RAGE and Its Ligands: Molecular Interplay Between Glycation, Inflammation, and Hallmarks of Cancer—a Review

Risk of cancer especially of colon, breast, and pancreas is high in diabetic and obese patients, with potential involvement of augmented expression of RAGE (receptor for advanced glycation end products) and its ligands, namely AGEs (advanced glycation end products), HMGB1 (high-mobility group box 1 protein), and S100 group of proteins. Studies have reported the involvement of RAGE activation by its ligands in growth and survival of cancers, including metastasis and poor prognosis. We propose that this receptor-ligand axis provides the molecular link between certain pre-existing states as hypoxia, hyperglycemia, glycation, inflammation, oxidative stress, and onset of cancers. The chronic inflammatory, hyperglycemic milieu accompanied by glycoxidative stress as in diabetes and obesity, concomitant with the formation of RAGE ligands, instigates RAGE and cancer stem cells, leading to the oncogenic transformation of normal and pre-malignant tissues towards development of neoplasms. We have aimed to elucidate the complete signalling map initiated upon RAGE-ligand splicing, from oncogenesis to progression, epithelial-mesenchymal transition, invasion, cancer stem cell renewal, chemo-resistance, and cancer relapse. We have attributed the complex molecular functions of RAGE-ligand signalling cues to every aspect of cancer promotion, explaining the central network in bridging glycation, inflammation, oxidation, and the hallmarks of cancer. Underlining the substantial requisite for anti-neoplastic agents targeting RAGE and its ligands, we have explicitly discoursed RAGE and its allied components (AGEs, soluble RAGE, RAGE gene polymorphisms) as potential diagnostic and prognostic biomarkers for prompt detection of cancers and implication in impending RAGE-ligand directed, novel combinatorial, and targeted onco-therapeutics.