2022 Sep;22(9):515-532. doi: 10.1038/s41568-022-00490-1. The telomere, after all, represents a DNA end, which is at the end of the linear chromosomal DNA, but it has to be treated in a different way from an accidental DNA break in a chromosome. One reason is that, as was predicted in the 1970s, the known mechanism of DNA polymerase prevents complete DNA replication all the way to the ends of the chromosome at every round of replication. The fact that telomerase activity declines in somatic cells during adulthood, and that cell transformation and im-mortalization are often associated with increased telom-erase activity (Greider, 1998; Liu, 1999), suggests that telomerase has an antiaging function. Interpretation Comprehensive lifestyle changes signi cantly increase telomerase activity and consequently telomere maintenance capacity in human immune-system cells. government site. Federal government websites often end in .gov or .mil. The .gov means its official. official website and that any information you provide is encrypted The .gov means its official. FOIA Humans also have telomerase. Too much telomerase can help confer immortality onto cancer cells and actually increase the likelihood of cancer, . An important conclusion of this work is that telomerase participates in cell responses in ways that do not seem to involve the telomere itself. MeSH Lower left, schematic of the uncapping of telomeres. 2007 Apr-May;25(3):197-208. doi: 10.1080/07357900701208683. Similarly, using inhibitors of telomerase activity, which prevent telomeric DNA synthesis but do not affect the level of telomerase ribonucleoprotein, elicits the same expected time course of events (Table 1). One line of evidence for the lack of p53 protein requirement came from the use of a p53-null human colon cancer cell line kindly provided by Dr. Burt Vogelstein. It is this addition of telomeric DNA in increments to the ends of chromosomes that offsets and counterbalances the shortening of chromosome ends. Telomerase activity has been detected in 85% of tumors representing 15 cancer types, whereas most benign tumors and somatic tissues have very low levels or lack detectable telomerase activity Furthermore, in special metastatic tumor types such as neuroblastoma stage IVs, in which there is a high rate of spontaneous regression, telomerase . eCollection 2021 Jan 19. 2008 Nov;9(11):1023-4. doi: 10.1016/S1470-2045(08)70266-3. Telomerase activity in hematopoietic cells is associated with self-renewal potential. Dybiec J, Szlagor M, Mynarska E, Rysz J, Franczyk B. Int J Mol Sci. Lai K. L and T.Y.W. 2022 Sep;25(3):444-452. doi: 10.1038/s41391-022-00553-2. The primary endpoint was telomerase enzymatic activity per viable cell, measured at baseline and after 3 months. A delay ensues, during which telomeres shorten, before the cells finally cease to grow. scientists may be able to stop cancer progression and potentially increase mortality. MAIA is designing and evaluating multiple telomere-targeting compounds designed to modify the telomeric structure through the cancer cell - intrinsic telomerase activity - and thus cause the death . The ribozyme treatment decreased the metastatic burden. Mutat Res. Telomerase has long been considered as a biomarker for cancer diagnosis and a therapeutic target for drug discovery. Careers. Accessibility Note that not all telomeres (TRF2 spots) overlap with DNA damage foci, although each of the large DNA damage focal spots overlaps with one or more telomeres. FOIA The improbable targeted therapy: KRAS as an emerging target in non-small cell lung cancer (NSCLC). Carol Greider and I identified the telomerase enzyme first in the ciliated protozoan Tetrahymena. Li S, Rosenberg JE, Donjacour AA, et al. A low threshold level of expression of mutant-template telomerase RNA inhibits human tumor cell proliferation. Telomerase is commonly expressed in human cancer cells. Valdiani A, Ofoghi H, Akbarizare M, Talei D. 3 Biotech. Comprehensive lifestyle changes significantly increase telomerase activity and consequently telomere maintenance capacity in human immune-system cells. The p53 response pathway is commonly abrogated in human cancers. strategy was developed for reliable and highly sensitive telomerase activity assay based on the increased electrochem. Elizabeth H. Blackburn; Telomerase and Cancer: Kirk A. Landon - AACR Prize for Basic Cancer Research Lecture. Anticancer therapy targeting telomeres and telomerase : current status. Herein, an enzyme-free electroanal. and transmitted securely. Choi JE, Kang HG, Jang JS, Choi YY, Kim MJ, Kim JS, Jeon HS, Lee WK, Cha SI, Kim CH, Kam S, Jung TH, Park JY. See this