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Kienzl P, Deloria AJ, Hunjadi M, Hadolt JM, Haering MF, Bothien A, Mejri D, Korkut-Demirbaş M, Sampl S, Weber G, Pirker C, Laengle S, Braunschmid T, Dragona E, Marian B, Gagos S, Lu L, Henson JD, Lau LMS, Reddel RR, Mikulits W, Stättner S, Holzmann K. Telomere transcripts act as tumor suppressor and are associated with favorable prognosis in colorectal cancer with low proliferating cell nuclear antigen expression. Cell Oncol (Dordr) 2024:10.1007/s13402-024-00986-y. [PMID: 39222177 DOI: 10.1007/s13402-024-00986-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2024] [Indexed: 09/04/2024] Open
Abstract
Telomeric repeat-containing RNAs (TERRA) and telomerase RNA component (TERC) regulate telomerase activity (TA) and thereby contribute to telomere homeostasis by influencing telomere length (TL) and the cell immortality hallmark of cancer cells. Additionally, the non-canonical functions of telomerase reverse transcriptase (TERT) and TERRA appear to be involved in the epithelial-mesenchymal transition (EMT), which is important for cancer progression. However, the relationship between TERRA and patient prognosis has not been fully characterized. In this small-scale study, 68 patients with colorectal cancer (CRC) were evaluated for correlations between telomere biology, proliferation, and EMT gene transcripts and disease outcome. The proliferating cell nuclear antigen (PCNA) and the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2) showed a positive correlation with TERRA, while TA and TERRA exhibited an inverse correlation. Consistent with previous findings, the present study revealed higher expression levels of TERT and TERC, and increased TA and TL in CRC tumor tissue compared to adjacent non-tumor tissue. In contrast, lower expression levels of TERRA were observed in tumor tissue. Patients with high TERRA expression and low PCNA levels exhibited favorable overall survival rates compared to individuals with the inverse pattern. Furthermore, TERRA suppressed CRC tumor growth in severe combined immunodeficiency disease (SCID) mice. In conclusion, our study extends previously published research on TERRA suggesting its potential therapeutic role in telomerase-positive CRC.
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Affiliation(s)
- Philip Kienzl
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Abigail J Deloria
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Monika Hunjadi
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Juliane M Hadolt
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Max-Felix Haering
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Angrit Bothien
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Doris Mejri
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Medina Korkut-Demirbaş
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Sandra Sampl
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Gerhard Weber
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Christine Pirker
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Severin Laengle
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Tamara Braunschmid
- Department of Surgery, Social Medical Center South, Kaiser Franz Josef Hospital, Vienna, Austria
- Department of Surgery, Klinik Floridsdorf, Wiener Gesundheitsverbund, Vienna, Austria
| | - Eleni Dragona
- Laboratory of Genetics Center of Clinical Research, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Greece (BRFAA), Soranou Efesiou 4, Athens, 115 27, Greece
| | - Brigitte Marian
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Sarantis Gagos
- Laboratory of Genetics Center of Clinical Research, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Greece (BRFAA), Soranou Efesiou 4, Athens, 115 27, Greece
| | - Lingeng Lu
- Department of Chronic Disease Epidemiology, Yale School of Public Health, School of Medicine, Yale Cancer Center, Yale University, New Haven, USA
| | - Jeremy D Henson
- Prince of Wales Clinical School, University of NSW, UNSW, Sydney, 2052, Australia
| | - Loretta M S Lau
- Children's Cancer Research Unit, The Children's Hospital at Westmead, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, Australia
| | - Roger R Reddel
- Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, 2145, Australia
| | - Wolfgang Mikulits
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria
| | - Stefan Stättner
- Department of Surgery, Social Medical Center South, Kaiser Franz Josef Hospital, Vienna, Austria
- Department of General, Visceral and Vascular Surgery, Salzkammergut Klinikum, OÖG, Dr. Wilhelm Bock Strasse 1, Vöcklabruck, 4840, Austria
| | - Klaus Holzmann
- Center for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, Vienna, A-1090, Austria.
