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Dive into the research topics where Frederico Omar Gleber-Netto is active.

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Featured researches published by Frederico Omar Gleber-Netto.


Journal of Experimental & Clinical Cancer Research | 2010

Clinical significance of EGFR, Her-2 and EGF in oral squamous cell carcinoma: a case control study

Vanessa Fátima Bernardes; Frederico Omar Gleber-Netto; Sílvia Ferreira de Sousa; Tarcília Aparecida Silva; Maria Cássia Ferreira de Aguiar

BackgroundThe erbB receptors and their ligands are involved in the pathogenesis and progression of oral squamous cell carcinoma (OSCC). Although EGFR and Her-2 are frequently overexpressed in OSCC, few studies evaluated these proteins in saliva and their association with the tumor, which may represent potential usefulness in a clinical setting.MethodsThe levels of EGFR, Her-2, and EGF were evaluated in saliva of 46 patients with OSCC before and after the surgical removal of the lesion, as well as in matched healthy controls. The relationship of salivary levels and EGFR and Her-2 immunoexpression in tumor samples with clinicopathological features was analyzed.ResultsEGFR and Her-2 salivary levels did not show difference between to pre-surgery and control groups, however, both demonstrated an increase after surgical removal of the tumor. No association was detectable among receptor salivary levels, tissue expression and clinicopathological features. EGF levels in pre-surgery group were significantly lower when compared to the control group.ConclusionsEGFR and Her-2 were not considered to be valuable salivary tumor markers in OSCC, however, lower levels of EGF in saliva may suggest a higher susceptibility for OSCC development.


Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology | 2012

A comparative study of microvessel density in squamous cell carcinoma of the oral cavity and lip

Helenisa Helena Oliveira-Neto; Frederico Omar Gleber-Netto; Sílvia Ferreira de Sousa; Cristiane Miranda França; Maria Cássia Ferreira de Aguiar; Tarcília Aparecida Silva; Aline Carvalho Batista

OBJECTIVES The objective of this study was to comparatively evaluate the density of lymphatic vessels (LVD) and neoformed microvessels (NMVD) in squamous cell carcinoma of the oral cavity (OCSCC) and lip (LSCC). Association between LVD/NMVD and vascular endothelial growth factor (VEGF)-A/-C was also assessed. STUDY DESIGN OCSCC and LSCC were compared with regard to immunoexpression of LVD, NMVD, and vascular endothelial growth factor-A (VEGF)-A/-C. Association between VEGF-A/-C with vascularity was also assessed. Statistical analyses were performed using t test, Pearson χ(2), and Mann-Whitney tests. Statistical significance was accepted at P less than .05. RESULTS The NMVD and VEGF-C expressions were significantly higher in OCSCC compared with LSCC. NMVD was associated with VEGF-C in OCSCC, but not in LSCC. CONCLUSIONS Differences in NMVD and VEGF-C were found between OCSCC and LSCC. Positive association between VEGF-C and NMVD was observed in OCSCC, but not in LSCC, which may be one of the contributing factors that account for the distinctive clinical-biological behavior of these lesions.


Applied Immunohistochemistry & Molecular Morphology | 2012

Lymphangiogenesis and podoplanin expression in oral squamous cell carcinoma and the associated lymph nodes.

Sílvia Ferreira de Sousa; Frederico Omar Gleber-Netto; Helenisa Helena Oliveira-Neto; Aline Carvalho Batista; Mauro Henrique Nogueira Guimarães Abreu; Maria Cássia Ferreira de Aguiar

