Roger Chammas
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Research Interests
Roger Chammas has a total of 1000 co-authors. Here are the top co-authors by number of shared publications:
- Luciana Nogueira de Sousa Andrade
Center for Translational Research in Oncology (LIM/24), Instituto do Cancer do Estado de Sao Paulo, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil; Comprehensive Center for Precision Oncology (C2PO), Universidade de Sao Paulo, São Paulo, SP, Brazil
17 shared publications - Andreia Hanada Otake
Center for Translational Research in Oncology (LIM/24), Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo CEP 01246-000, Brazil
13 shared publications Fu-Tong Liu
Department of Dermatology, University of California, Davis, School of Medicine, Sacramento, CA, USA
12 shared publications- Mara de Souza Junqueira
Center for Translational Research in Oncology, Cancer Institute of the State of Sao Paulo—ICESP, São Paulo 01246-000, SP, Brazil
10 shared publications - Alexis Germán Murillo Carrasco
Center for Translational Research in Oncology (LIM24), Instituto do Cancer do Estado de Sao Paulo (ICESP), Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (HCFMUSP), São Paulo 01246-000, Brazil, São Paulo, Brazil
9 shared publications - Felipe Leite Oliveira
Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
9 shared publications
Latest Publications
- Open Access
- 12 October 2026
- Published by Elsevier in The Lancet Regional Health - Americas
Resilience in cancer control in times of crisis: a vision for action in Brazil
- 12 October 2026
- Published by Elsevier in The Lancet Regional Health - Americas
Open AccessResilience in cancer control in times of crisis: a vision for action in Brazil
- Open Access
- 25 August 2026
- Published by MDPI AG in International Journal of Molecular Sciences
- Vol. 27 (17) , 7617
Long Noncoding RNAs (lncRNAs) as Biomarkers of Prognosis in TNBC and Non-TNBC Breast Cancer Patients
Functional studies have shown that long noncoding RNAs (lncRNAs) play different roles in gene expression regulation, acting as epigenetic factors. Accumulating evidence indicates that lncRNAs modulate diverse biological processes, and their altered expression is associated with the development and progression of cancer, including BC. Here, aiming to identify lncRNAs associated with breast cancer, we performed a re-analysis of the expression data from 1071 tumors of eligible patients in the LACRN-MPBC Study. Using normalized data, we compared the expression profiles of triple-negative breast cancer (TNBC; 170 cases) and a heterogeneous group of non-TNBC tumors (782 cases). A total of 59 differentially expressed lncRNAs (DELncRNAs) could be identified based on the criteria of |log2FC| ≥ 1 and FDR < 0.05, using the DESeq2 R package. In the Kaplan–Meier survival analysis, we identified DELncRNAs that affect disease-free survival and/or overall survival, with eight of them in TNBC and 27 in non-TNBC patients. Multivariate Cox proportional-hazards models were used to evaluate independent predictors of survival. Two DELncRNAs, VLDLR-AS1 and PART1, were identified as independent prognostic markers for TNBC patients, while seven (LINC00239, FAM30A, LINC00842, LINC01315, EGOT, LY6E-DT, and SLC25A21-AS1) were independent prognostic markers for non-TNBC patients. Our computational study identifies several candidate lncRNAs associated with clinical outcomes in breast cancer. However, the DELncRNAs identified here should be interpreted as preliminary candidates, which require future validation and functional studies to determine their biological roles and evaluate their potential as prognostic biomarkers.
