scholarly journals TERT biology and function in cancer: beyond immortalisation

2017 ◽  
Vol 58 (2) ◽  
pp. R129-R146 ◽  
Author(s):  
Ana Pestana ◽  
João Vinagre ◽  
Manuel Sobrinho-Simões ◽  
Paula Soares

Evasion of replicative senescence and proliferation without restriction, sometimes designated as immortalisation, is one of the hallmarks of cancer that may be attained through reactivation of telomerase in somatic cells. In contrast to most normal cells in which there is lack of telomerase activity, upregulation ofTERTtranscription/activity is detected in 80–90% of malignant tumours. In several types of cancer, there is a relationship between the presence ofTERTpromoter mutations,TERTmRNA expression and clinicopathological features, but the biological bridge between the occurrence ofTERTpromoter mutations and the aggressive/invasive features displayed by the tumours remains unidentified. We and others have associated the presence ofTERTpromoter mutations with metastisation/survival in several types of cancer. In follicular cell-derived thyroid cancer, such mutations are associated with worse prognostic features (age of patients, tumour size and tumour stage) as well as with distant metastases, worse response to treatment and poorer survival. In this review, we analyse the data reported in several studies that implyTERTtranscription reactivation/activity with cell proliferation, tumour invasion and metastisation. A particular attention is given to the putative connections betweenTERTtranscriptional reactivation and signalling pathways frequently altered in cancer, such as c-MYC, NF-κB and B-Catenin.

2021 ◽  
Vol 11 ◽  
Author(s):  
Yujiro Hayashi ◽  
Kazutoshi Fujita ◽  
George J. Netto ◽  
Norio Nonomura

Urothelial carcinoma (UC) is a common urological malignancy with a high rate of disease recurrence. Telomerase activity, a hallmark of cancer characterized by overcoming the replicative senescence, is upregulated in over 90% of patients with UC. Somatic mutations in the promoter region of telomerase reverse transcriptase (TERT) are frequently detected in UC, and drive telomerase activity. Recent studies have demonstrated a strong association between TERT promoter mutation and tumorigenesis of UC. Also, TERT promoter mutation has great potential for diagnosis, as well as prognosis in UC treatment, and this is also applicable for the liquid biopsy techniques. In this review, we discuss the progress in these areas and highlight the challenges, clinical potential, and future direction for developing UC treatment methods.


2020 ◽  
Vol 27 (17) ◽  
pp. 2792-2813
Author(s):  
Martina Strudel ◽  
Lucia Festino ◽  
Vito Vanella ◽  
Massimiliano Beretta ◽  
Francesco M. Marincola ◽  
...  

Background: A better understanding of prognostic factors and biomarkers that predict response to treatment is required in order to further improve survival rates in patients with melanoma. Predictive Biomarkers: The most important histopathological factors prognostic of worse outcomes in melanoma are sentinel lymph node involvement, increased tumor thickness, ulceration and higher mitotic rate. Poorer survival may also be related to several clinical factors, including male gender, older age, axial location of the melanoma, elevated serum levels of lactate dehydrogenase and S100B. Predictive Biomarkers: Several biomarkers have been investigated as being predictive of response to melanoma therapies. For anti-Programmed Death-1(PD-1)/Programmed Death-Ligand 1 (PD-L1) checkpoint inhibitors, PD-L1 tumor expression was initially proposed to have a predictive role in response to anti-PD-1/PD-L1 treatment. However, patients without PD-L1 expression also have a survival benefit with anti-PD-1/PD-L1 therapy, meaning it cannot be used alone to select patients for treatment, in order to affirm that it could be considered a correlative, but not a predictive marker. A range of other factors have shown an association with treatment outcomes and offer potential as predictive biomarkers for immunotherapy, including immune infiltration, chemokine signatures, and tumor mutational load. However, none of these have been clinically validated as a factor for patient selection. For combined targeted therapy (BRAF and MEK inhibition), lactate dehydrogenase level and tumor burden seem to have a role in patient outcomes. Conclusions: With increasing knowledge, the understanding of melanoma stage-specific prognostic features should further improve. Moreover, ongoing trials should provide increasing evidence on the best use of biomarkers to help select the most appropriate patients for tailored treatment with immunotherapies and targeted therapies.


Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1839
Author(s):  
Karolina Seborova ◽  
Radka Vaclavikova ◽  
Lukas Rob ◽  
Pavel Soucek ◽  
Pavel Vodicka

Ovarian cancer is one of the most common causes of death among gynecological malignancies. Molecular changes occurring in the primary tumor lead to metastatic spread into the peritoneum and the formation of distant metastases. Identification of these changes helps to reveal the nature of metastases development and decipher early biomarkers of prognosis and disease progression. Comparing differences in gene expression profiles between primary tumors and metastases, together with disclosing their epigenetic regulation, provides interesting associations with progression and metastasizing. Regulatory elements from the non-coding RNA families such as microRNAs and long non-coding RNAs seem to participate in these processes and represent potential molecular biomarkers of patient prognosis. Progress in therapy individualization and its proper targeting also rely upon a better understanding of interactions among the above-listed factors. This review aims to summarize currently available findings of microRNAs and long non-coding RNAs linked with tumor progression and metastatic process in ovarian cancer. These biomolecules provide promising tools for monitoring the patient’s response to treatment, and further they serve as potential therapeutic targets of this deadly disease.


