Department of Emergency Medicine, Changhua Christian Hospital, Changhua, Taiwan.
J Formos Med Assoc. 2010 Jan;109(1):25-31. doi: 10.1016/s0929-6646(10)60018-6.
BACKGROUND/PURPOSE: Human KIT protooncogene is the cellular homolog of v-kit from the Hardy-Zuckerman 4 feline sarcoma virus, and encodes a 145-kDa type III tyrosine kinase growth factor receptor that is often mutated in gastrointestinal stromal tumors (GIST). Standardized mutation analysis is not available in many countries; therefore, we aimed to determine if the presence of KIT mutation in GIST can be predicted by the immunoprofile of the tumor cells.
One hundred and forty-nine GIST were subjected to mutation analysis for KIT and immunohistochemical analysis for the expression of CD117, CD34, alpha-smooth muscle actin (SMA), and S100 protein. Mutation and immunohistochemistry data were correlated.
KIT mutation rates were higher in certain immunoprofile subsets of GIST than in GIST in general. Compared with the overall mutation rate of KIT (70%), all GIST with CD117+ and S100+ had > 80% probability of harboring mutated KIT, and the subset with additional CD34+ and SMA- had a mutation rate of 88%. The overall KIT mutation rate in CD117- GIST was 31%. However, the probability of KIT mutation in CD117- GIST with CD34+SMA+S100-, CD34-SMA-S100+, and CD34+SMA-S100+ was 100%, 100%, and 67%, respectively. Compared with the overall mutation rate (8.7%) of exon 9, GISTs with CD34+SMA+ had > or = 20% probability of harboring an exon 9 mutation, and all GISTs in the small intestine had a probability of 19%.
When mutation analysis is not available, immunoprofiles based on CD117, CD34, SMA, and S100 can be used to predict the presence of KIT mutation, but it is less useful for the prediction of exon 9 mutation in GISTs.
背景/目的：人类 KIT 原癌基因是 Hardy-Zuckerman 4 猫肉瘤病毒 v-kit 的细胞同源物，编码一种 145kDa 的 III 型酪氨酸激酶生长因子受体，该受体在胃肠道间质瘤（GIST）中经常发生突变。在许多国家，没有标准化的突变分析可用；因此，我们旨在确定 GIST 中 KIT 突变的存在是否可以通过肿瘤细胞的免疫表型来预测。
对 149 例 GIST 进行 KIT 突变分析和 CD117、CD34、α-平滑肌肌动蛋白（SMA）和 S100 蛋白的免疫组织化学分析。对突变和免疫组织化学数据进行了相关性分析。
与 GIST 的总体突变率（70%）相比，KIT 突变率在 GIST 的某些免疫表型亚组中更高。与 KIT 的总体突变率（70%）相比，所有 CD117+和 S100+的 GIST 都有>80%的可能性携带突变的 KIT，而另外具有 CD34+和 SMA-的亚组的突变率为 88%。CD117- GIST 的总体 KIT 突变率为 31%。然而，CD117- GIST 中 KIT 突变的概率为 CD34+SMA+S100-、CD34-SMA-S100+和 CD34+SMA-S100+分别为 100%、100%和 67%。与外显子 9 的总体突变率（8.7%）相比，具有 CD34+SMA+的 GIST 有>或=20%的可能性携带外显子 9 突变，所有小肠 GIST 的概率为 19%。
当突变分析不可用时，基于 CD117、CD34、SMA 和 S100 的免疫表型可用于预测 KIT 突变的存在，但对于 GIST 中外显子 9 突变的预测则不太有用。