The objective of this study was to evaluate lymphangiogenesis in oral squamous cell carcinoma and in the associated lymph nodes and podoplanin expression in neoplastic cells at the invasive front. In addition, the association of the above parameters with lymph node metastasis was also investigated. We used immunohistochemistry to examine primary tumors and lymph nodes, regardless of metastasis. Lymphatic vessel density (LVD) and microvessel density (MVD) were assessed by antibodies D2-40 and CD105, respectively, in intratumoral and peritumoral areas and in lymph node regions. Vascular endothelial growth factor-C and vascular endothelial growth factor receptor-3 expression was evaluated in tumor cells and D2-40 (podoplanin) expression in parenchymal cells found at the invasive front. The majority of cases with nodal involvement presented a high peritumoral LVD. In addition, a strong association of LVD with size and site of primary tumors could also be identified. MVD was statistically associated with metastasis, and a significant association between the lymphangiogenic factors and the density of vessels in the intratumoral region was also seen. The well-differentiated tumors did not express podoplanin. LVD and MVD were higher in metastatic lymph nodes than in nonmetastatic lymph nodes. The enhanced vascular network in metastatic lymph nodes reinforces the previous reports of lymphangiogenesis occurrence in lymph nodes. Moreover, the expression of podoplanin by more undifferentiated tumor cells suggests that this protein could be an indicator of tumor aggressiveness.


BMJ Open | 2013

EGFR status in oral squamous cell carcinoma: comparing immunohistochemistry, FISH and CISH detection in a case series study.

Vanessa Fátima Bernardes; Frederico Omar Gleber-Netto; Sílvia Ferreira de Sousa; Rafael Malagoli Rocha; Maria Cássia Ferreira de Aguiar

Objectives To compare the immunohistochemistry (IHC) expression of epidermal growth factor receptor (EGFR) in oral squamous cell carcinomas (OSCC) with the gene amplification evaluated by fluorescence in situ hybridization (FISH) and chromogenic in situ hybridization (CISH) and their association with clinicopathological parameters. Additionally, we tested the sensibility and specificity of CISH in comparison with FISH. Design Case series study Setting Oral surgery and pathology department in a school of dentistry. Participants 52 patients with histopathological diagnosis of OSCC. Methods Tumour tissue samples from 52 patients with OSCC were evaluated by IHC, FISH and CISH using tissue microarray technology. Clinicopathological data from all patients were collected. Results EGFR+ rates were 53.8% (28/52) by IHC, 5.8% (3/52) by CISH and 15.4% (8/52) by FISH. Amplification detected by CISH and FISH with IHC negative occurred in 3.8% (2/52), and one case (1.9%) showed amplification detected by CISH and FISH and protein overexpression concomitantly. There were 9.6% FISH+ cases with IHC and CISH negative rates and 6/8 (75%) FISH+ and also EGFR+ cases; however, an association between protein expression and gene amplification was not found for both techniques. IHC and FISH rates were not associated with clinicopathological features. CISH+ rates were associated with T3–T4 status. Compared with FISH assay, CISH reached a sensitivity of 37.5% and specificity of 100%. Conclusions There is no association between EGFR expression and gene amplification in OSCC when the IHC is driven to external epitopes of the protein. Although CISH demonstrates specificity, technical problems may influence sensibility when compared with FISH.


Medicina Oral Patologia Oral Y Cirugia Bucal | 2012

Immunohistochemical expression of EGFR in oral leukoplakia: association with clinicopathological features and cellular proliferation.

Daniela Cotta Ribeiro; Frederico Omar Gleber-Netto; Sílvia Ferreira de Sousa; Vanessa Fátima Bernardes; Mauro Henrique Nogueira Guimarães-Abreu; Maria Cássia Ferreira de Aguiar

Objectives: to investigate the immunoexpression of epidermal growth factor receptor (EGFR) in a sample of oral leukoplakias (OL) and to determine the receptor’s association with dysplasia, tobacco consumption, lesion site, and proliferation rate. Although EGFR should be overexpressed in some oral leukoplakias, the factors that may interfere with this expression and the influence of this receptor on epithelial proliferation have yet to be investigated. Study Design: Samples of oral leukoplakias (48) and of normal oral epithelium (10) were immunohistologically examined for expression of EGFR. Immunohistochemistry for Ki-67, and p27 were also performed in leukoplakias. EGFR expression was associated with clinical and pathological features. Results: EGFR was positive in 62.5% of the leukoplakias and 50% of normal oral epithelium. The number of EGFR positive OL located in high-risk sites was significantly higher than EGFR positive OL located in low-risk sites. Most of the p27 negative leukoplakias were EGFR positive, and the p27 index in the parabasal layer was diminished in the presence of dysplasia. Positivity for EGFR was not associated with dysplasia, tobacco exposure, or Ki-67. Conclusion: EGFR is expressed in leukoplakia regardless of dysplasia, but EGFR positivity should be more frequent in lesions sited in areas of high cancer risk. The association between EGFR and p27 may represent an important mechanism in the control of cellular proliferation and malignant progression of oral epithelium and therefore warrants further investigation. Key words:Oral leukoplakia, EGFR, p27, Ki-67, epithelial dysplasia.


