title: hepaCAM and p-mTOR closely correlate in bladder transitional cell carcinoma and hepaCAM expression inhibits proliferation via an AMPK/mTOR dependent pathway in human bladder cancer cells.
abstract: OBJECTIVE
  We explored the correlation between hepaCAM and activated p-mTOR in bladder transitional cell carcinoma. We also determined whether the antiproliferation effect of hepaCAM is associated with the AMPK/mTOR pathway.
  
  
  METHODS
  We performed quantitative reverse transcriptase-polymerase chain reaction to determine hepaCAM mRNA expression as well as Western blot to measure hepaCAM and p-mTOR protein levels in 25 men and 5 women. Disease was Ta-T1 in 7 patients, T2-T4 in 23, grade 1 in 13, grade 2 in 9, grade 3 in 8, primary in 13 and recurrent in 17. The WST-8 assay was used to study the effect of hepaCAM on cellular proliferation. p-AMPK, p-mTOR, total AMPK, total mTOR, c-Myc and cyclin D1 were also determined by Western blot.
  
  
  RESULTS
  hepaCAM mRNA and protein levels were significantly decreased, while p-mTOR protein was remarkably increased in bladder transitional cell carcinoma compared to adjacent tissues (each p<0.01). Spearman correlation analysis revealed that the hepaCAM decrease was associated with an increase in p-mTOR (r=-0.533, p=0.002). Also, hepaCAM inhibited the proliferation of human bladder transitional cell carcinoma cells. hepaCAM over expression activated AMPK and down-regulated p-mTOR, and its targets c-Myc and cyclin D1. Treatment with the AMPK inhibitor compound C prevented the antiproliferation effect of hepaCAM. Compound C completely blocked hepaCAM induced activation of AMPK and down-regulation of p-mTOR and its targets c-Myc and cyclin D1.
  
  
  CONCLUSIONS
  Results suggest an important correlation between hepaCAM and p-mTOR. hepaCAM can inhibit bladder cancer cell proliferation through an AMPK/mTOR dependent pathway.
authors.affiliation: Key Laboratory of Diagnostics Medicine designated by the Ministry of Education, Chongqing Medical University and Department of Urology, First Affiliated Hospital of Chongqing Medical University (XW), Chongqing, People's Republic of China.
authors.forename: Qiuju
authors.initials: Q
authors.lastname: Wang
authors.forename: Chunli
authors.initials: C
authors.lastname: Luo
authors.forename: Xiaohou
authors.initials: X
authors.lastname: Wu
authors.forename: Hongfei
authors.initials: H
authors.lastname: Du
authors.forename: Xuedong
authors.initials: X
authors.lastname: Song
authors.forename: Yanru
authors.initials: Y
authors.lastname: Fan
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000502:physiology*; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D018797:Cell Cycle Proteins; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000502:physiology*; D058570:TOR Serine-Threonine Kinases / Q000502:physiology*; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
chemical_list: D018797:Cell Cycle Proteins; C487620:HEPACAM protein, human; D011506:Proteins; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases
keywords: AMP; AMP-activated protein kinase; AMPK; GFP; HEPACAM protein; PCR; RT-PCR; TCCB; adenosine monophosphate; bladder transitional cell carcinoma; carcinoma; cell proliferation; green fluorescent protein; hepaCAM; hepatocyte cell adhesion molecule; human; mTOR; mTOR protein; mammalian target of rapamycin; p-AMPK; p-mTOR; phosphorylation of AMPK; phosphorylation of mTOR; polymerase chain reaction; qRT-PCR; quantitative RT-PCR; reverse transcriptase-PCR; transitional cell; urinary bladder