Original articles
Zhaoming Lu, Xiaojing Shi, Fanghua Gong, Shenglei Li, Yang Wang, Yandan Ren, Mengyin Zhang, Bin Yu, Yan Li, Wen Zhao, Jianying Zhang, Guiqin Hou. RICTOR/mTORC2 affects tumorigenesis and therapeutic efficacy of mTOR inhibitors in esophageal squamous cell carcinoma[J]. Acta Pharmaceutica Sinica B, 2020, 10(6): 1004-1019

RICTOR/mTORC2 affects tumorigenesis and therapeutic efficacy of mTOR inhibitors in esophageal squamous cell carcinoma
Zhaoming Lua,b, Xiaojing Shia, Fanghua Gongc, Shenglei Lid, Yang Wanga, Yandan Rena, Mengyin Zhanga, Bin Yua, Yan Lie, Wen Zhaoa, Jianying Zhangf, Guiqin Houa
a School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China;
b Collaborative Innovation Center of Cancer Chemoprevention, Zhengzhou 450001, China;
c School of Pharmacy, Wenzhou Medical University, Wenzhou 325035, China;
d The First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China;
e Center of Advanced Analysis & Gene Sequencing, Zhengzhou University, Zhengzhou 450001, China;
f Henan Academy of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450052, China
Abstract:
Dysregulation of mTORC1/mTORC2 pathway is observed in many cancers and mTORC1 inhibitors have been used clinically in many tumor types; however, the mechanism of mTORC2 in tumorigenesis is still obscure. Here, we mainly explored the potential role of mTORC2 in esophageal squamous cell carcinoma (ESCC) and its effects on the sensitivity of cells to mTOR inhibitors. We demonstrated that RICTOR, the key factor of mTORC2, and p-AKT (Ser473) were excessively activated in ESCC and their overexpression is related to lymph node metastasis and the tumor-node-metastasis (TNM) phase of ESCC patients. Furthermore, we found that mTORC1/mTORC2 inhibitor PP242 exhibited more efficacious anti-proliferative effect on ESCC cells than mTORC1 inhibitor RAD001 due to RAD001-triggered feedback activation of AKT signal. Another, we demonstrated that down-regulating expression of RICTOR in ECa109 and EC9706 cells inhibited proliferation and migration as well as induced cell ycle arrest and apoptosis. Noteworthy, knocking-down stably RICTOR significantly suppresses RAD001-induced feedback activation of AKT/PRAS40 signaling, and enhances inhibition efficacy of PP242 on the phosphorylation of AKT and PRAS40, thus potentiates the antitumor effect of RAD001 and PP242 both in vitro and in vivo. Our findings highlight that selective targeting mTORC2 could be a promising therapeutic strategy for future treatment of ESCC.
Key words:    RICTOR    AKT    RAD001    pp242    Esophageal squamous cell carcinoma   
Received: 2019-09-01     Revised: 2019-11-01
DOI: 10.1016/j.apsb.2020.01.010
Funds: This work was supported by the Open Foundation Project of Pharmacy in Zhejiang Province, China (Grant No.YKFJ2-010), the National Natural Science Foundation of Henan Province, China (Grant No.182300410312), Henan Provincial University Science and Technology Innovation Team, Department of Education of Henan Province (Grant No. 19IRTSTHN001, China), Key Research Project of University, Department of Education of Henan Province (Grant No. 20A350019, China) and the National Science and Technology Major Project of China (Grant No. 2018ZX10302205). The authors would like to thank all members of the study team, the patients involved in this study and Dr. Xuejian Feng from School of Pharmaceutical Sciences of Zhengzhou University (Zhengzhou, China).
Corresponding author: Guiqin Hou     Email:hougq@zzu.edu.cn
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Zhaoming Lu
Xiaojing Shi
Fanghua Gong
Shenglei Li
Yang Wang
Yandan Ren
Mengyin Zhang
Bin Yu
Yan Li
Wen Zhao
Jianying Zhang
Guiqin Hou

References:
1. Network CGAR. Integrated genomic characterization of oesophageal carcinoma. Nature 2017;541:169-75.
2. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2016. CA Cancer J Clin 2016;66:7-30.
