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Inhibition of mTOR complex 1/p70 S6 kinase signaling elevates PD-L1 levels in human cancer cells through enhancing protein stabilization accompanied with enhanced β-TrCP degradation

Oncogene volume 38, pages 6270–6282 (2019)Cite this article

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Abstract

The involvement of mammalian target of rapamycin (mTOR) in the positive regulation of oncogenesis has been well documented and thus mTOR has emerged as an attractive cancer therapeutic target. Although rapamycin and its analogues (rapalogs) are FDA-approved for the treatment of certain cancers, major success in targeting mTOR, particularly with new generation mTOR kinase inhibitors, for the effective treatment of cancers has not been achieved. Hence, a thorough understanding of the biology of the mTOR axis in cancer is still needed. It is now recognized that programmed death-ligand 1 (PD-L1) expression on cancer cells is a critical mechanism contributing to immunosuppression and immune escape via interacting with program death-1 (PD-1) on immune cells. This study has revealed a previously undiscovered role of the mTOR complex 1 (mTORC1)/p70 S6 kinase (p70S6K) in the negative regulation of PD-L1 on cancer cells and tissues. We demonstrate that disruption of this signaling pathway with mTOR inhibitors, raptor knockdown or p70S6K inhibitors elevated PD-L1 levels in some lung and other cancer cell lines. Elevation of PD-L1 by inhibition of mTORC1/p70S6K signaling is likely due to suppression of β-TrCP-mediated proteasomal degradation of PD-L1, because inhibition of either mTORC1 or p70S6K facilitated β-TrCP degradation accompanied with enhanced PD-L1 protein stabilization. Our current findings indicate the complexity of the mTOR axis in cancer, which should be considered when targeting this axis for effective cancer treatment. Our findings also suggest a strong scientific rationale for enhancing PD-1/PD-L1-targeted cancer immunotherapy through co-targeting mTORC1/p70S6K signaling.

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References

  1. Ilagan E, Manning BD. Emerging role of mTOR in the response to cancer therapeutics. Trends cancer 2016;2:241–51.

    Article  Google Scholar 

  2. Saxton RA, Sabatini DM. mTOR signaling in growth, metabolism, and disease. Cell 2017;168:960–76.

    Article  CAS  Google Scholar 

  3. Ben-Sahra I, Manning BD. mTORC1 signaling and the metabolic control of cell growth. Curr Opin Cell Biol. 2017;45:72–82.

    Article  CAS  Google Scholar 

  4. Duan S, Skaar JR, Kuchay S, Toschi A, Kanarek N, Ben-Neriah Y, et al. mTOR generates an auto-amplification loop by triggering the betaTrCP- and CK1alpha-dependent degradation of DEPTOR. Mol Cell 2011;44:317–24.

    Article  CAS  Google Scholar 

  5. Gao D, Inuzuka H, Tan MK, Fukushima H, Locasale JW, Liu P, et al. mTOR drives its own activation via SCF(betaTrCP)-dependent degradation of the mTOR inhibitor DEPTOR. Mol Cell 2011;44:290–303.

    Article  CAS  Google Scholar 

  6. Zhao Y, Xiong X, Sun Y. DEPTOR, an mTOR inhibitor, is a physiological substrate of SCF(betaTrCP) E3 ubiquitin ligase and regulates survival and autophagy. Mol Cell 2011;44:304–16.

    Article  CAS  Google Scholar 

  7. Shimizu K, Fukushima H, Ogura K, Lien EC, Nihira NT, Zhang J, et al. The SCFbeta-TRCP E3 ubiquitin ligase complex targets Lipin1 for ubiquitination and degradation to promote hepatic lipogenesis. Sci Signal. 2017;10:eaah4117. pii

    Article  Google Scholar 

  8. Sparks CA, Guertin DA. Targeting mTOR: prospects for mTOR complex 2 inhibitors in cancer therapy. Oncogene. 2010;29:3733–44.

    Article  CAS  Google Scholar 

  9. Wander SA, Hennessy BT, Slingerland JM. Next-generation mTOR inhibitors in clinical oncology: how pathway complexity informs therapeutic strategy. J Clin Invest. 2011;121:1231–41.

    Article  CAS  Google Scholar 

  10. Zhang YJ, Duan Y, Zheng XF. Targeting the mTOR kinase domain: the second generation of mTOR inhibitors. Drug Disco Today 2011;16:325–31.

    Article  CAS  Google Scholar 

  11. Sun SY. mTOR kinase inhibitors as potential cancer therapeutic drugs. Cancer Lett. 2013;340:1–8.

    Article  CAS  Google Scholar 

  12. Hudes G, Carducci M, Tomczak P, Dutcher J, Figlin R, Kapoor A, et al. Temsirolimus, interferon alfa, or both for advanced renal-cell carcinoma. N Engl J Med. 2007;356:2271–81.

