mTORC1 inhibition restricts inflammation-associated gastrointestinal tumorigenesis in mice.

Published

Journal Article

Gastrointestinal cancers are frequently associated with chronic inflammation and excessive secretion of IL-6 family cytokines, which promote tumorigenesis through persistent activation of the GP130/JAK/STAT3 pathway. Although tumor progression can be prevented by genetic ablation of Stat3 in mice, this transcription factor remains a challenging therapeutic target with a paucity of clinically approved inhibitors. Here, we uncovered parallel and excessive activation of mTOR complex 1 (mTORC1) alongside STAT3 in human intestinal-type gastric cancers (IGCs). Furthermore, in a preclinical mouse model of IGC, GP130 ligand administration simultaneously activated mTORC1/S6 kinase and STAT3 signaling. We therefore investigated whether mTORC1 activation was required for inflammation-associated gastrointestinal tumorigenesis. Strikingly, the mTORC1-specific inhibitor RAD001 potently suppressed initiation and progression of both murine IGC and colitis-associated colon cancer. The therapeutic effect of RAD001 was associated with reduced tumor vascularization and cell proliferation but occurred independently of STAT3 activity. We analyzed the mechanism of GP130-mediated mTORC1 activation in cells and mice and revealed a requirement for JAK and PI3K activity but not for GP130 tyrosine phosphorylation or STAT3. Our results suggest that GP130-dependent activation of the druggable PI3K/mTORC1 pathway is required for inflammation-associated gastrointestinal tumorigenesis. These findings advocate clinical application of PI3K/mTORC1 inhibitors for the treatment of corresponding human malignancies.

Full Text

Duke Authors

Cited Authors

  • Thiem, S; Pierce, TP; Palmieri, M; Putoczki, TL; Buchert, M; Preaudet, A; Farid, RO; Love, C; Catimel, B; Lei, Z; Rozen, S; Gopalakrishnan, V; Schaper, F; Hallek, M; Boussioutas, A; Tan, P; Jarnicki, A; Ernst, M

Published Date

  • February 2013

Published In

Volume / Issue

  • 123 / 2

Start / End Page

  • 767 - 781

PubMed ID

  • 23321674

Pubmed Central ID

  • 23321674

Electronic International Standard Serial Number (EISSN)

  • 1558-8238

Digital Object Identifier (DOI)

  • 10.1172/JCI65086

Language

  • eng

Conference Location

  • United States