大肠癌中胰岛素样生长因子2基因的印迹状态和表达

The expression and imprinting status of insulin-like growth factor 2 gene in colorectal cancer

目的 研究胰岛素样生长因子 2 (insulin- like growth factor2 ,IGF2 )基因的印迹状态和表达与大肠癌的关系 ,为研究大肠癌的发生机理提供线索。方法 用逆转录 -聚合酶链反应半定量检测 IGF2的表达量 ,比较其在大肠癌及癌旁组织中有无差异 ,用限制性片段长度多态检测 IGF2的印迹状态 ,分析印迹状态、表达量与大肠癌的关系。结果 82 .4 % (2 8/ 34)大肠癌有 IGF2的表达增加 ,IGF2的表达量在肿瘤组织与癌旁组织中差异有显著性 (P<0 .0 1,t=3.0 1)。IGF2在 87.5 % (14 / 16 )大肠癌组织中发生了印迹丢失 ,但其相对应的癌旁组织也有 71.4 % (10 / 14 )存在 IGF2的印迹丢失。结论 IGF2的表达增加是大肠癌发生的相关因素 ,IGF2的印迹丢失可能是大肠癌发生的前期表现。

Objective: To study the imprinting status and expression level of insulin-like growth factor 2 (IGF 2) gene in colorectal cancer and to provide a clue for the mechanism of carcinogenesis of colorectal cancer. Methods: The expression levels of IGF2 in the paired colorectal cancer and adjacent normal tissue were examined and compared by use of semi-quantitative reverse transcription-polymerase chain reaction. The imprinting status of IGF2 was detected by restriction fragment length polymorphism. The relationships between the expression level of IGF2, its imprinting status, and the carcinogenesis of colorectal cancer were analyzed. Results: IGF2 was overexpressed in 82.4% (28/34) of colorectal cancer tissues which was significantly higher than those of the matched normal tissues (P<0.01, t = 3.01). 87.5% (14/16) of colorectal cancer showed loss of imprinting (LOI), while 71. 4%(10/14) of normal tissues also displayed LOI of IGF2. Conclusion: Overexpression of IGF2 was found to play an important role in carcinogenesis of colorectal cancer. LOI of IGF2 may be a prophase manifestation of colorectal cancer.