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Haraguchi K, Yada N, Sato S, Habu M, Hayakawa M, Takahashi O, Sasaguri M, Takenaka S, Yoshioka I, Matsuo K, Tominaga K. The methylation status and expression of human telomerase reverse transcriptase is significantly high in oral carcinogenesis. APMIS 2017; 125:797-807. [PMID: 28766760 DOI: 10.1111/apm.12723] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 04/25/2017] [Indexed: 12/29/2022]
Abstract
Telomerase activity is present in most cancers and is tightly regulated by the expression of human telomerase reverse transcriptase (hTERT). Hypermethylation in the promoter region of hTERT contributes to the regulation of hTERT expression. In this study, we investigated the methylation and expression of hTERT in oral squamous cell carcinoma (OSCC), oral leukoplakia, and normal oral mucosa. Furthermore, we investigated the significance of hTERT to the clinicopathological findings of OSCC. 35 OSCC, 50 oral leukoplakia (epithelial dysplasia n = 25, squamous cell hyperplasia n = 25), and 10 normal oral mucosa samples were investigated through methylation-specific PCR. Immunohistochemistry was analyzed in 35 OSCC, 50 oral leukoplakia, and 4 normal oral mucosa samples. The methylation and expression of hTERT increased from normal oral mucosa to oral leukoplakia to OSCC. In OSCC, all samples were methylated. However, partial methylation (20%) or unmethylation (80%), but never complete methylation, was observed in normal oral mucosa. Additionally, hTERT expression correlated with cervical lymph node metastasis. These results suggested that the methylation and expression of hTERT is high in oral carcinogenesis and may play an important role in oral cancer. hTERT expression may also be predictive of cervical lymph node metastasis.
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Affiliation(s)
- Kazuya Haraguchi
- Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - Naomi Yada
- Division of Oral Pathology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, Japan
| | - Shinobu Sato
- Department of Applied Chemistry, Research Center for Bio-microsensing Technology, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Manabu Habu
- Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - Mana Hayakawa
- Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - Osamu Takahashi
- Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - Masaaki Sasaguri
- Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - Shigeori Takenaka
- Department of Applied Chemistry, Research Center for Bio-microsensing Technology, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Izumi Yoshioka
- Division of Oral Medicine, Department of Science of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - Kou Matsuo
- Division of Oral Pathology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, Japan
| | - Kazuhiro Tominaga
- Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
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Guan GG, Wang WB, Lei BX, Wang QL, Wu L, Fu ZM, Zhou FX, Zhou YF. UBE2D3 is a positive prognostic factor and is negatively correlated with hTERT expression in esophageal cancer. Oncol Lett 2015; 9:1567-1574. [PMID: 25789002 PMCID: PMC4356423 DOI: 10.3892/ol.2015.2926] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/13/2015] [Indexed: 12/20/2022] Open
Abstract
Human telomerase reverse transcriptase (hTERT) is a critical factor in unlimited cell proliferation and immortalization, with numerous studies demonstrating that high expression of hTERT is a poor prognostic factor in various types of cancer. Ubiquitin-conjugating enzyme E2D 3 (UBE2D3) is a member of the E2 family, and participates in the ubiquitin proteasome pathway to regulate basic cellular activities, such as cell cycle control, the DNA damage response, apoptosis, and tumorigenesis. Our previous study initially determined that downregulation of UBE2D3 expression increases hTERT expression and cell proliferation, however, the association between the expression of these two proteins and their functions in cancer tissues remains unknown. Therefore, the protein expression levels of hTERT and UBE2D3 were evaluated in 150 esophageal cancer and 30 adjacent healthy tissue samples by performing immunohistochemical analysis. Concurrently, the clinicopathological data of the enrolled patients were obtained to allow correlation analysis. It was identified that the expression of hTERT in the esophageal cancer tissues was significantly higher compared with that of the adjacent tissues (P=0.015), however, the expression of UBE2D3 was significantly lower in esophageal cancer tissues than the adjacent tissues (P=0.001). Additionally, the study demonstrated that hTERT was significantly upregulated in poorly-differentiated, advanced tumor-node-metastasis (TNM) stage cancer tissues (P<0.05 for all), however, UBE2D3 expression was downregulated in poorly-differentiated, lymph node invaded cancer tissues and recurrent cases. It was also identified that traditional factors, including tumor location, T stage, lymph node status, TNM stage, and molecular factors of hTERT and UBE2D3, were significantly associated with overall survival time (P<0.05 for all). Furthermore, UBE2D3, lymph node status and tumor location were independent prognostic factors for esophageal cancer in multivariate analysis. Most notably, hTERT and UBE2D3 expression were negatively correlated with each other. In conclusion, the findings of the present study indicated that hTERT and UBE2D3 proteins appear to be involved in the development of esophageal cancer, that UBE2D3 may a positive prognostic factor for esophageal cancer, and that UBE2D3 and hTERT expression levels are inversely correlated.
