荧光原位杂交技术检测胃肠道外间质瘤p16基因改变的意义

目的探讨应用荧光原位杂交(FISH)技术检测胃肠道外间质瘤(EGIST)中p16基因缺失及17号染色体非整倍性的发生情况及其临床病理学意义。方法收集18例EGIST病例,采用p16/CSP17双色探针在石蜡切片上与瘤细胞杂交,所有病例同时用免疫组织化学技术检测P16蛋白的表达。结果FISH结果显示,p16基因缺失病例11例(61%),免疫组织化学检测到P16蛋白缺失病例13例(72%),基因缺失与蛋白表达差异具有统计学意义(P<0.05);共检出17号染色体非整倍体EGIST病例5例(28%)。EGIST病例中p16基因缺失、17号染色体倍体改变与各临床病理学因素间差异无统计学意义(P>0.05)。结论EGIST中存在p16基因缺失和(或)17号染色体非整倍体改变。应用FISH技术检测二者改变对于EGIST生物学行为预测具有指导意义。

Fluorescence in situ hybridization analysis of p16 gene alter in extra-gastrointestinal stromal tumor

Objective To investigate the p16 gene deletion as well as the rate and significance of chromosome 17 aneusomy by fluorescence in-situ hybridization （FISH） in extra-gastrointestinal stromal tumor （EGIST）. Methods Eighteen cases of EGIST with formalin-fixed and paraffin-embedded tumor tissues were tested with pl6/CSP17 probe by FISH for p16 gene status and the rate of chromosome 17 aneusomy. Expression of p16 protein was assessed by immunohistochemistry. Results Amongst the 18 EGIST samples, p16 gene deletion was identified in 11 cases（61.1%）. study showed 13 cases （72.2%） with low or absent p16 immunostaining, p16 gene deletion positively correlated with p16 protein loss （P〈0.05） but not with sex and age of EGIST patients （P〉0.05）. Chromosome 17 aneusomy was detected in 5 of 18 patients （27.8%）. Significant correlation among p16 gene deletion, chromosome 17 aneusomy and clinical pathology was not demonstrated （P〉0.05）. Conclusion EGIST exhibited p16 gene deletion and/ or chromosome 17 aneusomy. Detection with FISH may be useful in predicting prognosis of EGIST.