[PDF][PDF] Noncanonical pathway for regulation of CCL2 expression by an mTORC1-FOXK1 axis promotes recruitment of tumor-associated macrophages

H Nakatsumi, M Matsumoto, KI Nakayama - Cell reports, 2017 - cell.com
H Nakatsumi, M Matsumoto, KI Nakayama
Cell reports, 2017cell.com
Summary CC chemokine ligand 2 (CCL2) plays pivotal roles in tumor formation,
progression, and metastasis. Although CCL2 expression has been found to be dependent
on the nuclear factor (NF)-κB signaling pathway, the regulation of CCL2 production in tumor
cells has remained unclear. We have identified a noncanonical pathway for regulation of
CCL2 production that is mediated by mammalian target of rapamycin complex 1 (mTORC1)
but independent of NF-κB. Multiple phosphoproteomics approaches identified the …
Summary
C-C chemokine ligand 2 (CCL2) plays pivotal roles in tumor formation, progression, and metastasis. Although CCL2 expression has been found to be dependent on the nuclear factor (NF)-κB signaling pathway, the regulation of CCL2 production in tumor cells has remained unclear. We have identified a noncanonical pathway for regulation of CCL2 production that is mediated by mammalian target of rapamycin complex 1 (mTORC1) but independent of NF-κB. Multiple phosphoproteomics approaches identified the transcription factor forkhead box K1 (FOXK1) as a downstream target of mTORC1. Activation of mTORC1 induces dephosphorylation of FOXK1, resulting in transactivation of the CCL2 gene. Inhibition of the mTORC1-FOXK1 axis attenuated insulin-induced CCL2 production as well as the accumulation of tumor-associated monocytes-macrophages and tumor progression in mice. Our results suggest that FOXK1 directly links mTORC1 signaling and CCL2 expression in a manner independent of NF-κB and that CCL2 produced by this pathway contributes to tumor progression.
cell.com