XAF1在结直肠腺瘤中的表达及其意义

Expression and significance of XAF1 in colorectal adenoma

目的检测抑癌基因XAF1在结直肠腺瘤中的表达情况,初步探讨其在结直肠腺瘤发生发展中的作用。方法半定量RT-PCR方法检测71例结直肠腺瘤性息肉、9例增生性息肉及25例正常黏膜组织中XAF1的表达情况,免疫组织化学方法检测51例结直肠腺瘤性息肉、24例增生性息肉及36例正常黏膜组织中XAF1的表达情况。结果XAF1mRNA在结直肠腺瘤性息肉、增生性息肉及正常黏膜组织中均表达,其相对表达强度分别为0.65±0.39、0.67±0.23、0.67±0.31,腺瘤中表达偏低,但差异无显著性(F=0.035,P=0.966)。XAF1蛋白在结直肠正常黏膜及增生性息肉中主要表达于细胞核,胞浆也有表达;在腺瘤中细胞核表达减少(P<0.05),而细胞浆表达相对增多(P<0.05),总体表达强度降低(P<0.05)。结论XAF1蛋白在结直肠腺瘤中存在表达降低和胞浆异位表达,XAF1基因在结直肠腺瘤的发生及向腺癌的演变中可能起抑癌基因的作用。

Objective To study the expression and significance of XAF1 gene in colorectal adenoma. Methods The expression of XAF1 mRNA in 71 cases of human colorectal adenoma, 9 cases of hyperplasia and 25 normal cases were detected by RT-PCR. Immunohistochemistry was used to determine the XAF1 protein in semi-quantitative and location in 51 cases of human colorectal adenoma, 24 cases of hyperplasia and 36 normal cases. Results XAF1 mRNA was detecta- ble in all of the human colorectal adenoma, hyperplasia and normal tissues, and the Semi-quantified analysis showed that the level of XAF1 mRNA expression in adenoma （0.65±0.39） was slightly lower than that in hyperplasia （0.67±0.23） and normal tissues （0.67± 0.31 ）. In normal or hyperplasia tissues, XAF1 protein was predominant in cell nucleus with strong expression. XAF1 expression in adenoma tissues was significantly reduced compared with normal or hyperplasia tissues （P〈0.05）. And in adenoma, the staining was predominant in cytoplasm （P〈0.05）. Conclusion XAF1 expression in adenoma tissues was disorderly reduced, that may contribute to the formation and succession of human colorectal adenoma.