Zhao Wei, Wu Mei, Yang Mo, Zhang Zun-Zhen
Department of Environmental Health, West China School of Public Health, Sichuan University, Chengdu 610041, China.
Sichuan Da Xue Xue Bao Yi Xue Ban. 2012 Nov;43(6):801-6.
To explore the mechanism of the hyper-expression of DNA polymerase beta (polbeta) in benzo[a]pyrene (BaP) induced malignant transformed cell (polbeta-T).
The mutation of polbeta 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 polbeta-T cell and control cell (polbeta cell) were investigated by RT-PCR and Western blot.
RT-PCR-SSCP and gene sequencing revealed that the hyper-expression of polbeta in polbeta-T cell was not associated with the mutation of polbeta gene exon while insert mutation (G) and point mutation (C-->A) were found located in the core region of polbeta gene promoter. Furthermore, the expression of PRMT6 mRNA and protein also increased in polbeta-T cell compared with control cell (P<0.05).
The enhancement of expression of polbeta in polbeta-T cell might be attributed to the mutations locating in polbeta gene promoter on transcription level of polbeta gene, and PRMT6 might also enhance the expression of polbeta in polbeta-T cell through relative epigenetic pathways.
探讨苯并[a]芘（BaP）诱导的恶性转化细胞（polbeta-T）中DNA聚合酶β（polbeta）高表达的机制。
采用逆转录聚合酶链反应-单链构象多态性（RT-PCR-SSCP）和基因测序检测polbeta基因外显子和启动子的突变情况。通过RT-PCR和蛋白质免疫印迹法检测polbeta-T细胞和对照细胞（polbeta细胞）中蛋白质精氨酸N-甲基转移酶6（PRMT6）mRNA和蛋白质的表达。
RT-PCR-SSCP和基因测序显示，polbeta-T细胞中polbeta的高表达与polbeta基因外显子突变无关，而在polbeta基因启动子核心区域发现插入突变（G）和点突变（C→A）。此外，与对照细胞相比，polbeta-T细胞中PRMT6 mRNA和蛋白质的表达也增加（P<0.05）。
polbeta-T细胞中polbeta表达增强可能归因于polbeta基因启动子上的突变导致polbeta基因转录水平的改变，并且PRMT6也可能通过相关表观遗传途径增强polbeta-T细胞中polbeta的表达。