image and copyright information in PMC. These findings suggest that telomerase activity may affect telomere maintenance, thereby contributing to susceptibility to lung cancer. Wu X, Wu J, Dai J, Chen B, Chen Z, Wang S, Wu F, Lou X, Xia F. Natl Sci Rev. Liu Y, Betori RC, Pagacz J, Frost GB, Efimova EV, Wu D, Wolfgeher DJ, Bryan TM, Cohen SB, Scheidt KA, Kron SJ. We are hopeful that these avenues will lead us to a greater understanding of the biology that is being played out in the progression to a more malignant state of cancer cells, particularly metastasis. Unlike viral or retroviral reverse transcriptases, such as that of HIV-1, the cellular enzyme telomerase specializes in making the multiple short tandem repeats that are at the ends of chromosomes. NCI CPTC Antibody Characterization Program, Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A. Science. The https:// ensures that you are connecting to the Kapranov 2007 FANTOMcDNAcDNACarninci 2005 . Disclaimer, National Library of Medicine We also address some of the challenges to telomerase-directed therapies including potential therapeutic resistance and considerations for future therapeutic applications and translation into the clinical setting. 2022 Oct 26;14(21):5257. doi: 10.3390/cancers14215257. Influences of Long-Term Exercise and High-Fat Diet on Age-Related Telomere Shortening in Rats. The solution to this theoretical problem was the enzyme telomerase (1). This work comprises one approach by which one might exploit the increased expression of telomerase, which is so common in cancer cells by forcing them to make toxic telomeres. However, previous studies have not addressed whether improvements in nutrition and lifestyle are associated with increases in telomerase activity. Recent studies also suggest that telomerase is implicated in tumor progression in unexpected ways. 2021 Dec 16;13(24):6332. doi: 10.3390/cancers13246332. As you might expect, telomerase is active in human stem cells and in germ line cells. Resulting in the overall . These experiments demonstrated that the telomerase RNA was being expressed in a way that supported its assembly into functional telomerase. 4). 2005;6:611622. Moreover, when the subjects were categorized based on the median value of telomerase activity, subjects with low telomerase activity were at a significantly increased risk of lung cancer compared to subjects with high telomerase activity (adjusted odds ratio = 3.05, 95% confidence interval = 1.60-5.82, P = 7 10(-4)). An increase in telomerase activity in one context could be viewed as beneficial because it might lead to an increase in relative telomere length . The human telomerase RNA, a non-mRNA, can be efficiently knocked down by expression of a short hairpin RNA from a lentiviral construct. -cancer . Due to telomerase inhibition, activity, or expression, these drugs might kill tumor cells by allowing . Instead, the affinity was increased by almost 3-fold as shown by the em K /em M values for the L-cysteine analog, RD-PNB (29 2.2 M) Mephenesin compared to the D-cysteine analog, L-70 (11 0.9 M). Lifestyle factors known to promote cancer and cardiovascular disease might also adversely affect telomerase function. Bookshelf The number of papillomas showing higher levels of telomerase activity increased at 20 weeks, and at 30 weeks of promotion, 100% of papillomas expressed significantly higher levels of telomerase. Telomerase is silenced in most normal cells but is active in an estimated 85% to 95% of human cancer cells. Telomerase inhibitor BIBR1532 shortens telomere length and suppresses mutant Kras-induced cell long-term proliferation, Figure 3. Telomerase inhibitor BIBR1532 inhibits Kras mutations-induced cell transformation and migration capability, Figure 4. Please enable it to take advantage of the complete set of features! Published in Cancer Research 1996. After much study, it has emerged that the RNAs from evolutionarily diverse eukaryotes share a common core structure (2). Cold Spring Harbor Lab; 2005;19:210010. We chose as examples for study two mutant-template telomerase RNAs, which were mutated in such a way that they dictated the synthesis of DNA that would be unable to bind the sequence-specific telomere-protective proteins. 