title: Expression of DNA cytosine deaminase APOBEC3 proteins, a potential source for producing mutations, in gastric, colorectal and prostate cancers.
abstract: OBJECTIVE
  APOBEC3B is a deaminase that possesses DNA C-to-T editing activity. A recent report showed that APOBEC3B mRNA was overexpressed in breast cancer and that its expression was responsible for the high C-to-T mutation spectrum in breast cancer, suggesting that APOBEC3B could serve as a source for producing mutations. To see whether APOBEC3B is overexpressed in other common cancers at the protein level, we investigated APOBEC3 protein expression in 100 gastric, 103 colorectal and 107 prostate cancer tissues as well as in 10 breast cancers by immunohistochemistry using antibody that could detect APOBEC3B, APOBEC3F and APOBEC3D proteins.
  
  
  RESULTS
  In the cancers, APOBEC3 expression was detected in 100% of breast cancers, 67% of gastric, 84% of colorectal and 67% of prostate cancer. Also, it was expressed in 100% of normal breast, 90% of normal stomach, 82% of normal colon and 93% of normal prostate tissues. In contrast to earlier data that showed an increased APOBEC3B expression in breast cancer cells compared to normal breast cells, APOBEC3 expression in cancers was lower than in normal tissues (gastric and prostate cancer) or was not different from normal tissues (colorectal and breast cancer). There was no significant association of APOBEC3 expression with clinocopathological parameters, including histology, metastasis and stage.
  
  
  CONCLUSIONS
  Our data indicate that APOBEC3 overexpression might not be restricted to specific cancer types. Also, APOBEC3 expression in many normal epithelial cells suggests that there might be a mutation unrelated function of APOBEC3 in the normal cells.
authors.forename: Min
authors.initials: M
authors.lastname: Gwak
authors.forename: Youn Jin
authors.initials: YJ
authors.lastname: Choi
authors.forename: Nam Jin
authors.initials: NJ
authors.lastname: Yoo
authors.forename: SugHyung
authors.initials: S
authors.lastname: Lee
mesh_terms: D000071478:APOBEC Deaminases; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000737:chemistry* / Q000235:genetics; D003564:Cytidine Deaminase; D043525:Cytosine Deaminase / Q000032:analysis* / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011471:Prostatic Neoplasms / Q000737:chemistry* / Q000235:genetics; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000235:genetics; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D043525:Cytosine Deaminase; D000071478:APOBEC Deaminases; C502889:APOBEC3 proteins, human; D003564:Cytidine Deaminase