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Abstract Introduction: Proliferation markers play a significant role in the biologic behavior of tumors. Geminin is a known inhibitor of the cell cycle and DNA replication and has not been previously reported in cutaneous basal and squamous cell carcinomas of the head and neck. Objectives: We aimed to investigate proliferation markers ki67, MCM2, and geminin in head and neck cutaneous basal and squamous cell carcinomas. Methods: Forty cases of each tumor were immuostained with ki67, MCM2, and geminin followed by assessment of labeling indices (LIs). MCM2/ki67- and geminin/ki67-ratios were also determined; t-test was used for statistical analysis (p<0.05). Results: There was no significant difference in ki67 (p = 0.06) and MCM2 (p = 0.46) between cutaneous basal and squamous cell carcinomas; however, geminin LI was significantly higher in squamous cell carcinomas compared to cutaneous basal cell carcinomas (p < 0.001). Only geminin/ki67 showed a significant difference between the two tumors with the ratio showing significantly higher numbers in squamous cell carcinomas (p = 0.015). Conclusions: Geminin could be regarded as an effective factor in the pathogenesis of head and neck cutaneous cutaneous basal cell carcinomas and squamous cell carcinomas and may be one of the responsible elements in the difference between the biologic behavior of these tumors. © 2020 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/).

Resumo Introdução: Marcadores de proliferação têm um papel significativo no comportamento biológico dos tumores. A geminina é um inibidor conhecido do ciclo celular e da replicação do DNA e não foi relatada anteriormente em carcinomas basocelulares e espinocelulares cutâneos de cabeça e pescoço. Objetivo: Investigar os marcadores de proliferação ki67, MCM2 e geminina em carcinomas basocelulares e espinocelulares cutâneos de cabeça e pescoço. Método: Foram submetidos 40a casos de cada tumor à imunocoloração com ki67, MCM2 e geminina, seguida pela avaliação do índice de marcação.Também foram determinadas as razões MCM2/ki67 e geminina/ki67 e o teste t foi usado na análise estatística (p < 0,05). Resultados: Não houve diferença significativa no ki67 (p = 0,06) e no MCM2 (p = 0,46) entre carcinomas basocelulares e espinocelulares; no entanto, o índice de marcação da geminina foi significativamente maior no carcinomas espinocelulares em comparação ao carcinomas basocelulares (p < 0,001). Somente a razão geminina/ki67 mostrou diferença significativa entre os dois tumores, a razão mostrou números significativamente mais altos nos carcinomas espinocelulares (p = 0,015). Conclusões: A geminina pode ser considerada um fator efetivo na patogênese dos carcinomas basocelulares e espinocelulares cutâneos de cabeça e pescoço e pode ser um dos elementos responsáveis pela diferença entre o comportamento biológico desses tumores.

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INTRODUCTION: Proliferation markers play a significant role in the biologic behavior of tumors. Geminin is a known inhibitor of the cell cycle and DNA replication and has not been previously reported in cutaneous basal and squamous cell carcinomas of the head and neck. OBJECTIVES: We aimed to investigate proliferation markers ki67, MCM2, and geminin in head and neck cutaneous basal and squamous cell carcinomas. METHODS: Forty cases of each tumor were immuostained with ki67, MCM2, and geminin followed by assessment of labeling indices (LIs). MCM2/ki67- and geminin/ki67-ratios were also determined; t-test was used for statistical analysis (p<0.05). RESULTS: There was no significant difference in ki67 (p=0.06) and MCM2 (p=0.46) between cutaneous basal and squamous cell carcinomas; however, geminin LI was significantly higher in squamous cell carcinomas compared to cutaneous basal cell carcinomas (p<0.001). Only geminin/ki67 showed a significant difference between the two tumors with the ratio showing significantly higher numbers in squamous cell carcinomas (p=0.015). CONCLUSIONS: Geminin could be regarded as an effective factor in the pathogenesis of head and neck cutaneous cutaneous basal cell carcinomas and squamous cell carcinomas and may be one of the responsible elements in the difference between the biologic behavior of these tumors.

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INTRODUCTION: Gingiva fibromatosis is a relatively rare condition characterized by diffuse enlargement of the gingiva, which is caused by expansion and accumulation of the connective tissue. OBJECTIVE: The aim of the present study was to investigate proliferative and apoptotic biomarker expression in normal gingiva and two forms of gingival fibromatosis. METHODS: Archived tissue specimens of hereditary gingival fibromatosis, gingival fibromatosis and dental abnormality syndrome and normal gingiva were subject to morphological analysis and immunohistochemical staining. The results were analyzed statistically. RESULTS: Proteins associated with proliferation were found in the nuclei of epithelial cells from the basal and suprabasal layers, whereas apoptotic proteins were detected in the cytoplasm of the upper layers of the epithelium. Increased expressions of minichromosome maintenance proteins 2 and 5 were observed in the gingival fibromatosis and dental abnormality syndrome samples. In contrast, geminin expression was higher in normal gingiva samples. No difference in the expression of apoptotic proteins was observed among the groups. CONCLUSION: Our findings support a role for augmented proliferation of epithelial cells within the overgrown tissues associated with gingival fibromatosis or dental abnormality syndrome. However, our data suggest that different biological mechanisms may account for the pathogenesis of different types of gingival fibromatosis.

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