The Expression And Significance Of IGF-I And Its Receptor In Human Gastric Cancer

Background & Aims: The insulin growth factors (IGFs) are mitogens that play key roles in the development and progression of neoplasia. The effects of IGFs are mediated mainly through the IGF-I receptor. In order to explore the significance of IGF-I and IGF-IR in human gastric cancer,the expression of IGF-I and IGF-IR were studied. Methods: We analyzed the expression of IGF-I and IGF-IR in 40 paired samples of normal and carcinomatous gastric tissue by immunohistochemistry. The relationship of expression of IGF-I and IGF-IR with various clinicopathological parameters were analyzed. The expression of IGF-IR in gastric cancer cells SGC7901and MGC803 were measured by western blot.Results: As measured by immunohistochemistry, the positive rates of IGF-I and IGF- IR expressions in tumor tissues were 75% and 75.5%, significantly higher than 27. 5% and 25% in normal tissues, respectively (P<0.005). No correlation were found between expression level of IGF-I/IGF-IR and patients sex, age, histological differentiation , invasion depth of gastric cancer ( P>0.05). The IGF-I and IGF-IR protein expression were higher in stage â…¢+â…£ of gastric cancer than that in stage â…  +â…¡ of gastric cancer, and were higher in gastric cancer with lymphnode metastasis than that in those without lymphnode metastasis( FKO. 05). The expressions of IGF-IR of gastric cancer cells SGC7901 andMGC803 were positive. There was a positive correlation between theoverexpression of IGF-I and IGF-IR in the gastric cancer.Cone I usions:Our results demonstrate that a strong overexpression ofIGF-I and IGF-IR was found in the majority of gastric cancer, supportingthe hypothesis of an important role of the IGF system in the pathogenesisgastric cancer.