title: Expression of methionine adenosyltransferase 2A in renal cell carcinomas and potential mechanism for kidney carcinogenesis.
abstract: BACKGROUND
  Methionine adenosyltransferase 2A (MAT2A) is an enzyme that catalyzes the formation of S-adenosylmethionine (SAMe) by joining methionine and ATP. SAMe is a methyl donor for transmethylation and has an important role for DNA and/or protein methylation. MAT2A is expressed widely in many tissues especially in kidney. Several studies have demonstrated that there are abnormal expressions of MAT2A in several kinds of cancers such as liver and colon cancers. But the relationship of MAT2A between renal cell carcinomas (RCC) is less understood.
  
  
  METHODS
  The mRNA expression level of the MAT2A gene was determined in 24 RCC patients and 4 RCC cell lines, using real-time quantitative-polymerase chain reaction (RT-PCR). The MAT2A protein content was measured by western blotting and immunohistochemical analysis in 55 RCC patients. The mRNA levels of heme oxygenase-1 (HO-1) and cyclooxygenase-2 (COX-2) were also analysized in patients using RT-PCR. The correlations between the MAT2A and HO-1 as well as COX-2 were analyzed with nonparametric Spearman method.
  
  
  RESULTS
  MAT2A transcript was significantly downregulated in cancer tissues compared to normal tissues (P < 0.05). Immunohistochemical analysis and western blotting indicated that level of MAT2A protein was decreased in cancer tissues. The statistical analysis reveals a negative correlation between MAT2A and HO-1 expression in RCC patients and cell lines (P < 0.01).
  
  
  CONCLUSIONS
  This study demonstrated that MAT2A was lower expression in cancer tissues, suggesting that it may be involved in the development of RCC. MAT2A is a transcriptional corepressor for HO-1 expression by supplying SAM for methyltransferases, which may be one of potential mechanism of MAT2A as tumor suppressor in kidney carcinogenesis.
authors.forename: Xuliang
authors.initials: X
authors.lastname: Wang
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Guo
authors.forename: Wenshui
authors.initials: W
authors.lastname: Yu
authors.forename: Cailing
authors.initials: C
authors.lastname: Li
authors.forename: Yaoting
authors.initials: Y
authors.lastname: Gui
authors.affiliation: Shenzhen Key Laboratory of Genitourinary Tumor, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen 518035, Guangdong, China. caizhiming2000@163.com.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Cai
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D057809:HEK293 Cells; D051547:Heme Oxygenase-1 / Q000235:genetics; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008716:Methionine Adenosyltransferase / Q000235:genetics* / Q000378:metabolism*; D008875:Middle Aged; D012436:S-Adenosylmethionine / Q000378:metabolism
chemical_list: D012436:S-Adenosylmethionine; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; C527161:MAT2A protein, human; D008716:Methionine Adenosyltransferase