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Affiliation(s)
- Ge Ge Guan
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Wen Bo Wang
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China ; Department of Radiation and Medical Oncology, Zhongnan Hospital, Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Bing Xin Lei
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Qiao Li Wang
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Lin Wu
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Zhen Ming Fu
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China ; Department of Radiation and Medical Oncology, Zhongnan Hospital, Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Fu Xiang Zhou
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China ; Department of Radiation and Medical Oncology, Zhongnan Hospital, Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Yun Feng Zhou
- Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan, Hubei 430071, P.R. China ; Department of Radiation and Medical Oncology, Zhongnan Hospital, Wuhan University, Wuhan, Hubei 430071, P.R. China
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Friis-Ottessen M, De Angelis PM, Schjølberg AR, Andersen SN, Clausen OPF. Reduced hTERT protein levels are associated with DNA aneuploidy in the colonic mucosa of patients suffering from longstanding ulcerative colitis. Int J Mol Med 2014; 33:1477-83. [PMID: 24676865 PMCID: PMC4055619 DOI: 10.3892/ijmm.2014.1708] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 02/24/2014] [Indexed: 12/24/2022] Open
Abstract
Longstanding ulcerative colitis (UC) is a disease of chronic inflammation of the colon. It is associated with the development of colorectal cancer through a multistep process including increasing degrees of dysplasia and DNA-ploidy changes. However, not all UC patients will develop these characteristics even during lifelong disease, and patients may therefore be divided into progressors who develop dysplasia or cancer, and non-progressors who do not exhibit such changes. In the present study, the amount of hTERT, the catalytic subunit of the enzyme telomerase, was estimated by using peroxidase immunohistochemistry (IHC) in a set of progressor and non-progressor UC colectomies. The protein levels in the colonic mucosa of the progressors and non-progressors were compared, and further comparisons between different categories of dysplastic development and to DNA-ploidy status within the progressors were made. Levels of hTERT were elevated in the colonic mucosa of the progressors and non-progressors when compared to non-UC control samples, but no difference was observed between the hTERT levels in the mucosa of progressors and non-progressors. The levels of hTERT associated with levels of Ki67 to a significant degree within the non-progressors. hTERT expression in lesions with DNA-aneuploidy were decreased as compared to diploid lesions, when stratified for different classes of colonic morphology. Our results indicate an association between hTERT protein expression and aneuploidy in UC-progressor colons, and also a possible protective mechanism in the association between hTERT and Ki67, against development of malignant features within the mucosa of a UC-colon.
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Affiliation(s)
- Mariann Friis-Ottessen
- Division of Diagnostics and Intervention, Department of Pathology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway
| | - Paula M De Angelis
- Division of Diagnostics and Intervention, Department of Pathology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway
| | | | - Solveig N Andersen
- Department of Pathology, Akershus University Hospital, Division of Medicine and Laboratory Sciences, University of Oslo, 1474 Nordbyhagen, Norway
| | - Ole Petter F Clausen
- Division of Diagnostics and Intervention, Department of Pathology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway
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Pellatt AJ, Wolff RK, Herrick J, Lundgreen A, Slattery ML. TERT's role in colorectal carcinogenesis. Mol Carcinog 2013; 52:507-13. [PMID: 22351525 PMCID: PMC3426620 DOI: 10.1002/mc.21885] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 12/16/2011] [Accepted: 01/20/2012] [Indexed: 01/09/2023]
Abstract
Telomerase reverse transcriptase (TERT) is one of the main functional subunits of the telomerase enzyme, which functions to increase telomere length. Studies have suggested that TERT may be important to the etiology of colorectal cancer. In this study we evaluate seven TERT SNPs in 1555 incident colon cancer cases and 1956 matched controls and in 754 incident rectal cancer cases and 959 matched controls. We observed that two TERT SNPs were associated with colon cancer. TERT rs2736118 was associated with increased risk of colon cancer (OR = 1.31, 95% CI 1.02, 1.69) and TERT-CLPTM1L rs2853668 was inversely associated with colon cancer (OR = 0.71, 95% CI 0.55, 0.92). TERT-CLPTM1L rs2853668 also was inversely associated with rectal cancer (OR 0.62, 95% CI 0.43, 0.90). BMI interacted significantly with three TERT SNPs to alter risk of colon cancer. Those with the variant allele and who were obese had the greatest risk of colon cancer. TERT-CLPTM1L rs2853668 interacted significantly with aspirin/NSAID use, where those with the AA genotype had a much lower risk of colon cancer when using aspirin/NSAIDs than those with the other genotypes. Several TERT SNPs were uniquely associated with CIMP+ and MSI tumors. These data confirm earlier reports of the association between TERT-CLPTM1L and colon and rectal cancer. Our detection of a significant interaction with BMI for multiple TERT SNPs and unique associations with CIMP+ tumors enhance our understanding of TERT's role in colon carcinogenesis.
