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Human telomerase reverse transcriptase (hTERT) synergistic with Sp1 upregulate Gli1 expression and increase gastric cancer invasion and metastasis. J Mol Histol 2021; 52:1165-1175. [PMID: 34601664 DOI: 10.1007/s10735-021-10019-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 09/14/2021] [Indexed: 11/12/2022]
Abstract
Abnormal expression of human telomerase reverse transcriptase (hTERT) has been widely identified in tumors, but the relevant mechanism is not well known. This study aims to investigate the role and mechanism of hTERT in gastric cancer metastasis. Gastric cancer and adjacent non-tumor tissues were collected and the expression levels of hTERT and Gli1 were detected by immunohistochemistry. The results demonstrated that hTERT and Gli1 expression levels in gastric cancer tissue were significantly higher than adjacent non-tumor tissues. Western blot and quantitative real-time PCR were used to an identified expression of the related protein in BGC-823 and SGC-7901 cells. The interactions between hTERT and Sp1 were tested by co-immunoprecipitation experiments. Chromatin immunoprecipitation was performed to confirm that Sp1 and hTERT could bind to the Gli1 promoter. Chromatin reimmunoprecipitation assay further demonstrated that both hTERT and Sp1 bind to the Sp1 site of the Gli1 promoter. Moreover, the hTERT, Sp1, and Gli1 were upregulate was verified in human gastric cancer tissues. These results showed that the expression levels of hTERT in GC tissues were strongly closed to the depth of invasion, lymph node metastasis, TNM (tumor, node, metastasis) stage, and distant metastasis. By combining Sp1 and Gli1 promoter, hTERT upregulated Gli1 expression and promoted invasion and metastasis of GC cells. Overall, these data provide a new molecular mechanism of hTERT to promotes gastric cancer progression. Targeting the hTERT/Sp1/Gli1 axis may represent a new therapeutic strategy.
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Wang Z, Koh WP, Jin A, Wang R, Yuan JM. Telomere length and risk of developing gastric adenocarcinoma: The Singapore Chinese Health Study. Gastric Cancer 2018; 21:598-605. [PMID: 29218426 PMCID: PMC9247872 DOI: 10.1007/s10120-017-0783-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 11/26/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Extreme telomere length has been previously reported to be associated with increased risk of gastric cancer. However, evidence from prospective studies on a relative large sample size with long-term follow-up to further corroborate previous study findings is meager. METHODS The association between peripheral blood leukocyte telomere length and risk of gastric adenocarcinoma was prospectively examined in a cohort of 26,540 middle-aged or older Chinese nested in the Singapore Chinese Health Study. Telomere length was determined using a validated qPCR-based method. The Cox proportional regression method was used to estimate hazard ratio (HR) and its 95% confidence interval (CI) of gastric adenocarcinoma associated with telomere length after adjustment for potential confounders. Restricted cubic spline analysis was applied to assess the nonlinear relationship between telomere length and gastric cancer risk. RESULTS A U-shaped association was found between telomere length and risk of gastric adenocarcinoma (P nonlinearity = 0.020). Compared with the second quintile of telomere length, a statistically significant higher risk of gastric adenocarcinoma was associated with either the lowest quintile (HR = 1.63, 95% CI, 1.07-2.47) or the highest quintile (HR = 1.55, 95% CI, 0.97-2.47) of telomere length. This U-shaped relationship was more apparent in men and younger individuals. CONCLUSIONS This is the first prospective study demonstrating a higher risk of gastric cancer to be associated with either extremely short or extremely long telomere length. Short and long telomere length may function differently in the early and late stages of gastric carcinogenesis.
