Protein phosphatase 2A is essential to maintain active Wnt signaling and its Aβ tumor suppressor subunit is not expressed in colon cancer cells

2014 ◽  
Vol 54 (11) ◽  
pp. 1430-1441 ◽  
Author(s):  
M. Carmen Figueroa-Aldariz ◽  
M. Cristina Castañeda-Patlán ◽  
Paula Santoyo-Ramos ◽  
Alejandro Zentella ◽  
Martha Robles-Flores
Keyword(s):  
Colon Cancer ◽  
Tumor Suppressor ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Colon Cancer Cells ◽  
Phosphatase 2A

Potential involvement of protein phosphatase 2A in temsirolimus-mediated resensitization to cetuximab in colon cancer cells

2014 ◽  
Vol 140 (7) ◽  
pp. 1249-1250 ◽  
Author(s):  
Ion Cristóbal ◽  
Rebeca Manso ◽  
Raúl Rincón ◽  
Juan Madoz-Gúrpide ◽  
Cristina Caramés ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Colon Cancer Cells ◽  
Phosphatase 2A

scholarly journals Regulation of Wnt signaling by the tumor suppressor adenomatous polyposis coli does not require the ability to enter the nucleus or a particular cytoplasmic localization

2012 ◽  
Vol 23 (11) ◽  
pp. 2041-2056 ◽  
Author(s):  
David M. Roberts ◽  
Mira I. Pronobis ◽  
John S. Poulton ◽  
Eric G. Kane ◽  
Mark Peifer
Keyword(s):  
Colon Cancer ◽  
Tumor Suppressor ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Adenomatous Polyposis Coli ◽  
Subcellular Location ◽  
Adenomatous Polyposis ◽  
Colon Cancer Cells ◽  
Polyposis Coli ◽  
Drosophila Embryos

Wnt signaling plays key roles in development and disease. The tumor suppressor adenomatous polyposis coli (APC) is an essential negative regulator of Wnt signaling. Its best-characterized role is as part of the destruction complex, targeting the Wnt effector β-catenin (βcat) for phosphorylation and ultimate destruction, but several studies suggested APC also may act in the nucleus at promoters of Wnt-responsive genes or to shuttle βcat out for destruction. Even in its role in the destruction complex, APC's mechanism of action remains mysterious. We have suggested APC positions the destruction complex at the appropriate subcellular location, facilitating βcat destruction. In this study, we directly tested APC's proposed roles in the nucleus or in precisely localizing the destruction complex by generating a series of APC2 variants to which we added tags relocalizing otherwise wild-type APC to different cytoplasmic locations. We tested these for function in human colon cancer cells and Drosophila embryos. Strikingly, all rescue Wnt regulation and down-regulate Wnt target genes in colon cancer cells, and most restore Wnt regulation in Drosophila embryos null for both fly APCs. These data suggest that APC2 does not have to shuttle into the nucleus or localize to a particular subcellular location to regulate Wnt signaling.

scholarly journals Protein Phosphatase 2A Regulatory Subunit B56α Associates with c-Myc and Negatively Regulates c-Myc Accumulation

2006 ◽  
Vol 26 (7) ◽  
pp. 2832-2844 ◽  
Author(s):  
Hugh K. Arnold ◽  
Rosalie C. Sears
Keyword(s):  
Tumor Suppressor ◽  
Protein Phosphatase ◽  
Cell Function ◽  
Cell Transformation ◽  
Protein Phosphatase 2A ◽  
Regulatory Subunit ◽  
Suppressor Activity ◽  
Tumor Suppressor Activity ◽  
Structural Subunit ◽  
Phosphatase 2A

ABSTRACT Protein phosphatase 2A (PP2A) plays a prominent role in controlling accumulation of the proto-oncoprotein c-Myc. PP2A mediates its effects on c-Myc by dephosphorylating a conserved residue that normally stabilizes c-Myc, and in this way, PP2A enhances c-Myc ubiquitin-mediated degradation. Stringent regulation of c-Myc levels is essential for normal cell function, as c-Myc overexpression can lead to cell transformation. Conversely, PP2A has tumor suppressor activity. Uncovering relevant PP2A holoenzymes for a particular target has been limited by the fact that cellular PP2A represents a large heterogeneous population of trimeric holoenzymes, composed of a conserved catalytic subunit and a structural subunit along with a variable regulatory subunit which directs the holoenzyme to a specific target. We now report the identification of a specific PP2A regulatory subunit, B56α, that selectively associates with the N terminus of c-Myc. B56α directs intact PP2A holoenzymes to c-Myc, resulting in a dramatic reduction in c-Myc levels. Inhibition of PP2A-B56α holoenzymes, using small hairpin RNA to knock down B56α, results in c-Myc overexpression, elevated levels of c-Myc serine 62 phosphorylation, and increased c-Myc function. These results uncover a new protein involved in regulating c-Myc expression and reveal a critical interconnection between a potent oncoprotein, c-Myc, and a well-documented tumor suppressor, PP2A.

scholarly journals The NF-κB/AKT-dependent Induction of Wnt Signaling in Colon Cancer Cells by Macrophages and IL-1β

2009 ◽  
Vol 2 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Pawan Kaler ◽  
Bramara N. Godasi ◽  
Leonard Augenlicht ◽  
Lidija Klampfer
Keyword(s):  
Colon Cancer ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Colon Cancer Cells

scholarly journals Correlation of GOLPH3 Gene with Wnt Signaling Pathway in Human Colon Cancer Cells

2016 ◽  
Vol 7 (8) ◽  
pp. 928-934 ◽  
Author(s):  
Cheng-Zhi Qiu ◽  
Ming-Zhen Wang ◽  
Wai-Shi Yu ◽  
Yan-Ta Guo ◽  
Chun-Xiao Wang ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
Wnt Signaling Pathway ◽  
Human Colon ◽  
Colon Cancer Cells ◽  
Human Colon Cancer ◽  
Human Colon Cancer Cells

Abstract 5328: Protein phosphatase 2A activity is a major determinant of therapy response in cancer cells

2015 ◽  
Author(s):  
Otto Kauko ◽  
Susumu Imanishi ◽  
Amanpreet Kaur ◽  
Daniel Laajala ◽  
Evgeny Kulesskiy ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Therapy Response ◽  
Major Determinant ◽  
Phosphatase 2A

Abstract 5494: Hypoxia via HIF1alpha can regulate Wnt signaling in human colon cancer cells

2017 ◽  
Author(s):  
Yung Lyou ◽  
Amber Habowski ◽  
Stephanie Sprowl-Tanio ◽  
Kira Pate ◽  
George Chen ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Human Colon ◽  
Colon Cancer Cells ◽  
Human Colon Cancer ◽  
Human Colon Cancer Cells

scholarly journals Hypoxia-Inducible Factors Modulate the Stemness and Malignancy of Colon Cancer Cells by Playing Opposite Roles in Canonical Wnt Signaling

PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e112580 ◽  
Author(s):  
Paula Santoyo-Ramos ◽  
María Likhatcheva ◽  
Eduardo A. García-Zepeda ◽  
M. Cristina Castañeda-Patlán ◽  
Martha Robles-Flores
Keyword(s):  
Colon Cancer ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Colon Cancer Cells ◽  
Hypoxia Inducible Factors ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt
Sign in / Sign up

Export Citation Format

Share Document