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Published Papers by Ricardo Hsieh

Research paper thumbnail of Does BCL-2 Play Role in the Pathogenesis of Primary Oral Mucosal Melanoma

Journal of Medical Research and Surgery, 2020

Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignan... more Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignant neoplasia. The etiology still unknown, however, it has been suggested that head and neck mucosal melanomas change their genetic and metabolic pathways through intracellular cascades, which are associated with its etiopathogenesis mechanisms. The BCL2 protein is an integral part of the cell membrane, and it is also found in the cell nucleus, mitochondria, and endoplasmic reticulum. It is overexpressed in several malignant neoplasms, including cutaneous e ocular melanomas. Among all evaluated cases, we found positive immunostaining of BCL-2 in 26/34 (76.47%) and they had a membrane and cytoplasmic pattern, and the intensity was variable. According to our results and the findings of the literature, it can be suggested that BCL-2 has an important role in melanoma pathogenesis, including Primary Oral Mucosal Melanoma and also melanoma metastases. It seems that BCL-2 could be an adjunct marker for POMM and also a target for treatment development. New researches involving BCL-2 and a larger primary oral mucosal melanoma cohort could corroborate the present study.

Papers by Ricardo Hsieh

Research paper thumbnail of Head and Neck Mucosal Melanoma

American Journal of Clinical Oncology, 2005

The purpose of this article is to discuss the optimal treatment and outcomes for head and neck mu... more The purpose of this article is to discuss the optimal treatment and outcomes for head and neck mucosal melanoma. Methods: Review the pertinent literature. Results: Head and neck mucosal melanoma is a rare entity comprising less than 1% for all Western melanomas. It usually arises in the nasal cavity, paranasal sinuses, and oral cavity. The optimal treatment is surgery. The likelihood of local recurrence after resection is approximately 50%. Radiotherapy (RT) reduces the likelihood of local failure but probably does not enhance survival, which is primarily impacted by advanced T stage and the presence of regional metastases. The 5-year survival rates vary from approximately 20 to 50%. Although the median time to relapse is roughly 1 year or less, late failures are common and cause-specific survival continues to decline after 5 years. Conclusion: The optimal treatment is surgery. Postoperative RT improves local-regional control but may not impact survival. Definitive RT may occasionally cure patients with unresectable localregional disease or at least provide long-term palliation.

Research paper thumbnail of The Role of Dentist in the Diagnosis of Primary Sjögren Syndrome

Research paper thumbnail of Use of uracil-DNA glycosylase enzyme to reduce DNA-related artifacts from formalin-fixed and paraffin-embedded tissues in diagnostic routine

Applied Cancer Research, Jul 10, 2019

Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in ... more Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in precision oncology. However, somatic mutation detection protocols use DNA from formalin-fixed and paraffin-embedded (FFPE) tumor tissues, which can result in detection of nonreproducible sequence artifacts, especially C:G > T:A transitions, in DNA. In recent studies, DNA pretreatment with uracil DNA glycosylase (UDG), an enzyme involved in base excision repair, significantly reduced the number of DNA artifacts after mutation detection by next-generation sequencing (NGS) and other methods, without affecting the capacity to detect real mutations. This study aimed to evaluate the effects of UDG enzymatic pretreatment in reducing the number of DNA sequencing artifacts from FFPE tumor samples, to improve the accuracy of genetic testing in the molecular diagnostic routine. Methods: We selected 12 FFPE tumor samples (10 melanoma, 1 lung, and 1 colorectal tumor sample) with different storage times. We compared sequencing results of a 16-hotspot gene panel of NGS libraries prepared with UDG-treated and untreated samples. Results: All UDG-treated samples showed large reductions in the total number of transitions (medium reduction of 80%) and the transition/transversion ratio (medium reduction of 75%). In addition, most sequence artifacts presented a low variant allele frequency (VAF < 10%) which are eliminated with UDG treatment. Conclusion: Including UDG enzymatic treatment before multiplex amplification in the NGS workflow significantly decreased the number of artifactual variants detected in FFPE samples. Thus, including this additional step in the current methodology should improve the rate of true mutation detection in the molecular diagnostic routine.

Research paper thumbnail of Primary oral mucosal melanoma: an immunohistochemistry and molecular study of MAPK pathway

INTRODUÇÃO: O melanoma primário da cavidade oral é uma neoplasia agressiva, rara e originada a pa... more INTRODUÇÃO: O melanoma primário da cavidade oral é uma neoplasia agressiva, rara e originada a partir da proliferação de melanócitos malignos da mucosa. Ele representa aproximadamente de 0,2 a 8% de todos os melanomas. Estudos recentes apontam algumas vias moleculares tem sido encontradas por estarem envolvidas na patogenia dos melanomas. Dentre essas vias destaca-se a via proliferativa da MAPK (mitogen activated protein kinase), esta cascata de sinalização está envolvida no controle do crescimento celular, proliferação e migração, e tem sido relacionada com um papel importante no desenvolvimento e progressão do melanoma cutâneo. OBJETIVOS: Analisar a expressão proteica e mutação pontual dos componentes da via MAPK e correlacionar com os dados clínicos-histológicos. MATERIAL E MÉTODOS: Através da imunoistoquímica avaliar a expressão proteica dos anticorpos RAS; BRAF; MEK1; MEK2; ERK1 e ERK2 em 35 casos de melanomas orais organizados em matriz (TMA: Tissue Microarray) e através de pi...

