ROGER CHAMMAS
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Radiologia, Faculdade de Medicina - Docente
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
LIM/24 - Laboratório de Oncologia Experimental, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
LIM/24 - Laboratório de Oncologia Experimental, Hospital das Clínicas, Faculdade de Medicina - Líder
232 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 232
- Melatonin treatment: A transcriptomic networks in a xenograft model of breast cancer(2017) JARDIM-PERASSI, B. V.; SONEHARA, N. M.; PAULA-JUNIOR, R. de; CHAMMAS, R.; COUTINHO, L. L.; REIS JUNIOR, O.; ALEXANDRE, P. A.; FUKUMASU, H.; ZUCCARI, D. A. P. C.
- Hedgehog signaling pathway mediates tongue tumorigenesis in wild-type mice but not in Ga13-deficient mice(2014) SANTOS, Debora de Oliveira; LOYOLA, Adriano Mota; CARDOSO, Sergio Vitorino; CHAMMAS, Roger; LIU, Fu-Tong; FARIA, Paulo Rogerio deOral squamous cell carcinoma (OSCC) is one of the most aggressive cancers of the oral cavity and an important cause of death worldwide. Currently, there are limited clinical tools aiding clinicians to establish its early diagnosis, and genetic and epigenetic events leading to the pathogenesis of OSCC remain unsolved. The use of carcinogen-induced knocked out mouse models would help to improve its early detection and also determine the role of proteins such as galectin-3 (Gal3) in this process. Here we used a mouse model of oral carcinogenesis employing two mouse genotypes: wild-type (Gal3 +/+) and galectin-3-deficient mice (Gal3 -/-) challenged by the carcinogen 4NQO for 16 weeks. After induction, the expression of Wnt1, Wnt3A, Shh and Gli3 proteins in tongue samples was evaluated using an immunohistochemistry approach. All samples of dysplasia and carcinoma were negative for Wnt1. Wnt3A expression was detected in both Gal3 +/+ and Gal3 -/- mice, at similar levels. Wnt3A expression did not predict tongue tumorigenesis in either genotype. Dysplastic- and carcinoma-expressing Shh was statistically significantly higher in Gal3 +/+ mice than Gal3 -/- mice (p < 0.0001), and was associated with tongue tumorigenesis only in the former. Gli3 expression decreased and increased from dysplasia to carcinoma in Gal3 +/+ and Gal3 -/- mice, respectively, although the difference was not significant. The results suggest that activated Wnt signaling is present in both mice, and that the Hh signaling pathway might play a role in tongue carcinoma development in Gal3 +/+ mice.
- The International Society of RNA Nanotechnology and Nanomedicine (ISRNN): The Present and Future of the Burgeoning Field(2021) CHANDLER, Morgan; JOHNSON, Brittany; KHISAMUTDINOV, Emil; DOBROVOLSKAIA, Marina A.; SZTUBA-SOLINSKA, Joanna; SALEM, Aliasger K.; BREYNE, Koen; CHAMMAS, Roger; WALTER, Nils G.; CONTRERAS, Lydia M.; GUO, Peixuan; AFONIN, Kirill A.The International Society of RNA Nanotechnology and Nanomedicine (ISRNN) hosts an annual meeting series focused on presenting the latest research achievements involving RNA-based therapeutics and strategies, aiming to expand their current biomedical applications while overcoming the remaining challenges of the burgeoning field of RNA nanotechnology. The most recent online meeting hosted a series of engaging talks and discussions from an international cohort of leading nanotechnologists that focused on RNA modifications and modulation, dynamic RNA structures, overcoming delivery limitations using a variety of innovative platforms and approaches, and addressing the newly explored potential for immunomodulation with programmable nucleic acid nanoparticles. In this Nano Focus, we summarize the main discussion points, conclusions, and future directions identified during this two-day webinar as well as more recent advances to highlight and to accelerate this exciting field.
- Correlation of a microRNA expression profile and the prognosis of penile cancer: A prospective study using microarray data analysis(2018) FURUYA, Tatiane K.; MURTA, Claudio B.; PONTES JR., Jose; UNO, Miyuki; CARRASCO, Alexis; SICHERO, Laura C.; VILLA, Luisa L.; COELHO, Rafael F.; GUGLIELMETTI, Giuliano B.; CORDEIRO, Mauricio D.; LEITE, Katia R.; SROUGI, Miguel; CHAMMAS, Roger; NAHAS, William C.
