A synthetic polyvalent ligand for α5β1 integrin activates components of the urothelial carcinoma cell response to bacillus Calmette-Guérin. J Urol 2013 Mar;189(3):1104-9
Date
09/25/2012Pubmed ID
22999999DOI
10.1016/j.juro.2012.08.218Scopus ID
2-s2.0-84873725495 (requires institutional sign-in at Scopus site) 3 CitationsAbstract
PURPOSE: Prior study has shown that bacillus Calmette-Guérin binds to and cross-links α5β1 integrins present on the surface of urothelial carcinoma cells. Antibody mediated cross-linking of α5β1 integrins can reproduce signal transduction, gene transactivation and phenotypic changes, similar to those observed in response to bacillus Calmette-Guérin. We evaluated the effect of a synthetic polyvalent ligand for α5β1 on these elements of the tumor response to bacillus Calmette-Guérin.
MATERIALS AND METHODS: The consensus α5β1 integrin binding tripeptide RGD was linked to a MAP8 backbone to result in an octavalent construct targeting α5β1 integrin. RGD-MAP8 was used to determine its effect on signaling pathway activation (nuclear factor-κB, NRF2 and CEBP), gene expression (p21, interleukin-6 and 8, CXCL1, CXCL2 and CCL20) and cytotoxicity (trypan blue exclusion and HMGB1 release) in human urothelial carcinoma cells. Results were compared to those of treatment with bacillus Calmette-Guérin or the missense peptide GRD-MAP8.
RESULTS: The RDG-MAP8 construct significantly increased nuclear factor-κB signaling and p21 expression relative to controls. Compared to bacillus Calmette-Guérin treatment, only p21 expression was comparable for cells treated with RGD-MAP8, averaging 70% of bacillus Calmette-Guérin induced expression. RGD-MAP8 failed to have a significant effect on CEBP or NRF2 activation, gene expression or cell viability.
CONCLUSIONS: Intracellular signaling, gene transactivation and phenotypic changes in response to RGD-MAP8 were qualitatively and quantitatively different than those observed in response to bacillus Calmette-Guérin. Results suggest that while α5β1 integrin cross-linking contributes to the bacillus Calmette-Guérin response, it alone is insufficient to duplicate the full spectrum of bacillus Calmette-Guérin induced changes in urothelial carcinoma cell biology.
Author List
Chen F, Zhang G, Cao Y, Wakim B, See WAMESH terms used to index this publication - Major topics in bold
Adjuvants, ImmunologicBCG Vaccine
Carcinoma, Transitional Cell
Cell Line, Tumor
DNA, Neoplasm
Enzyme-Linked Immunosorbent Assay
Flow Cytometry
Gene Expression Regulation, Neoplastic
Humans
Integrin alpha5beta1
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction
Urinary Bladder Neoplasms