Research paper thumbnail of The Role of Dentist in the Diagnosis of Primary Sjögren Syndrome

Research paper thumbnail of Malignant salivary gland tumors: A short review

Dental, Oral and Maxillofacial Research, 2021

Both major and minor salivary glands can develop benign or malignant tumors. Malignant Salivary G... more Both major and minor salivary glands can develop benign or malignant tumors. Malignant Salivary Gland Tumors (MSGT) are very rare and they haves a great pathological diversity. It is known that their tumorigenesis is a very complex and dynamic process, which is divided into three stages: initiation, progression and metastasis. In addition to grade and tumor stage, both the presence of lymph node and distant metastases are considered primary factors associated with disease prognosis, recurrence and survival in MSGT patients. The etiopathogenesis and biological behavior of these particular tumors remain unclear, thus, further new investigations involving protein and molecular analysis are needed to have a better understanding of these cancers.

Research paper thumbnail of Primary Oral Mucosal Melanoma: a Short Review

Journal of Pigmentary Disorders, 2015

Primary Oral Mucosal Melanoma (POMM) is a very rare entity and it develops from malignant transfo... more Primary Oral Mucosal Melanoma (POMM) is a very rare entity and it develops from malignant transformation of melanocytes from mucosal epithelium. POMM has a very poor prognosis and aggressive behavior. It represents only 0.5% of all oral malignancies, accounting 0.2 to 8% of all melanomas, with an incidence of 1.2 cases per 10 million per year. POMM is asymptomatic in its early stages and usually not noticed by the patients, resulting in the delay in diagnosis. Immunoreactivity of melanoma cells to antibodies against: S-100 protein; Melan-A (MART-1) and HMB-45 (gp100) can be very useful to distinguish POMM from other malignancies. Others markers may indicate variations in its biologic behavior and prognosis, such as Ki-67; P53 and P16, and maybe useful for prognostic prediction.

Research paper thumbnail of Use of uracil-DNA glycosylase enzyme to reduce DNA-related artifacts from formalin-fixed and paraffin-embedded tissues in diagnostic routine

Applied Cancer Research, 2019

Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in ... more Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in precision oncology. However, somatic mutation detection protocols use DNA from formalin-fixed and paraffin-embedded (FFPE) tumor tissues, which can result in detection of nonreproducible sequence artifacts, especially C:G > T:A transitions, in DNA. In recent studies, DNA pretreatment with uracil DNA glycosylase (UDG), an enzyme involved in base excision repair, significantly reduced the number of DNA artifacts after mutation detection by next-generation sequencing (NGS) and other methods, without affecting the capacity to detect real mutations. This study aimed to evaluate the effects of UDG enzymatic pretreatment in reducing the number of DNA sequencing artifacts from FFPE tumor samples, to improve the accuracy of genetic testing in the molecular diagnostic routine. Methods: We selected 12 FFPE tumor samples (10 melanoma, 1 lung, and 1 colorectal tumor sample) with different storage times. We compared sequencing results of a 16-hotspot gene panel of NGS libraries prepared with UDG-treated and untreated samples. Results: All UDG-treated samples showed large reductions in the total number of transitions (medium reduction of 80%) and the transition/transversion ratio (medium reduction of 75%). In addition, most sequence artifacts presented a low variant allele frequency (VAF < 10%) which are eliminated with UDG treatment. Conclusion: Including UDG enzymatic treatment before multiplex amplification in the NGS workflow significantly decreased the number of artifactual variants detected in FFPE samples. Thus, including this additional step in the current methodology should improve the rate of true mutation detection in the molecular diagnostic routine.

Research paper thumbnail of RTKs and transcription factors proteins analysis in a series of head and neck mucosal melanoma

Journal of Clinical & Experimental Dermatology Research, 2016

Although skin is the largest organ of the body, there are no standardized reproducible methods fo... more Although skin is the largest organ of the body, there are no standardized reproducible methods for assessing severity of many skin diseases. Due to lack of consensus, methods of assessment and inexistence of precise scoring system, there is no application for vitiligo estimation in real practice. In this paper the author describes VETI score as a new treatment evaluation criteria and severity assessment method for vitiligo. This new tool, as does the PASI score in psoriasis, may be able to produce a constant and reproducible number and to help clinical research on vitiligo patients. Additionally it has a potential to be a source of any computed application for researchers working on vitiligo patients.

