Noncanonical Pathway for Regulation of CCL2 Expression by an mTORC1-FOXK1 Axis Promotes Recruitment of Tumor-Associated Macrophages
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 nonc...
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Published in | Cell reports (Cambridge) Vol. 21; no. 9; pp. 2471 - 2486 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
28.11.2017
Elsevier |
Subjects | |
Online Access | Get full text |
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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.
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•mTORC1 regulates CCL2 expression via FOXK1 activation•FOXK1 is dephosphorylated and thereby activated in response to mTORC1 activation•The mTORC1-FOXK1-CCL2 pathway is independent of classical NF-κB signaling•This pathway promotes macrophage accumulation and associated tumor growth
Nakatsumi et al. show that mTORC1 regulates CCL2 expression in a manner independent of NF-κB signaling by dephosphorylating the transcription factor FOXK1. Moreover, they demonstrate that hyperactivation of mTORC1 results in attraction of M2-type tumor-associated macrophages and promotes tumor growth in vivo via the mTORC1-FOXK1-CCL2 pathway. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2211-1247 2211-1247 |
DOI: | 10.1016/j.celrep.2017.11.014 |