Autophagy favors both cell survival and cancer suppression, and increasing evidence reveals that microRNAs (MIRs) regulate autophagy. Previously we reported that MIR126 is downregulated in malignant mesothelioma (MM). Therefore, we investigated the role of MIR126 in the regulation of cell metabolism and autophagy in MM models. We report that MIR126 induces autophagic flux in MM cells by downregulating insulin receptor substrate-1 (IRS1) and disrupting the IRS1 signaling pathway. This was specific to MM cells, and was not observed in non-malignant cells of mesothelial origin or in MM cells expressing MIR126-insensitive IRS1 transcript. The MIR126 effect on autophagy in MM cells was recapitulated by IRS1 silencing, and antagonized by IRS1 overexpression or antisense MIR126 treatment. The MIR126-induced loss of IRS1 suppressed glucose uptake, leading to energy deprivation and AMPK-dependent phosphorylation of ULK1. In addition, MIR126 stimulated lipid droplet accumulation in a hypoxia-inducible factor-1α (HIF1α)-dependent manner. MIR126 also reduced pyruvate dehydrogenase kinase (PDK) and acetyl-CoA-citrate lyase (ACL) expression, leading to the accumulation of cytosolic citrate and paradoxical inhibition of pyruvate dehydrogenase (PDH) activity. Simultaneous pharmacological and genetic intervention with PDK and ACL activity phenocopied the effects of MIR126. This suggests that in MM MIR126 initiates a metabolic program leading to high autophagic flux and HIF1α stabilization, incompatible with tumor progression of MM. Consistently, MIR126-expressing MM cells injected into immunocompromised mice failed to progress beyond the initial stage of tumor formation, showing that increased autophagy has a protective role in MM.

Department of Clinical and Molecular Science Polytechnic University of Marche 60020 Ancona Italy

Institute of Biotechnology Czech Academy of Sciences BIOCEV Vestec Prague West 25242 Czech Republic

Institute of Molecular Genetics Czech Academy of Sciences Prague 4 142 20 Czech Republic

School of Medical Science and Griffith Health Institute Griffith University Southport Qld 4222 Australia

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Cairns RA, Harris IS, Mak TW. Regulation of cancer cell metabolism. Nat Rev Cancer. 2011;11:85–95. PubMed

Liu H, He Z, Simon H. Protective role of autophagy and autophagy-related protein 5 in early tumorigenesis. J Mol Med. 2015;93:159–164. PubMed

Gozuacik D, Kimchi A. Autophagy as a cell death and tumor suppressor mechanism. Oncogene. 2004;23:2891–2906. PubMed

Green DR, Galluzzi L, Kroemer G. Metabolic control of cell death. Science. 2014;345:125–156. PubMed PMC

Kenific CM, Debnath J. Cellular and metabolic functions for autophagy in cancer cells. Trends Cell Biol. 2015;25:37–45. PubMed PMC

Kim KM, Kim SG. Autophagy and microRNA dysregulation in liver diseases. Arch Pharm Res. 2014;37:1097–1116. PubMed

Ebrahimi F, Gopalan V, Smith RA, Lam AK. MiR-126 in human cancers: clinical roles and current perspectives. Exp Mol Pathol. 2014;96:98–107. PubMed

Tai HC, Chang AC, Yu HJ, Huang CY, Tsai YC, Lai YW, Sun HL, Tang CH, Wang SW. Osteoblast-derived WNT-induced secreted protein 1 increases VCAM-1 expression and enhances prostate cancer metastasis by down-regulating miR-126. Oncotarget. 2014;5:7589–7598. doi: 10.18632/oncotarget.2280. PubMed DOI PMC

Chakraborty C, Sharma AR, Patra BC, Bhattacharya M, Sharma G, Lee SS. MicroRNAs mediated regulation of MAPK signaling pathways in chronic myeloid leukemia. Oncotarget. 2016 Mar 8; doi: 10.18632/oncotarget.7977. in press. PubMed DOI PMC

Guo C, Sah JF, Beard L, Willson JK, Markowitz SD, Guda K. The noncoding RNA, miR-126, suppresses the growth of neoplastic cells by targeting phosphatidylinositol 3-kinase signaling and is frequently lost in colon cancers. Genes Chromosomes Cancer. 2008;47:939–946. PubMed PMC