Research paper thumbnail of Expressão da proteína p16, ciclina D1, CDK4 e proteína do retinoblastoma no melanoma acral lentiginoso

À minha orientadora Profa. Dra. Mirian Nacagami Sotto, por incentivar o meu progresso acadêmico e... more À minha orientadora Profa. Dra. Mirian Nacagami Sotto, por incentivar o meu progresso acadêmico e confiar no meu potencial; pela sua paciência, ajuda e dedicação durante todo este projeto, por toda sua dedicação à pesquisa, pela qual eu me inspiro. Agradeço a confiança e apoio nos bons momentos e também nas horas mais difíceis, e por estar sempre presente durante todas as etapas deste percurso, desde a iniciação científica até a pós-graduação, como professora e orientadora dedicada. À Profa. Dra. Sílvia Vanessa Lourenço, por incentivar e ensinar o papel importante da pesquisa. Agradeço a confiança e apoio, desde a iniciação científica até a pós-graduação, como professora dedicada e como amiga. Ao Prof. Dr. Fernando Augusto Soares, Professor Titular da disciplina de Patologia Geral da FOUSP, pela ajuda no fornecimento e padronização dos anticorpos utilizados neste trabalho. À Aline Firmiano, por sua dedicação, apoio e auxilio na execução e realização deste trabalho. À Sabrina Hitomi Uyekita e ao Fábio Rodrigues Gonçalves de Carvalho, grandes amigos, colegas de graduação, de iniciação científica e de pósgraduação. Obrigado pela amizade, apoio, ajuda e incentivo ao longo destes anos. A todos os colegas do Instituto de Medicina Tropical (IMT), pela ajuda e cooperação e pelo ótimo ambiente que desfrutei ao longo destes anos. Aos funcionários da Divisão de Dermatologia do HC-FMUSP por toda a ajuda e contribuição neste trabalho. Aos meus pais pelo amor, apoio incondicional, educação, compreensão, ajuda nos momentos mais complicados e confiança nas minhas decisões. A CAPES pelo incentivo à pesquisa através contemplação da bolsa de Mestrado (Portaria CAPES No. 52/002).

Research paper thumbnail of Neural and Vascular Invasions of Oral Squamous Cell Carcinomas

Journal of Oral Hygiene & Health, 2015

Objective: The aim of this retrospective study was to identify perineural and vascular invasions ... more Objective: The aim of this retrospective study was to identify perineural and vascular invasions in Oral Squamous Cell Carcinoma lesions. Methods: A series of 29 OSSC-diagnosed patients and their clinical and demographic data were collected. In order to identify invasive process, Hematoxiline and Eosin (HE) staining of all cases were analysed and CD31, CD34, S100 and PGP9.5 protein expression were performed by immunhistochemistry. Results: All data were statistically assessed by Kappa test and McNemar's. We identified vascular and perineural invasions in 17.2% and 31% of cases, respectively, by HE staining analysis. We found intense peritumoral microvascular density in 82.8% of cases, by CD31 immunostaining. The CD34 antibody was recorded only 6.9% of cases with vascular invasion. Perineural invasion was detected in 44.8% of S100 protein immunostained cases, and 58.6% of cases were immunostained by PGP9.5 protein. Conclusion: According to our H/E and immunohistochemistry analysis, regarding the presence of perineural invasion, PGP9.5 protein was more effective than the others. It was concluded that the identification of vascular and perineural invasions is a useful tool for the prognosis of patients with oral squamous cell carcinoma, thus histopathological and immunohistochemistry methods should be combined for an effective analysis for this tumor.

Research paper thumbnail of Does BCL-2 Play Role in the Pathogenesis of Primary Oral Mucosal Melanoma?

Journal of Medical Research and Surgery

Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignan... more Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignant neoplasia. The etiology still unknown, however, it has been suggested that head and neck mucosal melanomas change their genetic and metabolic pathways through intracellular cascades, which are associated with its etiopathogenesis mechanisms. The BCL2 protein is an integral part of the cell membrane, and it is also found in the cell nucleus, mitochondria, and endoplasmic reticulum. It is overexpressed in several malignant neoplasms, including cutaneouse ocular melanomas. Among all evaluated cases, we found positive immunostaining of BCL-2 in 26/34 (76.47%) and they had a membrane and cytoplasmic pattern, and the intensity was variable. According to our results and the findings of the literature, it can be suggested that BCL-2 has an important role in melanoma pathogenesis, including Primary Oral Mucosal Melanoma and also melanoma metastases. It seems that BCL-2 could be an adjunct marke...

Research paper thumbnail of Estudo imuno‐histoquímico de citoqueratinas no folículo piloso humano em desenvolvimento

Anais Brasileiros De Dermatologia, 2020

a Programa de Pós-Graduação em Medicina e Saúde, Faculdade de Medicina da Bahia, Universidade Fed... more a Programa de Pós-Graduação em Medicina e Saúde, Faculdade de Medicina da Bahia, Universidade Federal da Bahia, Salvador, BA, Brasil b Serviço de Dermatologia, Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brasil c Serviço de Dermatologia, Hospital Santa IzabelSalvador, BA, Brasil d Departamento de Dermatologia, Faculdade de Medicina, Universidade Federal da Bahia, Salvador, BA, Brasil e Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brasil f Departamento de Patologia, Universidade Federal de Alfenas, Alfenas, MG, Brasil g Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP, Brasil h Departamento de Dermatologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil i Setor de Patologia, Hospital Santa Izabel, Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brasil

Research paper thumbnail of Could mucin 16 and colony-stimulating factor 2-receptor beta possible graft versus host disease biomarkers? Medical hypotheses