2015 ◽  
Vol 22 (6) ◽  
pp. 901-908 ◽  
Author(s):  
Ebtesam Qasem ◽  
Avaniyapuram Kannan Murugan ◽  
Hindi Al-Hindi ◽  
Mingzhao Xing ◽  
Mai Almohanna ◽  
...  

Telomerase reverse transcriptase (TERT) promoter mutations C228T and C250T have recently been described in follicular cell-derived thyroid cancer (TC) in patients from North America and Europe. In this study, we explored whether these findings could be replicated in patients from a different ethnic group. We screened 17 benign thyroid adenomas and 265 TC samples from patients in the Middle East for these mutations by PCR and direct sequencing using DNA isolated from paraffin-embedded tumor tissues. None of the 17 benign adenomas harbored TERT promoter mutations. Of 265 TC, 34 (12.8%) harbored TERT promoter mutations, including 10/153 (6.5%) conventional papillary TC (CPTC), 8/57 (14.0%) follicular variant PTC, 9/30 (30%) tall cell variant PTC, 1/3 (30%) Hurthle cell thyroid cancer (HTC), 1/5 (20%) follicular TC, and 5/13 (38.5%) poorly differentiated TC. C250T mutation was present in only 6/265 (2.3%) cases, while C228T mutation was present in a total of 28/265 (10.6%) cases. These two mutations were mutually exclusive. TERT promoter mutations were significantly more common in older (≥45 years) than younger patients and were associated with larger tumour size, vascular invasion, higher TNM stage (stage III and IV), BRAFV600E mutation and persistent/recurrent disease at 6–12 months after initial treatment and at the last follow up. These associations were stronger in non-CPTC. Thus, this study on a large cohort of TC patients from Middle East demonstrates that TERT promoter mutations are relatively common, especially in the non-CPTC, and are associated with more aggressive histopathological features, BRAFV600E mutation, and disease persistence/recurrence than the WT TERT.


1993 ◽  
Vol 107 (11) ◽  
pp. 1066-1069 ◽  
Author(s):  
Alexandra C. Athanassopoulou ◽  
Labros L. Vlahos ◽  
Athanassios D. Gouliamos ◽  
Eliana D. Kailidou ◽  
John G. Papailiou ◽  
...  

AbstractMagnetic resonance imaging (MRI) features in a case of malignant glomus jugulare tumour are reported. Chemodectomas are benign in 95 per cent of cases and malignant in five per cent. Only one case report of CT findings in this unusual CP angle tumour with pulmonary metastases has been cited in the literature.It is concluded that MRI can provide useful information about the nature of chemodectomas although it cannot dislinguish between benign and malignant tumours, except when regional lymph nodes are involved or when distant metastases exist.


2017 ◽  
Vol 63 (1) ◽  
pp. 13-26 ◽  
Author(s):  
D.D. Zhdanov ◽  
D.A. Vasina ◽  
E.V. Orlova ◽  
V.S. Orlova ◽  
V.S. Pokrovsky ◽  
...  

Alternative splicing of telomerase catalytic subunit hTERT pre-mRNA (human Telomerase Reverse Transcriptase) regulates telomerase activity. Increased expression of non-active splice variant hTERT results in inhibition of telomerase. Apoptotic endonuclease EndoG is known to participate in hTERT alternative splicing. Expression of EndoG can be induced in response to DNA damages. The aim of this study was to determine the ability of a DNA-damaging compound, cisplatin, to induce EndoG and its influence on alternative splicing of hTERT and telomerase activity in human CD4+ Т lymphocytes. Overexpression of EndoG in CD4+ T cells downregulated the expression of active full-length hTERT variant and upregulated its non-active spliced variant. Reduction of full-length hTERT caused downregulation of telomerase activity, shortening of telomeres length during cell divisions, converting cells to the replicative senescence state, activation of apoptosis and finally cell death. Few cells survived and underwent malignant transformation. Transformed cells have increased telomerase activity and proliferative potential compare to initial CD4+ T cells. These cells have phenotype of T lymphoblastic leukemic cells and are able to form tumors and cause death in experimental mice.


2021 ◽  
Vol 11 ◽  
Author(s):  
Huan Chen ◽  
Tao Pan ◽  
Yizi He ◽  
Ruolan Zeng ◽  
Yajun Li ◽  
...  

