喉鳞癌组织中RB1.20座位杂合性丢失和p110^(RB1)蛋白表达的检测

Loss of heterozygosity on chromosome RB1.20 locus and p110 RB1 protein state in squmous cell carcinomas of larynx

目的探讨喉鳞状细胞癌组织中ＲＢ１基因在喉癌发生发展中的意义，为发现和定位新的抑癌基因提供线索和依据。方法应用聚合酶链反应（ｐｏｌｙｍｅｒａｓｅｃｈａｉｎｒｅａｃｔｉｏｎ，ＰＣＲ），选择１３号染色体上ＲＢ１．２０座位的微卫星多态标记，对５８例喉鳞状细胞癌组织进行杂合性丢失（ｌｏｓｏｆｈｅｔｅｒｏｚｙｇｏｓｉｔｙ，ＬＯＨ）分析和ｐ１１０ＲＢ１蛋白表达的检测。结果３例原位癌中均无ＲＢ１．２０座位杂合性丢失，５５例浸润癌中４５例可提供信息，杂合性丢失的频率为４０％（１８／４５），４１例中仅有８例ＲＢ蛋白表达缺失，其中６例伴有ＲＢ１．２０座位的杂合性丢失。结论ＲＢ１基因在部分喉癌中发生失活；在ＲＢ１．２０座位附近可能还存在与喉癌发生发展密切相关的抑癌基因。

Objective To study the RB1 gene in squamous cell carcinoma of larynx(LSCC) and to find clue for discovering and locating new suppressor gene. Methods Loss of heterozygosity (LOH) of microsatellite polymorphic sequence on chromosomes 13 at RB1.20 locus of 58 LSCC patients were analyzed. The p110 RB1 protein state was detected by immunohistochemical staining using the polyclonal antibody to the RB1 products. Results It showed that 3 cases in the preinvasive stage (i.e. carcinoma in situ) had no any LOH on chromosome 13. Forty pereent of the 55 invasive LSCC showed LOH at RB1.20 locus.By immunohistochemical staining p110 RB1 protein negative reaction was observed in 8 LSCCs in which 6 cases associated with LOH at RB1.20 locus. Conclusions RB1 gene was inactivated in some LSCCs. It is putative that there is another tumor suppressor gene on chromesome 13 near by RB1.20 locas.The inactivation of the genes at the chromosome 13q region including RB1 involved genesis and development of invasive LSCC.