胃肠道间质瘤C-kit及PDGFRA基因突变检测及分析

Assay of C-kit and PDGFRA gene mutations in gastrointestinal stromal tumors

目的检测胃肠道间质瘤(gastrointestinal stromal tumors,GIST)患者中酪氨酸激酶受体基因C-kit及血小板源性生长因子受体A(platelet derived growth factor receptor A,PDGFRA)基因突变情况,探讨其与GIST发病的相关性。方法从武汉大学人民医院及武汉大学中南医院收集的102例GIST患者石蜡肿瘤切片样本中提取DNA,采用PCR技术扩增特异性目的片段,并直接进行序列测定,分析样本中C-kit及PDGFRA基因突变情况。结果在102份石蜡肿瘤切片样本中共检出C-kit基因突变76例,其中大多数突变发生于第11号外显子上,共65例,包括缺失突变43例,占66.15%(43/65),点突变12例,占18.46%(12/65),插入突变4例,占6.15%(4/65),点突变伴随缺失突变6例,占9.23%(6/65);7例样本存在第9号外显子突变;3例样本存在第13号外显子突变;2例样本检测出第17号外显子突变。共检出PDGFRA基因突变4例,其中第12号外显子突变的有3例,第18号外显子突变仅检出1例。结论大多数GIST患者中存在C-kit基因的突变,且主要突变位置在第11号外显子;PDGFRA基因突变存在于C-kit未突变患者中。

Objective To analyze the mutation status of C-kit and platelet derived growth factor receptor A（PDGFRA）genes in gastrointestinal stromal tumor（GIST）, and investigate the relationship between the mutation and the pathogenesis of GIST. Methods Genomic DNA was extracted from the paraffin sections of tumor tissues of 102 patients with GIST from Renmin Hosptital of Wuhan University and Zhongnan Hospital of Wuhan University, based on which the specific target gene fragments were amplified by PCR, identified by sequencing, and analyzed for mutations of C-kit and PDGFRA genes. Results C-kit mutations were detected in 76 of the 102 samples, of which 65 occurred in exon 11, including deletion（43 cases, 66. 15%）, point mutation（12 cases, 18. 46%）, insertion（4 cases, 6. 15%）, and point mutation accompanied by deletion（6 cases, 9. 23%）. The mutations in exons 9, 13 and 17 were detected in 7, 3 and 2 cases respectively. PDGFRA mutations were detected in 4 cases, of which 4 in exon 12 and only one in exon 18. Conclusion C-kit mutations are common in the majority of GIST patients, most of which are located in exon 11. However, PDGFRA mutation exists in the patients without C-kit mutation.