Dataset Information

NRF3 activates mTORC1 arginine-dependently for cancer cell viability.

ABSTRACT: Cancer cells coordinate the mTORC1 signals and the related metabolic pathways to robustly and rapidly grow in response to nutrient conditions. Although a CNC-family transcription factor NRF3 promotes cancer development, the biological relevance between NRF3 function and mTORC1 signals in cancer cells remains unknown. Hence, we showed that NRF3 contributes to cancer cell viability through mTORC1 activation in response to amino acids, particularly arginine. NRF3 induced SLC38A9 and RagC expression for the arginine-dependent mTORC1 recruitment onto lysosomes, and it also enhanced RAB5-mediated bulk macropinocytosis and SLC7A1-mediated selective transport for arginine loading into lysosomes. Besides, the inhibition of the NRF3-mTORC1 axis impaired mitochondrial function, leading to cancer cell apoptosis. Consistently, the aberrant upregulation of the axis caused tumor growth and poor prognosis. In conclusion, this study sheds light on the unique function of NRF3 in arginine-dependent mTORC1 activation and the pathophysiological aspects of the NRF3-mTORC1 axis in cancer development.

SUBMITTER: Hirose S

PROVIDER: S-EPMC9932127 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

NRF3 activates mTORC1 arginine-dependently for cancer cell viability.

Hirose Shuuhei S Waku Tsuyoshi T Tani Misato M Masuda Haruka H Endo Keiko K Ashitani Sanae S Aketa Iori I Kitano Hina H Nakada Sota S Wada Ayaka A Hatanaka Atsushi A Osawa Tsuyoshi T Soga Tomoyoshi T Kobayashi Akira A

iScience 20230125 2

Cancer cells coordinate the mTORC1 signals and the related metabolic pathways to robustly and rapidly grow in response to nutrient conditions. Although a CNC-family transcription factor NRF3 promotes cancer development, the biological relevance between NRF3 function and mTORC1 signals in cancer cells remains unknown. Hence, we showed that NRF3 contributes to cancer cell viability through mTORC1 activation in response to amino acids, particularly arginine. NRF3 induced <i>SLC38A9</i> and <i>RagC< ...[more]

PMID: 36818298

Similar Datasets

Project description:ObjectiveTetrameric α(2)-macroglobulin (α(2)M), a plasma panproteinase inhibitor, is activated upon interaction with a proteinase, and undergoes a major conformational change exposing a receptor recognition site in each of its subunits. Activated α(2)M (α(2)M*) binds to cancer cell surface GRP78 and triggers proliferative and antiapoptotic signaling. We have studied the role of α(2)M* in the regulation of mTORC1 and TORC2 signaling in the growth of human prostate cancer cells.MethodsEmploying immunoprecipitation techniques and Western blotting as well as kinase assays, activation of the mTORC1 and mTORC2 complexes, as well as down stream targets were studied. RNAi was also employed to silence expression of Raptor, Rictor, or GRP78 in parallel studies.ResultsStimulation of cells with α(2)M* promotes phosphorylation of mTOR, TSC2, S6-Kinase, 4EBP, Akt(T308), and Akt(S473) in a concentration and time-dependent manner. Rheb, Raptor, and Rictor also increased. α(2)M* treatment of cells elevated mTORC1 kinase activity as determined by kinase assays of mTOR or Raptor immunoprecipitates. mTORC1 activity was sensitive to LY294002 and rapamycin or transfection of cells with GRP78 dsRNA. Down regulation of Raptor expression by RNAi significantly reduced α(2)M*-induced S6-Kinase phosphorylation at T389 and kinase activity in Raptor immunoprecipitates. α(2)M*-treated cells demonstrate about a twofold increase in mTORC2 kinase activity as determined by kinase assay of Akt(S473) phosphorylation and levels of p-Akt(S473) in mTOR and Rictor immunoprecipitates. mTORC2 activity was sensitive to LY294002 and transfection of cells with GRP78 dsRNA, but insensitive to rapamycin. Down regulation of Rictor expression by RNAi significantly reduces α(2)M*-induced phosphorylation of Akt(S473) phosphorylation in Rictor immunoprecipitates.ConclusionBinding of α(2)M* to prostate cancer cell surface GRP78 upregulates mTORC1 and mTORC2 activation and promotes protein synthesis in the prostate cancer cells.

Project description:BackgroundCryptotanshinone (CPT), a fat-soluble phenanthraquinone from Salvia miltiorrhiza Bunge, has been demonstrated to inhibit phosphorylation of p70 S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E binding protein 1 (4E-BP1), a couple of direct downstream effectors of the mammalian target of rapamycin complex 1 (mTORC1), resulting in cancer cell arrested in G0 phase and subsequent inhibition of proliferation. However, its concrete molecular mechanism about how CPT inhibits mTORC1 signaling pathway is unclear.Methodsone solution was used to check cell viability and western blotting for determining expression of the indicated proteins. Molecular docking was performed to assess the binding of CPT with mTOR. The co-immunoprecipitation assay was to analyze whether CPT could disrupt the mTORC1 and TSC1/TSC2 complex. Recombinant adenoviral dominant-negative AMPKα was used to downregulate expression of AMPKα and lentiviral AMPK and TSC2 to silence the AMPK and TSC2 in Rh30 cells.ResultsPrimarily, Rh30 cells expressing rapamycin-resistant mutant mTOR are also sensitive to CPT, while the molecular docking result for CPT binding to mTOR is negative, suggesting that CPT inhibition of mTORC1 is different from rapamycin. Then the related proteins of PTEN-PI3K pathway was proved not to be affected, but the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) was activated by a concentration- and time- dependent manner, meaning that it may be associated with AMPK. Further results indicated that compound C, inhibitor of AMPK, could clearly reversed CPT inhibitory effect on Rh30 cells, and dominant-negative AMPK in cancer cells conferred resistance to CPT inhibition of 4E-BP1 and phosphorylation of S6K1, as well as sh-AMPK. Furthermore, compared with AMPK-positive MEF cells, AMPK-negative MEF cells are less sensitive to CPT by the findings that 4E-BP1 and phosphorylation of S6K1 express comparatively more. Additionally, phosphorylation of tuberous sclerosis complex 2 (TSC2) was activated under the treatment of CPT, and down-expression of TSC2 by shRNA slightly recovered expression of 4E-BP1 and phosphorylation of S6K1, while co-immunoprecipitation of TSC2 did not alter expression of TSC1 by CPT.ConclusionCPT inhibiting mTORC1 pathway was mostly due to activation of AMPK-TSC2 axis rather than specific binding to mTORC1. CPT is a potent anticancer agent targeting AMPK.

Dataset Information

NRF3 activates mTORC1 arginine-dependently for cancer cell viability.

Publications

NRF3 activates mTORC1 arginine-dependently for cancer cell viability.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets