RESUMO
Oral squamous cell carcinoma (OSCC) is among the leading causes of cancer-associated death worldwide. miR-31 is an oncogenic miRNA in OSCC. NUMB is an adaptor protein capable of suppressing malignant transformation. Disruption of the miR-31-NUMB regulatory axis has been demonstrated in malignancies. Mitochondrial dysfunction and adaptation to glycolytic respiration are frequent events in malignancies. Monocarboxylate transporters (MCTs) function to facilitate lactate flux in highly glycolytic cells. Upregulation of MCT1 and MCT4 has been shown to be a prognostic factor of OSCC. Here, we reported that miR-31-NUMB can modulate glycolysis in OSCC. Using the CRISPR/Cas9 gene editing strategy, we identified increases in oncogenic phenotypes, MCT1 and MCT4 expression, lactate production, and glycolytic respiration in NUMB-deleted OSCC subclones. Transfection of the Numb1 or Numb4 isoform reversed the oncogenic induction elicited by NUMB deletion. This study also showed, for the first time, that NUMB4 binds MCT1 and MCT4 and that this binding increases their ubiquitination, which may decrease their abundance in cell lysates. The disruptions in oncogenicity and metabolism associated with miR-31 deletion and NUMB deletion were partially rescued by MCT1/MCT4 expression or knockdown. This study demonstrated that NUMB is a novel binding partner of MCT1 and MCT4 and that the miR-31-NUMB-MCT1/MCT4 regulatory cascade is present in oral carcinoma.
Assuntos
Neoplasias de Cabeça e Pescoço/genética , Proteínas de Membrana/genética , MicroRNAs/genética , Transportadores de Ácidos Monocarboxílicos/genética , Proteínas Musculares/genética , Proteínas do Tecido Nervoso/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Simportadores/genética , Sistemas CRISPR-Cas , Carcinogênese/genética , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Ácido Láctico/metabolismo , Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Proteínas Musculares/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Simportadores/metabolismoRESUMO
BACKGROUND: MicroRNAs (miRNAs) play crucial roles in head and neck squamous cell carcinoma (HNSCC). This study investigates whether miR-31, miR-96, and miR-182 are involved in targeting Numb during HNSCC. METHODS: The expression of miR-31/96/182 in tumor tissues was analyzed. Reporter assay, knockdown, expression, and oncogenic analysis were carried out in cell lines. RESULTS: Upregulation of miR-31/96/182 was detected in tumor tissues. In addition, advanced tumors showed higher expression levels of these miRNAs. The expression of these miRNAs was upregulated after treatment with areca ingredients (P < .01 or P < .001). These miRNAs directly targeted the 3' untranslated region (UTR) sequence of the Numb gene. An increased migration and invasion of HNSCC cells was associated with the exogenous expression of miR-31/96/182 (P < .01 or P < .001), and this was reverted by expression of Numb. CONCLUSION: This study provides new evidence demonstrating that there is frequent and concordant upregulation of miR-31, miR-96, and miR-182 during HNSCC and these miRNAs co-target Numb.