Applied Immunohistochemistry & Molecular Morphology | 2011

EGF in saliva and tumor samples of oral squamous cell carcinoma.

Vanessa Fátima Bernardes; Frederico Omar Gleber-Netto; Sílvia Ferreira de Sousa; Tarcília Aparecida Silva; Mauro Henrique Nogueira Guimarães de Abreu; Maria Cássia Ferreira de Aguiar

The objective of this research was to investigate the salivary levels of epidermal growth factor (EGF) in patients with oral squamous cell carcinoma (OSCC) in comparison with clinically healthy individuals and to verify the immunoexpression of EGF in tumor samples. In addition, the relationship between salivary levels and tumoral EGF expression with clinicopathologic features was investigated. We carried out an investigation on EGF expression in lesion samples and in saliva of OSCC patients through immunohistochemistry and enzyme-linked immunosorbent assay, respectively. EGF salivary levels of OSCC patients were also compared with levels in saliva of healthy controls. EGF levels were significantly lower in OSCC patients in comparison with the control group. Smoking, tumor location, and alcohol consumption affected salivary levels of EGF. Strong immunoexpression of EGF was associated with a more aggressive histologic pattern of the lesion. There was no significant association among salivary levels and immunohistochemical expression of EGF. Although EGF expression is frequently observed in tumors, salivary levels of EGF are reduced in patients with OSCC samples. Tobacco and alcohol may decrease EGF in saliva, which may contribute to oral carcinogenesis. Indeed, further investigations are needed to elucidate the EGF pathways.


Journal of Oral Pathology & Medicine | 2012

Angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma of minor salivary glands

Frederico Omar Gleber-Netto; Taynara Nunes Guedes Florêncio; Sílvia Ferreira de Sousa; Mauro Henrique Nogueira Guimarães de Abreu; Elismauro Francisco Mendonça; Maria Cássia Ferreira de Aguiar

BACKGROUND Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands. This tumor is characterized by a great variability in clinical behavior, and little is known about the pathological mechanisms involved in its variance. Angiogenesis is an important step in tumor progression and is believed to be an essential event for metastatic dissemination. METHODS We aimed to investigate angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma measuring the density of neoformed and lymphatic vessels using CD105 and D2-40 antibodies, respectively, and by immunohistochemical evaluation of VEGF-A and VEGF-C proteins. It was also investigated the expression of D2-40 in neoplastic cells. RESULTS We studied 26 cases of mucoepidermoid carcinoma, which showed great angiogenic activity measured by neoformed vessel density. However, a low density of lymphatics was observed. VEGF-A, VEGF-C, and D2-40 were commonly detected in mucoepidermoid carcinoma, but only VEGF-A expression correlated with neoformed vessel density. Recurrence and nodal metastasis were associated with low VEGF-A expression and low neoformed vessel density, indicating that impaired angiogenesis could lead to an aggressive phenotype. CONCLUSIONS Angiogenesis seems important in the modulation of mucoepidermoid carcinoma pathogenesis; however, none of the parameters analyzed could predict tumor behavior.


