A preliminary study on the relationship of insulin-like growth factor-Ⅰ receptor and the carcinogenesis of gastde cancer / 中华消化杂志

ABSTRACT

Objective To study the relationship of insulin-like growth factor-Ⅰ receptor(IGF-ⅠR)and carcinogenesis of gastric cancer.Methods The expression of IGF-ⅠR was detected in 40 cases of resected gastric cancer tissues and adjacent normal gastric mucosa by immunohistochemistry.The expression of IGF-ⅠR in gastric cancer cell lines(MGC803 and SGC7901)was detected by Western Blot.siRNAs targeted to IGF-ⅠR were designed,synthesized and transfected into MGC803 cells,the changes of IGF-IR protein level were detected by Western Blot at 48 h after transfection,the cell proliferation was examined by MTT,and then the growth curve was obtained.Results The positive rate of IGF-IR expression in gastric cancer tissues was 75.5%,significantly higher than that of adjacent normal tissues (25%,P＜0.01).The expression level of IGF-IR was related with TNM stage,lymphnode metastasis (P＜0.05),but not related with sex,age,histological differentiation,invasion depth of gastric cancer (P＞0.05).Intense expression of IGF-ⅠR was showed in gastric cancer cell lines.The inhibition ratio of IGF-ⅠR expression in sigNAl group were 89.80%±4.10%,the cell proliferation decreased to mininlunl level at the fifth day aftertransfection(by 29.0%±4.0%of mock-treated group),the cell number decreased by 21.15%±1.10%of mock treated group at the same time.Conclusions IGF-ⅠR is over-expressed in gastric cancer cells and can be effectively silenced by RNA interferes,therefore the growth of tmnor cell Was inhibited.Thus,it indicates that IGF-ⅠR may be a promising target for gene therapy of gastric cancer.