title: Involvement of DNA polymerase β overexpression in the malignant transformation induced by benzo[a]pyrene.
abstract: OBJECTIVE
  To explore the relationship between DNA polymerase β (pol β) overexpression and benzo[a]pyrene (BaP) carcinogenesis.
  
  
  METHODS
  Firstly, mouse embryonic fibroblasts that express wild-type level of DNA polymerase β (pol β cell) and high level of pol β (pol β oe cell) were treated by various concentrations of BaP to determine genetic instability induced by BaP under differential expression levels of pol β. Secondly, malignant transformation of pol β cells by low concentration of BaP (20 μM) was determined by soft agar colony formation assay and transformation focus assay. Thirdly, the mRNA and protein levels of BaP-transformed pol β cells (named pol β-T cells) was measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot, and the genetic instability of these cells were examined by HPRT gene mutation assay and random amplified polymorphic DNA (RAPD) assay.
  
  
  RESULTS
  Pol β cells were successfully transformed into malignant pol β-T cells by an exposure to low concentration of BaP for 6 months. Pol β-T cells exhibited increased levels of pol β gene expression, HPRT gene mutation frequency and polymorphisms of RAPD products that were comparable to those of pol β oe cells.
  
  
  CONCLUSIONS
  Pol β overexpression and its-associated genetic instability may play a key role in BaP carcinogenesis.
authors: Department of Environmental Health, West China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors: Wei
authors: W
authors: Zhao
authors: Mei
authors: M
authors: Wu
authors: Yanhao
authors: Y
authors: Lai
authors: Wenwen
authors: W
authors: Deng
authors: Yuan
authors: Y
authors: Liu
authors: Zunzhen
authors: Z
authors: Zhang
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D019951:DNA Polymerase beta / Q000096:biosynthesis* / Q000235:genetics*; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology*; D015971:Gene Expression Regulation, Enzymologic; D051379:Mice; D011897:Random Allocation
chemical_list: D001564:Benzo(a)pyrene; D019951:DNA Polymerase beta
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