Abstracts: AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; April 23-25, 2017; San Diego, CA | 2017

Abstract 42: Identification of gene expression patterns distinguishing responders and non-responders to induction chemotherapy in sinonasal undifferentiated carcinoma

Yoko Takahashi; Diana Bell; Frederico Omar Gleber-Netto; Tongxin Xie; Dianna B. Roberts; Curtis R. Pickering; Jeffrey N. Myers; Ehab Y. Hanna

Background: Sinonasal undifferentiated carcinoma (SNUC) is a rare, highly aggressive cancer that arises in the nasal cavity and paranasal sinuses. Despite aggressive multimodal therapy the prognosis remains poor, and the median survival time is less than 18 months. Because of its locally advanced nature, cisplatin-based induction chemotherapy has been used in our institution to downstage unresectable tumors before definitive surgery or radiation therapy. Interestingly, our previous study showed that response to induction chemotherapy is a prognostic indicator and may be used to select patients for definitive local treatment. In this study, we performed gene expression analysis on SNUC specimens to identify molecular markers to predict/distinguish between responders and non-responders to induction chemotherapy. Materials and Methods: Twenty-seven formalin-fixed paraffin-embedded samples from 24 patients treated at MD Anderson Cancer Center between 1999 to 2016 were used in this study. Among them, 12 specimens were treatment-naive. Gene expression analysis was performed on an HTG EdgeSeq Oncology Biomarker Panel. Unsupervised clustering analysis and Mann-Whitney test were performed using JMP software and IBM SPSS Statistics 23, previously. Pathway analysis was performed using Ingenuity Pathway Analysis. Results: First, we attempted to identify a set of genes which could predict response to induction chemotherapy. Unfortunately, unsupervised clustering analysis on treatment-naive specimen was incapable of distinguishing between responders and non-responders. However, using discriminant analysis we succeeded in finding genes classifying patients into responders and non-responders. Then we studied the tumor specimens harvested after induction chemotherapy; differentially expressed genes between the two groups (Mann-Whitney test; p Conclusions: Our study revealed the possibility that cell survival and proliferation pathways are upregulated in non-responders to induction chemotherapy in SNUC. This finding suggests that non-responders to induction chemotherapy might be treated by inhibiting those pathways. Our comprehensive gene expression study is a significant step towards developing new therapeutic approaches in SNUC. Citation Format: Yoko Takahashi, Diana Bell, Frederico O. Gleber-Netto, Tong-Xin Xie, Dianna Roberts, Curtis Pickering, Jeffrey N. Myers, Ehab Y. Hanna. Identification of gene expression patterns distinguishing responders and non-responders to induction chemotherapy in sinonasal undifferentiated carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; April 23-25, 2017; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(23_Suppl):Abstract nr 42.


Cancer Research | 2016

Abstract 3697: Gastric adenocarcinoma TP53 mutations in an ethnically admixed population

Melissa Pool Pizzi; Helano Carioca Freitas; Maria Galli Amorim; Bruna D. F. Barros; Frederico Omar Gleber-Netto; Ana Flávia Mattos Costa; Maria Dirlei Begnami; Adriane Pelosof; Diana N. Nunes; Emmanuel Dias-Neto

TP53 protein is one of the most important and studied human tumor suppressors. Whereas TP53 drives the malignant transformation and is the most frequently mutated gene in human cancers, the location and the type of its mutations for specific tumor types in ethnically admixed populations have not been evaluated. In this study we employed an amplicon panel to capture and to deep-sequence all the exons of TP53 in a series of 29 tumor biopsy samples derived from Brazilian individuals diagnosed with gastric adenocarcinomas (GACs), which were compared to Asian and Europeans. TP53 sequences were obtained from Brazilian samples with the Ion Torrent AmpliSeq TP53-panel and determined in the Ion PGM Torrent and Ion Proton platforms. We generated a mean of 7.25 million reads per patient, resulting in a median coverage >13,000X. All samples were covered above 6,400X. The mutations observed here were compared to those described in patients from different ethnic groups obtained from TCGA composed for 103 Asians patients (Japan, Hong-Kong, South Korea, Vietnam) and 78 cases of Europeans. The Asian and European populations showed higher prevalence of intestinal type GAC (53.7% and 61.6%, respectively) in contrast to our cohort, in which 69% of the patients had diffuse-type GACs (p A p.Arg282Trp in the DNA binding domain in exon 8, was found in all three sample groups studied, suggesting a possible role for this mutation in GAC pathogenesis. Although TP53 is the most frequently mutated gene in GACs we found no specific patterns that could explain the differences in the clinical behavior of this tumor between Asian and non-Asian patients. Further analyses are being performed trying to correlate mutations in TP53 and other genes with the different clinical outcomes observed in GACs from Asians and non-Asians, and in a setting of high genetic admixture, as observed in Brazil. Citation Format: Melissa Pool Pizzi, Helano Carioca Freitas, Maria Galli Amorim, Bruna Duraes de Figueiredo Barros, Frederico Omar Gleber-Netto, Ana Flavia Mattos Costa, Maria Dirlei Begnami, Adriane Graicer Pelosof, Diana Noronha Nunes, Emmanuel Dias-Neto. Gastric adenocarcinoma TP53 mutations in an ethnically admixed population. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3697.


