BACKGROUND: The mechanistic target of rapamycin (mTOR) is a crucial regulator of cell metabolic activity. It forms part of several distinct protein complexes, particularly mTORC1 and mTORC2. The lack of specific inhibitors still hampers the attribution of mTOR functions to these complexes. JR-AB2-011 has been reported as a specific mTORC2 inhibitor preventing mTOR binding to RICTOR, a unique component of mTORC2. We aimed to describe the effects of JR-AB2-011 in leukemia/lymphoma cells, where the mTOR pathway is often aberrantly activated. METHODS: The impact of JR-AB2-011 on leukemia/lymphoma cell metabolism was analyzed using the Seahorse platform. AKT phosphorylation at Ser473 was used as a marker of mTORC2 activity. mTOR binding to RICTOR was assessed by co-immunoprecipitation. RICTOR-null cells were derived from the Karpas-299 cell line using CRISPR/Cas9 gene editing. RESULTS: In leukemia/lymphoma cell lines, JR-AB2-011 induced a rapid drop in the cell respiration rate, which was variably compensated by an increased glycolytic rate. In contrast, an increase in the respiration rate due to JR-AB2-011 treatment was observed in primary leukemia cells. Unexpectedly, JR-AB2-011 did not affect AKT Ser473 phosphorylation. In addition, mTOR did not dissociate from RICTOR in cells treated with JR-AB2-011 under the experimental conditions used in this study. The effect of JR-AB2-011 on cell respiration was retained in RICTOR-null cells. CONCLUSION: JR-AB2-011 affects leukemia/lymphoma cell metabolism via a mechanism independent of mTORC2.

Department of Proteomics Institute of Hematology and Blood Transfusion U Nemocnice 1 Prague 128 20 Czech Republic

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Jhanwar-Uniyal M, Wainwright JV, Mohan AL, Tobias ME, Murali R, Gandhi CD, et al. Diverse signaling mechanisms of mTOR complexes: mTORC1 and mTORC2 in forming a formidable relationship. Adv Biol Regul. 2019;72:51–62. 10.1016/j.jbior.2019.03.003. PubMed

Gkountakos A, Pilotto S, Mafficini A, Vicentini C, Simbolo M, Milella M, et al. Unmasking the impact of Rictor in cancer: novel insights of mTORC2 complex. Carcinogenesis. 2018;39:971–80. 10.1093/carcin/bgy086. PubMed

Wu F, Chen Z, Liu J, Hou Y. The Akt-mTOR network at the interface of hematopoietic stem cell homeostasis. Exp Hematol. 2021;103:15–23. 10.1016/j.exphem.2021.08.009. PubMed

Harwood FC, Klein Geltink RI, O’Hara BP, Cardone M, Janke L, Finkelstein D, et al. ETV7 is an essential component of a rapamycin-insensitive mTOR complex in cancer. Sci Adv. 2018;4:eaar3938. 10.1126/sciadv.aar3938. PubMed PMC

Szwed A, Kim E, Jacinto E. Regulation and metabolic functions of mTORC1 and mTORC2. Physiol Rev. 2021;101:1371–426. 10.1152/physrev.00026.2020. PubMed PMC

Benavides-Serrato A, Lee J, Holmes B, Landon KA, Bashir T, Jung ME, et al. Specific blockade of Rictor-mTOR association inhibits mTORC2 activity and is cytotoxic in glioblastoma. PLoS ONE. 2017;12:e0176599. 10.1371/journal.pone.0176599. [doi]. PubMed PMC

Herschbein L, Liesveld JL. Dueling for dual inhibition: means to enhance effectiveness of PI3K/Akt/mTOR inhibitors in AML. Blood Rev. 2018;32:235–48. 10.1016/j.blre.2017.11.006. PubMed

Chen W, Drakos E, Grammatikakis I, Schlette EJ, Li J, Leventaki V, et al. mTOR signaling is activated by FLT3 kinase and promotes survival of FLT3-mutated acute myeloid leukemia cells. Mol Cancer. 2010;9:292–292. 10.1186/1476-4598-9-292. PubMed PMC

Park HJ, Gregory MA, Zaberezhnyy V, Goodspeed A, Jordan CT, Kieft JS, et al. Therapeutic resistance in acute myeloid leukemia cells is mediated by a novel ATM/mTOR pathway regulating oxidative phosphorylation. eLife. 2022;11. 10.7554/eLife.79940. PubMed PMC

You R, Hou D, Wang B, Liu J, Wang X, Xiao Q, et al. Bone marrow microenvironment drives AML cell OXPHOS addiction and AMPK inhibition to resist chemotherapy. J Leukoc Biol. 2022;112:299–311. 10.1002/JLB.6A0821-409RR. PubMed PMC

Efeyan A, Sabatini DM. mTOR and cancer: many loops in one pathway. Curr Opin Cell Biol. 2010;22:169–76. 10.1016/j.ceb.2009.10.007. PubMed PMC

Oki T, Mercier F, Kato H, Jung Y, McDonald TO, Spencer JA, et al. Imaging dynamic mTORC1 pathway activity in vivo reveals marked shifts that support time-specific inhibitor therapy in AML. Nat Commun. 2021;12:245–8. 10.1038/s41467-020-20491-8. PubMed PMC

