Maso V.,University of Campinas |
Calgarotto A.K.,University of Campinas |
Franchi G.C.,University of Campinas |
Nowill A.E.,University of Campinas |
And 3 more authors.
Chest | Year: 2014
This study proposes to investigate quercetin antitumor efficacy in vitro and in vivo, using the P39 cell line as a model. The experimental design comprised leukemic cells or xenografts of P39 cells, treated in vitro or in vivo, respectively, with quercetin; apoptosis, cell-cycle and autophagy activation were then evaluated. Quercetin caused pronounced apoptosis in P39 leukemia cells, followed by Bcl-2, Bcl-xL, Mcl-1 downregulation, Bax upregulation, and mitochondrial translocation, triggering cytochrome c release and caspases activation. Quercetin also induced the expression of FasL protein. Furthermore, our results demonstrated an antioxidant activity of quercetin. Quercetin treatment resulted in an increased cell arrest in G1 phase of the cell cycle, with pronounced decrease in CDK2, CDK6, cyclin D, cyclin E, and cyclin A proteins, decreased Rb phosphorylation and increased p21 and p27 expression. Quercetin induced autophagosome formation in the P39 cell line. Autophagy inhibition induced by quercetin with chloroquine triggered apoptosis but did not alter quercetin modulation in the G1 phase. P39 cell treatment with a combination of quercetin and selective inhibitors of ERK1/2 and/or JNK (PD184352 or SP600125, respectively), significantly decreased cells in G1 phase, this treatment, however, did not change the apoptotic cell number. Furthermore, in vivo administration of quercetin significantly reduced tumor volume in P39 xenografts and confirmed in vitro results regarding apoptosis, autophagy, and cell-cycle arrest. The antitumor activity of quercetin both in vitro and in vivo revealed in this study, point to quercetin as an attractive antitumor agent for hematologic malignancies. © 2014 American Association for Cancer Research.
Moreira L.R.,Laboratory of Investigative and Molecular Pathology |
Schenka A.A.,Laboratory of Investigative and Molecular Pathology |
Latuf-Filho P.,Laboratory of Investigative and Molecular Pathology |
Penna A.L.,Laboratory of Investigative and Molecular Pathology |
And 4 more authors.
Tumor Biology | Year: 2011
Analysis of blood and lymphatic vessel in colorectal cancer is controversial in the literature, possibly due to variations in the methods of analysis. In this study, it was aimed to search for a reliable approach in the quantification of angio-and lymphangiovascular density and area as a prognostic factor and to compare such vessel counts in normal mucosa, adenomas and cancer. A retrospective study was performed on 60 sporadic colorectal cancer, 30 colorectal adenomas, and 10 colorectal nonneoplastic lesions. Archival tissues were submitted to immunohistochemical evaluation using antibodies to CD31, CD34, CD105, VEGF-A, VEGF-C, and D2-40. Microvessel density and total vascular area were determined by computer image analysis and values were compared in the three groups of lesions; the prognostic value of these parameters was evaluated in the group of colorectal cancer. Most markers showed progressive vessel counts from non-neoplastic tissue to carcinoma, both for microvessel density and total vascular area. Only microvessel density determined by CD34 in the central areas of the cancer correlated with recurrence/metastasis (p=0.04) and survival (p=0.02). Different methods of quantification (microvessel counting versus estimation of total vascular area), immunohistochemical markers (pan-endothelial marker versus neovessels and lymphatic markers), and areas of analysis (periphery versus inner portions of the lesion) were assessed using image analysis. The results corroborate the increase in vascularization of carcinoma and suggest that microvessel density determined by immunostaining for CD34 in the inner portion of the tumor might represent a prognostically relevant parameter in colorectal cancer. © 2010 International Society of Oncology and BioMarkers (ISOBM).