A tumor suppressor role for PP2AB56α through nega

Authors: Hugh K Arnold Rosalie C Sears

Publish Date: 2008/02/02

Volume: 27, Issue: 2, Pages: 147-158

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Abstract

Loss or inhibition of the serine/threonine protein phosphatase 2A PP2A has revealed a critical tumor suppressor function for PP2A However PP2A has also been shown to have important roles in cell cycle progression and survival Therefore PP2A is not a typical tumor suppressor This is most likely due to the fact that PP2A represents a large number of different holoenzymes Further understanding of PP2A functions and especially its tumor suppressor activity will depend largely on our ability to determine specific targets for these different PP2A holoenzymes and to gain an understanding of how these targets confer tumor suppressor activity or contribute to cell cycle progression and cell survival Recent work has identified cMyc as a target of the PP2A holoenzyme PP2AB56α This holoenzyme also negatively regulates βcatenin expression and modulates the antiapoptotic activity of Bcl2 thus characterizing PP2AB56α as a tumor suppressor PP2A holoenzyme This review will focus on the role of PP2AB56α in regulating cMyc and will place this tumor suppressor activity of PP2A within the context of its other tumor suppressor functions Finally the mechanisms through which PP2AB56α tumor suppressor activity may be lost in cancer will be discussed

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