Medical Hypotheses, 2017

Graft versus host disease (GVHD) occurs after bone marrow transplantation and is one of the most ... more Graft versus host disease (GVHD) occurs after bone marrow transplantation and is one of the most important causes of death worldwide. Reviews demonstrated GVHD patients with involvement of various tissues and organs, such as salivary glands. The diagnosis of acute GVHD has been the biopsies and the histopathologic evaluation of tissue from an involved organ. These procedures are invasive. Saliva proteins as possible biomarker for GVHD could facilitate the management and diagnosis accuracy. For support the proposed hypotheses, in this pilot study we collected whole saliva samples from patients with undergoing allogeneic hematopoietic cell transplantation (HCT) and from healthy subjects. Samples were collected prospectively between pre-transplant, thirty days, one hundred and, two hundred days after transplant. The proteomic profile was analyzed using SDS-PAGE and LCMS-ESI-IT-TOF mass spectrometry. The relevant personal data, past medical history were also recorded. The most relevant proteins found exclusively in GVHD patients were: CSF2RB, Protocadherin (Pcdh) Fat 2 precursor, protein capicua homolog isoform CIC-S, MUC16 and RGPD8_HUMAN RANBP2. This study aims to conduct an initial evaluation of the possible presence of such biomarkers in saliva from GVHD patients, and suggested a potential application of proteomics analysis as a alternative method to diagnose GVHD.

Research paper thumbnail of Melanoma primário da mucosa oral: estudo imunoistoquímico e molecular da via da MAPK

Research paper thumbnail of Actionable Mutation Profile of Sun-Protected Melanomas in South America

The American Journal of Dermatopathology

Research paper thumbnail of Claudin expression is maintained in mucoepidermoid carcinoma of the salivary gland

Pathology - Research and Practice

The aim of the present study was to investigate the expression of claudin-1,-3,-4,-5 and-7 protei... more The aim of the present study was to investigate the expression of claudin-1,-3,-4,-5 and-7 proteins in mucoepidermoid carcinoma of oral cavity and analyze whether EGF may interfere in the expression of the genes that encode claudins using in vitro models. Material and methods: Using immunohistochemistry, the expression of claudins was searched in 36 histologically graded cases of mucoepidermoid carcinoma. The association of expression of claudins with clinical-pathological parameters was evaluated. An in vitro step investigated the influence of EGF on gene expression of claudins by real time RT-PCR technique. Results: Claudin-1,-3,-4,-5, and-7 were highly expressed in most mucoepidermoid carcinomas. These expressions were compared with clinicopathological parameters. High expression of claudin-1 was associated with patients over 40 years-old (p = 0.05) and Caucasians (p = 0.024). In vitro experiments demonstrated a tendency for Claudin gene expression increase after EGF stimulus. Conclusions: The expression of claudins is maintained in mucoepidermoid carcinoma cells and EGF could be related with this expression. Our results point out to a fundamental biological importance to CLDNs in normal and neoplastic tissue. The expression patterns of CLDNs does not yet allow a clinical application, but the biological knowledge will ground evidence to new studies towards possible target-therapies.

Research paper thumbnail of Immunoexpression of Adhesion Molecules During Human Fetal Hair Development

Revista Científica Hospital Santa Izabel, 2021

SummaryBackground: Hair follicles are produced in a cyclical manner and the machinery involved in... more SummaryBackground: Hair follicles are produced in a cyclical manner and the machinery involved in the reproduction of these follicles is present since the fetal stage. Although extensive research has been done on the human hair follicle, very little is known about the importance of adhesion molecules in its development. Methods: We analyzed here, the immunoexpression of beta-1 integrin, p-cadherin, e- cadherin, and beta-catenin in hair follicles from 26 formalin-fixed and paraffin-embedded skin samples from human embryos and fetus between 12-23 weeks of gestational age. Findings: The adhesion molecules beta-1 integrin and e-cadherin/p-cadherin were expressed from 12 weeks and seemed to play a role in regulating epidermis invagination. Beta-catenin immuno stainingwas negative in all cases; down regulation of this protein may be necessary for fetal hair development and thus facilitating hair follicle down growth. Conclusion: Adhesion molecules are essential for hair follicle down grow...

Research paper thumbnail of Epithelial-mesenchymal transition related to bone invasion in oral squamous cell carcinoma

Journal of Bone Oncology, 2022

Highlights • Presence of epithelial-mesenchymal transition markers in tumor-bone interface.• Domi... more Highlights • Presence of epithelial-mesenchymal transition markers in tumor-bone interface.• Dominant infiltrative pattern in bone tissue is associated with lower survival.• E-cadherin-positive cases were associated with tobacco smoking.• Vimentin-positive cases were associated with tumors under 4 cm.• Twist could be strongly involved in bone invasion and in disease progression.

Research paper thumbnail of Does BCL-2 Play Role in the Pathogenesis of Primary Oral Mucosal Melanoma

Journal of Medical Research and Surgery, 2020

Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignan... more Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignant neoplasia. The etiology still unknown, however, it has been suggested that head and neck mucosal melanomas change their genetic and metabolic pathways through intracellular cascades, which are associated with its etiopathogenesis mechanisms. The BCL2 protein is an integral part of the cell membrane, and it is also found in the cell nucleus, mitochondria, and endoplasmic reticulum. It is overexpressed in several malignant neoplasms, including cutaneous e ocular melanomas. Among all evaluated cases, we found positive immunostaining of BCL-2 in 26/34 (76.47%) and they had a membrane and cytoplasmic pattern, and the intensity was variable. According to our results and the findings of the literature, it can be suggested that BCL-2 has an important role in melanoma pathogenesis, including Primary Oral Mucosal Melanoma and also melanoma metastases. It seems that BCL-2 could be an adjunct marker for POMM and also a target for treatment development. New researches involving BCL-2 and a larger primary oral mucosal melanoma cohort could corroborate the present study.