Germano CA, Clemente G, Storniolo A, Romeo MA, Ferretti E, Cirone M, et al. mTORC1/ERK1/2 Interplay Regulates Protein Synthesis and survival in acute myeloid leukemia cell lines. Biology (Basel). 2023;12:676. 10.3390/biology12050676. PubMed PMC

Fooks K, Galicia-Vazquez G, Gife V, Schcolnik-Cabrera A, Nouhi Z, Poon WWL, et al. EIF4A inhibition targets bioenergetic homeostasis in AML MOLM-14 cells in vitro and in vivo and synergizes with cytarabine and venetoclax. J Exp Clin Cancer Res. 2022;41:340–8. 10.1186/s13046-022-02542-8. PubMed PMC

Feng Y, Wu L. mTOR up-regulation of PFKFB3 is essential for acute myeloid leukemia cell survival. Biochem Biophys Res Commun. 2017;483:897–903. 10.1016/j.bbrc.2017.01.031. PubMed

Satta T, Li L, Chalasani SL, Hu X, Nkwocha J, Sharma K, et al. Dual mTORC1/2 inhibition synergistically enhances AML cell death in combination with the BCL2 antagonist venetoclax. Clin Cancer Res. 2023;29:1332–43. 10.1158/1078-0432.CCR-22-2729. PubMed PMC

Braun C, Weichhart T. mTOR-dependent immunometabolism as achilles’ heel of anticancer therapy. Eur J Immunol. 2021;51:3161–75. 10.1002/eji.202149270. PubMed

Fang Y, Yang Y, Hua C, Xu S, Zhou M, Guo H, et al. Rictor has a pivotal role in maintaining quiescence as well as stemness of leukemia stem cells in MLL-driven leukemia. Leukemia. 2017;31:414–22. 10.1038/leu.2016.223. PubMed

Cunningham JT, Rodgers JT, Arlow DH, Vazquez F, Mootha VK, Puigserver P. mTOR controls mitochondrial oxidative function through a YY1-PGC-1alpha transcriptional complex. Nature. 2007;450:736–40. 10.1038/nature06322. PubMed

Morita M, Gravel S, Chénard V, Sikström K, Zheng L, Alain T, et al. mTORC1 controls mitochondrial activity and biogenesis through 4E-BP-dependent translational regulation. Cell Metab. 2013;18:698–711. 10.1016/j.cmet.2013.10.001. PubMed

Wu M, Wang Q, Huang B, Mai C, Wang C, Wang T, et al. Dioscin ameliorates murine ulcerative colitis by regulating macrophage polarization. Pharmacol Res. 2021;172:105796. 10.1016/j.phrs.2021.105796. PubMed

Xu Z, Gu Y, Wang C, Jin Y, Wen X, Ma J, et al. The M2 macrophage marker CD206: a novel prognostic indicator for acute myeloid leukemia. Oncoimmunology. 2019;9:1683347. 10.1080/2162402X.2019.1683347. PubMed PMC

Marzec M, Kasprzycka M, Liu X, El-Salem M, Halasa K, Raghunath PN, et al. Oncogenic tyrosine kinase NPM/ALK induces activation of the rapamycin-sensitive mTOR signaling pathway. Oncogene. 2007;26:5606–14. 10.1038/sj.onc.1210346. PubMed

Zhao Y, Zhou Q, Xu Y, Lai X, Huang H. Antiproliferative effect of rapamycin on human T-cell leukemia cell line Jurkat by cell cycle arrest and telomerase inhibition. Acta Pharmacol Sin. 2008;29:481–8. 10.1111/j.1745-7254.2008.00767.x. PubMed

Chen WL, Wang JH, Zhao AH, Xu X, Wang YH, Chen TL, et al. A distinct glucose metabolism signature of acute myeloid leukemia with prognostic value. Blood. 2014;124:1645–54. 10.1182/blood-2014-02-554204. PubMed PMC

Lagadinou ED, Sach A, Callahan K, Rossi RM, Neering SJ, Minhajuddin M, et al. BCL-2 inhibition targets oxidative phosphorylation and selectively eradicates quiescent human leukemia stem cells. Cell Stem Cell. 2013;12:329–41. 10.1016/j.stem.2012.12.013. PubMed PMC

Farge T, Saland E, de Toni F, Aroua N, Hosseini M, Perry R, et al. Chemotherapy-resistant human acute myeloid leukemia cells are not enriched for leukemic stem cells but require oxidative metabolism. Cancer Discov. 2017;7:716–35. 10.1158/2159-8290.CD-16-0441. PubMed PMC

Zhang A, Liu Y, Xu H, Zhang Z, Wang X, Yuan L, et al. CCL17 exerts neuroprotection through activation of CCR4/mTORC2 axis in microglia after subarachnoid haemorrhage in rats. Stroke Vasc Neurol. 2022;8:4–16. 10.1136/svn-2022-001659. PubMed PMC

Guenzle J, Akasaka H, Joechle K, Reichardt W, Venkatasamy A, Hoeppner J, et al. Pharmacological inhibition of mTORC2 reduces migration and metastasis in melanoma. Int J Mol Sci. 2020;22:30. 10.3390/ijms22010030. PubMed PMC