Role of mitochondria in head and neck cancer

It is known that cancer cells have a different metabolic profile when compared to normal cells. Generally, increased aerobic glycolysis, glutaminolysis (mitochondrial activity from glutamine catabolism), lactate production, production of reactive oxygen species (ROS), and frequent mitochondrial DNA (mtDNA) mutations, are all hallmarks of cancer. In addition, cancer cells need a proper microenvironment for them to grow and metastasize. In this regard, a series of recent studies have elegantly shown that the ROS and reactive nitrogen species (RNS) may provide the necessary stimulus by driving DNA damage, inflammation, and cancer metabolism in the tumor microenvironment. The essential roles of mitochondria in energy metabolism, generation of ROS, initiation of apoptosis, and other aspects of tumor biology have implicated the importance of mitochondrial function in the neoplastic process. In this chapter, we will focus on the metabolism of head and neck squamous cell carcinoma (HNSCC), trying to debate the role of mitochondria in the process of malignant cell transformation. The text will be divided in three parts. First, will be an introduction to mitochondrial biogenesis and bioenergetics. Then we will address the reaction involved in the production and removal of reactive oxygen and reactive of nitrogen species. Finally, we will cover how mitochondria can be considered a new candidate to target and treat cancer, including HNSCC therapeutically.