Research paper thumbnail of Head and Neck Mucosal Melanoma

American Journal of Clinical Oncology, 2005

The purpose of this article is to discuss the optimal treatment and outcomes for head and neck mu... more The purpose of this article is to discuss the optimal treatment and outcomes for head and neck mucosal melanoma. Methods: Review the pertinent literature. Results: Head and neck mucosal melanoma is a rare entity comprising less than 1% for all Western melanomas. It usually arises in the nasal cavity, paranasal sinuses, and oral cavity. The optimal treatment is surgery. The likelihood of local recurrence after resection is approximately 50%. Radiotherapy (RT) reduces the likelihood of local failure but probably does not enhance survival, which is primarily impacted by advanced T stage and the presence of regional metastases. The 5-year survival rates vary from approximately 20 to 50%. Although the median time to relapse is roughly 1 year or less, late failures are common and cause-specific survival continues to decline after 5 years. Conclusion: The optimal treatment is surgery. Postoperative RT improves local-regional control but may not impact survival. Definitive RT may occasionally cure patients with unresectable localregional disease or at least provide long-term palliation.

Research paper thumbnail of The Role of Dentist in the Diagnosis of Primary Sjögren Syndrome

Research paper thumbnail of Use of uracil-DNA glycosylase enzyme to reduce DNA-related artifacts from formalin-fixed and paraffin-embedded tissues in diagnostic routine

Applied Cancer Research, Jul 10, 2019

Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in ... more Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in precision oncology. However, somatic mutation detection protocols use DNA from formalin-fixed and paraffin-embedded (FFPE) tumor tissues, which can result in detection of nonreproducible sequence artifacts, especially C:G > T:A transitions, in DNA. In recent studies, DNA pretreatment with uracil DNA glycosylase (UDG), an enzyme involved in base excision repair, significantly reduced the number of DNA artifacts after mutation detection by next-generation sequencing (NGS) and other methods, without affecting the capacity to detect real mutations. This study aimed to evaluate the effects of UDG enzymatic pretreatment in reducing the number of DNA sequencing artifacts from FFPE tumor samples, to improve the accuracy of genetic testing in the molecular diagnostic routine. Methods: We selected 12 FFPE tumor samples (10 melanoma, 1 lung, and 1 colorectal tumor sample) with different storage times. We compared sequencing results of a 16-hotspot gene panel of NGS libraries prepared with UDG-treated and untreated samples. Results: All UDG-treated samples showed large reductions in the total number of transitions (medium reduction of 80%) and the transition/transversion ratio (medium reduction of 75%). In addition, most sequence artifacts presented a low variant allele frequency (VAF < 10%) which are eliminated with UDG treatment. Conclusion: Including UDG enzymatic treatment before multiplex amplification in the NGS workflow significantly decreased the number of artifactual variants detected in FFPE samples. Thus, including this additional step in the current methodology should improve the rate of true mutation detection in the molecular diagnostic routine.

Research paper thumbnail of Primary oral mucosal melanoma: an immunohistochemistry and molecular study of MAPK pathway

INTRODUÇÃO: O melanoma primário da cavidade oral é uma neoplasia agressiva, rara e originada a pa... more INTRODUÇÃO: O melanoma primário da cavidade oral é uma neoplasia agressiva, rara e originada a partir da proliferação de melanócitos malignos da mucosa. Ele representa aproximadamente de 0,2 a 8% de todos os melanomas. Estudos recentes apontam algumas vias moleculares tem sido encontradas por estarem envolvidas na patogenia dos melanomas. Dentre essas vias destaca-se a via proliferativa da MAPK (mitogen activated protein kinase), esta cascata de sinalização está envolvida no controle do crescimento celular, proliferação e migração, e tem sido relacionada com um papel importante no desenvolvimento e progressão do melanoma cutâneo. OBJETIVOS: Analisar a expressão proteica e mutação pontual dos componentes da via MAPK e correlacionar com os dados clínicos-histológicos. MATERIAL E MÉTODOS: Através da imunoistoquímica avaliar a expressão proteica dos anticorpos RAS; BRAF; MEK1; MEK2; ERK1 e ERK2 em 35 casos de melanomas orais organizados em matriz (TMA: Tissue Microarray) e através de pi...

Research paper thumbnail of The Role of Dentist in the Diagnosis of Primary Sjögren Syndrome

Research paper thumbnail of Malignant salivary gland tumors: A short review

Dental, Oral and Maxillofacial Research, 2021

Both major and minor salivary glands can develop benign or malignant tumors. Malignant Salivary G... more Both major and minor salivary glands can develop benign or malignant tumors. Malignant Salivary Gland Tumors (MSGT) are very rare and they haves a great pathological diversity. It is known that their tumorigenesis is a very complex and dynamic process, which is divided into three stages: initiation, progression and metastasis. In addition to grade and tumor stage, both the presence of lymph node and distant metastases are considered primary factors associated with disease prognosis, recurrence and survival in MSGT patients. The etiopathogenesis and biological behavior of these particular tumors remain unclear, thus, further new investigations involving protein and molecular analysis are needed to have a better understanding of these cancers.