Cancer Research | 2011

Abstract LB-289: Angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma of the minor salivary glands

Frederico Omar Gleber-Netto; Taynara Nunes Guedes Florêncio; Sílvia Ferreira de Sousa; Elismauro Francisco Mendonça; Carolina Cavaliéri Gomes; Maria Cássia Ferreira de Aguiar

The purpose of this study was to investigate angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma (MEC) of the minor salivary glands as potential predictors of tumor behavior. Intratumoral and peritumoral neoformed (NMVD) and lymphatic microvessel density (LMVD) were evaluated by CD105 and D2–40 immunohistochemistry, respectively. D2–40, VEGF-A, and VEGF-C immunoexpression were also investigated in tumor parenchyma. Twenty-six paraffin-embedded MEC samples were included in the study. Palate (50%) and buccal mucosa (19.2%) were the main affected sites. Sixteen (61.5%) tumors were low-grade, 6 (23.1%) intermediate-grade, and 4 (15.4%) high-grade. Twenty (77%) cases were clinically T1-T2, and 6 (23%) were T3-T4. Nodal metastasis occurred in 3 (11.5%) cases and distant metastasis in 1 (3.8%). Three (11.5%) cases recurred, and 3 (11.5%) patients died from disease. NMVD mean was 19.58±13.91 (400x field) for intratumoral evaluation and 10.90±7.79 (400x field) for peritumoral evaluation. LMVD mean was 5.66±3.43 (400x field) for peritumoral evaluation and 0.54±3.43 (400x field) for intratumoral evaluation. Just 6 (23.1%) cases reveal intratumoral lymphatic vessels. Twenty-two (84,6%) cases showed D2–40 in neoplastic cells, mainly in epidermoid type. Fifteen (57.7%) cases were positive for VEGFA, and 11 (42.3%) were positive for VEGF-C. A positive association was observed between VEGF-A positivity and intratumoral NMVD (p=0.05). Cases with nodal metastasis, altogether, were related to low intratumoral NMVD, high peritumoral LMVD, D2–40 expression and absence of VEGF-A. Distant metastasis was associated with low intratumoral NMVD, high peritumoral LMVD, D2–40 positivity and absence of VEGF-A and VEGF-C expression. Recurrent cases presented low intratumoral NMVD, and absence of VEGF-A and VEGF-C expression. Low intratumoral NMVD, and D2–40 positive cells were found in all tumors of patients that died of the disease. In conclusion, although NMVD, LMVD, D2–40, VEGF-A, and VEGF-C could not predict the prognosis of MEC, intratumoral NMVD, peritumoral LMVD, D2–40 and VEGF-A expression seems play a role in the occurrence of a worse behavior in this disease. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-289. doi:10.1158/1538-7445.AM2011-LB-289

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Dive into the Frederico Omar Gleber-Netto's collaboration.

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Maria Cássia Ferreira de Aguiar

Universidade Federal de Minas Gerais

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Sílvia Ferreira de Sousa

Universidade Federal de Minas Gerais

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Vanessa Fátima Bernardes

Universidade Federal de Minas Gerais

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Aline Carvalho Batista

Universidade Federal de Goiás

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Helenisa Helena Oliveira-Neto

Universidade Federal de Minas Gerais

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Tarcília Aparecida Silva

Universidade Federal de Minas Gerais

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Carolina Cavaliéri Gomes

Universidade Federal de Minas Gerais

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Taynara Nunes Guedes Florêncio

Universidade Federal de Minas Gerais

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