伴有微卫星不稳定性的散发性结直肠癌转化生长因子-betaⅡ型受体基因突变的研究

目的:为了探讨在散发性结直肠癌的发生过程中转化生长因子βⅡ型受体基因(RII)的突变与微卫星不稳定性(RER)间的关系。方法: 我们应用PCR-SSCP-银染方法检测了50例散发性结直肠癌中的RER状态及RII基因突变情况(近端结肠19例,远端31例)。结果: RER+的共有13例(8例在近端,5例在远端),RII基因突变的共有5例。所有5例RII基因突变者均同时伴有RER+,而所有RER-病例均无RII基因突变。其中4例RII基因突变者位于回盲部肿瘤中。结论: 这些数据提示在散发性结直肠癌中,尤其是在回盲部肿瘤中,TGF-β RII基因的A₁₀重复序列是微卫星不稳定性的靶点,在肿瘤形成过程中可能起重要作用。

Mutation of the transforming growth factor- β type Ⅱ receptor gene in sporadic colorectal cancers with microsatellite instability

AIM: To determine the relationship between the mutation of the RⅡ gene and RER status in the tumorigenesis of sporadic colorectal cancer. METHODS: We screened RER status and mutation of the RⅡ gene from 50 sporadic colorectal cancers (19 in the proximal colon, 31 in the distal colorectum).RESULTS: RER was found in 13 cases (8 in the proximal colon, 5 in the distal colorectum), and 5 of them showed mutations of the RⅡ gene. All 5 cancers carrying a TGF - β RⅡ gene mutation showed RER + , but there wasn' t any mutation of RⅡ gene in RER( - ) cases. Four of 5 RⅡ mutation were located at the cecum.CONCLUSION: These data indicate that the TGF- β RⅡ gene is a major target of microsatellite instability and mutation of the RⅡ gene play an important role in carcinogenesis of sporadic colorectal cancer with microsatellite instability, especially at the cecum.