Research paper thumbnail of Primary Oral Mucosal Melanoma: a Short Review

Journal of Pigmentary Disorders, 2015

Primary Oral Mucosal Melanoma (POMM) is a very rare entity and it develops from malignant transfo... more Primary Oral Mucosal Melanoma (POMM) is a very rare entity and it develops from malignant transformation of melanocytes from mucosal epithelium. POMM has a very poor prognosis and aggressive behavior. It represents only 0.5% of all oral malignancies, accounting 0.2 to 8% of all melanomas, with an incidence of 1.2 cases per 10 million per year. POMM is asymptomatic in its early stages and usually not noticed by the patients, resulting in the delay in diagnosis. Immunoreactivity of melanoma cells to antibodies against: S-100 protein; Melan-A (MART-1) and HMB-45 (gp100) can be very useful to distinguish POMM from other malignancies. Others markers may indicate variations in its biologic behavior and prognosis, such as Ki-67; P53 and P16, and maybe useful for prognostic prediction.

Research paper thumbnail of Use of uracil-DNA glycosylase enzyme to reduce DNA-related artifacts from formalin-fixed and paraffin-embedded tissues in diagnostic routine

Applied Cancer Research, 2019

Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in ... more Background: Detection of somatic mutations is a mandatory practice for therapeutic definition in precision oncology. However, somatic mutation detection protocols use DNA from formalin-fixed and paraffin-embedded (FFPE) tumor tissues, which can result in detection of nonreproducible sequence artifacts, especially C:G > T:A transitions, in DNA. In recent studies, DNA pretreatment with uracil DNA glycosylase (UDG), an enzyme involved in base excision repair, significantly reduced the number of DNA artifacts after mutation detection by next-generation sequencing (NGS) and other methods, without affecting the capacity to detect real mutations. This study aimed to evaluate the effects of UDG enzymatic pretreatment in reducing the number of DNA sequencing artifacts from FFPE tumor samples, to improve the accuracy of genetic testing in the molecular diagnostic routine. Methods: We selected 12 FFPE tumor samples (10 melanoma, 1 lung, and 1 colorectal tumor sample) with different storage times. We compared sequencing results of a 16-hotspot gene panel of NGS libraries prepared with UDG-treated and untreated samples. Results: All UDG-treated samples showed large reductions in the total number of transitions (medium reduction of 80%) and the transition/transversion ratio (medium reduction of 75%). In addition, most sequence artifacts presented a low variant allele frequency (VAF < 10%) which are eliminated with UDG treatment. Conclusion: Including UDG enzymatic treatment before multiplex amplification in the NGS workflow significantly decreased the number of artifactual variants detected in FFPE samples. Thus, including this additional step in the current methodology should improve the rate of true mutation detection in the molecular diagnostic routine.

Research paper thumbnail of RTKs and transcription factors proteins analysis in a series of head and neck mucosal melanoma

Journal of Clinical & Experimental Dermatology Research, 2016

Although skin is the largest organ of the body, there are no standardized reproducible methods fo... more Although skin is the largest organ of the body, there are no standardized reproducible methods for assessing severity of many skin diseases. Due to lack of consensus, methods of assessment and inexistence of precise scoring system, there is no application for vitiligo estimation in real practice. In this paper the author describes VETI score as a new treatment evaluation criteria and severity assessment method for vitiligo. This new tool, as does the PASI score in psoriasis, may be able to produce a constant and reproducible number and to help clinical research on vitiligo patients. Additionally it has a potential to be a source of any computed application for researchers working on vitiligo patients.

Research paper thumbnail of Expressão da proteína p16, ciclina D1, CDK4 e proteína do retinoblastoma no melanoma acral lentiginoso

À minha orientadora Profa. Dra. Mirian Nacagami Sotto, por incentivar o meu progresso acadêmico e... more À minha orientadora Profa. Dra. Mirian Nacagami Sotto, por incentivar o meu progresso acadêmico e confiar no meu potencial; pela sua paciência, ajuda e dedicação durante todo este projeto, por toda sua dedicação à pesquisa, pela qual eu me inspiro. Agradeço a confiança e apoio nos bons momentos e também nas horas mais difíceis, e por estar sempre presente durante todas as etapas deste percurso, desde a iniciação científica até a pós-graduação, como professora e orientadora dedicada. À Profa. Dra. Sílvia Vanessa Lourenço, por incentivar e ensinar o papel importante da pesquisa. Agradeço a confiança e apoio, desde a iniciação científica até a pós-graduação, como professora dedicada e como amiga. Ao Prof. Dr. Fernando Augusto Soares, Professor Titular da disciplina de Patologia Geral da FOUSP, pela ajuda no fornecimento e padronização dos anticorpos utilizados neste trabalho. À Aline Firmiano, por sua dedicação, apoio e auxilio na execução e realização deste trabalho. À Sabrina Hitomi Uyekita e ao Fábio Rodrigues Gonçalves de Carvalho, grandes amigos, colegas de graduação, de iniciação científica e de pósgraduação. Obrigado pela amizade, apoio, ajuda e incentivo ao longo destes anos. A todos os colegas do Instituto de Medicina Tropical (IMT), pela ajuda e cooperação e pelo ótimo ambiente que desfrutei ao longo destes anos. Aos funcionários da Divisão de Dermatologia do HC-FMUSP por toda a ajuda e contribuição neste trabalho. Aos meus pais pelo amor, apoio incondicional, educação, compreensão, ajuda nos momentos mais complicados e confiança nas minhas decisões. A CAPES pelo incentivo à pesquisa através contemplação da bolsa de Mestrado (Portaria CAPES No. 52/002).