Primary mediastinal large B-cell lymphoma (PMBCL) is a distinct clinicopathologic disease from other types of diffuse large B-cell lymphoma (DLBCL) with unique prognostic features and limited availability of clinical data. The current standard treatment for newly diagnosed PMBCL has long been dependent on a dose-intensive, dose-adjusted multi-agent chemotherapy regimen of rituximab plus etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-R-EPOCH). Recent randomized trials have provided evidence that R-CHOP followed by consolidation radiotherapy (RT) is a valuable alternative option to first-line treatment. For recurrent/refractory PMBCL (rrPMBCL), new drugs such as pembrolizumab and CAR-T cell therapy have proven to be effective in a few studies. Positron emission tomography-computed tomography (PET-CT) is the preferred imaging modality of choice for the initial phase of lymphoma treatment and to assess response to treatment. In the future, baseline quantitative PET-CT can be used to predict prognosis in PMBCL. This review focuses on the pathology of PMBCL, underlying molecular basis, treatment options, radiotherapy, targeted therapies, and the potential role of PET-CT to guide treatment choices in this disease.


2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Anthony Kodzo-Grey Venyo

Background. Extrarenal retroperitoneal angiomyolipomas are rare.Aim. To review the literature.Results. Angiomyolipomas, previously classified as hamartomas, are now classified as benign tumours. Thirty cases of primary retroperitoneal angiomyolipomas have been reported. Diagnosis of the disease upon is based radiological and pathological findings of triphasic features of (a) fat and (b) blood vessels and myoid tissue. Immunohistochemistry tends to be positive for HMB45, MART1, HHF35, calponin, NKI-C3, and CD117. The lesion is common in women. Treatment options have included the following: (a) radical surgical excision of the lesion with renal sparing surgery or radical nephrectomy in cases where malignant tumours could not be excluded and (b) selective embolization of the lesion alone or prior to surgical excision. One case of retroperitoneal angiomyolipoma was reported in a patient 15 years after undergoing radical nephrectomy for angiomyolipoma of kidney and two cases of distant metastases of angiomyolipoma have been reported following radical resection of the tumour.Conclusions. With the report of two cases of metastases ensuing surgical resection of the primary lesions there is need for academic pathologists to debate and review angiomyolipomas to decide whether to reclassify angiomyolipomas as slow-growing malignant tumours or whether the reported cases of metastases were de novo tumours or metastatic lesions.


2015 ◽  
Vol 172 (4) ◽  
pp. 403-413 ◽  
Author(s):  
Greta Gandolfi ◽  
Moira Ragazzi ◽  
Andrea Frasoldati ◽  
Simonetta Piana ◽  
Alessia Ciarrocchi ◽  
...  

ObjectiveTranscriptional activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene were reported at high frequency in aggressive poorly differentiated and anaplastic thyroid cancers. By contrast, the relevance of these mutations in the metastatic behavior of well-differentiated thyroid cancer is still to be defined. The aim of this work was to investigate the frequency ofTERTpromoter mutations in a remarkable cohort of well-differentiated papillary thyroid carcinoma that developed distant metastases (DM-PTCs) and to establish whether these mutations may be predictive of metastatic behavior.DesignWe analyzed the frequency ofTERTpromoter mutations in a group of 43 highly aggressive DM-PTCs. As controls, we analyzed these mutations in a group of 78 PTCs without distant metastases (control-PTCs). The possible correlation betweenTERTpromoter mutations and BRAF V600E mutation was also investigated.MethodsTERTpromoter mutational status was evaluated by direct sequencing of the hotspot harboring the C228T and the C250T mutations.ResultsIn the overall cohort of 121 PTCs analyzed, 17% of cases (21/121) carried a mutation in theTERTpromoter. Noticeably, 33% of DM-PTCs were mutated in theTERTpromoter while only 9% of the control-PTCs showed a mutation in this locus. We also observed a positive association between BRAF V600E andTERTC228T mutations in the cohort of DM-PTCs.ConclusionsThese results indicate thatTERTpromoter mutations are associated with the development of distant metastases in PTCs and may help in predicting aggressive behavior in this type of tumor.


Author(s):  
Fatma Dogan ◽  
Nicholas R. Forsyth

The epigenetic nature of telomeres is still controversial and different human cell lines might show diverse histone marks at telomeres. Epigenetic modifications regulate telomere length and telomerase activity that influence telomere structure and maintenance. Telomerase is responsible for telomere elongation and maintenance and is minimally composed of the catalytic protein component, telomerase reverse transcriptase (TERT) and template forming RNA component, telomerase RNA (TERC). TERT promoter mutations may underpin some telomerase activation but regulation of the gene is not completely understood due to the complex interplay of epigenetic, transcriptional, and posttranscriptional modifications. Pluripotent stem cells (PSCs) can maintain an indefinite, immortal, proliferation potential through their endogenous telomerase activity, maintenance of telomere length, and a bypass of replicative senescence in vitro. Differentiation of PSCs results in silencing of the TERT gene and an overall reversion to a mortal, somatic cell phenotype. The precise mechanisms for this controlled transcriptional silencing are complex. Promoter methylation has been suggested to be associated with epigenetic control of telomerase regulation which presents an important prospect for understanding cancer and stem cell biology. Control of down-regulation of telomerase during differentiation of PSCs provides a convenient model for the study of its endogenous regulation. Telomerase reactivation has the potential to reverse tissue degeneration, drive repair, and form a component of future tissue engineering strategies. Taken together it becomes clear that PSCs provide a unique system to understand telomerase regulation fully and drive this knowledge forward into aging and therapeutic application.


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