RESUMO
This study aims to explore the regulatory mechanism of hypoxia-inducible factor HIF-1α on Kv3.4. Oral squamous cell carcinoma (OSCC) cell lines SCC3 and CAL27 were used in this study. Western blotting and qRT-PCR methods were used to detect Kv3.4 expression levels in OSCC and their adjacent tissues. The expression changes of Kv3.4 and HIF-1α in a hypoxic environment were detected in cell lines. The stable OSCC cell lines with knockouts of HIF-1α and Kv3.4 were constructed. Transwell and CCK-8 assays were used to detect changes in the invasion, migration and proliferation ability after transfection. Chromatin immunoprecipitation and luciferase reporter gene assays were used to determine the regulatory and binding sites of HIF-1α on Kv3.4. The expression level of Kv3.4 in oral cancer tissue was higher than normal oral epithelium's regular value. The expression level of HIF-1α and Kv3.4 increased under hypoxia. Knocking out HIF-1α and Kv3.4 could reduce the invasion, migration and proliferation of cells. A down regulation of HIF-1α will reduce the Kv3.4 expression level. Overexpressing Kv3.4 after knocking down HIF-1α partially restored the proliferation and invasion of cell lines. Therefore, HIF-1α regulates the invasion, migration and proliferation of oral cancer cells by regulating Kv3.4 expression.
Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Bucais/patologia , Canais de Potássio Shaw/metabolismo , Sequência de Bases , Hipóxia Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Neoplasias Bucais/genética , Invasividade Neoplásica , Regiões Promotoras Genéticas/genética , Ligação Proteica , Canais de Potássio Shaw/genéticaRESUMO
The protein voltage-gated sodium channel Nav1.5 is highly upregulated in various types of cancer and, in general, promotes cancer cell invasiveness and metastatic progression. A previous study found that Nav1.5 was highly expressed in poorly differentiated oral squamous cell carcinoma (OSCC). However, whether Nav1.5 enhances invasiveness and metastasis of OSCC are still unknown. In this study, we found that Nav1.5 was highly expressed in OSCC cell lines compared with normal oral keratinocyte HOK cell line by using western blot analysis. CCK-8 assay results revealed that downregulation of Nav1.5 expression by its specific siRNA reduced proliferation of OSCC HSC-3 cells. Moreover, transwell assay results showed Nav1.5 knockdown significantly inhibited migration and invasion of HSC-3 cells. Meanwhile, qRT-PCR and western blot analysis results showed that epidermal growth factor (EGF) induced Nav1.5 expression in a time- and dose-dependent manner. In addition, EGF promoted proliferation, migration and invasion of HSC-3 cells. Importantly, the Nav1.5 inhibitor tetrodotoxin significantly inhibited the proliferation of HSC-3 cells and impeded the migration and invasion of HSC-3 cells. Furthermore, it was found that siRNA-mediated knockdown of Nav1.5 also lessened the proliferation of HSC-3 cells and blocked the migration and invasion of HSC-3 cells. Taken together, these results indicate that Nav1.5 is involved in the progression of OSCC and Nav1.5 promotes the proliferation, migration and invasion of OSCC cells.