    Article  CAS  Google Scholar 

  13. Amato RJ, Jac J, Giessinger S, Saxena S, Willis JP. A phase 2 study with a daily regimen of the oral mTOR inhibitor RAD001 (everolimus) in patients with metastatic clear cell renal cell cancer. Cancer 2009;115:2438–46.

    Article  CAS  Google Scholar 

  14. Motzer RJ, Escudier B, Oudard S, Hutson TE, Porta C, Bracarda S, et al. Efficacy of everolimus in advanced renal cell carcinoma: a double-blind, randomised, placebo-controlled phase III trial. Lancet 2008;372:449–56.

    Article  CAS  Google Scholar 

  15. Yao JC, Shah MH, Ito T, Bohas CL, Wolin EM, Van Cutsem E, et al. Everolimus for advanced pancreatic neuroendocrine tumors. N Engl J Med. 2011;364:514–23.

    Article  CAS  Google Scholar 

  16. Baselga J, Campone M, Piccart M, Burris HA 3rd, Rugo HS, Sahmoud T, et al. Everolimus in postmenopausal hormone-receptor-positive advanced breast cancer. N Engl J Med. 2012;366:520–9.

    Article  CAS  Google Scholar 

  17. Abraham RT, Gibbons JJ. The mammalian target of rapamycin signaling pathway: twists and turns in the road to cancer therapy. Clin Cancer Res. 2007;13:3109–14.

    Article  CAS  Google Scholar 

  18. Guan J, Lim KS, Mekhail T, Chang CC. Programmed death ligand-1 (PD-L1) expression in the programmed death receptor-1 (PD-1)/PD-L1 blockade: a key player against various cancers. Arch Pathol Lab Med. 2017;141:851–61.

    Article  CAS  Google Scholar 

  19. Benson DM Jr., Bakan CE, Mishra A, Hofmeister CC, Efebera Y, Becknell B, et al. The PD-1/PD-L1 axis modulates the natural killer cell versus multiple myeloma effect: a therapeutic target for CT-011, a novel monoclonal anti-PD-1 antibody. Blood 2010;116:2286–94.

    Article  CAS  Google Scholar 

  20. Gordon SR, Maute RL, Dulken BW, Hutter G, George BM, McCracken MN, et al. PD-1 expression by tumour-associated macrophages inhibits phagocytosis and tumour immunity. Nature 2017;545:495–9.

    Article  CAS  Google Scholar 

  21. Iwai Y, Hamanishi J, Chamoto K, Honjo T. Cancer immunotherapies targeting the PD-1 signaling pathway. J Biomed Sci. 2017;24:26.

    Article  Google Scholar 

  22. Somasundaram A, Burns TF. The next generation of immunotherapy: keeping lung cancer in check. J Hematol Oncol. 2017;10:87.

    Article  Google Scholar 

  23. Stambrook PJ, Maher J, Farzaneh F. Cancer immunotherapy: Whence and Whither. Mol cancer Res: MCR. 2017;15:635–50.

    Article  CAS  Google Scholar 

  24. Remon J, Besse B, Soria JC. Successes and failures: what did we learn from recent first-line treatment immunotherapy trials in non-small cell lung cancer? BMC Med. 2017;15:55.

    Article  Google Scholar 

  25. Ott PA, Hodi FS, Kaufman HL, Wigginton JM, Wolchok JD. Combination immunotherapy: a road map. J Immunother cancer. 2017;5:16.

    Article  Google Scholar 

  26. Lastwika KJ, Wilson W 3rd, Li QK, Norris J, Xu H, Ghazarian SR, et al. Control of PD-L1 expression by oncogenic activation of the AKT-mTOR pathway in non-small cell lung cancer. Cancer Res. 2016;76:227–38.

    Article  CAS  Google Scholar 

  27. Sun SY, Rosenberg LM, Wang X, Zhou Z, Yue P, Fu H, et al. Activation of Akt and eIF4E survival pathways by rapamycin-mediated mammalian target of rapamycin inhibition. Cancer Res. 2005;65:7052–8.

    Article  CAS  Google Scholar 

  28. Koo J, Wang X, Owonikoko TK, Ramalingam SS, Khuri FR, Sun SY. GSK3 is required for rapalogs to induce degradation of some oncogenic proteins and to suppress cancer cell growth. Oncotarget. 2015;6:8974–87.

    PubMed  PubMed Central  Google Scholar 

  29. Wang X, Yue P, Kim YA, Fu H, Khuri FR, Sun SY. Enhancing mammalian target of rapamycin (mTOR)-targeted cancer therapy by preventing mTOR/raptor inhibition-initiated, mTOR/rictor-independent Akt activation. Cancer Res. 2008;68:7409–18.

