摘要
目的:研究人类胚胎肌肉源性自发恶性转化细胞系抑癌基因的改变.方法:运用免疫组化、PCR,PCR产物直接测序研究该类细胞系抑癌基因p16,p15,MTAP(甲硫氨酸磷酸化酶)和p53基因及蛋白的改变.结果:在染色体9p21处存在纯合性片段缺失,包括p16,p15及MTAP;对p53基因突变率高发的外显子7,8及内含子7测序发现存在范围较大的突变,外显子突变率高达13%,皆为点突变,而内含子变异更甚,包括小片段缺失、插入、移位及点突变,其几与正常p53序列无明显相似性,在测序的6个细胞系中(含5个不同遗传背景)突变序列具有高度一致性.结论:多种抑癌基因的变异在正常胚胎肌肉细胞自发恶性转化进程中具有重要的作用.
AIM： To study the tumor suppressor gene alterations of spontaneous malignant transformation cells from human embryonic muscle in vitro. METHODS： We used immunohistochemistry, PCR and DNA sequencing to assay several tumor suppressor genes （p16, p15, MTAP, p53） of this new type of cell lines. RESULTS： We found out the homozygous deletions within chromosomal bands 9p21, including MTAP（ methylthioadenosine phosphorylase）, p16 and p15 in the cell lines. The DNA-sequencing results showed that the exon 7, exon 8 and intron 7 of p53 gene presented the wide range of mutations in all of the cell lines. The mutation rate of exon reached as highly as 13% and all of them were point mutations. The intron 7 changed more strongly, including piece deletion, insertion, frameshift and point mutation. The results showed hardly any no similarity compared to the normal p53 sequence, and was totally different from other p53 mutation data published. More interestingly, the mutation sequences were nearly identical in our 6 cell lines （ including 5 different genetic backgrounds）, which suggested that there might exist a common mutation mechanism and strong selective advantage in our mutated cell lines. CONCLUSION： The inactivation of tumor suppressor gene, includingpl6, p15, may play an important role in the malignant transformation of embryonic muscle cells in vitro.
出处
《第四军医大学学报》
CAS
北大核心
2008年第15期1368-1372,共5页
Journal of the Fourth Military Medical University
基金
国家自然科学基金面上项目(30672359)
