title: α-Methylacyl-CoA racemase spliced variants and their expression in normal and malignant prostate tissues.
abstract: OBJECTIVE
  To evaluate the possibility of using α-methylacyl-CoA racemase (AMACR) variants to improve the specificity of prostate cancer (CaP) detection. AMACR has been used as a diagnostic biomarker for CaP and is now a standard biomarker for needle biopsy specimens with ambiguous lesions.
  
  
  METHODS
  We used in silico analysis and molecular cloning to discover new AMACR variants and quantitative reverse transcription-polymerase chain reaction (RT-PCR) to measure the transcript levels of AMACR and its variants in 4 prostate cell lines and in 23 pairs of CaP and adjacent normal tissue.
  
  
  RESULTS
  We found 4 novel variants, IAs, IBL, IBLd, and IBLi. Transcript levels of most AMACR variants were significantly upregulated in CaP compared with its adjacent normal counterparts. A variants, the functional variants based on bioinformatic analysis, showed levels of transcript expression in CaP in this order: IA≫IAd=IIA≫IIAs>IAs. In contrast, the expression of the B variants, which appear to be nonfunctional due to the absence of exon 3, was lower than that of the A variants. IB was the most abundant form of B variant; and expression of IIB was negligible. More important, the difference between levels of variant IA, IAd, IIA, IIAs, IB, and IBLi in CaP and normal tissue was significantly higher than the difference in levels of total AMACR.
  
  
  CONCLUSIONS
  Our data suggest that AMACR variants have better power than total AMACR in discriminating between CaP and adjacent normal tissue. These findings may be useful for the development of future diagnostic assays.
authors.affiliation: Department of Environmental Health, University of Cincinnati Medical Center, Cincinnati, Ohio 45267, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Ouyang
authors.forename: Yuet-Kin
authors.initials: YK
authors.lastname: Leung
authors.forename: Vinson
authors.initials: V
authors.lastname: Wang
authors.forename: Ethan
authors.initials: E
authors.lastname: Chung
authors.forename: Linda
authors.initials: L
authors.lastname: Levin
authors.forename: Bruce
authors.initials: B
authors.lastname: Bracken
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.forename: Shuk-Mei
authors.initials: SM
authors.lastname: Ho
mesh_terms: D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D011467:Prostate / Q000737:chemistry / Q000201:enzymology*; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics*; D020033:Protein Isoforms; D019998:Racemases and Epimerases / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D020033:Protein Isoforms; D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase