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
14 resultados
Resultados de Busca
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- Amblyomin-X induces ER stress, mitochondrial dysfunction, and caspase activation in human melanoma and pancreatic tumor cell(2016) MORAIS, Katia L. P.; PACHECO, Mario Thiego Fernandes; BERRA, Carolina Maria; BOSCH, Rosemary V.; SCIANI, Juliana Mozer; CHAMMAS, Roger; SAITO, Renata de Freitas; IQBAL, Asif; CHUDZINSKI-TAVASSI, Ana MarisaDuring the last two decades, new insights into proteasome function and its role in several human diseases made it a potential therapeutic target. In this context, Amblyomin-X is a Kunitz-type FXa inhibitor similar to endogenous tissue factor pathway inhibitor (TFPI) and is a novel proteasome inhibitor. Herein, we have demonstrated Amblyomin-X cytotoxicity to different tumor cells lines such as pancreatic (Panc1, AsPC1BxPC3) and melanoma (SK-MEL-5 and SK-MEL-28). Of note, Amblyomin-X was not cytotoxic to normal human fibroblast cells. In addition, Amblyomin-X promoted accumulation of ER stress markers (GRP78 and GADD153) in sensitive (SK-MEL-28) and bortezomib-resistant (Mia-PaCa-2) tumor cells. The intracellular calcium concentration [Ca2+] (i) was slightly modulated in human tumor cells (SK-MEL-28 and Mia-PaCa-2) after 24 h of Amblyomin-X treatment. Furthermore, Amblyomin-X induced mitochondrial dysfunction, cytochrome-c release, PARP cleavage, and activation of caspase cascade in both human tumor (SK-MEL-28 and Mia-PaCa-2) cells. These investigations might help in further understanding of the antitumor properties of Amblyomin-X.
- Preclinical anticancer effectiveness of a fraction from Casearia sylvestris and its component Casearin X: in vivo and ex vivo methods and microscopy examinations(2016) FERREIRA, Paulo Michel Pinheiro; BEZERRA, Daniel Pereira; SILVA, Jurandy do Nascimento; COSTA, Marcilia Pinheiro da; FERREIRA, Jose Roberto de Oliveira; ALENCAR, Nylane Maria Nunes; FIGUEIREDO, Ingrid Samantha Tavares de; CAVALHEIRO, Alberto Jose; MACHADO, Camila Maria Longo; CHAMMAS, Roger; ALVES, Ana Paula Negreiros Nunes; MORAES, Manoel Odorico de; PESSOA, ClaudiaEthnopharmacological relevance: Casearia sylvestris (Salicaceae) is found in South America and presents antiulcerogenic, cytotoxic, antimicrobial, anti-inflammatory and antihypertensive activities. Aim of the study: To assess the in vivo and ex vivo antitumor action of a fraction with casearins (FC) and its main component- Casearin X-isolated from C sylvestris leaves. Materials and methods: Firstly, Sarcoma 180 bearing Swiss mice were treated with FC and Cas X for 7 days. Secondly, BALB/c nude animals received hollow fibers with colon carcinoma (HCT-116) or glioblastoma (SF-295) cells and were treated with FC for 4 days. On 5th day, proliferation was determined by MIT assay. Results: FC 10 and 25 mg/kg/day i.p. and 50 mg/kg/day oral and Cas X 25 mg/kg/day i.p. and 50 mg/kg/ day oral revealed tumor growth inhibition rates of 35.8, 86.2, 53.7, 90.0 and 65.5% and such tumors demonstrated rare mitoses and coagulation necrosis areas. Similarly, FC reduced multiplying of HCT-116 and SF-295 cells when evaluated by the Hollow Fiber Assay (2.5 and 5 mg/kg/day i.p. and 25 and 50 mg/ kg/day oral), with cell growth inhibition rates ranging from 33.3 to 67.4% (p < 0.05). Flow cytometry experiments revealed that FC reduced membrane integrity and induced DNA fragmentation and mitochondrial depolarization (p < 0.05). Conclusions: FC and Cas X were efficient antitumor substances against murine and human cancer cells and caused reversible morphological changes in liver, kidneys and spleens, emphasizing clerodane diterpenes as an emerging class of anticancer molecules.