3. Pickens A, Orringer MB. Geographical distribution and racial disparity in esophageal cancer. Ann Thorac Surg 2003;76:S1367-9.
4. De Angelis R, Sant M, Coleman MP, Francisci S, Baili P, Pierannunzio D, et al. Cancer survival in Europe 1999-2007 by country and age:results of EUROCARE-5-a population-based study. Lancet Oncol 2014;15:23-34.
5. Chiarini F, Evangelisti C, McCubrey JA, Martelli AM. Current treatment strategies for inhibiting mTOR in cancer. Trends Pharmacol Sci 2015;36:124-35.
6. Laplante M, Sabatini DM. mTOR signaling in growth control and disease. Cell 2012;149:274-93.
7. Li G, Boyle JW, Ko CN, Zeng W, Wong VKW, Wan JB, et al. Aurone derivatives as Vps34 inhibitors that modulate autophagy. Acta Pharm Sin B 2019;9:537-44.
8. Sengupta S, Peterson TR, Sabatini DM. Regulation of the mTOR complex 1 pathway by nutrients, growth factors, and stress. Mol Cell 2010;40:310-22.
9. Sarbassov DD, Guertin DA, Ali SM, Sabatini DM. Phosphorylation and regulation of Akt/PKB by the rictor-mTOR complex. Science 2005;307:1098-101.
10. 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.
11. Zhao W, Qiu Y, Kon g D. Class I phosphatidylinositol 3-kinase inhibitors for cancer therapy. Acta Pharm Sin B 2017;7:27-37.
12. Basnet R, Gong GQ, Li C, Wang MW. Serum and glucocorticoid inducible protein kinases (SGKs):a potential target for cancer intervention. Acta Pharm Sin B 2018;8:767-71.
13. Baselga J, Campone M, Piccart M, Burris 3rd HA, Rugo HS, Sahmoud T, et al. Everolimus in postmenopausal hormone-receptorpositive advanced breast cancer. N Engl J Med 2012;366:520-9.
14. Kapoor A, Figlin RA. Targeted inhibition of mammalian target of rapamycin for the treatment of advanced renal cell carcinoma. Cancer 2009;115:3618-30.
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.
16. Efeyan A, Sabatini DM. mTOR and cancer:many loops in one pathway. Curr Opin Cell Biol 2010;22:169-76.
17. Breuleux M, Klopfenstein M, Stephan C, Doughty CA, Barys L, Maira SM, et al. Increased AKT S473 phosphorylation after mTORC1 inhibition is rictor dependent and does not predict tumor cell response to PI3K/mTOR inhibition. Mol Canc Therapeut 2009; 8:742-53.
18. Julien LA, Carriere A, Moreau J, Roux PP. mTORC1-activated S6K1 phosphorylates Rictor on threonine 1135 and regulates mTORC2 signaling. Mol Cell Biol 2010;30:908-21.
19. Nelson V, Altman JK, Platanias LC. Next generation of mammalian target of rapamycin inhibitors for the treatment of cancer. Expet Opin Invest Drugs 2013;22:715-22.
20. Yori JL, Lozada KL, Seachrist DD, Mosley JD, Abdul-Karim FW, Booth CN, et al. Combined SFK/mTOR inhibition prevents rapamycin-induced feedback activation of AKT and elicits efficient tumor regression. Cancer Res 2014;74:4762-71.
21. Zou Z, Chen J, Yang J, Bai X. Targeted inhibition of Rictor/mTORC2 in cancer treatment:a new era after rapamycin. Curr Cancer Drug Targets 2016;16:288-304.
22. Feldman ME, Apsel B, Uotila A, Loewith R, Knight ZA, Ruggero D, et al. Active-site inhibitors of mTOR target rapamycin-resistant outputs of mTORC1 and mTORC2. PLoS Biol 2009;7:e38.
