Protein expression profiling identifies cyclophilin A as a molecular target in Fhit-mediated tumor suppression.

Abstract

Loss of fragile histidine triad (Fhit) expression is often associated with human malignancies, and Fhit functions as a tumor suppressor in controlling cell growth and apoptosis, although specific signal pathways are still undefined. We have used a proteomic approach to define proteins in the Fhit-mediated tumor suppression pathway. Because substitution of Tyr(114) (Y114) with phenylalanine (Y114F) diminishes Fhit functions, we did protein expression profiling to identify proteins differentially expressed in Fhit-negative H1299 lung cancer cells infected with wild-type (Ad-FHIT-wt) and Y114 mutant FHIT-expressing (Ad-FHIT-Y114F) adenoviruses. Among 12 distinct proteins that exhibited 4-fold differences in expression on comparison of the two infected cell lysates, cyclophilin A, the intracellular reporter of the immunosuppressive drug cyclosporine A, showed a remarkably decreased protein level in cells infected with Ad-FHIT-wt versus Ad-FHIT-Y114F. Conversely, loss of Fhit expression resulted in increased cyclophilin A expression in mouse tissues and cell lines. Restoration of Fhit expression led to down-regulated cyclophilin A protein expression and subsequently prevented cyclophilin A-induced up-regulation of cyclin D1, Cdk4, and resultant cell cycle progression (G(1)-S transition), which was independent of Ca(2+)/calmodulin-dependent kinase inhibitor, KN-93. Interestingly, Fhit down-modulation of phosphatase activity of calcineurin, which controls cyclin D1/Cdk4 activation, was reversed by cyclophilin A treatment in a concentration-dependent manner, a reversal that was inhibited by additional cyclosporine A treatment. Thus, cyclophilin A is a downstream target in Fhit-mediated cessation of cell cycle progression at late G(1) phase. Elucidation of the protein effectors of Fhit signaling may lead to identification of targets for lung cancer therapy.

• Authors: Shuho Semba, Kay Huebner
• Journal: Molecular cancer research : MCR (Mol Cancer Res) Vol. 4 Issue 8 Pg. 529-38 (Aug 2006) ISSN: 1541-7786 [Print] United States
• PMID: 16885564 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Retracted Publication)

Chemical References

• Neoplasm Proteins
• fragile histidine triad protein
• Calcineurin
• Acid Anhydride Hydrolases
• Cyclophilin A

Topics

• Acid Anhydride Hydrolases (deficiency, genetics, physiology)
• Calcineurin (metabolism)
• Cell Cycle
• Cyclophilin A (physiology)
• G1 Phase (genetics)
• Genes, Tumor Suppressor (physiology)
• Humans
• Models, Biological
• Neoplasm Proteins (deficiency, genetics, physiology)
• Point Mutation
• Protein Array Analysis (methods)
• S Phase (genetics)
• Transduction, Genetic
• Transgenes
• Tumor Cells, Cultured