- O-glycan sialylation alters galectin-3 subcellular localization and decreases chemotherapy sensitivity in gastric cancer(2016) SANTOS, Sofia N.; JUNQUEIRA, Mara S.; FRANCISCO, Guilherme; VILANOVA, Manuel; MAGALHAES, Ana; BARUFFI, Marcelo Dias; CHAMMAS, Roger; HARRIS, Adrian L.; REIS, Celso A.; BERNARDES, Emerson S.ST6GalNAc-I, the sialyltransferase responsible for sialyl-Tn (sTn) synthesis, has been previously reported to be positively associated with cancer aggressiveness. Here we describe a novel sTn-dependent mechanism for chemotherapeutic resistance. We show that sTn protects cancer cells against chemotherapeutic-induced cell death by decreasing the interaction of cell surface glycan receptors with galectin-3 and increasing its intracellular accumulation. Moreover, exogenously added galectin-3 potentiated the chemotherapeutics-induced cytotoxicity in sTn non-expressing cells, while sTn overexpressing cells were protected. We also found that the expression of sTn was associated with a reduction in galectin-3-binding sites in human gastric samples tumors. ST6GalNAc-I knockdown restored galectin-3-binding sites on the cell surface and chemotherapeutics sensibility. Our results clearly demonstrate that an interruption of O-glycans extension caused by ST6GalNAc-I enzymatic activity leads to tumor cells resistance to chemotherapeutic drugs, highlighting the need for the development of novel strategies to target galectin-3 and/or ST6GalNAc-I.
- Cardiac dysfunction in Pkd1-deficient mice with phenotype rescue by galectin-3 knockout(2016) BALBO, Bruno E.; AMARAL, Andressa G.; FONSECA, Jonathan M.; CASTRO, Isac de; SALEMI, Vera M.; SOUZA, Leandro E.; SANTOS, Fernando dos; IRIGOYEN, Maria C.; QIAN, Feng; CHAMMAS, Roger; ONUCHIC, Luiz F.Alterations in myocardial wall texture stand out among ADPKD cardiovascular manifestations in hypertensive and normotensive patients. To elucidate their pathogenesis, we analyzed the cardiac phenotype in Pkd1(cond/cond) Nestin(cre) (CYG+) cystic mice exposed to increased blood pressure, at 5 to 6 and 20 to 24 weeks of age, and Pkd1(+/-) (HTG+) noncystic mice at 5-6 and 10-13 weeks. Echocardiographic analyses revealed decreased myocardial deformation and systolic function in CYG+ and HTG+ mice, as well as diastolic dysfunction in older CYG+ mice, compared to their Pkd1(cond/cond) and Pkd1(+/+) controls. Hearts from CYG+ and HTG+ mice presented reduced polycystin-1 expression, increased apoptosis, and mild fibrosis. Since galectin-3 has been associated with heart dysfunction, we studied it as a potential modifier of the ADPKD cardiac phenotype. Double-mutant Pkd1(cond/cond):Nestin(cre);Lgals(3-/-) (CYG-) and Pkd1(+/-);Lgals(3-/-) (HTG-) mice displayed improved cardiac deformability and systolic parameters compared to single -mutants, not differing from the controls. CYG- and HTG- showed decreased apoptosis and fibrosis. Analysis of a severe cystic model (Pkd1(v/v); VVG+) showed that Pkd1(v/v);Lgals(3-/-) (VVG-) mice have longer survival, decreased cardiac apoptosis and improved heart function compared to VVG+. CYG- and VVG- animals showed no difference in renal cystic burden compared to CYG+ and VVG+ mice. Thus, myocardial dysfunction occurs in different Pkdl-deficient models and suppression of galectin-3 expression rescues this phenotype.
- Lack of galectin-3 up-regulates IgA expression by peritoneal B1 lymphocytes during B cell differentiation(2016) OLIVEIRA, Felipe L.; BERNARDES, Emerson S.; BRAND, Camila; SANTOS, Sofia N. dos; CABANEL, Mariana P.; ARCANJO, Katia D.; BRITO, Jose M.; BOROJEVIC, Radovan; CHAMMAS, Roger; EL-CHEIKH, Marcia C.Galectin-3 is a beta-galactoside-binding protein with an inhibitory role in B cell differentiation into plasma cells in distinct lymphoid tissues. We use a model of chronic schistosomiasis, a well-characterized experimental disease hallmarked by polyclonal B cell activation, in order to investigate the role of galectin-3 in controlling IgA production through peritoneal B1 cells. Chronically infected, galectin-3-deficient mice (Lgals3 (-/-)) display peritoneal fluid hypercellularity, increased numbers of atypical peritoneal IgM(+)/IgA(+) B1a and B1b lymphocytes and histological disturbances in plasma cell niches when compared with Lgals3 (+/+) mice. Similar to our infection model, peritoneal B1 cells from uninfected Lgals3 (-/-) mice show enhanced switching to IgA after in vitro treatment with interleukin-5 plus transforming growth factor-beta (IL-5 + TGF-beta 1). A higher number of IgA(+) B1a lymphocytes was found in the peritoneal cavity of Lgals3 (-/-)-uninfected mice at 1 week after i.p. injection of IL-5 + TGF-beta 1; this correlates with the increased levels of secreted IgA detected in the peritoneal fluid of these mice after cytokine treatment. Interestingly, a higher number of degranulated mast cells is present in the peritoneal cavity of uninfected and Schistosoma mansoni-infected Lgals3 (-/-) mice, indicating that, at least in part, mast cells account for the enhanced differentiation of B1 into IgA-producing B cells found in the absence of galectin-3. Thus, a novel role is revealed for galectin-3 in controlling the expression of surface IgA by peritoneal B1 lymphocytes; this might have important implications for manipulating the mucosal immune response.
- Comments to: Recurrence and complications of pterygium extended removal followed by extended conjunctival transplant for primary pterygia(2016) MARTINS, Thiago Goncalves dos Santos; COSTA, Ana Luiza Fontes de Azevedo; CHAMMAS, Roger; ALVES, Milton Ruiz; SCHOR, Paulo
article 49 Citação(ões) na Scopus Mitomycin C in pterygium treatment(2016) MARTINS, Thiago Goncalves dos Santos; COSTA, Ana Luiza Fontes de Azevedo; ALVES, Milton Ruiz; CHAMMAS, Roger; SCHOR, PauloPterygium is a benign lesion usually growing from the nasal side of the conjunctiva onto the cornea. Most cases of pterygium does not cause problem or requires specific treatment. The exact cause of pterygium is not clear yet, but some factors are pointed as causes, being the most important the long term ultraviolet ray exposure. Pterygium surgery is usually considered when there are symptoms that do not respond to conservative treatment. Recurrence is the main complication of the surgery, and much has been done to avoid it. Mitomycin C (MMC) has been used as a fibroblast proliferation inhibitor during the surgery to reduce the chance of recurrence of the pterygium. This review describes the use of MMC as an adjunctive, the optimal dosage, the duration of administration of MMC and possible complications, when used during, after and before the surgery. Most studies suggest that increased exposure (dose or duration) of MMC is associated with a lower recurrence, but with higher risks of complications.- Galectin-3 Determines Tumor Cell Adaptive Strategies in Stressed Tumor Microenvironments(2016) CARDOSO, Ana Carolina Ferreira; ANDRADE, Luciana Nogueira de Sousa; BUSTOS, Silvina Odete; CHAMMAS, RogerGalectin-3 is a member of the beta-galactoside-binding lectin family, whose expression is often dysregulated in cancers. While galectin-3 is usually an intracellular protein found in the nucleus and in the cytoplasm, under certain conditions, galectin-3 can be secreted by an yet unknown mechanism. Under stressing conditions (e.g., hypoxia and nutrient deprivation) galectin-3 is upregulated, through the activity of transcription factors, such as HIF-1 alpha and NF-kappa B. Here, we review evidence that indicates a positive role for galectin-3 in MAPK family signal transduction, leading to cell proliferation and cell survival. Galectin-3 serves as a scaffold protein, which favors the spatial organization of signaling proteins as K-RAS. Upon secretion, extracellular galectin-3 interacts with a variety of cell surface glycoproteins, such as growth factor receptors, integrins, cadherins, and members of the Notch family, among other glycoproteins, besides different extracellular matrix molecules. Through its ability to oligomerize, galectin-3 forms lectin lattices that act as scaffolds that sustain the spatial organization of signaling receptors on the cell surface, dictating its maintenance on the plasma membrane or their endocytosis. Galectin-3 induces tumor cell, endothelial cell, and leukocyte migration, favoring either the exit of tumor cells from a stressed microenvironment or the entry of endothelial cells and leukocytes, such as monocytes/macrophages into the tumor organoid. Therefore, galectin-3 plays homeostatic roles in tumors, as (i) it favors tumor cell adaptation for survival in stressed conditions; (ii) upon secretion, galectin-3 induces tumor cell detachment and migration; and (iii) it attracts monocyte/macrophage and endothelial cells to the tumor mass, inducing both directly and indirectly the process of angiogenesis. The two latter activities are potentially targetable, and specific interventions may be designed to counteract the protumoral role of extracellular galectin-3.