- Melatonin Regulates the Daily Levels of Plasma Amino Acids, Acylcarnitines, Biogenic Amines, Sphingomyelins, and Hexoses in a Xenograft Model of Triple Negative Breast Cancer(2022) JUNIOR, Rubens Paula; CHUFFA, Luiz Gustavo de Almeida; SIMAO, Vinicius Augusto; SONEHARA, Nathalia Martins; CHAMMAS, Roger; REITER, Russel J.; ZUCCARI, Debora Aparecida Pires de CamposMetabolic dysregulation as a reflection of specific metabolite production and its utilization is a common feature of many human neoplasms. Melatonin, an indoleamine that is highly available during darkness, has a variety of metabolic functions in solid tumors. Because plasma metabolites undergo circadian changes, we investigated the role of melatonin on the profile of amino acids (AAs), biogenic amines, carnitines, sphingolipids, and hexoses present in the plasma of mice bearing xenograft triple negative breast cancer (MDA-MB-231 cells) over 24 h. Plasma concentrations of nine AAs were reduced by melatonin, especially during the light phase, with a profile closer to that of non-breast cancer (BC) animals. With respect to acylcarnitine levels, melatonin reduced 12 out of 24 molecules in BC-bearing animals compared to their controls, especially at 06:00 h and 15:00 h. Importantly, melatonin reduced the concentrations of asymmetric dimethylarginine, carnosine, histamine, kynurenine, methionine sulfoxide, putrescine, spermidine, spermine, and symmetric dimethylarginine, which are associated with the BC metabolite sets. Melatonin also led to reduced levels of sphingomyelins and hexoses, which showed distinct daily variations over 24 h. These results highlight the role of melatonin in controlling the levels of plasma metabolites in human BC xenografts, which may impact cancer bioenergetics, in addition to emphasizing the need for a more accurate examination of its metabolomic changes at different time points.
- Binding Affinity, Specificity and Comparative Biodistribution of the Parental Murine Monoclonal Antibody MX35 (Anti-NaPi2b) and Its Humanized Version Rebmab200(2015) LINDEGREN, Sture; ANDRADE, Luciana N. S.; BACK, Tom; MACHADO, Camila Maria L.; HORTA, Bruno Brasil; BUCHPIGUEL, Carlos; MORO, Ana Maria; OKAMOTO, Oswaldo Keith; JACOBSSON, Lars; CEDERKRANTZ, Elin; WASHIYAMA, Kohshin; ANEHEIM, Emma; PALM, Stig; JENSEN, Holger; TUMA, Maria Carolina B.; CHAMMAS, Roger; HULTBORN, Ragnar; ALBERTSSON, PerThe aim of this preclinical study was to evaluate the characteristics of the monoclonal antibody Rebmab200, which is a humanized version of the ovarian-specific murine antibody MX35. This investigation contributes to the foundation for future clinical alpha-radioimmunotherapy of minimal residual ovarian cancer with At-211-Rebmab200. Here, the biodistribution of 211At-Rebmab200 was evaluated, as was the utility of Tc-99m-Rebmab200 for bioimaging. Rebmab200 was directly compared with its murine counterpart MX35 in terms of its in-vitro capacity for binding the immobilized NaPi2B epitope and live cells; we also assessed its biodistribution in nude mice carrying subcutaneous OVCAR-3 tumors. Tumor antigen and cell binding were similar between Rebmab200 and murine MX35, as was biodistribution, including normal tissue uptake and in-vivo tumor binding. We also demonstrated that Tc-99m-Rebmab200 can be used for single-photon emission computed tomography of subcutaneous ovarian carcinomas in tumor-bearing mice. Taken together, our data support the further development of Rebmab200 for radioimmunotherapy and diagnostics.
- European ancestry and polymorphisms in DNA repair genes modify the risk of melanoma: A case-control study in a high UV index region in Brazil(2011) GONCALVES, Fernanda T.; FRANCISCO, Guilherme; SOUZA, Sonia P. de; LUIZ, Olinda C.; FESTA-NETO, Cyro; SANCHES, Jose A.; CHAMMAS, Roger; GATTAS, Gilka J. F.; ELUF-NETO, JoseBackground: UV radiation is the major environmental factor related to development of cutaneous melanoma. Besides sun exposure and the influence of latitude, some host characteristics such as skin phototype and hair and eye color are also risk factors for melanoma. Polymorphisms in DNA repair genes could be good candidates for susceptibility genes, mainly in geographical regions exposed to high solar radiation. Objective: Evaluate the role of host characteristic.; and DNA repair polymorphism in melanoma risk in Brazil. Methods: We carried out a hospital-based case-control study in Brazil to evaluate the contribution of host factors and polymorphisms in DNA repair to melanoma risk. A total of 412 patients (202 with melanoma and 210 controls) were analyzed regarding host characteristics for melanoma risk as well as for 11 polymorphisms in DNA repair genes. Results: We found an association of host characteristics with melanoma development, such as eye and hair color, fair skin, history of pigmented lesions removed, sunburns in childhood and adolescence, and also European ancestry. Regarding DNA repair gene polymorphisms, we found protection for the XPG 1104 His/His genotype (OR 0.32; 95% CI 0.13-0.75), and increased risk for three polymorphisms in the XPC gene (PAT+; IV-6A and 939Gln), which represent a haplotype for XPC. Melanoma risk was higher in individuals carrying the complete XPC haplotype than each individual polymorphism (OR 3.64; 95% CI 1.77-7.48). Conclusions: Our data indicate that the host factors European ancestry and XPC polymorphisms contributed to melanoma risk in a region exposed to high sun radiation.
