Activation of tumor suppressor protein PP2A inhibits KRAS-driven tumor growth

作者：Sangodkar Jaya; Perl Abbey; Tohme Rita; Kiselar Janna; Kastrinsky David B; Zaware Nilesh; Izadmehr Sudeh; Mazhar Sahar; Wiredja Danica D; O'Connor Caitlin M; Hoon Divya; Dhawan Neil S; Schlatzer Daniela; Yao Shen; Leonard Daniel; Borczuk Alain C; Gokulrangan Giridharan; Wang Lifu; Svenson Elena; Farrington Caroline C; Yuan Eric; Avelar Rita A; Stachnik Agnes; Smith Blake; Gidwani Vickram; Giannini Heather M; McQuaid Daniel; McClinch Kimberly; Wang Zhizhi

来源：Journal of Clinical Investigation, 2017, 127(6): 2081-2090.

DOI：10.1172/JCI89548

Targeted cancer therapies, which act on specific cancer-associated molecular targets, are predominantly inhibitors of oncogenic kinases. While these drugs have achieved some clinical success, the inactivation of kinase signaling via stimulation of endogenous phosphatases has received minimal attention as an alternative targeted approach. Here, we have demonstrated that activation of the tumor suppressor protein phosphatase 2A (PP2A), a negative regulator of multiple oncogenic signaling proteins, is a promising therapeutic approach for the treatment of cancers. Our group previously developed a series of orally bioavailable small molecule activators of PP2A, termed SMAPs. We now report that SMAP treatment inhibited the growth of KRAS-mutant lung cancers in mouse xenografts and transgenic models. Mechanistically, we found that SMAPs act by binding to the PP2A Aa scaffold subunit to drive conformational changes in PP2A. These results show that PP2A can be activated in cancer cells to inhibit proliferation. Our strategy of reactivating endogenous PP2A may be applicable to the treatment of other diseases and represents an advancement toward the development of small molecule activators of tumor suppressor proteins.

• 出版日期2017-6-1