Genetic instability of stromal cells in ulcerative colitis-associated carcinogenesis

为了解间质细胞遗传不稳定性在溃疡性结肠炎（UC）癌变中的作用，采用PCR-SSCP方法，对显微分离的UC上皮细胞和间质细胞进行微卫星不稳定性（MSI）和杂合性缺失（洛）检测。在散发性结肠癌中，上皮和间质组织均获得MSI阳性结果。上皮细胞MSI与分化程度和Dukes分期相关，而间质MSI与分化程度和Dukes分期呈负相关，在分化良好的腺癌和Dukes A型病变中尤为常见，提示结肠癌发生中存在间质遗传不稳定性的另一种致癌途径。相比之下，虽然上皮细胞中的17号染色体-MSI和-洛与组织学进展相关，但在间质中，它们在不同阶段显示出一致的高频率，表明UC的不同致癌途径。

To know roles of genetic instability of stromal cells on carcinogenesis in ulcerative colitis (UC), microsatellite instability (MSI) and loss of heterozygosity (LOH) were investigated in epithelial and stromal cells separated by microdissection, by using PCR-SSCP method. In sporadic colon cancers, MSI positive results were obtained for both epithelium and stromal tissue. While MSI in epithelium correlated with differentiation and Dukes' stage, that in stroma demonstrated an inverse correlation, being particularly frequent in well differentiated adenocarcinomas and Dukes' A lesions, suggesting an alternative pathway of carcinogenesis involving stromal genetic instability in the development of colon cancers. In contrast, although chromosome 17-MSI and -LOH in epithelium correlated with histological progression, in stroma they showed a consistently high frequency throughout the different stages, indicating a distinct carcinogenesis pathway of UC.