Triptolide inhibits human telomerase reverse transcriptase by downregulating translation factors SP1 and c‑Myc in Epstein‑Barr virus‑positive B lymphocytes

Long,Cong; Xu,Qiu-Bo; Ding,Li; Yang,Liu; Ji,Wei; Gao,Feng; Ji,Yong

doi:10.3892/ol.2021.12541

Triptolide inhibits human telomerase reverse transcriptase by downregulating translation factors SP1 and c‑Myc in Epstein‑Barr virus‑positive B lymphocytes

Authors:
- Cong Long
- Qiu-Bo Xu
- Li Ding
- Liu Yang
- Wei Ji
- Feng Gao
- Yong Ji
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Affiliations: Clinical Laboratory, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China, Department of General Surgery, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
Published online on: February 10, 2021 https://doi.org/10.3892/ol.2021.12541
Article Number: 280
Copyright: © Long et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

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Abstract

Epstein‑Barr virus (EBV) mainly causes infectious mononucleosis and is associated with several neoplasms, including Burkitt's lymphoma, nasopharyngeal carcinoma and lymphoproliferative disease. Human telomerase reverse transcriptase (hTERT) regulates enzymatic activity of telomerase and is closely associated with tumorigenesis and senescence evasion. Triptolide (TP) is a diterpenoid triepoxide, with a broad‑spectrum anticancer and immunosuppressive bioactivity profile. The present study investigated whether TP inhibited hTERT expression and suppressed its activity. The mRNA and protein levels of hTERT were examined by reverse transcription‑quantitative PCR and western blotting. The activity of hTERT promoter was determined by dual‑luciferase reporter assay. Cell Counting Kit‑8 assays were performed to analyze cell proliferation. The present study used EBV‑positive B lymphoma cells as a model system, and the results demonstrated that TP significantly decreased hTERT transcription and protein expression. Mechanistically, TP attenuated the hTERT promoter activity by downregulating the expression levels of specificityprotein 1 and c‑Myc transcription factors. Consistently, inhibition of hTERT via shRNA transfection efficiently enhanced the suppression of cell proliferation by TP. Furthermore, TP increased virus latent replication and promoted the lytic cycle of EBV in EBV‑positive B lymphoma cells, increasing the number of lytic cells and inhibiting the viability of tumor cells. Taken together, the results of the present study revealed a molecular mechanism of the pharmacological inhibition of tumor cell proliferation by TP, encouraging the translation of TP‑based therapeutics in EBV‑positive B lymphoma treatment.

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1	Epstein MA, Achong BG and Barr YM: Virus particles in cultured lymphoblasts from burkitt's lymphoma. Lancet. 1:702–703. 1964. View Article : Google Scholar : PubMed/NCBI
2	Farrell PJ: Epstein-barr virus and cancer. Annu Rev Pathol. 14:29–53. 2019. View Article : Google Scholar : PubMed/NCBI
3	Klein G: Tumor associations of EBV-historical perspectives. Curr Top Microbiol Immunol. 390:17–22. 2015.PubMed/NCBI
4	Niller HH, Wolf H and Minarovits J: Regulation and dysregulation of Epstein-Barr virus latency: Implications for the development of autoimmune diseases. Autoimmunity. 41:298–328. 2008. View Article : Google Scholar : PubMed/NCBI
5	Cohen JI: Primary immunodeficiencies associated with EBV disease. Curr Top Microbiol Immunol. 390:241–265. 2015.PubMed/NCBI
6	Blackburn EH: Switching and signaling at the telomere. Cell. 106:661–673. 2001. View Article : Google Scholar : PubMed/NCBI
7	Campisi J, Kim SH, Lim CS and Rubio M: Cellular senescence, cancer and aging: The telomere connection. Exp Gerontol. 36:1619–1637. 2001. View Article : Google Scholar : PubMed/NCBI
8	Zvereva MI, Shcherbakova DM and Dontsova OA: Telomerase: Structure, functions, and activity regulation. Biochemistry (Mosc). 75:1563–1583. 2010. View Article : Google Scholar : PubMed/NCBI
9	Gladych M, Wojtyla A and Rubis B: Human telomerase expression regulation. Biochem Cell Biol. 89:359–376. 2011. View Article : Google Scholar : PubMed/NCBI
10	Wright WE, Piatyszek MA, Rainey WE, Byrd W and Shay JW: Telomerase activity in human germline and embryonic tissues and cells. Dev Genet. 18:173–179. 1996. View Article : Google Scholar : PubMed/NCBI
11	Kyo S, Takakura M, Fujiwara T and Inoue M: Understanding and exploiting hTERT promoter regulation for diagnosis and treatment of human cancers. Cancer Sci. 99:1528–1538. 2008. View Article : Google Scholar : PubMed/NCBI
12	Jafri MA, Ansari SA, Alqahtani MH and Shay JW: Roles of telomeres and telomerase in cancer, and advances in telomerase-targeted therapies. Genome Med. 8:692016. View Article : Google Scholar : PubMed/NCBI
13	Lü MH, Liao ZL, Zhao XY, Fan YH, Lin XL, Fang DC, Guo H and Yang SM: hTERT-based therapy: A universal anticancer approach (Review). Oncol Rep. 28:1945–1952. 2012. View Article : Google Scholar : PubMed/NCBI
14	Mizukoshi E and Kaneko S: Telomerase-targeted cancer immunotherapy. Int J Mol Sci. 20:18232019. View Article : Google Scholar
15	Kupchan SM, Court WA, Dailey RG Jr, Gilmore CJ and Bryan RF: Triptolide and tripdiolide, novel antileukemic diterpenoid triepoxides from Tripterygium wilfordii. J Am Chem Soc. 94:7194–7195. 1972. View Article : Google Scholar : PubMed/NCBI
16	Wong KF, Yuan Y and Luk JM: Tripterygium wilfordii bioactive compounds as anticancer and anti-inflammatory agents. Clin Exp Pharmacol Physiol. 39:311–320. 2012. View Article : Google Scholar : PubMed/NCBI
17	Hou W, Liu B and Xu H: Triptolide: Medicinal chemistry, chemical biology and clinical progress. Eur J Med Chem. 176:378–392. 2019. View Article : Google Scholar : PubMed/NCBI
18	Noel P, Von Hoff DD, Saluja AK, Velagapudi M, Borazanci E and Han H: Triptolide and its derivatives as cancer therapies. Trends Pharmacol Sci. 40:327–341. 2019. View Article : Google Scholar : PubMed/NCBI
19	Jiang W, Chen M, Xiao C, Yang W, Qin Q, Tan Q, Liang Z, Liao X, Mao A and Wei C: Triptolide suppresses growth of breast cancer by targeting HMGB1 in vitro and in vivo. Biol Pharm Bull. 42:892–899. 2019. View Article : Google Scholar : PubMed/NCBI
20	Liang X, Xie R, Su J, Ye B, Wei S, Liang Z, Bai R, Chen Z, Li Z and Gao X: Inhibition of RNA polymerase III transcription by Triptolide attenuates colorectal tumorigenesis. J Exp Clin Cancer Res. 38:2172019. View Article : Google Scholar : PubMed/NCBI
21	Huang W, He T, Chai C, Yang Y, Zheng Y, Zhou P, Qiao X, Zhang B, Liu Z, Wang J, et al: Triptolide inhibits the proliferation of prostate cancer cells and down-regulates SUMO-specific protease 1 expression. PLoS One. 7:e376932012. View Article : Google Scholar : PubMed/NCBI
22	Zhou H, Guo W, Long C, Wang H, Wang J and Sun X: Triptolide inhibits proliferation of Epstein-Barr virus-positive B lymphocytes by down-regulating expression of a viral protein LMP1. Biochem Biophys Res Commun. 456:815–820. 2015. View Article : Google Scholar : PubMed/NCBI