Research paper thumbnail of Neural and Vascular Invasions of Oral Squamous Cell Carcinomas

Journal of Oral Hygiene & Health, 2015

Objective: The aim of this retrospective study was to identify perineural and vascular invasions ... more Objective: The aim of this retrospective study was to identify perineural and vascular invasions in Oral Squamous Cell Carcinoma lesions. Methods: A series of 29 OSSC-diagnosed patients and their clinical and demographic data were collected. In order to identify invasive process, Hematoxiline and Eosin (HE) staining of all cases were analysed and CD31, CD34, S100 and PGP9.5 protein expression were performed by immunhistochemistry. Results: All data were statistically assessed by Kappa test and McNemar's. We identified vascular and perineural invasions in 17.2% and 31% of cases, respectively, by HE staining analysis. We found intense peritumoral microvascular density in 82.8% of cases, by CD31 immunostaining. The CD34 antibody was recorded only 6.9% of cases with vascular invasion. Perineural invasion was detected in 44.8% of S100 protein immunostained cases, and 58.6% of cases were immunostained by PGP9.5 protein. Conclusion: According to our H/E and immunohistochemistry analysis, regarding the presence of perineural invasion, PGP9.5 protein was more effective than the others. It was concluded that the identification of vascular and perineural invasions is a useful tool for the prognosis of patients with oral squamous cell carcinoma, thus histopathological and immunohistochemistry methods should be combined for an effective analysis for this tumor.

Research paper thumbnail of Does BCL-2 Play Role in the Pathogenesis of Primary Oral Mucosal Melanoma?

Journal of Medical Research and Surgery

Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignan... more Primary Oral Mucosal Melanoma represents 0.2 to 8% of all melanomas and 0.5% of all oral malignant neoplasia. The etiology still unknown, however, it has been suggested that head and neck mucosal melanomas change their genetic and metabolic pathways through intracellular cascades, which are associated with its etiopathogenesis mechanisms. The BCL2 protein is an integral part of the cell membrane, and it is also found in the cell nucleus, mitochondria, and endoplasmic reticulum. It is overexpressed in several malignant neoplasms, including cutaneouse ocular melanomas. Among all evaluated cases, we found positive immunostaining of BCL-2 in 26/34 (76.47%) and they had a membrane and cytoplasmic pattern, and the intensity was variable. According to our results and the findings of the literature, it can be suggested that BCL-2 has an important role in melanoma pathogenesis, including Primary Oral Mucosal Melanoma and also melanoma metastases. It seems that BCL-2 could be an adjunct marke...

Research paper thumbnail of Estudo imuno‐histoquímico de citoqueratinas no folículo piloso humano em desenvolvimento

Anais Brasileiros De Dermatologia, 2020

a Programa de Pós-Graduação em Medicina e Saúde, Faculdade de Medicina da Bahia, Universidade Fed... more a Programa de Pós-Graduação em Medicina e Saúde, Faculdade de Medicina da Bahia, Universidade Federal da Bahia, Salvador, BA, Brasil b Serviço de Dermatologia, Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brasil c Serviço de Dermatologia, Hospital Santa IzabelSalvador, BA, Brasil d Departamento de Dermatologia, Faculdade de Medicina, Universidade Federal da Bahia, Salvador, BA, Brasil e Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brasil f Departamento de Patologia, Universidade Federal de Alfenas, Alfenas, MG, Brasil g Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP, Brasil h Departamento de Dermatologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil i Setor de Patologia, Hospital Santa Izabel, Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brasil

Research paper thumbnail of Could mucin 16 and colony-stimulating factor 2-receptor beta possible graft versus host disease biomarkers? Medical hypotheses

Medical Hypotheses, 2017

Graft versus host disease (GVHD) occurs after bone marrow transplantation and is one of the most ... more Graft versus host disease (GVHD) occurs after bone marrow transplantation and is one of the most important causes of death worldwide. Reviews demonstrated GVHD patients with involvement of various tissues and organs, such as salivary glands. The diagnosis of acute GVHD has been the biopsies and the histopathologic evaluation of tissue from an involved organ. These procedures are invasive. Saliva proteins as possible biomarker for GVHD could facilitate the management and diagnosis accuracy. For support the proposed hypotheses, in this pilot study we collected whole saliva samples from patients with undergoing allogeneic hematopoietic cell transplantation (HCT) and from healthy subjects. Samples were collected prospectively between pre-transplant, thirty days, one hundred and, two hundred days after transplant. The proteomic profile was analyzed using SDS-PAGE and LCMS-ESI-IT-TOF mass spectrometry. The relevant personal data, past medical history were also recorded. The most relevant proteins found exclusively in GVHD patients were: CSF2RB, Protocadherin (Pcdh) Fat 2 precursor, protein capicua homolog isoform CIC-S, MUC16 and RGPD8_HUMAN RANBP2. This study aims to conduct an initial evaluation of the possible presence of such biomarkers in saliva from GVHD patients, and suggested a potential application of proteomics analysis as a alternative method to diagnose GVHD.

