Metformin, independent of AMPK, inhibits mTORC1 in a rag GTPase-dependent manner.

Journal Article (Journal Article)

Dysfunctional mTORC1 signaling is associated with a number of human pathologies owing to its central role in controlling cell growth, proliferation, and metabolism. Regulation of mTORC1 is achieved by the integration of multiple inputs, including those of mitogens, nutrients, and energy. It is thought that agents that increase the cellular AMP/ATP ratio, such as the antidiabetic biguanides metformin and phenformin, inhibit mTORC1 through AMPK activation of TSC1/2-dependent or -independent mechanisms. Unexpectedly, we found that biguanides inhibit mTORC1 signaling, not only in the absence of TSC1/2 but also in the absence of AMPK. Consistent with these observations, in two distinct preclinical models of cancer and diabetes, metformin acts to suppress mTORC1 signaling in an AMPK-independent manner. We found that the ability of biguanides to inhibit mTORC1 activation and signaling is, instead, dependent on the Rag GTPases.

Full Text

Duke Authors

Cited Authors

  • Kalender, A; Selvaraj, A; Kim, SY; Gulati, P; Brûlé, S; Viollet, B; Kemp, BE; Bardeesy, N; Dennis, P; Schlager, JJ; Marette, A; Kozma, SC; Thomas, G

Published Date

  • May 5, 2010

Published In

Volume / Issue

  • 11 / 5

Start / End Page

  • 390 - 401

PubMed ID

  • 20444419

Pubmed Central ID

  • PMC3081779

Electronic International Standard Serial Number (EISSN)

  • 1932-7420

Digital Object Identifier (DOI)

  • 10.1016/j.cmet.2010.03.014


  • eng

Conference Location

  • United States