    Article  CAS  Google Scholar 

  30. Sarbassov dos D, Ali SM, Sengupta S, Sheen JH, Hsu PP, Bagley AF, et al. Prolonged rapamycin treatment inhibits mTORC2 assembly and Akt/PKB. Mol Cell 2006;22:159–68.

    Article  CAS  Google Scholar 

  31. Li CW, Lim SO, Xia W, Lee HH, Chan LC, Kuo CW, et al. Glycosylation and stabilization of programmed death ligand-1 suppresses T-cell activity. Nat Commun. 2016;7:12632.

    Article  CAS  Google Scholar 

  32. Shien K, Papadimitrakopoulou VA, Wistuba II. Predictive biomarkers of response to PD-1/PD-L1 immune checkpoint inhibitors in non-small cell lung cancer. Lung Cancer 2016;99:79–87.

    Article  Google Scholar 

  33. Hirayama Y, Gi M, Yamano S, Tachibana H, Okuno T, Tamada S, et al. Anti-PD-L1 treatment enhances antitumor effect of everolimus in a mouse model of renal cell carcinoma. Cancer Sci. 2016;107:1736–44.

    Article  CAS  Google Scholar 

  34. Song Y, Li Z, Xue W, Zhang M. Predictive biomarkers for PD-1 and PD-L1 immune checkpoint blockade therapy. Immunotherapy 2019;11:515–29.

    Article  CAS  Google Scholar 

  35. Lim SO, Li CW, Xia W, Cha JH, Chan LC, Wu Y, et al. Deubiquitination and stabilization of PD-L1 by CSN5. Cancer Cell 2016;30:925–39.

    Article  CAS  Google Scholar 

  36. Araki K, Youngblood B, Ahmed R. The role of mTOR in memory CD8 T-cell differentiation. Immunol Rev. 2010;235:234–43.

    Article  CAS  Google Scholar 

  37. Chi H. Regulation and function of mTOR signalling in T cell fate decisions. Nat Rev Immunol. 2012;12:325–38.

    Article  CAS  Google Scholar 

  38. Chapman NM, Chi H. mTOR signaling, Tregs and immune modulation. Immunotherapy 2014;6:1295–311.

    Article  CAS  Google Scholar 

  39. Fantus D, Thomson AW. Evolving perspectives of mTOR complexes in immunity and transplantation. Am J Transplant: Off J Am Soc Transplant Am Soc Transpl Surg. 2015;15:891–902.

    Article  CAS  Google Scholar 

  40. Araki K, Turner AP, Shaffer VO, Gangappa S, Keller SA, Bachmann MF, et al. mTOR regulates memory CD8 T-cell differentiation. Nature 2009;460:108–12.

    Article  CAS  Google Scholar 

  41. Mannick JB, Del Giudice G, Lattanzi M, Valiante NM, Praestgaard J, Huang B, et al. mTOR inhibition improves immune function in the elderly. Sci Transl Med. 2014;6:268ra179.

    Article  Google Scholar 

  42. Beziaud L, Mansi L, Ravel P, Marie-Joseph EL, Laheurte C, Rangan L, et al. Rapalogs efficacy relies on the modulation of antitumor t-cell immunity. Cancer Res. 2016;76:4100–12.

    Article  CAS  Google Scholar 

  43. Amiel E, Everts B, Freitas TC, King IL, Curtis JD, Pearce EL, et al. Inhibition of mechanistic target of rapamycin promotes dendritic cell activation and enhances therapeutic autologous vaccination in mice. J Immunol. 2012;189:2151–8.

    Article  CAS  Google Scholar 

  44. Thomas DL, Doty R, Tosic V, Liu J, Kranz DM, McFadden G, et al. Myxoma virus combined with rapamycin treatment enhances adoptive T cell therapy for murine melanoma brain tumors. Cancer Immunol Immunother. 2011;60:1461–72.

    Article  CAS  Google Scholar 

  45. Diken M, Kreiter S, Vascotto F, Selmi A, Attig S, Diekmann J, et al. mTOR inhibition improves antitumor effects of vaccination with antigen-encoding RNA. Cancer Immunol Res. 2013;1:386–92.

    Article  CAS  Google Scholar 

  46. Mineharu Y, Kamran N, Lowenstein PR, Castro MG. Blockade of mTOR signaling via rapamycin combined with immunotherapy augments antiglioma cytotoxic and memory T-cell functions. Mol Cancer Ther. 2014;13:3024–36.

    Article  CAS  Google Scholar 

  47. Moore EC, Cash HA, Caruso AM, Uppaluri R, Hodge JW, Van Waes C, et al. Enhanced tumor control with combination mTOR and PD-L1 inhibition in syngeneic oral cavity cancers. Cancer Immunol Res. 2016;4:611–20.

    Article  CAS  Google Scholar 

  48. Koo J, Yue P, Gal AA, Khuri FR, Sun SY. Maintaining glycogen synthase kinase-3 activity is critical for mTOR kinase inhibitors to inhibit cancer cell growth. Cancer Res. 2014;74:2555–68.

    Article  CAS  Google Scholar 

  49. Koo J, Yue P, Deng X, Khuri FR, Sun SY. mTOR complex 2 stabilizes Mcl-1 protein by suppressing its GSK3-dependent and SCF-FBXW7-mediated degradation. Mol Cell Biol. 2015;35:2344–55.

    Article  CAS  Google Scholar 

  50. Shi P, Oh YT, Zhang G, Yao W, Yue P, Li Y, et al. Met gene amplification and protein hyperactivation is a mechanism of resistance to both first and third generation EGFR inhibitors in lung cancer treatment. Cancer Lett. 2016;380:494–504.

    Article  CAS  Google Scholar 

  51. Yao W, Yue P, Zhang G, Owonikoko TK, Khuri FR, Sun SY. Enhancing therapeutic efficacy of the MEK inhibitor, MEK162, by blocking autophagy or inhibiting PI3K/Akt signaling in human lung cancer cells. Cancer Lett. 2015;364:70–8.

    Article  CAS  Google Scholar 

  52. Fu L, Lin YD, Elrod HA, Yue P, Oh Y, Li B, et al. c-Jun NH2-terminal kinase-dependent upregulation of DR5 mediates cooperative induction of apoptosis by perifosine and TRAIL. Mol Cancer 2010;9:315.

    Article  CAS  Google Scholar 

  53. Ou JN, Wiedeman AE, Stevens AMTNF-alpha. and TGF-beta counter-regulate PD-L1 expression on monocytes in systemic lupus erythematosus. Sci Rep. 2012;2:295.

    Article  Google Scholar 

  54. Sarbassov DD, Guertin DA, Ali SM, Sabatini DM. Phosphorylation and regulation of Akt/PKB by the rictor-mTOR complex. Science. 2005;307:1098–101.

    Article  CAS  Google Scholar 

  55. Wen Q, Wang W, Luo J, Chu S, Chen L, Xu L, et al. CGP57380 enhances efficacy of RAD001 in non-small cell lung cancer through abrogating mTOR inhibition-induced phosphorylation of eIF4E and activating mitochondrial apoptotic pathway. Oncotarget. 2016;7:27787–801.

    PubMed  PubMed Central  Google Scholar 

  56. Fan SQ, Ma J, Zhou J, Xiong W, Xiao BY, Zhang WL, et al. Differential expression of Epstein-Barr virus-encoded RNA and several tumor-related genes in various types of nasopharyngeal epithelial lesions and nasopharyngeal carcinoma using tissue microarray analysis. Hum Pathol. 2006;37:593–605.

    Article  CAS  Google Scholar 

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Acknowledgements

We are grateful to Dr. Wenyi Wei for providing β-TrCP shRNAs and expression plasmids. We also thank Dr. Anthea Hammond in our department for editing the paper. This work was supported by Winship Cancer Institute lung cancer pilot award of Emory University (S-YS). S-YS, TKO and SSR are Georgia Research Alliance Distinguished Cancer Scientists. S-YS is a Halpern Research Scholar. LD was a visiting medical student participating in the Xiangya-Emory Visiting Medical Student Program.

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  1. These authors contributed equally: Liang Deng, Guoqing Qian

Authors and Affiliations

  1. Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China

    Liang Deng

  2. Department of Hematology and Medical Oncology, Emory University School of Medicine and Winship Cancer Institute, Atlanta, GA, USA

    Liang Deng, Guoqing Qian, Shuo Zhang, Gregory B. Lesinski, Taofeek K. Owonikoko, Suresh S. Ramalingam & Shi-Yong Sun

  3. First Affiliated Hospital of Medical College of Xi’an Jiaotong University, Xi’an, Shaanxi, P. R. China

    Shuo Zhang

  4. Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China

    Hongmei Zheng & Sonqing Fan

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Deng, L., Qian, G., Zhang, S. et al. Inhibition of mTOR complex 1/p70 S6 kinase signaling elevates PD-L1 levels in human cancer cells through enhancing protein stabilization accompanied with enhanced β-TrCP degradation. Oncogene 38, 6270–6282 (2019). https://doi.org/10.1038/s41388-019-0877-4

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