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Affiliation(s)
- Andrew J. Pellatt
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
| | - Roger K. Wolff
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
| | - Jennifer Herrick
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
| | - Abbie Lundgreen
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
| | - Martha L. Slattery
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
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Adamo R, Comandini A, Aquino A, Bonmassar L, Guglielmi L, Bonmassar E, Franzese O. The antiretroviral agent saquinavir enhances hTERT expression and telomerase activity in human T leukaemia cells in vitro. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2013; 32:38. [PMID: 23759068 PMCID: PMC3682913 DOI: 10.1186/1756-9966-32-38] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 05/17/2013] [Indexed: 02/02/2023]
Abstract
BACKGROUND Saquinavir, a protease inhibitor utilized in HIV infection, shows antitumor activity in various experimental models. In previous studies performed in our laboratory the drug was found to induce a substantial increase of telomerase activity in normal peripheral blood mononuclear cells. Aim of the present investigation was to test whether saquinavir was able to increase telomerase activity and the expression of the catalytic subunit of telomerase, hTERT, in human malignant hematopoietic cells. METHODS Human Jurkat CD4+ T cell leukaemia cell line was used throughout the present study. The antiproliferative effect of saquinavir was tested by the MTT assay. Telomerase activity was determined according to the telomeric repeat amplification protocol. The expression of hTERT mRNA was semi-quantitative evaluated by RT-PCR amplification and quantitative Real Time PCR. The binding of the transcription factor c-Myc to its specific E-Box DNA binding-site of hTERT promoter was analyzed by Electophoretic Mobility Shift Assay (EMSA). The amount of c-Myc in cytoplasm and nucleus of leukemia cells was determined by Western Blot analysis, and c-Myc down-regulation was obtained by siRNA transfection. RESULTS Saquinavir produced a substantial increase of telomerase activity in Jurkat cells in vitro without increasing but rather reducing target cell proliferation rate. Telomerase up-regulation appeared to be the result of enhanced expression of hTERT. Saquinavir-mediated up-regulation of hTERT gene was the result of the increased binding of proteins to the E-Box sequence of the promoter. Moreover, saquinavir amplified the expression of c-Myc especially in the nuclear cell fraction. The direct influence of saquinavir on this transcription factor was also demonstrated by the antagonistic effect of the drug on siRNA induced c-Myc suppression. Since c-Myc is the main responsible for hTERT transcription, these findings suggest that the main mechanism underlying saquinavir-induced telomerase activation is mediated by c-Myc up-regulation. CONCLUSIONS Saquinavir augments hTERT expression while inhibiting leukemic cell growth. Experimental evidences show that this effect is mediated by saquinavir-influenced increase of c-Myc levels. This could have relevance in terms of enhanced hTERT-dependent tumor cell immunogenicity and suggests new paharmacological approaches interfering with c-Myc dependent pathways.
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Affiliation(s)
- Riccardo Adamo
- Department of Systems Medicine, Pharmacology Section, University of Rome Tor Vergata, Rome, Italy
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Tai CJ, Lee CH, Chen HC, Wang HK, Jiang MC, Su TC, Shen KH, Lin SH, Yeh CM, Chen CJ, Yeh KT, Chang CC. High nuclear expression of phosphorylated extracellular signal-regulated kinase in tumor cells in colorectal glands is associated with poor outcome in colorectal cancer. Ann Diagn Pathol 2012. [PMID: 23183114 DOI: 10.1016/j.anndiagpath.2012.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Extracellular signal-regulated kinase (ERK) is a major downstream transducer of Ras and plays an important role in transducing extracellular signals to the nuclei of cells. It is located in both the cytoplasm and the nucleus of cells. The nuclear localization of phosphorylated or activated ERK is involved in the invasive behavior of tumor cells. We studied the association between Ras mutation/ERK activation and the prognosis of patients with colorectal cancer. We analyzed 126 surgically resected colorectal cancer specimens for K-Ras mutation using direct sequencing. Activation/phosphorylation of ERK was assayed by immunohistochemistry with tissue microarray, and the staining intensity was analyzed using a semiquantitative scoring system. K-Ras mutations were detected in 32.5% (41/126) of the colorectal tumors. Colorectal glands are important functional organs in colorectal tissue and form the origin of colorectal carcinomas. Tissue microarray immunohistochemistry tests showed that tumors in colorectal cancer specimens were significantly stained for phospho-ERK (100%; 126/126), whereas nonneoplastic colorectal glands mainly showed faint phosphorylated ERK staining. High nuclear phospho-ERK expression in tumors was associated with highly invasive cancer stage and T status of the disease. Kaplan-Meier analysis showed that nuclear but not cytoplasmic phosphorylated ERK expression correlated with the patients' overall survival rate (P = .039). Colorectal adenomas including tubular adenomas and tubulovillous adenomas mainly showed weak cytoplasmic phospho-ERK expression. Our results suggest that immunohistologic analysis of phosphorylated ERK expression in colorectal glands may aid the diagnosis of colorectal cancer and that nuclear phosphorylated ERK might be a valuable prognostic marker for colorectal cancer.
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Affiliation(s)
- Cheng-Jeng Tai
- Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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