2003 Oct 1;289(2):326-34. doi: 10.1016/s0014-4827(03)00281-7. Without new synthesis of telomeres at chromosome ends the chromosomes shorten with progressive cell division, eventually triggering either replicative senescence or apoptosis when telomere length becomes critically short. Incorporation of nucleoside analogues into newly synthesized telomeres impairs POT1 binding, causing telomere dysfunction that elicits a DNA damage response and cell death. Genes Dev. The primary endpoint was telomerase enzymatic activity per viable cell, measured at baseline and after 3 months. Telomere shortness in human beings is emerging as a prognostic marker of disease risk, progression, and premature mortality in many types of cancer, including breast, prostate, colorectal, bladder, head and neck, lung, and renal cell. 2002 Mar;2(1):1-17. doi: 10.2174/1568009023334015. 2021 Jan 2;8(6):nwaa306. Use of the D- in place of L-cysteine did not prevent hydrolysis by PMPMEase. 2022 Nov 7;10:1060201. doi: 10.3389/fcell.2022.1060201. Clipboard, Search History, and several other advanced features are temporarily unavailable. "Inhibition of Telomerase activity in human cancer cells by RNA interference". . The findings give new insights into cellular aging and the development of cancer. Curr Cancer Drug Targets. 2022 Sep 16;10(9):2299. doi: 10.3390/biomedicines10092299. Epub 2018 Aug 2. 3. Careers. NOTE: Comparison of human cancer cell growth inhibitory effects predicted and observed when telomerase enzymatic activity was only inhibited (Old) versus those observed in cells in which total telomerase RNA levels were knocked down (New). Telomerase activity is essential for the maintenance of critical telomere length, enabling cell replicative immortality, one of the hallmarks of cancer . 2008;14:57315734. Clipboard, Search History, and several other advanced features are temporarily unavailable. Would you like email updates of new search results? 2009 Oct;18(10):2773-81. doi: 10.1158/1055-9965.EPI-09-0323. We found that Kras mutations increased TERT (telomerase reverse transcriptase) mRNA expression and telomerase activity and telomere length in both immortalized bronchial epithelial cells (BEAS-2B) and lung adenocarcinoma cells (Calu-3). 8600 Rockville Pike Efficient platforms for detecting telomerase activity are essential for early tumor monitoring and diagnosis. When compared with the parent cell line, in which the p53 locus is left intact, the responses between the lines were similar. The template is only a minor part of the entire telomerase RNA molecule. We found that the cellular response to this way of uncapping of telomeres in cancer cells was a very robust apoptotic response (Fig. However, blocking telomerase activity could affect cells where telomerase activity is . Jacobs F, Cani M, Malapelle U, Novello S, Napoli VM, Bironzo P. Cancers (Basel). The replaced promotor E2F1 was specifically activated in Rb-defected tumor cells and hTERT promoters activated in telomerase-positive cancer cells increased the therapeutic efficacy of these OVs . Which of the following statements is accurate about the activity of the telomerase enzyme in cancer cells? Previous studies have shown that injecting the telomerase gene into the immune cells (T cells) in our body can help keep the telomeres from getting shorter and enabling them to maintain their anti-viral functioning longer. eCollection 2021. Before Karadayi S, Arslan S, Sumer Z, Turan M, Sumer H, Karadayi K. Mol Biol Rep. 2013 Aug;40(8):4701-4. doi: 10.1007/s11033-013-2565-8. (7)]. -, Riely GJ, Marks J, Pao W. KRAS mutations in non-small cell lung cancer. Kenessey I, Ki K, Horvth O, Cserepes M, Molnr D, Izsk V, Dobos J, Hegeds B, Tvri J, Tmr J. Oncotarget. To determine whether the telomeres had become uncapped, we looked for the appearance of DNA damage foci at telomeres (Fig. Northern blot analysis of RNA extracted from a human cancer cell line, MCF-7. Ashwagandha root extract increased telomerase activity with highest enhancement of ~45% at 10 - 50 g concentration. -cancer cells show increased telomerase activity and the telomeres are not shortened. Would you like email updates of new search results? Figure 1. Mammalian telomeres end in a large duplex loop. Disclaimer, National Library of Medicine However, development of telomerase inhibitors has been challenging and thus far there are no clinically approved strategies exploiting this cancer target. In one experiment, researchers blocked telomerase activity in human breast and prostate cancer cells growing in the laboratory, prompting the tumor cells to die. These applications include inhibiting or targeting telomerase as a novel antineoplastic strategy and using cells immortalized by telomerase for therapeutic applications. Prospects for anti-neoplastic therapies based on telomere biology. That telomerase knockdown produced down-regulation of a specific subset of genes that included those implicated in tumor progression properties, such as metastasis, was intriguing. PMC To detect telomerase, a novel surface-enhanced