Impaired Mitochondrial Protein Synthesis in Head and Neck Squamous Cell Carcinoma

Human Head and Neck Squamous Cell Carcinoma (HNSCC) ranks among the sixth most common cancer types worldwide possibly due to the significant role of alcohol and tobacco use in the development of HNSCC. Interestingly, mutations in mitochondrial DNA (mtDNA) have been found to be associated with human head and neck cancers. Here, we investigated the changes in oxidative phosphorylation (OXPHOS) complexes and contribution of mitochondrial translation components in HNSCC. Immunoblotting analyses of human HNSCC tumors have shown that the expression of OXPHOS was impaired at the protein level. Specifically, an overall reduction in one of the mitochondrially encoded subunits of the OXPHOS complexes accentuated a possible defect in mitochondrial translation machinery. Evidence provided in this study suggests that the mitochondrial translation defect(s) could be due to a decrease in expression of one of the essential mitochondrial ribosomal proteins, MRPL11, in head and neck tumor biopsies. We also observed an acqu...