression on cell proliferation,invasion and migration of in hu man gastric cancer HGC-27cells in vitro.METHODS The expression of IGF-1 was determined in 78 gastric cancer tissues,30 adjacent tissues and culturic carcinoma cells respectively.The interference expression vector was constructed using the shRNA interference sequences which were designed according to IGF-1 sequence,the interference vector was transfected into gastric cancer HGC 27 cells with higher efficiency.The expression of IGF-1 in HGC-27 cells was detected by real-time quantitative PCR and Western blotting.CCK-8 assay,Wound-Healing assay and Transwell assay were used to detect the effect of down-regulation of IGF1 on the proliferation,migration and invasion of HGC27 cells in vitro respectively.RESULTS Immunohistochemical staining showed that the positive expression rate of IGF-1 in poorly differentiated and high/middle differentiated gastric cancer tissues was 76％(29/38) and 53％(21/40),respectively,while the positive expression rate of IGF-1 in the adjacent normal tissues was 27％ (8/30).The difference was statistically signifi cant in different gastric cancer tissue and adjacent tissues (x2=16.66,P＜0.01).Furthermore,the expression of IGF-1 was related to pathological factors such as pathological stage (x2 =7.430,P=0.007) and histological differentiation (x2=4.618,P=0.032),et al.IGF-1 in different gastric cancer cell lines showed high expression,but there was no significant difference.IGF-1 expression could be effectively decreased in mRNA and protein levels by RNAi vector.Down-regulation of IGF-1 inhibited the proliferation,invasion and migration ability in vitro apparently compared to the control group transfected with the empty vector and the blank control group of wild-type HGC 27 cells.CONCLUSION IGF-1 is highly expressed in gastric cancer tissues and gastric cells in vitro,down regulated expression of IGF-1 can inhibit the proliferation,invasion and migration of human gastric cancer cell line HGC-27.