- Resistance Mechanisms Influencing Oncolytic Virotherapy, a Systematic Analysis(2021) BHATT, Darshak K.; CHAMMAS, Roger; DAEMEN, ToosResistance to therapy is a frequently observed phenomenon in the treatment of cancer, and as with other cancer therapeutics, therapies based on oncolytic viruses also face the challenges of resistance, such as humoral and cellular antiviral responses, and tumor-associated interferon-mediated resistance. In order to identify additional mechanisms of resistance that may contribute to therapeutic failure, we developed a systematic search strategy for studies published in PubMed. We analyzed 6143 articles on oncolytic virotherapy and found that approximately 8% of these articles use resistance terms in the abstract and/or title. Of these 439 articles, 87 were original research. Most of the findings reported pertain to resistance mediated by tumor-cell-dependent interferon signaling. Yet, mechanisms such as epigenetic modifications, hypoxia-mediated inhibition, APOBEC-mediated resistance, virus entry barriers, and spatiotemporal restriction to viral spread, although not frequently assessed, were demonstrated to play a major role in resistance. Similarly, our results suggest that the stromal compartment consisting of, but not limited to, myeloid cells, fibroblasts, and epithelial cells requires more study in relation to therapy resistance using oncolytic viruses. Thus, our findings emphasize the need to assess the stromal compartment and to identify novel mechanisms that play an important role in conferring resistance to oncolytic virotherapy.
- Exercise Training Preserves Myocardial Strain and Improves Exercise Tolerance in Doxorubicin-Induced Cardiotoxicity(2021) GOMES-SANTOS, Igor L.; JORDAO, Camila P.; PASSOS, Clevia S.; BRUM, Patricia C.; OLIVEIRA, Edilamar M.; CHAMMAS, Roger; CAMARGO, Anamaria A.; NEGRAO, Carlos E.Doxorubicin causes cardiotoxicity and exercise intolerance. Pre-conditioning exercise training seems to prevent doxorubicin-induced cardiac damage. However, the effectiveness of the cardioprotective effects of exercise training concomitantly with doxorubicin treatment remains largely unknown. To determine whether low-to-moderate intensity aerobic exercise training during doxorubicin treatment would prevent cardiotoxicity and exercise intolerance, we performed exercise training concomitantly with chronic doxorubicin treatment in mice. Ventricular structure and function were accessed by echocardiography, exercise tolerance by maximal exercise test, and cardiac biology by histological and molecular techniques. Doxorubicin-induced cardiotoxicity, evidenced by impaired ventricular function, cardiac atrophy, and fibrosis. Exercise training did not preserve left ventricular ejection fraction or reduced fibrosis. However, exercise training preserved myocardial circumferential strain alleviated cardiac atrophy and restored cardiomyocyte cross-sectional area. On the other hand, exercise training exacerbated doxorubicin-induced body wasting without affecting survival. Finally, exercise training blunted doxorubicin-induced exercise intolerance. Exercise training performed during doxorubicin-based chemotherapy can be a valuable approach to attenuate cardiotoxicity.
- Endostatin gene therapy stimulates upregulation of ICAM-1 and VCAM-1 in a metastatic renal cell carcinoma model(2012) CHAVES, K. C. B.; PERON, J. P. S.; CHAMMAS, R.; TURACA, L. T.; PESQUERO, J. B.; BRAGA, M. S.; FOGUER, K.; SCHOR, N.; BELLINI, M. H.One of the greatest challenges in urological oncology is renal cell carcinoma (RCC), which is the third leading cause of death in genitourinary cancers. RCCs are highly vascularized and respond positively to antiangiogenic therapy. Endostatin (ES) is a fragment of collagen XVIII that possesses antiangiogenic activity. In this study, we examined the potential of ES-based antiangiogenic therapy to activate tumor-associated endothelial cells in metastatic RCC (mRCC). Balb/c-bearing Renca cells were treated with NIH/3T3-LendSN or, as a control, with NIH/3T3-LXSN cells. The T-cell subsets and lymphocyte populations of tumors, mediastinal lymph nodes and the spleen were assessed by flow cytometry. The expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) was assessed by real-time PCR, flow cytometry and immunohistochemistry analysis. ES gene therapy led to an increase in the percentage of infiltrating CD4-interferon (IFN)-gamma cells (P<0.05), CD8-IFN-gamma cells (P<0.01) and CD49b-tumor necrosis factor-alpha cells (P<0.01). In addition, ES therapy caused an increase at the mRNA level of ICAM-1 (1.4-fold; P<0.01) and VCAM-1 (1.5-fold) (control vs treated group; P<0.001). Through flow cytometry, we found a significant increase in the CD34/ICAM-1 cells (8.1-fold; P<0.001) and CD34/VCAM-1 cells (1.6-fold; P<0.05). ES gene therapy induced a significant increase in both T CD4 and CD8 cells in the lymph nodes and the spleen, suggesting that ES therapy may facilitate cell survival or clonal expansion. CD49b cells were also present in increased quantities in all of these organs. In this study, we demonstrate an antitumor inflammatory effect of ES in an mRCC model, and this effect is mediated by an increase in ICAM-1 and VCAM-1 expression in tumor-associated endothelial cells.