- 25 August 2026
- Published by MDPI AG in International Journal of Molecular Sciences
- Vol. 27 (17) , 7617
Open AccessLong Noncoding RNAs (lncRNAs) as Biomarkers of Prognosis in TNBC and Non-TNBC Breast Cancer Patients
Functional studies have shown that long noncoding RNAs (lncRNAs) play different roles in gene expression regulation, acting as epigenetic factors. Accumulating evidence indicates that lncRNAs modulate diverse biological processes, and their altered expression is associated with the development and progression of cancer, including BC. Here, aiming to identify lncRNAs associated with breast cancer, we performed a re-analysis of the expression data from 1071 tumors of eligible patients in the LACRN-MPBC Study. Using normalized data, we compared the expression profiles of triple-negative breast cancer (TNBC; 170 cases) and a heterogeneous group of non-TNBC tumors (782 cases). A total of 59 differentially expressed lncRNAs (DELncRNAs) could be identified based on the criteria of |log2FC| ≥ 1 and FDR < 0.05, using the DESeq2 R package. In the Kaplan–Meier survival analysis, we identified DELncRNAs that affect disease-free survival and/or overall survival, with eight of them in TNBC and 27 in non-TNBC patients. Multivariate Cox proportional-hazards models were used to evaluate independent predictors of survival. Two DELncRNAs, VLDLR-AS1 and PART1, were identified as independent prognostic markers for TNBC patients, while seven (LINC00239, FAM30A, LINC00842, LINC01315, EGOT, LY6E-DT, and SLC25A21-AS1) were independent prognostic markers for non-TNBC patients. Our computational study identifies several candidate lncRNAs associated with clinical outcomes in breast cancer. However, the DELncRNAs identified here should be interpreted as preliminary candidates, which require future validation and functional studies to determine their biological roles and evaluate their potential as prognostic biomarkers.
- Open Access
- 14 August 2026
- Published by Elsevier in Biomedicine & Pharmacotherapy
- Vol. 203
Phenotype-driven screening of semi-synthetic terpene analogs identifies TRX-41 as a lead compound active in chemotherapy-resistant breast cancer organoids
- 14 August 2026
- Published by Elsevier in Biomedicine & Pharmacotherapy
- Vol. 203
Open AccessPhenotype-driven screening of semi-synthetic terpene analogs identifies TRX-41 as a lead compound active in chemotherapy-resistant breast cancer organoids
- Open Access
- 10 August 2026
- Published by MDPI AG in Biomolecules
- Vol. 16 (8) , 1160
miRNA484 and miRNA335-5p as Potential Diagnostic Biomarkers for CA19-9-Negative Pancreatic Ductal Adenocarcinoma
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide, largely because it is diagnosed late. Diagnosis typically relies on imaging and biopsy, but only after tumors have advanced, which reduces treatment effectiveness. Current biochemical biomarkers are limited to CA19-9, which is more useful for prognosis and monitoring than for diagnosis. Circulating miRNAs may offer minimally invasive complementary biomarkers for PDAC diagnosis, potentially accounting for ethnic and treatment-related variables. We performed small RNA sequencing on plasma from five non-metastatic-stage and five metastatic-stage PDAC patients and 10 healthy controls to generate an exploratory miRNA profile. Candidate miRNAs were then validated by RT-qPCR in an independent cohort of 70 PDAC patients and 106 healthy controls, and nine miRNAs showed promising differential plasma expression. Notably, miRNA484 and miRNA335-5p were associated with PDAC in CA19-9-negative patients, with ROC AUCs of 0.984 and 0.88, respectively. Overall, these results indicate that miRNA484 and miRNA335-5p may have clinical value as complementary biomarkers for PDAC patients who are CA19-9-negative.
- 10 August 2026
- Published by MDPI AG in Biomolecules
- Vol. 16 (8) , 1160
Open AccessmiRNA484 and miRNA335-5p as Potential Diagnostic Biomarkers for CA19-9-Negative Pancreatic Ductal Adenocarcinoma
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide, largely because it is diagnosed late. Diagnosis typically relies on imaging and biopsy, but only after tumors have advanced, which reduces treatment effectiveness. Current biochemical biomarkers are limited to CA19-9, which is more useful for prognosis and monitoring than for diagnosis. Circulating miRNAs may offer minimally invasive complementary biomarkers for PDAC diagnosis, potentially accounting for ethnic and treatment-related variables. We performed small RNA sequencing on plasma from five non-metastatic-stage and five metastatic-stage PDAC patients and 10 healthy controls to generate an exploratory miRNA profile. Candidate miRNAs were then validated by RT-qPCR in an independent cohort of 70 PDAC patients and 106 healthy controls, and nine miRNAs showed promising differential plasma expression. Notably, miRNA484 and miRNA335-5p were associated with PDAC in CA19-9-negative patients, with ROC AUCs of 0.984 and 0.88, respectively. Overall, these results indicate that miRNA484 and miRNA335-5p may have clinical value as complementary biomarkers for PDAC patients who are CA19-9-negative.
