The roles of ret/PTC fusion genes in thyroid papillary carcinoma

背景：ret原癌基因的激活，通过染色体易位，被报道是唯一的乳头状甲状腺癌。然而，RET/PTC激活在乳头状癌中的流行率是可变的，RET/PTC重排在乳头状癌中的临床相关性仍然存在争议。方法：为了研究ret重排在乳头状甲状腺癌发生中的作用，我们通过免疫组化技术研究了日本人群各种甲状腺病变中的ret激活和p53过表达。结果：对40例乳头状癌、5例低分化癌、1例未分化癌、2例髓样癌、2例滤泡状癌、19例滤泡状腺瘤中的Ret活化和p53过表达进行了研究。在40例乳头状癌中有12例观察到RET激活，而在其他病变中未检测到RET免疫反应性。结论：日本人乳头状癌中RET/PTC激活的发生率高于以往的报道。免疫组化被证明是一个有用的工具来检测甲状腺肿瘤中的RET/PTC激活。RET重排仅限于分化良好的乳头状癌，表明RET/PTC阳性的乳头状癌不会进展为未分化癌。

Background: The activation of ret proto-oncogene, through chromosomal translocation, is reported as unique to papillary thyroid carcinomas. However, the prevalence of RET/PTC activation in papillary carcinoma reported was variable and the clinical relevance of RET/PTC rearrangements in papillary carcinomas is still controversial.Methods: To investigate the roles of ret rearrangement in the carcinogenesis of papillary thyroid carcinoma, we have studied ret activation and p53 overexpression in various thyroid lesions of Japanese population by immunohistochemical technique.Results: Ret activation and p53 overexpression were studied in 40 papillary carcinomas, 5 poorly differentiated carcinomas, 1 undifferentiated carcinoma, 2 medullary carcinoma, 2 follicular carcinomas, 19 follicular adenomas. RET activation was observed in 12 out of 40 papillary carcinomas, while no immunoreactivity of ret was detected in other lesions. P53 overexpression was observed in only one of 40 papillary carcinomas.Conclusion: The prevalence of RET/PTC activation in papillary carcinoma among Japanese population was higher than previous reports. Immunohistochemistry is proved as a useful tool to detect RET/PTC activation in thyroid tumors. RET rearrangements are restricted to a well-differentiated papillary carcinoma, suggesting that RET/PTC positive papillary carcinomas do not progress to undifferentiated carcinoma.