Roger Chammas

Prof. Dr. Roger Chammas

Center for Translational Research in Oncology (LIM24), Department of Radiology and Oncology, Faculdade de Medicina da Universidade de São Paulo, São Paulo 01246-903, Brazil
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Research Focus & Metrics

Academic Career Length

38Years (1989-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2009 in Cancer Letters
Verified
Journal Article
Closed access
LLLuize G. Lima
Luize G. Lima
Roger ChammasRoger Chammas
Roger Chammas
Robson MonteiroRobson Monteiro
Robson Monteiro
MMMaria Elisabete C. Moreira
Maria Elisabete C. Moreira
MBMarcello A. Barcinski
Marcello A. Barcinski

15 February 2022 in Frontiers in Immunology
Verified
Journal Article
Open access
RSRenata de Freitas Saito
Renata de Freitas Saito
LALuciana Nogueira de Sousa Andrade
Luciana Nogueira de Sousa Andrade
SBSilvina Odete Bustos
Silvina Odete Bustos
Roger ChammasRoger Chammas
Roger Chammas
To become resistant, cancer cells need to activate and maintain molecular defense mechanisms that depend on an energy trade-off between resistance and essential functions. Metabolic reprogramming has been shown to fuel cell growth and contribute to cancer drug resistance. Recently, changes in lipid metabolism have emerged as an important driver of resistance to anticancer agents. In this review, we highlight the role of choline metabolism with a focus on the phosphatidylcholine cycle in the regulation of resistance to therapy. We analyze the contribution of phosphatidylcholine and its metabolites to intracellular processes of cancer cells, both as the major cell membrane constituents and source of energy. We further extended our discussion about the role of phosphatidylcholine-derived lipid mediators in cellular communication between cancer and immune cells within the tumor microenvironment, as well as their pivotal role in the immune regulation of therapeutic failure. Changes in phosphatidylcholine metabolism are part of an adaptive program activated in response to stress conditions that contribute to cancer therapy resistance and open therapeutic opportunities for treating drug-resistant cancers.

27 February 2014 in Expert Review of Molecular Diagnostics
Verified
Journal Article
Closed access
SJShidong Jia
Shidong Jia
DZDavide Zocco
Davide Zocco
MSMichael L Samuels
Michael L Samuels
MCMichael F Chou
Michael F Chou
Roger ChammasRoger Chammas
Roger Chammas
WKWinston Patrick Kuo
Winston Patrick Kuo
Extracellular vesicles (EVs), including exosomes and microvesicles, have been shown to carry a variety of biomacromolecules including mRNA, microRNA and other non-coding RNAs. Within the past 5 years, EVs have emerged as a promising minimally invasive novel source of material for molecular diagnostics. Although EVs can be easily identified and collected from biological fluids, further research and proper validation is needed in order for them to be useful in the clinical setting. In addition, innovative and more efficient means of nucleic acid profiling are needed to facilitate investigations into the cellular and molecular mechanisms of EV function and to establish their potential as useful clinical biomarkers and therapeutic tools. In this article, we provide an overview of recent technological improvements in both upstream EV isolation and downstream analytical technologies, including digital PCR and next generation sequencing, highlighting future prospects for EV-based molecular diagnostics.

1 April 2014 in Cancer Letters
Verified
Journal Article
Open access
PCPatrícia L.N. da Costa
Patrícia L.N. da Costa
PSPierre Sirois
Pierre Sirois
ITIan F. Tannock
Ian F. Tannock
Roger ChammasRoger Chammas
Roger Chammas
Kinins are generated within inflammatory tissue microenvironments, where they exert diverse functions, including cell proliferation, leukocyte activation, cell migration, endothelial cell activation and nociception. These pleiotropic functions depend on signaling through two cross talking receptors, the constitutively expressed kinin receptor 2 (B2R) and the inducible kinin receptor 1 (B1R). We have reviewed evidence, which supports the concept that kinin receptors, especially kinin receptor 1, are promising targets for cancer therapy, since (1) many tumor cells express aberrantly high levels of these receptors; (2) some cancers produce kinins and use them as autocrine factors to stimulate their growth; (3) activation of kinin receptors leads to activation of macrophages, dendritic cells and other cells from the tumor microenvironment; (4) kinins have pro-angiogenic properties; (5) kinin receptors have been implicated in cancer migration, invasion and metastasis; and (6) selective antagonists for either B1R or B2R have shown anti-proliferative, anti-inflammatory, anti-angiogenic and anti-migratory properties. The multiple cross talks between kinin receptors and renin-angiotensin system (RAS) as well as its implications for targeting KKS or RAS for the treatment of malignancies are also discussed. It is expected that B1R antagonists would interfere less with housekeeping functions and therefore would be attractive compounds to treat selected types of cancer. Reliable clinical studies are needed to establish the translatability of these data to human settings and the usefulness of kinin receptor antagonists.

1 June 2006 in The American Journal of Pathology
Verified
Journal Article
Closed access
EBEmerson Soares Bernardes
Emerson Soares Bernardes
NSNeide M. Silva
Neide M. Silva
LRLuciana Pereira Ruas
Luciana Pereira Ruas
JMJose Roberto Mineo
Jose Roberto Mineo
ALAdriano Motta Loyola
Adriano Motta Loyola
MRMaria Cristina Roque-Barreira
Maria Cristina Roque-Barreira

1 January 2014 in PLOS ONE
Verified
Journal Article
Open access
PDF file
DADaniel Nascimento Do Amaral
Daniel Nascimento Do Amaral
BCBruno C. Cavalcanti
Bruno C. Cavalcanti
Daniel P. BezerraDaniel P. Bezerra
Daniel P. Bezerra
PFPaulo Michel Pinheiro Ferreira
Paulo Michel Pinheiro Ferreira
RCRosane de Paula Castro
Rosane de Paula Castro
Lidia Moreira LimaLidia Moreira Lima
Lidia Moreira Lima
Cancer is the second most common cause of death in the USA. Among the known classes of anticancer agents, the microtubule-targeted antimitotic drugs are considered to be one of the most important. They are usually classified into microtubule-destabilizing (e.g., Vinca alkaloids) and microtubule-stabilizing (e.g., paclitaxel) agents. Combretastatin A4 (CA-4), which is a natural stilbene isolated from Combretum caffrum, is a microtubule-destabilizing agent that binds to the colchicine domain on β-tubulin and exhibits a lower toxicity profile than paclitaxel or the Vinca alkaloids. In this paper, we describe the docking study, synthesis, antiproliferative activity and selectivity index of the N-acylhydrazone derivatives (5a–r) designed as CA-4 analogues. The essential structural requirements for molecular recognition by the colchicine binding site of β-tubulin were recognized, and several compounds with moderate to high antiproliferative potency (IC50 values ≤18 µM and ≥4 nM) were identified. Among these active compounds, LASSBio-1586 (5b) emerged as a simple antitumor drug candidate, which is capable of inhibiting microtubule polymerization and possesses a broad in vitro and in vivo antiproliferative profile, as well as a better selectivity index than the prototype CA-4, indicating improved selective cytotoxicity toward cancer cells.