摘要
目的探讨苯并[a]芘(BaP)诱导的恶性转化细胞中DNA聚合酶β(polβ)表达增加的可能机制。方法采用RT-PCR-单链构象多态性(RT-PCR-SSCP)分析及基因测序检测BaP诱导的恶性转化细胞(polβ-T细胞)中polβ基因外显子序列;基因测序检测polβ基因启动子序列。采用RT-PCR和Western blot检测polβ-T细胞和未经BaP处理的对照细胞(polβ细胞)中蛋白精氨酸甲基转移酶6(PRMT6)mRNA及蛋白质表达水平。结果RT-PCR-SSCP和基因测序未发现polβ-T细胞中polβ基因外显子序列改变,但其启动子区域经基因测序证实5′端上游-10位和-61位分别存在插入突变(插入G)和点突变(C→A)。此外,polβ-T细胞中PRMT6mRNA和蛋白表达量均较对照polβ细胞增高(P<0.05)。结论 BaP诱导的恶性转化细胞中polβ基因的高表达不伴随其外显子序列的突变,但与启动子序列遗传学突变密切相关,PRMT6还可能通过表观遗传学途径导致polβ的高表达。
Objective To explore the mechanism of the hyper-expression of DNA polymerase beta （polβ） in benzo[a]pyrene （BaP） induced malignant transformed cell （polβ-T）. Methods The mutation of polfl gene exon and promoter were examined using reverse transcriptase-polymerase chain reaction-single strand conformation polymorphism （RT-PCR-SSCP） and gene sequencing. The expression of protein-arginine N-methyhransferase 6 （PRMT6） mRNA and protein in polβ-T cell and control cell （polβ cell） were investigated by RT-PCR and Western blot. Results RT-PCR-SSCP and gene sequencing revealed that the hyper-expression of polfl in polβ-T cell was not associated with the mutation of polβ gene exon while insert mutation （G） and point mutation （C→A） were found located in the core region of polβ gene promoter. Furthermore, the expression of PRMT6 mRNA and protein also increased in polβ-T cell compared with control cell （P〈0. 05）. Conclusion The enhancement of expression of polβ in polβ-T cell might be attributed to the mutations locating in polfl gene promoter on transcription level of polfl gene, and PRMT6 might also enhance the expression of polβ in polβ-T cell through relative epigenetic pathways.
出处
《四川大学学报（医学版）》
CAS
CSCD
北大核心
2012年第6期801-806,共6页
Journal of Sichuan University(Medical Sciences)
基金
国家自然科学基金(No.30872079
81172632和81001230)资助
关键词
苯并芘细胞转化
肿瘤蛋白精氨酸甲基转移酶6
DNA聚合酶Β
Benzo[a]pyrene Cell transformation, neoplastic Protein-arginine N-methyhransferase 6 DNA polymerase beta