Raman scattering (SERS) biosensor was constructed using the dual DNA-catalyzed amplification strategy composed of strand displacement amplification (SDA . False. Disclaimer, National Library of Medicine The effects were different from the gene expression effects elicited by mutant-template telomerase RNA expression (7). Therapies that increase telomerase activity can also slow the rate of telomere shortening. In control cells, the wild-type telomerase RNA was introduced, and big robust tumors formed. The authors declare that they have no conflict of interest. Would you like email updates of new search results? We therefore investigated what happens when you knock down the high levels of telomerase in human cancer cells. 2000;10:147154. Growth Inhibitory Effects of Knocking Down Telomerase in Cancer Cells. . Melanoma, an aggressive form of skin cancer, is highly dependent on telomerase to grow, . In contrast, telomerase activity is silenced in most adult somatic cells. -, Levy MZ, Allsopp RC, Futcher AB, Greider CW, Harley CB. Researchers found that the enzyme telomerase, which is active in most tumor cells, may also protect healthy adult cells from becoming cancerous. Telomere length and the risk of lung cancer. Not all cellsonly about 90% to 95% of the cellswere infected. Bodnar AG, Ouellette M, Frolkis M, et al. . Sunaga N, Kaira K, Imai H, Shimizu K, Nakano T, Shames DS, Girard L, Soh J, Sato M, Iwasaki Y, Ishizuka T, Gazdar AF, Minna JD, Mori M. Oncogene. An official website of the United States government. Bethesda, MD 20894, Web Policies -. Ovals and diamonds, sequence-specific DNA binding proteins that protect telomeric DNA and cap it; red, telomerase; blue Xs, mutated telomerase RNA template and correspondingly mutated telomeric DNA sequence. Expression of TERT mRNA is higher in Kras mut lung adenocarcinoma than in, MeSH The Renaissance of KRAS Targeting in Advanced Non-Small-Cell Lung Cancer: New Opportunities Following Old Failures. J. Mol. DNA damage foci accumulate at a subset of telomeres in cells expressing a mutant-template telomerase RNA. Kras mutations-induced lung tumorigenesis and chemoresistance are attenuated by telomerase inhibition. Accessibility 1998 Apr;102(4):397-402. doi: 10.1007/s004390050711. This site uses cookies. 2009;361:23532365. The https:// ensures that you are connecting to the The fruit fly Drosophila melanogaster . Even people living in the Blue Zones eat fish in moderation. In contrast, the controls, which received either a wild-type-template telomerase RNA construct or just the empty lentiviral vector, grew normally. Recently, 108 novel genetic loci within genes involved in telomere biology and DNA repair have been linked to LTL in UK Biobank. This had the consequence of leaving the telomeric tip uncapped (Fig. Targeting. tumours. This was first shown in a model organism, the ciliate Tetrahymena, and subsequently in many other organisms. Macek P, Poreba R, Gac P, Bogunia-Kubik K, Dratwa M, Wieckiewicz M, Wojakowska A, Michalek-Zrabkowska M, Mazur G, Martynowicz H. Biomedicines. Telomerase inhibitor BIBR1532 increases sensitivities of Kras G12D and Kras G12V -Calu-3 cells, Figure 5. Before The slowing of cellular proliferation did not require the protein p53, which is ordinarily involved in the responses of cells to DNA damage. Disclaimer, National Library of Medicine Accessibility Geron Corporation GERN, a late-stage clinical biopharmaceutical company, today highlighted multiple additions to its senior commercial leadership team, as it prepares for the potential . Telomeres, telomerase, and myc. Here we discuss recent efforts targeting telomerase, including immunotherapies and direct telomerase inhibitors, as well as emerging approaches such as targeting TERT gene expression driven by TERT promoter mutations. Background: Thus, again, no evidence was found for any resistant subpopulation of cells that evade the effect of mutant-template telomerase RNA expression. Gupta N, Patel HD, Taylor J, Borin JF, Jacobsohn K, Kenfield SA, Eggener SE, Price C, Davuluri M, Byrne N, Bivalacqua TJ, Loeb S. Prostate Cancer Prostatic Dis. -, Shields JM, Pruitt K, McFall A, Shaub A, Der CJ. 8600 Rockville Pike For example, up-regulation of p21 expression was seen, consistent with a DNA damage response. The response to mutant-template telomerase RNA is highly specific for cells that have high levels of telomerase. Hiyama, E; Yokoyama, T; Tatsumoto, N; Hiyama, K; Imamura, Y; Murakami, Y; Kodama, T; Piatyszek, M A; Shay, J W . Findings: Delayed effect: bulk telomeres decline to critical short length? 