Gene

HIF1A

Cell biology

Metastasis

Biology

Glycolysis

Angiogenesis

Warburg effect

Endocrinology

Metabolism

Protein kinase B

Signal transduction

Cancer research

Hypoxia (environmental)

Genetics

Epithelial–mesenchymal transition

Organic chemistry

Oxygen

Chemistry

Carcinogenesis

PI3K/AKT/mTOR pathway

Cancer

Hypoxia-inducible factors

Cancer cell

Wnt signaling pathway

International Journal of Molecular Sciences

Hypoxia represents a frequent player in a number of malignancies, contributing to the development of the neoplastic disease. This review will discuss the means by which hypoxia powers the mechanisms behind cancer progression, with a majority of examples from lung cancer, the leading malignancy in terms of incidence and mortality rates (the frequent reference toward lung cancer is also for simplification purposes and follow up of the global mechanism in the context of a disease). The effects induced by low oxygen levels are orchestrated by hypoxia-inducible factors (HIFs) which regulate the expression of numerous genes involved in cancer progression. Hypoxia induces epithelial-to-mesenchymal transition (EMT) and metastasis through a complex machinery, by mediating various pathways such as TGF-β, PI3k/Akt, Wnt, and Jagged/Notch. Concomitantly, hypoxic environment has a vast implication in angiogenesis by stimulating vessel growth through the HIF-1α/VEGF axis. Low levels of oxygen can also promote the process through several other secondary factors, including ANGPT2, FGF, and HGF. Metabolic adaptations caused by hypoxia include the Warburg effect—a metabolic switch to glycolysis—and GLUT1 overexpression. The switch is achieved by directly increasing the expression of numerous glycolytic enzymes that are isoforms of those found in non-malignant cells.

Hypoxia: Overview on Hypoxia-Mediated Mechanisms with a Focus on the Role of HIF Genes