23. Huang Y, Xi Q, Chen Y, Wang J, Peng P, Xia S, et al. A dual mTORC1 and mTORC2 inhibitor shows antitumor activity in esophageal squamous cell carcinoma cells and sensitizes them to cisplatin. Anti Cancer Drugs 2013;24:889-98.
24. Zeng Z, Shi Y, Tsao T, Qiu Y, Kornblau SM, Baggerly KA, et al. Targeting of mTORC1/2 by the mTOR kinase inhibitor PP242 induces apoptosis in AML cells under conditions mimicking the bone marrow microenvironment. Blood 2012;120:2679-89.
25. Bian YH, Xu J, Zhao WY, Zhang ZZ, Tu L, Cao H, et al. Targeting mTORC2 component rictor inhibits cell proliferation and promotes apoptosis in gastric cancer. Am J Transl Res 2017;9:4317-30.
26. 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.
27. Jebali A, Dumaz N. The role of RICTOR downstream of receptor tyrosine kinase in cancers. Mol Canc 2018;17:39.
28. Li H, Lin J, Wang X, Yao G, Wang L, Zheng H, et al. Targeting of mTORC2 prevents cell migration and promotes apoptosis in breast cancer. Breast Canc Res Treat 2012;134:1057-66.
29. Sakre N, Wildey G, Behtaj M, Kresak A, Yang M, Fu P, et al. RICTOR amplification identifies a subgroup in small cell lung cancer and predicts response to drugs targeting mTOR. Oncotarget 2017;8:5992-6002.
30. Schmidt KM, Hellerbrand C, Ruemmele P, Michalski CW, Kong B, Kroemer A, et al. Inhibition of mTORC2 component RICTOR impairs tumor growth in pancreatic cancer models. Oncotarget 2017;8:24491-505.
31. Jiang WJ, Feng RX, Liu JT, Fan LL, Wang H, Sun GP. RICTOR expression in esophageal squamous cell carcinoma and its clinical significance. Med Oncol 2017;34:32.
32. Hou G, Zhang Q, Wang L, Liu M, Wang J, Xue L. mTOR inhibitor rapamycin alone or combined with cisplatin inhibits growth of esophageal squamous cell carcinoma in nude mice. Cancer Lett 2010; 290:248-54.
33. Hou G, Xue L, Lu Z, Fan T, Tian F, Xue Y. An activated mTOR/p70S6K signaling pathway in esophageal squamous cell carcinoma cell lines and inhibition of the pathway by rapamycin and siRNA against mTOR. Cancer Lett 2007;253:236-48.
34. Hou G, Zhao Q, Zhang M, Fan T, Liu M, Shi XJ, et al. Down-regulation of Rictor enhances cell sensitivity to PI3K inhibitor LY294002 by blocking mTORC2-medicated phosphorylation of Akt/PRAS40 in esophageal squamous cell carcinoma. Biomed Pharmacother 2018; 106:1348-56.
35. Dong M, Nio Y, Sato Y, Tamura K, Song M, Tian Y, et al. Comparative study of p53 expression in primary invasive ductal carcinoma of the pancreas between Chinese and Japanese. Pancreas 1998;17:229-37.
36. Peng KZ, Ke Y, Zhao Q, Tian F, Liu HM, Hou G, et al. OP16, a novel ent-kaurene diterpenoid, potentiates the antitumor effect of rapamycin by inhibiting rapamycin-induced feedback activation of Akt signaling in esophageal squamous cell carcinoma. Biochem Pharmacol 2017; 140:16-27.
37. Wu YJ, Ko BS, Liang SM, Lu YJ, Jan YJ, Jiang SS, et al. ZNF479 downregulates metallothionein-1 expression by regulating ASH2L and DNMT1 in hepatocellular carcinoma. Cell Death Dis 2019;10:408.
38. Hou G, Yang S, Zhou Y, Wang C, Zhao W, Lu Z. Targeted inhibition of mTOR signaling improves sensitivity of esophageal squamous cell carcinoma cells to cisplatin. J Immunol Res 2014;2014:845763.