- The deficiency of galectin-3 in stromal cells leads to enhanced tumor growth and bone marrow metastasis(2016) PEREIRA, Jonathas Xavier; AZEREDO, Maria Carolina Braga; MARTINS, Felipe Sa; CHAMMAS, Roger; OLIVEIRA, Felipe Leite; SANTOS, Sofia Nascimento; BERNARDES, Emerson Soares; EL-CHEIKH, Marcia CuryBackground: Galectin-3 is a multifunctional beta-galactoside-binding lectin that once synthesized, is expressed in the nucleus, cytoplasm, cell surface and in the extracellular environment. Because of its unique structure, galectin-3 can oligomerize forming lattice upon binding to multivalent oligossacharides and influence several pathologic events such as tumorigenesis, invasion and metastasis. Methods: In our study, balb/c Lgals3+/+ and Lgals3-/- female mice were inoculated in the fourth mammary fat pad with 4T1 breast cancer cell line. The primary tumor, inguinal lymph nodes and iliac bone marrow were evaluated 15, 21 and 28 days post-injection. The primary tumor growth was evaluated by measuring the external diameter, internal growth by ultrasound and weight of the excised tumor. The presence of cancer cells in the draining lymph nodes and iliac crest bone marrow were performed by immunohistochemistry, PCR and clonogenic metastatic assay. Results: In this study we demonstrated that the deletion of galectin-3 in the host affected drastically the in vivo growth rate of 4T1 tumors. The primary tumors in Lgals3-/- mice displayed a higher proliferative rate (p < 0,05), an increased necrotic area (p < 0,01) and new blood vessels with a wider lumen in comparison with tumors from Lgals3+/+ mice (P < 0,05). Moreover, we detected a higher number of 4T1-derived metastatic colonies in the lymph nodes and the bone marrow of Lgals3-/- mice (p < 0,05). Additionally, healthy Lgals3-/- control mice presented an altered spatial distribution of CXCL12 in the bone marrow, which may explain at least in part the initial colonization of this organ in Lgals3-/- injected with 4T1 cells. Conclusions: Taken together, our results demonstrate for the first time that the absence of galectin-3 in the host microenvironment favors the growth of the primary tumors, the metastatic spread to the inguinal lymph nodes and bone marrow colonization by metastatic 4T1 tumor cells.
- Germline mutations in BRCA1 and BRCA2 in epithelial ovarian cancer patients in Brazil(2016) MAISTRO, Simone; TEIXEIRA, Natalia; ENCINAS, Giselly; KATAYAMA, Maria Lucia Hirata; NIEWIADONSKI, Vivian Dionisio Tavares; CABRAL, Larissa Garcia; RIBEIRO, Roberto Marques; GABURO JUNIOR, Nelson; GOUVEA, Ana Carolina Ribeiro Chaves de; CARRARO, Dirce Maria; SABINO, Ester Cerdeira; DIZ, Maria del Pilar Estevez; CHAMMAS, Roger; BOCK, Geertruida Hendrika de; FOLGUEIRA, Maria Aparecida Azevedo KoikeBackground: Approximately 8-15% epithelial ovarian cancer patients are BRCA1 or BRCA2 germline mutation carriers. Brazilian inhabitants may have peculiar genetic characteristics associated with ethnic diversity, and studies focusing on the entire BRCA1/BRCA2 gene sequencing in Brazilian ovarian cancer patients are still lacking. The aim of this study was to evaluate BRCA1/2 mutations, through entire gene sequencing, in a Brazilian population of women with epithelial ovarian cancer. Methods: In a cross sectional study performed in one reference centre for cancer treatment in Sao Paulo, Brazil, 100 patients diagnosed with epithelial ovarian cancer unselected for family history of breast and/or ovarian cancer were included. The complete coding sequence of BRCA1/2 genes was evaluated through Next-Generation or capillary sequencing. Large deletions were investigated through Multiplex Ligation-dependent Probe Amplification (MLPA). Results: Nineteen pathogenic mutations (BRCA1: n = 17 and BRCA2: n = 2) featuring 14 different mutations, including two large deletions in BRCA1 (exon 1-2 deleted and exon 5-7 deleted) were identified. Three mutations were detected more than once (c.3331_3334delCAAG, c.5266dupC and c.4484G > T). Two novel frameshift mutations were identified, one in BRCA1 (c.961_962delTG) and one in BRCA2 (c.1963_1963delC). BRCA1/2 mutations were seen in 35.5% of the patients with first and/or second-degree relatives with breast and/or ovarian cancer. Nineteen variants of uncertain significance (VUS) were detected (BRCA1: n = 2 and BRCA2: n = 17), including five distinct missense variants (BRCA1: c. 5348 T > C; BRCA2: c.2350A > G, c.3515C > T, c.7534C > T, and c.8351G > A). Conclusions: Among epithelial ovarian cancer patients unselected for family history of cancer, 19% were BRCA1/2 germline mutation carriers. Almost 3/4 of the BRCA mutations, including two large deletions, were detected only once. Our work emphasizes the need of entire gene sequencing and MLPA screening in Brazil.