儿童神经母细胞瘤中ALK基因突变的研究

ALK gene mutations in childhood neuroblastoma

摘要:

目的：探讨中国儿童神经母细胞瘤（NB）中间变性淋巴瘤激酶（ALK）基因的突变情况。方法：从22例石蜡包埋的NB肿瘤组织中提取基因组DNA，通过PCR-DNA直接测序技术分析儿童NB肿瘤组织中ALK突变热点区域第20~26号外显子的突变情况。结果：22 例儿童NB中，有10例（46%）在ALK第21号外显子上存在已知同义突变C3375A（Gly1125Gly），等位基因频率为27%；1例（5%）在ALK第23号外显子上发现一个新的同义突变C3586T（Leu1196Leu）。ALK突变C3375A的发生频率在NB患儿的年龄、性别、肿瘤分化程度和是否转移方面差异无统计学意义（P＞0.05）。在其他5个ALK外显子中未发现突变。结论：采用PCR-DNA测序技术发现了ALK一个新的同义突变C3586T，并证实了儿童ALK存在已知突变C3375A，其发生率不受NB患儿临床特征的影响。

Abstract:

OBJECTIVE: To investigate mutations of anaplastic lymphoma kinase (ALK) in Chinese children with neuroblastoma (NB). METHODS: Genomic DNA was extracted from 22 cases of paraffin-embedding NB tumor tissues. Gene mutations in the exons 20-26 which were mutational hotspots of ALK were analyzed by PCR-DNA direct sequencing. RESULTS: A novel synonymous mutation C3586T (Leu1196Leu) and a known synonymous mutation C3375A (Gly1125Gly) were found and located at exon 23 and exon 21 of ALK respectively. There were 10 cases (46%) of known synonymous mutation C3375A in 22 cases of NB. The C3375A allelic frequency was 27%. No statistically significant correlation was found between mutation C3375A and clinical parameters of NB such as age, sex, metastasis and tumor differentiation. Mutation was not found in the other 5 exons. CONCLUSIONS: A novel ALK gene synonymous mutation C3586T was identified using PCR-DNA sequencing. A known mutation C3375A in ALK was successfully identified in children, and its incidence is not influenced by the clinical features of childhood NB.