2). In the context of cancer cells, particularly those that are well on the way to a malignant state, telomerase has cancer-promoting properties. DNA glycosylase is the critical enzyme that initiates the base excision repair (BER) pathway, recognizing and excising damaged bases. 2016 Nov 29;7(48):79503-79514. doi: 10.18632/oncotarget.12806. The proteins come on and off the telomere with surprising speed. Telomerase activity in gastric cancer. Jang JS, Choi YY, Lee WK, Choi JE, Cha SI, Kim YJ, Kim CH, Kam S, Jung TH, Park JY. In addition, higher TERT expression was seen in Kras-mutant NSCLC than that with wild-type Kras. Indeed, that expected result is exactly what is seen when the telomerase activity in cells is inhibited by, for example, expressing an excess of a catalytically dead version of the protein TERT, which, although it can still assemble into the telomerase ribonucleoprotein complex, forms a complex that is not catalytically active. Targeting telomerase reverse transcriptase with the covalent inhibitor NU-1 confers immunogenic radiation sensitization. An official website of the United States government. The regulation of telomerase activity in human cells plays a significant role in the development of cancer. Oncogenic KRAS-induced epiregulin overexpression contributes to aggressive phenotype and is a promising therapeutic target in non-small-cell lung cancer. Effects of low-level expression of mutant-template telomerase RNA in MCF-7 breast cancer cells. Specific association of human telomerase activity with immortal cells and cancer. Epub 2022 Aug 16. Semeraro MD, Almer G, Renner W, Gruber HJ, Herrmann M. Cells. Bookshelf The Molecular Interplay between Human Oncoviruses and Telomerase in Cancer Development. Thus far, everything discussed has related to telomerase acting in its familiar mode: making telomeric DNA longer. Hence, the DNA at the ends of the chromosomes was effectively naked. Accessibility This site needs JavaScript to work properly. Cell. The problem was that previously, the only stable lines that grew out were those that had expressed extremely low levels of mutant-template telomerase RNA. The .gov means its official. Does hydatid disease have protective effects against lung cancer? Telomere shortening is counteracted by the cellular enzyme telomerase. Although in many normal adult human cell types telomerase is often expressed at very low, sometimes undetectable, levels, it is clear that telomerase has some protective role in such normal cells. GFP lane, Northern blot analysis of RNA from cells expressing GFP alone from the control lentiviral vector [adapted from Li et al. US11007255B2 - Cancer vaccines and methods of treatment using the same - Google Patents . government site. The site is secure. In collaboration with Jerry Cunha's lab at University of California, San Francisco, human bladder tumor cells were xenografted under the renal capsule in a mouse. 1). Telomerase is tightly repressed in the vast majority of normal human somatic cells but becomes activated during cellular immortalization and in cancers. 2016 Jul;23(4):346-53. doi: 10.1097/MOH.0000000000000252. Careers. This site needs JavaScript to work properly. Epub 2022 Sep 14. Irradiation-induced telomerase activity and gastric cancer risk: a case-control analysis in a Chinese Han population. Bethesda, MD 20894, Web Policies PMC It is in that latter context that we are interested in intervening in telomerase action. . sharing sensitive information, make sure youre on a federal Furthermore, the underlying DNA is also dynamic, for two reasons. Moreover, increased telomerase activity enhanced self-renewal ability, proliferation, and differentiation efficiency in Tert-overexpressing ES cells (Armstrong et al, 2005). government site. Cancer research, 1995. PBMC telomerase activity, but not leukocyte telomere length, correlates with hippocampal volume in major depression. Methods: 30 men with biopsy-diagnosed low-risk prostate cancer were asked to make comprehensive lifestyle changes. Thus, we converted an effectively immortal, perpetually growing organism into a mortal one by the simple action of making its telomerase nonfunctional, thereby showing that telomerase was important for the continued maintenance of the telomeres and of cell proliferation (3). (IC50 = 15 M - 33 M) with significant increase in the calcium level in dose- and time-dependent manner. Curiously, however, the high level of telomerase in the majority of cancer cellswhich is typically a couple of orders of magnitude higher in cancer cells than in the differentiated normal cells around itusually does not lead to the cancer cells having long telomeres. Mutat Res. Tumor cells in control . Remember, this