23	Long C, Wang J, Guo W, Wang H, Wang C, Liu Y and Sun X: Triptolide inhibits transcription of hTERT through down-regulation of transcription factor specificityprotein 1 in primary effusion lymphoma cells. Biochem Biophys Res Commun. 469:87–93. 2016. View Article : Google Scholar : PubMed/NCBI
24	Wang J, Jiang J, Chen H, Wang L, Guo H, Yang L, Xiao D, Qing G and Liu H: FDA-approved drug screen identifies proteasome as a synthetic lethal target in MYC-driven neuroblastoma. Oncogene. 38:6737–6751. 2019. View Article : Google Scholar : PubMed/NCBI
25	Long C, Guo W, Zhou H, Wang J, Wang H and Sun X: Triptolide decreases expression of latency-associated nuclear antigen 1 and reduces viral titers in Kaposi's sarcoma-associated and herpesvirus-related primary effusion lymphoma cells. Int J Oncol. 48:1519–1530. 2016. View Article : Google Scholar : PubMed/NCBI
26	Livak KJ and Schmittgen TD: Analysis of relative gene expression data using real-time quantitative PCR and the 2(−Delta Delta C(T)) Method. Methods. 25:402–408. 2001. View Article : Google Scholar : PubMed/NCBI
27	Beishline K and Azizkhan-Clifford J: Sp1 and the ‘hallmarks of cancer’. FEBS J. 282:224–258. 2015. View Article : Google Scholar : PubMed/NCBI
28	Verma SC, Borah S and Robertson ES: Latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus up-regulates transcription of human telomerase reverse transcriptase promoter through interaction with transcription factor Sp1. J Virol. 78:10348–10359. 2004. View Article : Google Scholar : PubMed/NCBI
29	Dang CV, O'Donnell KA, Zeller KI, Nguyen T, Osthus RC and Li F: The c-Myc target gene network. Semin Cancer Biol. 16:253–264. 2006. View Article : Google Scholar : PubMed/NCBI
30	Pica F, Serafino A, Garaci E and Volpi A: Cidofovir on HHV-8 in BCBL-1 cells. Antivir Ther. 9:823–825. 2004.PubMed/NCBI
31	Miller G, El-Guindy A, Countryman J, Ye J and Gradoville L: Lytic cycle switches of oncogenic human gammaherpesviruses. Adv Cancer Res. 97:81–109. 2007. View Article : Google Scholar : PubMed/NCBI
32	Zhang Y, Sun M, Shi W, Yang Q, Chen C, Wang Z and Zhou X: Arsenic trioxide suppresses transcription of hTERT through down-regulation of multiple transcription factors in HL-60 leukemia cells. Toxicol Lett. 232:481–489. 2015. View Article : Google Scholar : PubMed/NCBI
33	Meyer N and Penn LZ: Reflecting on 25 years with MYC. Nat Rev Cancer. 8:976–990. 2008. View Article : Google Scholar : PubMed/NCBI
34	Cong YS, Wen J and Bacchetti S: The human telomerase catalytic subunit hTERT: Organization of the gene and characterization of the promoter. Hum Mol Genet. 8:137–142. 1999. View Article : Google Scholar : PubMed/NCBI
35	Toaldo C, Pizzimenti S, Cerbone A, Pettazzoni P, Menegatti E, Daniela B, Minelli R, Giglioni B, Dianzani MU, Ferretti C and Barrera G: PPARgamma ligands inhibit telomerase activity and hTERT expression through modulation of the Myc/Mad/Max network in colon cancer cells. J Cell Mol Med. 14:1347–1357. 2010. View Article : Google Scholar : PubMed/NCBI
36	Tsurumi T, Fujita M and Kudoh A: Latent and lytic Epstein-Barr virus replication strategies. Rev Med Virol. 15:3–15. 2005. View Article : Google Scholar : PubMed/NCBI
37	Kerr JR: Epstein-Barr virus (EBV) reactivation and therapeutic inhibitors. J Clin Pathol. 72:651–658. 2019. View Article : Google Scholar : PubMed/NCBI
38	Kanda T: EBV-encoded latent genes. Adv Exp Med Biol. 1045:377–394. 2018. View Article : Google Scholar : PubMed/NCBI
39	McKenzie J and El-Guindy A: Epstein-barr virus lytic cycle reactivation. Curr Top Microbiol Immunol. 391:237–261. 2015.PubMed/NCBI
40	Bhende PM, Seaman WT, Delecluse HJ and Kenney SC: BZLF1 activation of the methylated form of the BRLF1 immediate-early promoter is regulated by BZLF1 residue 186. J Virol. 79:7338–7348. 2005. View Article : Google Scholar : PubMed/NCBI
41	Tikhmyanova N, Paparoidamis N, Romero-Masters J, Feng X, Mohammed FS, Reddy PAN, Kenney SC, Lieberman PM and Salvino JM: Development of a novel inducer for EBV lytic therapy. Bioorg Med Chem Lett. 29:2259–2264. 2019. View Article : Google Scholar : PubMed/NCBI
42	Murata T and Tsurumi T: Switching of EBV cycles between latent and lytic states. Rev Med Virol. 24:142–153. 2014. View Article : Google Scholar : PubMed/NCBI
43	Ben Yebdri F, Van Grevenynghe J, Tang VA, Goulet ML, Wu JH, Stojdl DF, Hiscott J and Lin R: Triptolide-mediated inhibition of interferon signaling enhances vesicular stomatitis virus-based oncolysis. Mol Ther. 21:2043–2053. 2013. View Article : Google Scholar : PubMed/NCBI