Chen SW, Wang TB, Tian YH, Zheng YG. Down-regulation of microRNA-126 and microRNA-133b acts as novel predictor biomarkers in progression and metastasis of non small cell lung cancer. Int. J. Clin. Exp. Pathol. 2015;8:14983–14988. PubMed PMC

Tomasetti M, Nocchi L, Staffolani S, Manzella N, Amati M, Goodwin J, Kluckova K, Nguyen M, Strafella E, Bajzikova M, Peterka M, Lettlova S, Truksa J, et al. MicroRNA-126 suppresses mesothelioma malignancy by targeting IRS1 and interfering with the mitochondrial function. Antioxid Redox Signal. 2014;21:2109–2125. PubMed PMC

Zhang J, Du YY, Lin YF, Chen YT, Yang L, Wang HJ, Ma D. The cell growth suppressor, mir-126, targets IRS-1. Biochem Biophys Res Commun. 2008;377:136–140. PubMed

Ryu HS, Park SY, Ma D, Zhang J, Lee W. The induction of microRNA targeting IRS-1 is involved in the development of insulin resistance under conditions of mitochondrial dysfunction in hepatocytes. PLoS One. 2011;6:e17343. PubMed PMC

Felli N, Felicetti F, Lustri AM, Errico MC, Bottero L, Cannistraci A, De Feo A, Petrini M, Pedini F, Biffoni M, Alvino E, Negrini M, Ferracin M, et al. MiR-126 & 126* restored expressions play a tumor suppressor role by directly regulating ADAM9 and MMP7 in melanoma. PLoS One. 2013;8:e56824. PubMed PMC

Hara T, Jones MF, Subramanian M, Li XL, Ou O, Zhu Y, Yang Y, Wakefield LM, Hussain SP, Gaedcke J, Ried T, Luo J, Caplen NJ, et al. Selective targeting of KRAS-mutant cells by miR-126 through repression of multiple genes essential for the survival of KRAS-mutant cells. Oncotarget. 2014;5:7635–7650. doi: 10.18632/oncotarget.2284. PubMed DOI PMC

Yang C, Hou C, Zhang H, Wang D, Ma Y, Zhang Y, Xu X, Bi Z, Geng S. MiR-126 functions as a tumor suppressor in osteosarcoma by targeting Sox2. Int J Mol Sci. 2013;15:423–437. PubMed PMC

Miko E, Margitai Z, Czimmerer Z, Várkonyi I, Dezso B, Lányi A, Bacsó Z, Scholtz B. MiR-126 inhibits proliferation of small cell lung cancer cells by targeting SLC7A5. FEBS Lett. 2011;585:1191–1196. PubMed

Sun Y, Bai Y, Zhang F, Wang Y, Guo Y, Guo L. MiR-126 inhibits non-small cell lung cancer cells proliferation by targeting EGFL7. Biochem Biophys Res Commun. 2010;391:1483–1489. PubMed

Chen H, Li L, Wang S, Lei Y, Ge Q, Lv N, Zhou X, Chen C. Reduced miR-126 expression facilitates angiogenesis of gastric cancer through its regulation on VEGF-A. Oncotarget. 2014;5:11873–11885. doi: 10.18632/oncotarget.2662. PubMed DOI PMC

Wu YT, Tan HL, Shui G, Bauvy C, Huang Q, Wenk MR, Ong CN, Codogno P, Shen HM. Dual role of 3-methyladenine in modulation of autophagy via different temporal patterns of inhibition on class I and III phosphoinositide 3-kinase. J Biol Chem. 2010;285:10850–10861. PubMed PMC

Meijer AJ, Codogno P. Autophagy: regulation and role in disease. Crit Rev Clin Lab Sci. 2009;46:210–240. PubMed

Marín-Juez R, Diaz M, Morata J, Planas JV. Mechanisms regulating GLUT4 transcription in skeletal muscle cells are highly conserved across vertebrates. PLoS One. 2013;8:e80628. PubMed PMC

Geng Y, Ju Y, Ren F, Qiu Y, Tomita Y, Tomoeda M, Kishida M, Wang Y, Jin L, Su F, Wei C, Jia B, Li Y, Chang Z. Insulin receptor substrate 1/2 (IRS1/2) regulates Wnt/β-catenin signaling through blocking autophagic degradation of disheveled-2. J Biol Chem. 2014;289:11230–11241. PubMed PMC

