The interaction of SET and protein phosphatase 2A as target for cancer therapy

In cancer cells, tumor suppressor proteins loss-of-function are usually the result of genetic mutations. Protein Phosphatase 2A is a tumor suppressor that inactivates several signaling pathways through removal of phosphate residues important for other proteins stability and/or activation. Different from other tumor suppressors, PP2A is, in many cancer types, inactivated by endogenous inhibitors. In physiological conditions, these inhibitors are important to balance PP2A activity. However, in cancer cells, overexpression of these inhibitors can keep PP2A inactive, resulting in sustained activation of mitogenic signaling pathways and transcription factors, metabolic reprogramming, with the resulting cancer progression and the resistance to anti-cancer therapies. One of these endogenous inhibitors is the protein SET (SE Translocation). SET is a multifunctional protein, which high expression has been associated with several types of cancer, as well as other diseases such as Alzheimer's disease. Disruption of the interaction between SET and PP2A to rescue the activity of PP2A may represent a new therapeutic strategy and opportunity for cancer treatment. This review brings up-to-date advances on the interactions between SET and PP2A and their biological consequences. Moreover, we review reported inhibitors of SET-PP2A interaction under investigation as therapeutic opportunities for the treatment of cancers.