Journal Article

Rapamycin (mTORC1 inhibitor) reduces the production of lactate and 2-hydroxyglutarate oncometabolites in IDH1 mutant fibrosarcoma cells

Dankó, Titanilla, Paku, Sándor, Kriston, Csilla, Krencz, Ildikó, Drahos, László, Petővári, Gábor, Szoboszlai, Norbert, Jeney, András, Ozohanics, Olivér, Sebestyén, Anna, Nagy, Noémi, Hujber, Zoltán

2017

Overview

Background Multiple studies concluded that oncometabolites (e.g. D-2-hydroxyglutarate (2-HG) related to mutant isocitrate dehydrogenase 1/2 ( IDH1/2 ) and lactate) have tumour promoting potential. Regulatory mechanisms implicated in the maintenance of oncometabolite production have great interest. mTOR (mammalian target of rapamycin) orchestrates different pathways, influences cellular growth and metabolism. Considering hyperactivation of mTOR in several malignancies, the question has been addressed whether mTOR operates through controlling of oncometabolite accumulation in metabolic reprogramming. Methods HT-1080 cells – carrying originally endogenous IDH1 mutation – were used in vitro and in vivo. Anti-tumour effects of rapamycin were studied using different assays. The main sources and productions of the oncometabolites (2-HG and lactate) were analysed by 13 C-labeled substrates. Alterations at protein and metabolite levels were followed by Western blot, flow cytometry, immunohistochemistry and liquid chromatography mass spectrometry using rapamycin, PP242 and different glutaminase inhibitors, as well. Results Rapamycin (mTORC1 inhibitor) inhibited proliferation, migration and altered the metabolic activity of IDH1 mutant HT-1080 cells. Rapamycin reduced the level of 2-HG sourced mainly from glutamine and glucose derived lactate which correlated to the decreased incorporation of 13 C atoms from 13 C-substrates. Additionally, decreased expressions of lactate dehydrogenase A and glutaminase were also observed both in vitro and in vivo. Conclusions Considering the role of lactate and 2-HG in regulatory network and in metabolic symbiosis it could be assumed that mTOR inhibitors have additional effects besides their anti-proliferative effects in tumours with glycolytic phenotype, especially in case of IDH1 mutation (e.g. acute myeloid leukemias, gliomas, chondrosarcomas). Based on our new results, we suggest targeting mTOR activity depending on the metabolic and besides molecular genetic phenotype of tumours to increase the success of therapies.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: 2-hydroxyglutarate / Animals / Antibiotics, Antineoplastic - pharmacology / Apoptosis / Apoptosis - drug effects / Autophagy / Biomedical and Life Sciences / Biomedicine / Cancer Research / Cancer therapies / Cell Movement - drug effects / Cell Proliferation - drug effects / Complications and side effects / DNA methylation / Dosage and administration / Drug therapy / Fibrosarcoma / Fibrosarcoma - drug therapy / Fibrosarcoma - genetics / Fibrosarcoma - metabolism / Fibrosarcoma - pathology / Genetic aspects / Glioma / Glutarates - metabolism / Growth factors / Humans / Immunology / Isocitrate Dehydrogenase - genetics / Kinases / Lactate / Lactic Acid - metabolism / Mechanistic Target of Rapamycin Complex 1 - antagonists & inhibitors / Medical prognosis / Metabolism / Mice / Mice, SCID / mTOR / Mutation / Oncology / Oncometabolite / Phenotype / Physiological aspects / Proteins / Rapamycin / Sirolimus - pharmacology / Stem cells / Studies / Tumor Cells, Cultured / Tumors / Tumour metabolism / Xenograft Model Antitumor Assays