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Affiliation(s)
- Zhensheng Wang
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Woon-Puay Koh
- Duke-NUS Medical School, Singapore, Singapore,Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Aizhen Jin
- National Registry of Diseases Office, Health Promotion Board, Singapore, Singapore
| | - Renwei Wang
- Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, 5150 Centre Avenue, Cancer Pavilion Suite 4C, Pittsburgh 15232-1309, Pennsylvania, USA
| | - Jian-Min Yuan
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA,Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, 5150 Centre Avenue, Cancer Pavilion Suite 4C, Pittsburgh 15232-1309, Pennsylvania, USA
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Baena-Del Valle JA, Zheng Q, Esopi DM, Rubenstein M, Hubbard GK, Moncaliano MC, Hruszkewycz A, Vaghasia A, Yegnasubramanian S, Wheelan SJ, Meeker AK, Heaphy CM, Graham MK, De Marzo AM. MYC drives overexpression of telomerase RNA (hTR/TERC) in prostate cancer. J Pathol 2017; 244:11-24. [PMID: 28888037 DOI: 10.1002/path.4980] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 08/07/2017] [Accepted: 08/24/2017] [Indexed: 01/21/2023]
Abstract
Telomerase consists of at least two essential elements, an RNA component hTR or TERC that contains the template for telomere DNA addition and a catalytic reverse transcriptase (TERT). While expression of TERT has been considered the key rate-limiting component for telomerase activity, increasing evidence suggests an important role for the regulation of TERC in telomere maintenance and perhaps other functions in human cancer. By using three orthogonal methods including RNAseq, RT-qPCR, and an analytically validated chromogenic RNA in situ hybridization assay, we report consistent overexpression of TERC in prostate cancer. This overexpression occurs at the precursor stage (e.g. high-grade prostatic intraepithelial neoplasia or PIN) and persists throughout all stages of disease progression. Levels of TERC correlate with levels of MYC (a known driver of prostate cancer) in clinical samples and we also show the following: forced reductions of MYC result in decreased TERC levels in eight cancer cell lines (prostate, lung, breast, and colorectal); forced overexpression of MYC in PCa cell lines, and in the mouse prostate, results in increased TERC levels; human TERC promoter activity is decreased after MYC silencing; and MYC occupies the TERC locus as assessed by chromatin immunoprecipitation (ChIP). Finally, we show that knockdown of TERC by siRNA results in reduced proliferation of prostate cancer cell lines. These studies indicate that TERC is consistently overexpressed in all stages of prostatic adenocarcinoma and that its expression is regulated by MYC. These findings nominate TERC as a novel prostate cancer biomarker and therapeutic target. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Javier A Baena-Del Valle
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Pathology and Laboratory Medicine, Fundacion Santa Fe De Bogota University Hospital, Bogota, DC, Colombia
| | - Qizhi Zheng
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - David M Esopi
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael Rubenstein
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Gretchen K Hubbard
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Maria C Moncaliano
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andrew Hruszkewycz
- Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, Maryland, USA
| | - Ajay Vaghasia
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Srinivasan Yegnasubramanian
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Departments of Urology and Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,The Brady Urological Research Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Sarah J Wheelan
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Departments of Urology and Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,The Brady Urological Research Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Alan K Meeker
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,The Brady Urological Research Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christopher M Heaphy
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,The Brady Urological Research Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mindy K Graham
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,The Brady Urological Research Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Angelo M De Marzo
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Departments of Urology and Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,The Brady Urological Research Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Antisense human telomerase reverse transcriptase could partially reverse malignant phenotypes of gastric carcinoma cell line in vitro. Eur J Cancer Prev 2008; 17:209-17. [PMID: 18414191 DOI: 10.1097/cej.0b013e3282b71f0d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Telomerase activity is detected in more than 90% of examined tumors but not in most normal somatic cells. Among three subunits of human telomerase, human telomerase reverse transcriptase (hTERT) is the rate-limiting component for telomerase activity. Therefore, targeting hTERT represents a promising approach for diminishing telomerase function that will probably not cause substantial side effects on telomerase negative somatic cells. To explore the effects of antisense hTERT (ahTERT) on the malignant phenotypes of human SGC-7901 gastric cancer cell line in vitro, an antisense eukaryotic expression vector of hTERT was constructed by gene recombinant technology. Telomerase activity by telomeric repeat amplification protocol-ELISA, mRNA of telomerase subunits, c-myc and bcl-2 by reverse transcript-PCR, terminal restriction fragment (TRF) by Southern blot, cell cycle distribution by flow cytometry and protein expression of hTERT, c-myc and bcl-2 by Western blot were analyzed in SGC-7901 cells before and after transfection. Cloning efficiency assay in soft agar and tumorigenesis in nude mice were also examined and evaluated in the above cells. The results demonstrated that after ahTERT transfection, the proliferation of SGC-7901 cells was significantly inhibited. Further study showed that telomerase activity, telomere length, the mRNA and protein expression of hTERT, bcl-2 and c-myc were decreased in ahTERT-transfected cells. There were, however, no obvious effects on transcription of human telomerase RNA (hTR) and human telomerase associated protein1 (TP1) in both transfected and untransfected cells. Flow cytometric analysis displayed an accumulation of G0/G1 phase and a decreasing proliferation index (PI) in ahTERT-transfected cells. Moreover, no tumorigenicity was found after subcutaneous injection of ahTERT-transfected cells in nude mice, whereas palpable tumors were observed in mice injected with control cells. Our study indicates that exogenous ahTERT can inhibit proliferation and partially reverse malignant phenotypes of SGC-7901 cells via the suppression of telomerase activity, hTERT, c-myc and bcl-2 expression. Antisense technology targeted hTERT strategy might be a potential approach for gastric cancer therapy.
