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Madrid, Spain

Thomas S.,University of Virginia | Overdevest J.B.,University of Virginia | Nitz M.D.,University of Virginia | Williams P.D.,University of Virginia | And 6 more authors.
Cancer Research | Year: 2011

In bladder cancer, increased caveolin-1 (Cav-1) expression and decreased Src expression and kinase activity correlate with tumor aggressiveness. Here, we investigate the clinical and functional significance, if any, of this reciprocal expression in bladder cancer metastasis. We evaluated the ability of tumor Cav-1 and Src RNA and protein expression to predict outcome following cystectomy in 257 patients enrolled in two independent clinical studies. In both, high Cav-1 and low Src levels were associated with metastasis development. We overexpressed or depleted Cav-1 and Src protein levels in UMUC-3 and RT4 human bladder cancer cells and evaluated the effect of this on actin stress fibers, migration using Transwells, and lung metastasis following tail vein inoculation. Cav-1 depletion or expression of active Src in metastatic UMUC-3 cells decreases actin stress fibers, cell migration, and metastasis, while Cav-1 overexpression or Src depletion increased the migration of nonmetastatic RT4 cells. Biochemical studies indicated that Cav-1 mediates these effects via its phosphorylated form (pY14), whereas Src effects are mediated through phosphorylation of p190RhoGAP and these pathways converge to reduce activity of RhoA, RhoC, and Rho effector ROCK1. Treatment with a ROCK inhibitor reduced UMUC-3 lung metastasis in vivo, phenocopying the effect of Cav-1 depletion or expression of active Src. Src suppresses whereas Cav-1 promotes metastasis of bladder cancer through a pharmacologically tractable common downstream signaling pathway. Clinical evaluation of personalized therapy to suppress metastasis development based on Cav-1 and Src profiles seems warranted. ©2010 AACR. Source

Sanchez-Carbayo M.,Tumor Markers Group
Tumor Biology | Year: 2012

A compelling body of evidences sustains the importance of epigenetic mechanisms in the development and progression of cancer. Assessing the epigenetic component of bladder tumors is strongly improving our understanding of their biology and clinical behavior. In terms of DNA methylation, cancer cells show genome-wide hypomethylation and site-specific CpG island promoter hypermethylation. In the context of other epigenetic alterations, this review will focus on the hypermethylation of CpG islands in promoter regions, as the most widely described epigenetic modification in bladder cancer. CpG islands hypermethylation is believed to be critical in the transcriptional silencing and regulation of tumor suppressor and crucial cancer genes involved in the major molecular pathways controlling bladder cancer development and progression. In particular, several biological pathways of frequently methylated genes include cell cycle, DNA repair, apoptosis, and invasion, among others. Furthermore, translational aspects of bladder cancer methylomes described to date will be discussed towards their potential application as bladder cancer biomarkers. Several tissue methylation signatures and individual candidates have been evidenced, that could potentially stratify tumors histopathologically, and discriminate patients in terms of their clinical outcome. Tumor methylation profiles could also be detected in urinary specimens showing a promising role as non-invasive markers for cancer diagnosis towards an early detection and potentially for the surveillance of bladder cancer patients in a near future. However, the epigenomic exploration of bladder cancer has only just begun. Genome-scale DNA methylation profiling studies will further highlight the relevance of the epigenetic component to gain knowledge of bladder cancer biology and identify those profiles and candidates better correlating with clinical behavior. © International Society of Oncology and BioMarkers (ISOBM) 2011. Source

In the context of other proteomic technologies, targeted antibody arrays are strongly contributing for protein profiling and functional proteomics analyses in serum specimens. Protein-protein interactions, post-translational modifications, and interaction between protein and DNA or RNA can all shift the activity of a protein from what would have been predicted by its level of transcription. Functional proteomics studies the interaction of proteins within their cellular environment to determine how a given protein accomplishes its specific cellular task. Accordingly, the promise of protein profiling and functional proteomics is that by chronicling the function of aberrant or over-expressed proteins, it will be possible to characterize the mechanism of the disease-sustaining proteins. The further understanding of the disease networks will eventually lead to targeted cancer therapy and specific biomarkers for diagnosis, prognosis or therapeutic response prediction based on disease specific proteins. This review describes how such strategies reported to date in serum specimens may assist in characterizing tumor biology, and for the diagnosis, surveillance, prognosis, and potentially for predictive and therapeutic purposes for patients affected with solid and hematological neoplasias. © 2010 International Society of Oncology and BioMarkers (ISOBM). Source

Karni-Schmidt O.,Columbia University | Castillo-Martin M.,Columbia University | HuaiShen T.,Columbia University | Gladoun N.,Columbia University | And 6 more authors.
American Journal of Pathology | Year: 2011

The TP63 gene, a member of the TP53 tumor suppressor gene family, can be expressed as at least six isoforms due to alternative promoter use and alternative splicing. The lack of p63 isoform-specific antibodies has limited the analysis of the biological significance of p63. We report a novel set of well-defined antibodies to examine p63 isoforms in mouse and human urothelium during embryogenesis and tumor progression, respectively. We provide evidence that basal and intermediate urothelial cells express p63 isoforms, with the TAp63 variant the first to be detected during development, whereas umbrella cells are characterized by a p63-negative phenotype. Notably, we report that p63-null mice develop a bladder with an abnormal urothelium, constituted by a single layer of cells that express uroplakin II and low molecular weight cytokeratins, consistent with an umbrella cell phenotype. Finally, analysis of 202 human bladder carcinomas revealed a new categorization of invasive tumors into basal-like (positive for ΔNp63 and high molecular weight cytokeratins and negative for low molecular weight cytokeratins) versus luminal-like (negative for ΔNp63 and high molecular weight cytokeratins and positive for low molecular weight cytokeratins) phenotypes, with ΔNp63 expression associated with an aggressive clinical course and poor prognosis. This study highlights the relevance of p63 isoforms in both urothelial development and bladder carcinoma progression, with ΔNp63 acting as an oncogene in certain invasive bladder tumors. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved. Source

Sanchez-Carbayo M.,Tumor Markers Group
Methods in Molecular Biology | Year: 2011

The cancer biomarkers field is being enriched by molecular profiling obtained by high-throughput approaches. Targeted antibody arrays are strongly contributing to the identification of protein cancer -biomarker candidates and functional proteomic analyses. Due to their versatility, novel technological and experimental design implementations are broadening the applications of antibody arrays. However, the cancer biomarker candidates delivered to date using this technology are still in their early developmental phase, requiring validation with high number of specimens focusing on specific clinical endpoints. Innovative strategies multiplexing protein measurements of protein extracts of cultured cells, tissue and body fluids using antibody arrays combined with appropriate validation approaches are enabling the -discovery of cancer-associated biomarkers. This review describes these strategies and cancer biomarker candidates reported to date that may assist in the diagnosis, surveillance, prognosis, and potentially for predictive and therapeutic purposes for patients affected with solid and hematological neoplasias. © Springer Science+Business Media, LLC 2011. Source

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