原癌基因c-kit在胃肠道间质瘤中的表达及其临床意义

目的　通过检测胃肠道间质瘤 (gastrointestinalstromaltumor ,GIST)中原癌基因c kit蛋白表达 ,探讨c kit在GIST中的诊断及预后意义。　方法　应用免疫组织化学技术EnVision微波二步法检测了 12 2例GIST(良性 5 4例 ,潜在恶性 13例 ,恶性 5 5例 )中的c kit蛋白的表达情况 ,并与平滑肌瘤、神经鞘瘤进行对照研究。不着色或仅细胞核着色者为阴性 ,凡肿瘤细胞浆内或 (和 )细胞膜上有棕黄色颗粒者为阳性。　结果　GIST中c kit的阳性表达率为 97% (118/ 12 2 ) ,阳性信号定位准确。其中 ,良性组、潜在恶性组及恶性组c kit的阳性率分别为 98% (5 3/ 5 4 )、93% (12 / 13)、96 % (5 3/ 5 5 )。与良性组相比 ,转移或复发病例c kit蛋白着色较淡 ,但 3组之间c kit的表达水平差异无显著意义 (χ2 =1 16 7,P >0 0 5 )。平滑肌瘤和神经鞘瘤c kit阴性表达。　结论　c kit作为一种胃肠道间质瘤特异而敏感的标记物 ,对GIST的诊断及鉴别诊断有重要的意义 ,但其不能作为GIST分化程度的指标

Expression and clinical significance of c-kit oncogene in gastrointestinal stromal tumors

OBJECTIVE: To investigate the clinicopathological and prognostic significance of the c-kit protein in gastrointestinal stromal tumor (GIST). METHODS: Paraffin embedded materials from 53 benign GISTs, 13 potentially malignant and 55 malignant cases were analysed for c-kit expression by immunohistochemical method, while using leiomyomas and schwannomas as controls. Positive signals were shown in cytoplasma and cell membrane. RESULTS: Of 122 GISTs, 118 (97%) were positive for c-kit. Localization of positive signals was accurate. The rate of c-kit protein in benign, potentially malignant and malignant cases was 98% (53/54), 93% (12/13), 96% (53/55) respectively. Compared with benign GIST, the positivity of c-kit in metastasis or recurrent cases decreased, but c-kit protein expression rate was not significantly different between the three patterns of GIST (chi(2) = 1.167, P > 0.05). Leiomyomas and schwannomas were typically c-kit negative. CONCLUSION: As a sensitive and specific marker of GIST, c-kit seems to be a useful antibody in the diagnosis and differential diagnosis of GIST, but it may not be used as a prognostic index.