- Open Access
- 11 July 2026
- Published by Springer Nature in npj Breast Cancer
- Vol. 12 (1)
Ensemble machine learning for predicting breast cancer recurrence and mortality using clinical and hemogram data
Accurate prediction of breast cancer recurrence remains difficult because prognosis varies significantly across molecular subtypes. This underscores the need for scalable, affordable, and interpretable prognostic tools. We developed machine learning models integrating hematological indices with clinicopathologic data to predict 2- and 10-year recurrence or all-case death. We retrospectively analyzed 4277 women with primary breast cancer (2008-2022). The cohort included hormone receptor-positive (HR + ), HER2-positive, and triple-negative (TNBC) subtypes. We trained multiple classifiers and integrated them into a stacked ensemble using logistic regression as the final learner. Class imbalance was addressed with SMOTE applied to training sets. The ensemble achieved strong discrimination: general cohort AUC 0.859 (2-year) and 0.811 (10-year), with specificity 84-82% and sensitivity 68-61%. Subtype-specific performance remained robust across time horizons: HR + AUC 0.862/0.804, HER2 + AUC 0.877/0.831, and TNBC AUC 0.826/0.826 (2-year/10-year respectively). SHAP analysis identified advanced tumor stage, elevated inflammatory ratios (NLR, PLR, MLR), elevated red cell distribution width, and age as key adverse predictors with stronger effects on early recurrence. This interpretable tool uses routine blood tests and clinico-pathological data at diagnosis. It flaggs high-risk patients for intensified therapy, useful where genomic testing is unavailable.
- 11 July 2026
- Published by Springer Nature in npj Breast Cancer
- Vol. 12 (1)
Open AccessEnsemble machine learning for predicting breast cancer recurrence and mortality using clinical and hemogram data
Accurate prediction of breast cancer recurrence remains difficult because prognosis varies significantly across molecular subtypes. This underscores the need for scalable, affordable, and interpretable prognostic tools. We developed machine learning models integrating hematological indices with clinicopathologic data to predict 2- and 10-year recurrence or all-case death. We retrospectively analyzed 4277 women with primary breast cancer (2008-2022). The cohort included hormone receptor-positive (HR + ), HER2-positive, and triple-negative (TNBC) subtypes. We trained multiple classifiers and integrated them into a stacked ensemble using logistic regression as the final learner. Class imbalance was addressed with SMOTE applied to training sets. The ensemble achieved strong discrimination: general cohort AUC 0.859 (2-year) and 0.811 (10-year), with specificity 84-82% and sensitivity 68-61%. Subtype-specific performance remained robust across time horizons: HR + AUC 0.862/0.804, HER2 + AUC 0.877/0.831, and TNBC AUC 0.826/0.826 (2-year/10-year respectively). SHAP analysis identified advanced tumor stage, elevated inflammatory ratios (NLR, PLR, MLR), elevated red cell distribution width, and age as key adverse predictors with stronger effects on early recurrence. This interpretable tool uses routine blood tests and clinico-pathological data at diagnosis. It flaggs high-risk patients for intensified therapy, useful where genomic testing is unavailable.
- 25 June 2026
- Published by Oxford University Press (OUP) in Glycobiology
Aberrant O-glycosylation genes and miR-21-5p targets define a molecular signature of tumor aggressiveness in triple-negative breast cancer
Aberrant O-glycosylation and miRNA dysregulation are established features of tumor aggressiveness, particularly in triple-negative breast cancer (TNBC). Using a Cosmc-silenced 4 T1 murine model (Tn+), characterized by truncated O-glycans and enhanced metastatic potential, tissue and serum miRNA profiling identified miR-21-5p as a circulating marker associated with the Tn+ phenotype. Transcriptomic analysis revealed that miR-21-5p targets multiple tumor suppressor genes, including Btg2, Spry1, Tbx2, Rhob, and Dusp8, suggesting its involvement in epithelial–mesenchymal transition and immune modulation. Integrative single-cell RNA sequencing (scRNA-seq) of the 4 T1 tumor microenvironment revealed distinct cellular clusters with inverse expression patterns of GALNT enzymes (involved in Tn synthesis) and miR-21-5p target genes, defining Tn+-like and Tn—like subpopulations. Translating these findings to human breast cancer (TCGA-BRCA), a prognostic model combining clinical variables (age, metastasis, PAM50 subtype) with three-gene expression (OLR1, PCSK6, and GALNT6) significantly improved patient risk stratification (P = 0.015). By integrating multi-omics analyses (scRNA-seq, TCGA) with an aggressive Tn+ TNBC model, this study defines a novel three-gene prognostic signature that links the glyco-miRNA axis to tumor aggressiveness, offering a promising tool for advanced patient stratification and the development of precision glyco-therapeutics.
