[PDF][PDF] Focal adhesion-and IGF1R-dependent survival and migratory pathways mediate tumor resistance to mTORC1/2 inhibition

SO Yoon, S Shin, FA Karreth, GR Buel… - Molecular cell, 2017 - cell.com
SO Yoon, S Shin, FA Karreth, GR Buel, MP Jedrychowski, DR Plas, S Dedhar, SP Gygi
Molecular cell, 2017cell.com
Aberrant signaling by the mammalian target of rapamycin (mTOR) contributes to the
devastating features of cancer cells. Thus, mTOR is a critical therapeutic target and catalytic
inhibitors are being investigated as anti-cancer drugs. Although mTOR inhibitors initially
block cell proliferation, cell viability and migration in some cancer cells are quickly restored.
Despite sustained inhibition of mTORC1/2 signaling, Akt, a kinase regulating cell survival
and migration, regains phosphorylation at its regulatory sites. Mechanistically, mTORC1/2 …
Summary
Aberrant signaling by the mammalian target of rapamycin (mTOR) contributes to the devastating features of cancer cells. Thus, mTOR is a critical therapeutic target and catalytic inhibitors are being investigated as anti-cancer drugs. Although mTOR inhibitors initially block cell proliferation, cell viability and migration in some cancer cells are quickly restored. Despite sustained inhibition of mTORC1/2 signaling, Akt, a kinase regulating cell survival and migration, regains phosphorylation at its regulatory sites. Mechanistically, mTORC1/2 inhibition promotes reorganization of integrin/focal adhesion kinase-mediated adhesomes, induction of IGFR/IR-dependent PI3K activation, and Akt phosphorylation via an integrin/FAK/IGFR-dependent process. This resistance mechanism contributes to xenograft tumor cell growth, which is prevented with mTOR plus IGFR inhibitors, supporting this combination as a therapeutic approach for cancers.
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