The gene encoding the glycolytic enzyme Hexokinase 2 (HK2) is overexpressed in many cancers, which is often associated with a poor clinical prognosis in patients. Initially recognized for its role in metabolic reprogramming, the HK2 protein could play a more complex function in tumor progression. In cancer cells, HK2 is associated with multiple oncogenic processes, such as proliferation, migration, invasion, and the promotion of cancer stemness. During my thesis, I explored the molecular and functional consequences of HK2 overexpression in cancer cell lines to better characterize its functions. By combining -omics approaches with in vitro and in vivo molecular and functional assays, my work has highlighted new protein partners of HK2 and described new molecular pathways and biological processes regulated by HK2 in cancer cells. Specifically, the exploration of three axes has revealed that: (1) HK2 is a transcriptional target and a positive modulator of the Aryl Hydrocarbon Receptor (AHR) signaling pathway, at the interface between environment and cancer. (2) HK2 overexpression promotes the amoeboid state in cancer cells, characterized by a rounded morphology, through the regulation of the major constituent of caveolae CAV1. (3) HK2 is associated with tumorigenicity and/or the propagation of cells having cancer stem cells properties. Altogether, this work supports the crucial role of HK2 in regulating the plasticity of cancer cells at different scales, allowing us to better understand the function of this key protein in cancer.