- 25 June 2026
- Published by Oxford University Press (OUP) in Glycobiology
Aberrant O-glycosylation genes and miR-21-5p targets define a molecular signature of tumor aggressiveness in triple-negative breast cancer
Aberrant O-glycosylation and miRNA dysregulation are established features of tumor aggressiveness, particularly in triple-negative breast cancer (TNBC). Using a Cosmc-silenced 4 T1 murine model (Tn+), characterized by truncated O-glycans and enhanced metastatic potential, tissue and serum miRNA profiling identified miR-21-5p as a circulating marker associated with the Tn+ phenotype. Transcriptomic analysis revealed that miR-21-5p targets multiple tumor suppressor genes, including Btg2, Spry1, Tbx2, Rhob, and Dusp8, suggesting its involvement in epithelial–mesenchymal transition and immune modulation. Integrative single-cell RNA sequencing (scRNA-seq) of the 4 T1 tumor microenvironment revealed distinct cellular clusters with inverse expression patterns of GALNT enzymes (involved in Tn synthesis) and miR-21-5p target genes, defining Tn+-like and Tn—like subpopulations. Translating these findings to human breast cancer (TCGA-BRCA), a prognostic model combining clinical variables (age, metastasis, PAM50 subtype) with three-gene expression (OLR1, PCSK6, and GALNT6) significantly improved patient risk stratification (P = 0.015). By integrating multi-omics analyses (scRNA-seq, TCGA) with an aggressive Tn+ TNBC model, this study defines a novel three-gene prognostic signature that links the glyco-miRNA axis to tumor aggressiveness, offering a promising tool for advanced patient stratification and the development of precision glyco-therapeutics.
- Open Access
- 19 March 2026
- Published by MDPI AG in Biomolecules
- Vol. 16 (3) , 464
Ganglioside GM3 in the Tumor Microenvironment: Mechanisms of Signaling Regulation and Strategies for Angiogenesis Inhibition
Ganglioside GM3, a fundamental glycosphingolipid on the mammalian cell surface, is a key regulator of transmembrane signaling and cellular recognition. In oncology, GM3 acts as a tumor suppressor by modulating the activity of various receptor tyrosine kinases (RTKs) and their downstream pathways. Recent studies highlight its function in the tumor microenvironment (TME), specifically its ability to impede pathological angiogenesis. This review summarizes the molecular mechanisms by which GM3 interferes with pro-angiogenic signaling, such as the VEGF/VEGFR axis, and discusses how this inhibition can be used for therapy. We explore the clinical potential of GM3-based strategies, including monoclonal antibodies and cancer vaccines, discussing the potential of targeting GM3 to reshape the TME and suppress tumor-associated vascularization.
- 19 March 2026
- Published by MDPI AG in Biomolecules
- Vol. 16 (3) , 464
Open AccessGanglioside GM3 in the Tumor Microenvironment: Mechanisms of Signaling Regulation and Strategies for Angiogenesis Inhibition
Ganglioside GM3, a fundamental glycosphingolipid on the mammalian cell surface, is a key regulator of transmembrane signaling and cellular recognition. In oncology, GM3 acts as a tumor suppressor by modulating the activity of various receptor tyrosine kinases (RTKs) and their downstream pathways. Recent studies highlight its function in the tumor microenvironment (TME), specifically its ability to impede pathological angiogenesis. This review summarizes the molecular mechanisms by which GM3 interferes with pro-angiogenic signaling, such as the VEGF/VEGFR axis, and discusses how this inhibition can be used for therapy. We explore the clinical potential of GM3-based strategies, including monoclonal antibodies and cancer vaccines, discussing the potential of targeting GM3 to reshape the TME and suppress tumor-associated vascularization.