Chan SH, Kikkawa U, Matsuzaki H, Chen JH, Chang WC. Insulin receptor substrate-1 prevents autophagy-dependent cell death caused by oxidative stress in mouse NIH/3T3 cells. J Biomed Sci. 2012;19:64. PubMed PMC

Mihaylova MM, Shaw RJ. The AMPK signalling pathway coordinates cell growth, autophagy and metabolism. Nat Cell Biol. 2011;13:1016–1023. PubMed PMC

Sugden MC, Bulmer K, Holness MJ. Fuel-sensing mechanisms integrating lipid and carbohydrate utilization. Biochem Soc Trans. 2001;29:272–278. PubMed

Koukourakis MI, Giatromanolaki A, Sivridis E, Gatter KC, Harris AL. Pyruvate dehydrogenase and pyruvate dehydrogenase kinase expression in non-small cell lung cancer and tumor-associated stroma. Neoplasia. 2005;7:1–6. PubMed PMC

Lu CW, Lin SC, Chien CW, Lee CT, Lin BW, Lee JC, Tsai SJ. Overexpression of pyruvate dehydrogenase kinase 3 increases drug resistance and early recurrence in colon cancer. Am J Pathol. 2011;179:1405–1414. PubMed PMC

McFate T, Mohyeldin A, Lu H, Thakar J, Henriques J, Halim N D, Wu H, Schell MJ, Tsang TM, Teahan O, Zhou S, Califano JA, Jeoung NH, et al. Pyruvate dehydrogenase complex activity controls metabolic and malignant phenotype in cancer cells. J Biol Chem. 2008;283:22700–22708. PubMed PMC

Moore JD, Staniszewska A, Shaw T, D'Alessandro J, Davis B, Surgenor A, Baker L, Matassova N, Murray J, Macias A, Brough P, Wood M, Mahon PC. VER-246608, a novel pan-isoform ATP competitive inhibitor of pyruvate dehydrogenase kinase, disrupts Warburg metabolism and induces context-dependent cytostasis in cancer cells. Oncotarget. 2014;5:12862–12876. doi: 10.18632/oncotarget.2656. PubMed DOI PMC

Baggetto LG. Deviant energetic metabolism of glycolytic cancer cells. Biochimie. 1992;74:959–974. PubMed

Schroeder S, Pendl T, Zimmermann A, Eisenberg T, Carmona-Gutierrez D, Ruckenstuhl C, Mariño G, Pietrocola F, Harger A, Magnes C, Sinner F, Pieber TR, Dengjel J, et al. Acetyl-coenzyme A: a metabolic master regulator of autophagy and longevity. Autophagy. 2014;10:1335–1337. PubMed PMC

Rambold AS, Cohen S, Lippincott-Schwartz J. Fatty acid trafficking in starved cells: regulation by lipid droplet lipolysis, autophagy, and mitochondrial fusion dynamics. Dev Cell. 2015;32:678–692. PubMed PMC

Gimm T, Wiese M, Teschemacher B, Deggerich A, Schödel J, Knaup KX, Hackenbeck T, Hellerbrand C, Amann K, Wiesener MS, Höning S, Eckardt KU, Warnecke C. Hypoxia-inducible protein 2 is a novel lipid droplet protein and a specific target gene of hypoxia-inducible factor-1. FASEB J. 2010;24:4443–4458. PubMed

Rippo MR, Moretti S, Vescovi S, Tomasetti M, Orecchia S, Amici G, Catalano A, Procopio A. FLIP overexpression inhibits death receptor-induced apoptosis in malignant mesothelial cells. Oncogene. 2004;23:7753–7760. PubMed

Dong LF, Swettenham E, Eliasson J, Wang XF, Gold M, Medunic Y, Stantic M, Low P, Prochazka L, Witting PK, Turanek J, Akporiaye ET, Ralph SJ, et al. Vitamin E analogs inhibit angiogenesis by selective apoptosis induction in proliferating endothelial cells: The role of oxidative stress. Cancer Res. 2007;67:11906–119013. PubMed

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