Protein phosphatase 2A regulatory subunits and cancer

Upregulation of miR-27a contributes to the malignant transformation of human bronchial epithelial cells induced by SV40 small T antigen

“…These biological functions are believed to be mediated by the interaction between ST and PP2A (reviewed in Arroyo and Hahn, 2005;Eichhorn et al, 2009). The alteration of the phosphorylation status of signaling molecules has been demonstrated to be the primary action of the ST antigen in cell transformation (Janssens and Goris, 2001; Moreno Sablina and Hahn, 2008).…”

“…To date, the functional loss of PP2A B56g is believed to be the key factor in SV40 ST-induced tumorigenesis (reviewed in Eichhorn et al, 2009). PP2A B56g subunit appears to be a negative upstream regulator controlling miR-27a expression.…”

Evaluation of anti-Wnt/β-catenin signaling agents by pGL4-TOP transfected stable cells with a luciferase reporter system

“…Although mutation at the N-terminus of β-catenin has been found in some tumors, mutations at these sites have not been found in Jurkat cells (20). NCTD has been reported to inhibit protein phosphatase 2A (PP2A) activity and PP2A has been found to positively control Wnt/β-catenin signaling upon Wnt stimulation (31,32). In this context, inhibition of PP2A will promote β-catenin phosphorylation and degradation.…”

Restricted Protein Phosphatase 2A Targeting by Merkel Cell Polyomavirus Small T Antigen

“…Phosphatidylinositol 3-kinase (PI3K)/Akt, mitogen-activated protein kinase, c-Myc, and other cancer signaling pathways that impact cellular processes, including cell cycle progression and cellular tumorigenesis are regulated by specific PP2A isoforms (9). Aberrant expression and mutations in PP2A subunits have been implicated in human cancers (8,(10)(11)(12)(13)(14)(15)(16). …”

“…This core heterodimer can be purified, but the PP2A holoenzyme generally contains a third, regulatory B subunit that provides substrate specificity and subcellular localization (3)(4)(5)(6)(7). Among the many combinatorial possibilities, there are two C catalytic subunits, at least two 〈 scaffolding subunits, and multiple B substrate recognition subunits (8), which allow for potentially hundreds of different phosphatase specificities and activities. Phosphatidylinositol 3-kinase (PI3K)/Akt, mitogen-activated protein kinase, c-Myc, and other cancer signaling pathways that impact cellular processes, including cell cycle progression and cellular tumorigenesis are regulated by specific PP2A isoforms (9).…”