- Open Access
- 13 March 2026
- Published by Elsevier in Critical Reviews in Oncology/Hematology
- Vol. 222, 105274
MicroRNAs in penile cancer: challenges, opportunities, and translational perspectives
- 13 March 2026
- Published by Elsevier in Critical Reviews in Oncology/Hematology
- Vol. 222, 105274
Open AccessMicroRNAs in penile cancer: challenges, opportunities, and translational perspectives
- Open Access
- 1 January 2026
- Published by Royal Society of Chemistry (RSC) in Chemical Society Reviews
New approach methodologies in nanomedicine: bridging the gap between in silico , in vitro , and in vivo systems
Rapid advances in biomedical research and nanomedicine have driven the development and implementation of New Approach Methodologies (NAMs) for predictive evaluations of novel formulations.
- 1 January 2026
- Published by Royal Society of Chemistry (RSC) in Chemical Society Reviews
Open AccessNew approach methodologies in nanomedicine: bridging the gap between in silico , in vitro , and in vivo systems
Rapid advances in biomedical research and nanomedicine have driven the development and implementation of New Approach Methodologies (NAMs) for predictive evaluations of novel formulations.
- Open Access
- 1 January 2026
- Published by FapUNIFESP (SciELO) in Estudos Avançados
- Vol. 40 (117)
Novas terapias e o tratamento personalizado contra o câncer
RESUMO O conceito da “bala mágica” de Paul Ehrlich inspirou o desenvolvimento de terapias seletivas contra o câncer. A descoberta de que o câncer resulta do acúmulo de alterações genéticas e epigenéticas levou à identificação de alvos moleculares específicos e ao surgimento das terapias alvo-dirigidas. O sucesso do imatinibe na leucemia mieloide crônica marcou o início da oncologia de precisão, baseada na caracterização molecular dos tumores. Mais recentemente, imunoterapias, terapias celulares CAR-T, vacinas terapêuticas e abordagens teranósticas ampliaram as opções de tratamento personalizado. Entretanto, a heterogeneidade tumoral, a evolução clonal e os mecanismos de resistência limitam a eficácia dessas estratégias em todos os pacientes. No Brasil, a incorporação dessas tecnologias ao SUS depende de avaliação pela Conitec, considerando benefício clínico, custo-efetividade e impacto orçamentário. O desafio atual é expandir o acesso à medicina de precisão de forma sustentável, apoiada por diagnóstico molecular, pesquisa clínica e geração de evidências em condições reais de uso.
- 1 January 2026
- Published by FapUNIFESP (SciELO) in Estudos Avançados
- Vol. 40 (117)
Open AccessNovas terapias e o tratamento personalizado contra o câncer
RESUMO O conceito da “bala mágica” de Paul Ehrlich inspirou o desenvolvimento de terapias seletivas contra o câncer. A descoberta de que o câncer resulta do acúmulo de alterações genéticas e epigenéticas levou à identificação de alvos moleculares específicos e ao surgimento das terapias alvo-dirigidas. O sucesso do imatinibe na leucemia mieloide crônica marcou o início da oncologia de precisão, baseada na caracterização molecular dos tumores. Mais recentemente, imunoterapias, terapias celulares CAR-T, vacinas terapêuticas e abordagens teranósticas ampliaram as opções de tratamento personalizado. Entretanto, a heterogeneidade tumoral, a evolução clonal e os mecanismos de resistência limitam a eficácia dessas estratégias em todos os pacientes. No Brasil, a incorporação dessas tecnologias ao SUS depende de avaliação pela Conitec, considerando benefício clínico, custo-efetividade e impacto orçamentário. O desafio atual é expandir o acesso à medicina de precisão de forma sustentável, apoiada por diagnóstico molecular, pesquisa clínica e geração de evidências em condições reais de uso.