Research paper thumbnail of Melanoma primário da mucosa oral: estudo imunoistoquímico e molecular da via da MAPK

Research paper thumbnail of Actionable Mutation Profile of Sun-Protected Melanomas in South America

The American Journal of Dermatopathology

Research paper thumbnail of Claudin expression is maintained in mucoepidermoid carcinoma of the salivary gland

Pathology - Research and Practice

The aim of the present study was to investigate the expression of claudin-1,-3,-4,-5 and-7 protei... more The aim of the present study was to investigate the expression of claudin-1,-3,-4,-5 and-7 proteins in mucoepidermoid carcinoma of oral cavity and analyze whether EGF may interfere in the expression of the genes that encode claudins using in vitro models. Material and methods: Using immunohistochemistry, the expression of claudins was searched in 36 histologically graded cases of mucoepidermoid carcinoma. The association of expression of claudins with clinical-pathological parameters was evaluated. An in vitro step investigated the influence of EGF on gene expression of claudins by real time RT-PCR technique. Results: Claudin-1,-3,-4,-5, and-7 were highly expressed in most mucoepidermoid carcinomas. These expressions were compared with clinicopathological parameters. High expression of claudin-1 was associated with patients over 40 years-old (p = 0.05) and Caucasians (p = 0.024). In vitro experiments demonstrated a tendency for Claudin gene expression increase after EGF stimulus. Conclusions: The expression of claudins is maintained in mucoepidermoid carcinoma cells and EGF could be related with this expression. Our results point out to a fundamental biological importance to CLDNs in normal and neoplastic tissue. The expression patterns of CLDNs does not yet allow a clinical application, but the biological knowledge will ground evidence to new studies towards possible target-therapies.

Research paper thumbnail of Immunoexpression of Adhesion Molecules During Human Fetal Hair Development

Revista Científica Hospital Santa Izabel, 2021

SummaryBackground: Hair follicles are produced in a cyclical manner and the machinery involved in... more SummaryBackground: Hair follicles are produced in a cyclical manner and the machinery involved in the reproduction of these follicles is present since the fetal stage. Although extensive research has been done on the human hair follicle, very little is known about the importance of adhesion molecules in its development. Methods: We analyzed here, the immunoexpression of beta-1 integrin, p-cadherin, e- cadherin, and beta-catenin in hair follicles from 26 formalin-fixed and paraffin-embedded skin samples from human embryos and fetus between 12-23 weeks of gestational age. Findings: The adhesion molecules beta-1 integrin and e-cadherin/p-cadherin were expressed from 12 weeks and seemed to play a role in regulating epidermis invagination. Beta-catenin immuno stainingwas negative in all cases; down regulation of this protein may be necessary for fetal hair development and thus facilitating hair follicle down growth. Conclusion: Adhesion molecules are essential for hair follicle down grow...

Research paper thumbnail of Epithelial-mesenchymal transition related to bone invasion in oral squamous cell carcinoma

Journal of Bone Oncology, 2022

Highlights • Presence of epithelial-mesenchymal transition markers in tumor-bone interface.• Domi... more Highlights • Presence of epithelial-mesenchymal transition markers in tumor-bone interface.• Dominant infiltrative pattern in bone tissue is associated with lower survival.• E-cadherin-positive cases were associated with tobacco smoking.• Vimentin-positive cases were associated with tumors under 4 cm.• Twist could be strongly involved in bone invasion and in disease progression.

Research paper thumbnail of The role of melanocytes in oral mucosa: From embryologic origin to oral mucosal melanoma: A short review

Integrative molecular medicine, 2020

Melanoblasts are precursor cells of melanocytes, that arise from neural crest in vertebrates and ... more Melanoblasts are precursor cells of melanocytes, that arise from neural crest in vertebrates and through several cycles of migration and proliferation, they populate the basal layer of epidermis; hair bulb; eyes; ears and meninges. However, melanocytes also situate in the basal layer of stratified squamous epithelia that is lining in the mouth. The role of melanocytes in the pathophysiology of the oral mucosa still poor understand, and differently from skin melanocytes, they are in a photo-protected site Physiologically, oral melanocytes may or may not produce melanin, however non-physiological alterations related to genetic, metabolic, endocrine, chemical and physical factors, and to infections, inflammatory and neoplasic processes could interfere in the oral pigmentation Primary Oral Mucosal Melanoma (POMM) develops from malignant transformation of melanocytic cell localized in the basal layer of the oral mucosa, which incidence is between 0.2 to 8% of all melanomas, and representing 0.5% of all malignant neoplasias of the oral cavity A better comprehension of the neural crest cells; melanoblasts and melanocytes development and proliferation, and also the melanogenesis and molecular pathways, it could help to understand more about the role of the oral mucosal melanocytes, moreover, and to improve all diagnostic techniques and treatment for Primary Oral Mucosal Melanomas.