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Shariftabrizi A, Khorramizadeh MR, Saadat F, Alimoghadam K, Safavifar F, Ebrahimkhani MR. Concomitant reduction of matrix metalloproteinase-2 secretion and intracellular reactive oxygen species following anti-sense inhibition of telomerase activity in PC-3 prostate carcinoma cells. Mol Cell Biochem 2005; 273:109-16. [PMID: 16013445 DOI: 10.1007/s11010-005-8158-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The level of activity of the telomerase has been shown to correlate with the degree of invasiveness in several tumor types. In addition, cellular redox state is believed to regulate the secretion of matrix metalloproteinase-2 (MMP-2). AIMS To determine the effect of anti-sense telomerase treatment of prostate cancer cells on MMP-2 activity, and the reactive oxygen and nitrogen species (two effectors of cellular redox state). METHODS Anti-sense oligonucleotide against RNA component of human telomerase (hTR) was introduced into the cells using Fugene-6 transfection reagent. The activity of telomerase was assessed using Telomere Repeat Amplification Protocol (TRAP assay). Activity of matrix metalloproteinase-2 (MMP-2) was determined by zymography. Levels of intracellular reactive oxygen species (ROS) and nitric oxide metabolites were measured by dichlorofluorescein diacetate (DCFH-DA) staining and Griess reagent, respectively. The level of apoptosis was determined using TUNEL assay. RESULTS TRAP assay showed more than 90% inhibition of telomerase activity after 72 h of transfection. Pro-MMP-2 activity was decreased down to 50% of the control levels. Intracellular reactive oxygen species were also significantly decreased. Neither apoptosis rate nor the level of nitric oxide metabolites was significantly different between anti-sense treated and control cells. CONCLUSIONS Concomitant reduction of the pro-MMP-2 secretion and ROS in PC-3 cells following hTR inhibition suggests that over-activity of telomerase in cancer cells might increase the level of matrix metalloproteinase-2 and thus, be directly involved in the invasion process through enhancement of intracellular oxidative stress.
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Affiliation(s)
- Ahmad Shariftabrizi
- Hematology, Oncology and BMTResearch Center, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Zhao ZG, Shen WL. Heat shock protein 70 antisense oligonucleotide inhibits cell growth and induces apoptosis in human gastric cancer cell line SGC-7901. World J Gastroenterol 2005; 11:73-8. [PMID: 15609400 PMCID: PMC4205388 DOI: 10.3748/wjg.v11.i1.73] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: Heat shock protein (HSP)70 is over-expressed in human gastric cancer and plays an important role in the progression of this cancer. We investigated the effects of antisense HSP70 oligomer on human gastric cancer cell line SGC-7901, and its potential role in gene therapy for this cancer.
METHODS: Human gastric cancer cell line SGC-7901 was treated in vitro with various concentrations of antisense HSP70 oligonucleotides at different intervals. Growth inhibition was determined as percentage by trypan blue dye exclusion test. Extracted DNA was electrophoresed on agarose gel, and distribution of cell cycle and kinetics of apoptosis induction were analyzed by propidium iodide DNA incorporation using flow cytometry, which was also used to detect the effects of antisense oligomer pretreatment on the subsequent apoptosis induced by heat shock in SGC-7901 cells. Proteins were extracted for simultaneous measurement of HSP70 expression level by SDS-PAGE Western blotting.
RESULTS: The number of viable cells decreased in a dose- and time-dependent manner, and ladder-like patterns of DNA fragments were observed in SGC-7901 cells treated with antisense HSP70 oligomers at a concentration of 10 μmol/L for 48 h or 8 μmol/L for 72 h, which were consistent with inter-nucleosomal DNA fragmentation. Flow cytometric analysis showed a dose- and time-dependent increase in apoptotic rate by HSP70 antisense oligomers. This response was accompanied with a decrease in the percentage of cells in the G1 and S phases of the cell cycle, suggesting inhibition of cell proliferation. In addition, flow cytometry also showed that pretreatment of SGC-7901 cells with HSP70 antisense oligomers enhanced the subsequent apoptosis induced by heat shock treatment. Western blotting demonstrated that HSP70 antisense oligomers inhibited HSP70 expression, which preceded apoptosis, and HSP70 was undetectable at the concentration of 10 μmol/L for 48 h or 8 μmol/L for 72 h.
CONCLUSION: Antisense HSP70 oligomers can abrogate HSP70 expression in SGC-7901 cells, which may in turn induce apoptosis and inhibit cell proliferation, conversely suggesting that HSP70 is required for the proliferation and survival of human gastric cancer cells under normal conditions.
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Affiliation(s)
- Zhi-Gang Zhao
- Department of Surgery, Shantou University Medical College, Shantou, Guangdong Province, China.
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