39. Chen W, Zheng R, Baade PD, Zhang S, Zeng H, Bray F, et al. Cancer statistics in China, 2015. CA Cancer J Clin 2016;66:115-32.
40. Amornphimoltham P, Patel V, Sodhi A, Nikitakis NG, Sauk JJ, Sausville EA, et al. Mammalian target of rapamycin, a molecular target in squamous cell carcinomas of the head and neck. Cancer Res 2005;65:9953-61.
41. Lu Z, Peng K, Wang N, Liu HM, Hou G. Downregulation of p70S6K enhances cell sensitivity to rapamycin in esophageal squamous cell carcinoma. J Immunol Res 2016;2016:7828916.
42. Atkins MB, Hidalgo M, Stadler WM, Logan TF, Dutcher JP, Hudes GR, et al. Randomized phase II study of multiple dose levels of CCI-779, a novel mammalian target of rapamycin kinase inhibitor, in patients with advanced refractory renal cell carcinoma. J Clin Oncol 2004;22:909-18.
43. Evangelisti C, Ricci F, Tazzari P, Tabellini G, Battistelli M, Falcieri E, et al. Targeted inhibition of mTORC1 and mTORC2 by active-site mTOR inhibitors has cytotoxic effects in T-cell acute lymphoblastic leukemia. Leukemia 2011;25:781-91.
44. Wan X, Harkavy B, Shen N, Grohar P, Helman LJ. Rapamycin induces feedback activation of Akt signaling through an IGF-1R-dependent mechanism. Oncogene 2007;26:1932-40.
45. Carracedo A, Ma L, Teruya-Feldstein J, Rojo F, Salmena L, Alimonti A, et al. Inhibition of mTORC1 leads to MAPK pathway activation through a PI3K-dependent feedback loop in human cancer. J Clin Invest 2008;118:3065-74.
46. Gual P, Le Marchand-Brustel Y, Tanti JF. Positive and negative regulation of insulin signaling through IRS-1 phosphorylation. Biochimie 2005;87:99-109.
47. Rodrik-Outmezguine VS, Chandarlapaty S, Pagano NC, Poulikakos PI, Scaltriti M, Moskatel E, et al. mTOR kinase inhibition causes feedback-dependent biphasic regulation of AKT signaling. Cancer Discov 2011;1:248-59.
48. Ducker GS, Atreya CE, Simko JP, Hom YK, Matli MR, Benes CH, et al. Incomplete inhibition of phosphorylation of 4E-BP1 as a mechanism of primary resistance to ATP-competitive mTOR inhibitors. Oncogene 2014;33:1590-600.
49. Hisamatsu T, Mabuchi S, Matsumoto Y, Kawano M, Sasano T, Takahashi R, et al. Potential role of mTORC2 as a therapeutic target in clear cell carcinoma of the ovary. Mol Canc Therapeut 2013;12:1367-77.
50. Driscoll DR, Karim SA, Sano M, Gay DM, Jacob W, Yu J, et al. mTORC2 signaling drives the development and progression of pancreatic cancer. Canc Res 2016;76:6911-23.
51. Cheng H, Zou Y, Ross JS, Wang K, Liu X, Halmos B, et al. RICTOR amplification defines a novel subset of patients with lung cancer who may benefit from treatment with mTORC1/2 inhibitors. Cancer Discov 2015;5:1262-70.
52. Gulhati P, Bowen KA, Liu J, Stevens PD, Rychahou PG, Chen M, et al. mTORC1 and mTORC2 regulate EMT, motility, and metastasis of colorectal cancer via RhoA and Rac1 signaling pathways. Cancer Res 2011;71:3246-56.
53. Kim ST, Kim SY, Klempner SJ, Yoon J, Kim N, Ahn S, et al. Rapamycin-insensitive companion of mTOR (RICTOR) amplification defines a subset of advanced gastric cancer and is sensitive to AZD2014-mediated mTORC1/2 inhibition. Ann Oncol 2017;28:547-54.
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