title: Regulation of prostate-specific antigen expression by the junctional adhesion molecule A.
abstract: OBJECTIVE
  Prostate-specific antigen (PSA) is a protein specifically expressed in prostate cells. Therefore, the expression levels of PSA in the blood are an important indicator when diagnosing prostate cancer. Defining the mechanism of PSA expression in prostate cells will be helpful for interpreting the expression of this protein during prostate cancer progression. Reports show that a membrane protein, claudin-7 (CLDN-7), is involved in the expression of PSA. However, the mechanism by which CLDN-7 regulates PSA expression is not clear. Here we identify proteins that interact with CLDN-7 and determine whether such proteins can regulate PSA expression in a pattern similar to that of CLDN-7.
  
  
  METHODS
  Our previous studies have demonstrated that in prostate cells, PSA can be regulated by a membrane protein, CLDN-7. It is important to identify the proteins that associate with CLDN-7 in its pathway of regulating PSA expression, because it is very unlikely that CLDN-7 can directly regulate PSA expression in the nucleus. To identify potential proteins that may directly interact with CLDN-7, we studied proteins that can interact with claudins.
  
  
  RESULTS
  We found that CLDN-7 interacts with the junctional adhesion molecule A (JAM-A), which is expressed in the prostate cancer cell line, LNCaP, which expresses PSA, but not the PSA-negative prostate cell line, DU145. JAM-A regulates the expression of the prostate-specific antigen in LNCaP cells in a pattern similar to CLDN-7.
  
  
  CONCLUSIONS
  Our results suggest that JAM-A associates with CLDN-7 and it is a component in the pathway by which CLDN-7 regulates the expression of PSA.
authors.affiliation: University of California-Los Angeles Dental Research Institute and University of California-Los Angeles School of Dentistry, Los Angeles, California 90095-1668 , USA.
authors.forename: Qiuwei
authors.initials: Q
authors.lastname: Wang
authors.forename: Jun-Ying
authors.initials: JY
authors.lastname: Zheng
authors.forename: Jens
authors.initials: J
authors.lastname: Kreth
authors.forename: Xinmin
authors.initials: X
authors.lastname: Yan
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kamata
authors.forename: Richard A
authors.initials: RA
authors.lastname: Campbell
authors.forename: Yiming
authors.initials: Y
authors.lastname: Xie
authors.forename: Robert
authors.initials: R
authors.lastname: Chiu
authors.forename: James R
authors.initials: JR
authors.lastname: Berenson
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Shi
authors.forename: Irvin S Y
authors.initials: IS
authors.lastname: Chen
authors.forename: Shen
authors.initials: S
authors.lastname: Pang
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000378:metabolism; D057167:Claudins; D018450:Disease Progression; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D062726:Junctional Adhesion Molecules; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D017430:Prostate-Specific Antigen / Q000096:biosynthesis* / Q000235:genetics; D011471:Prostatic Neoplasms / Q000097:blood / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013329:Structure-Activity Relationship; D014162:Transfection; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; C473255:CLDN7 protein, human; D015815:Cell Adhesion Molecules; D057167:Claudins; D062726:Junctional Adhesion Molecules; D008565:Membrane Proteins; D012333:RNA, Messenger; D017430:Prostate-Specific Antigen