enzyme isn't found in . https://doi.org/10.1158/1541-7786.MCR-05-0147. The regulation of telomerase activity in human cells plays a significant role in the development of cancer. Increased telomerase expression produces vulnerability of cancer cells, distinguishing them from normal cells in the body, although normal cells do also have some active telomerase. By continuing to use our website, you are agreeing to, Kirk A. Landon - AACR Prize for Basic Cancer Research Lecture, Cancer Epidemiology, Biomarkers & Prevention, A Brief Review of Telomeres and Telomerase, Intervening in the Action of Telomerase in Human Cancer Cells, Forcing Telomerase to Make Mutant Telomeric DNA in Cancer Cells, Unexpected Short-term Effects of Knocking Down Telomerase Activity in Cancer Cells, https://doi.org/10.1158/1541-7786.MCR-05-0147, The Prostate Stromal Transcriptome in Aggressive and Lethal Prostate Cancer, IFT20 Confers Paclitaxel Resistance by Triggering -arrestin-1 to Modulate ASK1 Signaling in Breast Cancer, Malignant Progression of an Ancestral Bone Marrow Clone Harboring a, Improved Delineation of Colorectal Cancer Molecular Subtypes and Functional Profiles with a 62-Gene Panel, Cancer Epidemiology, Biomarkers, & Prevention. 2021 Dec 23;11:792385. doi: 10.3389/fonc.2021.792385. Targeting the "hallmarks of aging" to slow aging and treat age-related disease: fact or fiction? The telomerase RNA of mouse melanoma cells (B16 cells) was targeted using ribozymes, and the human telomerase RNA in human melanoma cells was targeted using the siRNA approach described previously (8). Telomere end-replication problem and cell aging. The activity of telomerase is relatively low in somatic cells and absent in normal cells, . Although much work remains to be done, effective strategies targeting telomerase will have a transformative impact for cancer therapy and the prospect of clinically effective drugs is boosted by recent advances in structural models of human telomerase. Effect is immediate*as fast as can be measured. Telomeric length and telomerase activity vary with age in peripheral blood cells obtained from normal individuals. 2023 Jan;28(1):242-255. doi: 10.1038/s41380-022-01680-x. Please enable it to take advantage of the complete set of features! Through this work, we learned, somewhat to our surprise, that we might also be able to incur a more rapid effect on cancer cell growth than expected and even change their cancerous properties in ways that were hitherto unsuspected (7). 2021 Jan 19;2(1):100186. doi: 10.1016/j.xcrm.2020.100186. Demethylation of the human telomerase catalytic subunit (hTERT) gene promoter reduced hTERT expression and telomerase activity and shortened telomeres. HHS Vulnerability Disclosure, Help Adv Pharm Bull. Systematic review of the impact of a plant-based diet on prostate cancer incidence and outcomes. 2022 Sep 7;58(9):1240. doi: 10.3390/medicina58091240. As shortened telomeres inhibit tumor formation and prolong life span in a KrasG12D mouse lung cancer model, we investigated the implications of telomerase in Kras-mutant NSCLC. Lancet Oncol. These included some intriguing genes, such as cyclin G2 or CDC27genes that have been implicated in cell cycle progression. Cancer Biol Ther. This increased expression of telomerase makes it an attractive target for intervention. Telomeres are located at the ends of chromosomes and protect them from degradation. While the mechanisms for telomerase activation in cancers have not been fully defined, they include telomerase catalytic subunit gene (hTERT) amplification and trans-activation of the hTERT promoter by the myc oncogene product. MeSH 4. Nuclear telomerase extracts were obtained from human breast cancer PMC42 cells transfected for 15 h with dierent hTERT cDNA expression constructs as indicated. Approximately 85% of human cancers achieve indefinite cell proliferation and avoidance of telomeric shortening through increased telomerase activity. Once again, the effects did not require p53 (7). Reproduced from the Proceedings of the National Academy of Sciences, U.S.A., 2001;98:79827 by copyright permission of the National Academy of Sciences, U.S.A. (5). Global cancer statistics, 2012. Relative Leukocyte Telomere Length and Telomerase Complex Regulatory Markers Association with Leber's Hereditary Optic Neuropathy. Telomere maintenance via telomerase reactivation is a nearly universal hallmark of cancer cells which enables replicative immortality. Bahcall M, Awad MM, Sholl LM, Wilson FH, Xu M, Wang S, Palakurthi S, Choi J, Ivanova EV, Leonardi GC, Ulrich BC, Paweletz CP, Kirschmeier PT, Watanabe M, Baba H, Nishino M, Nagy RJ, Lanman RB, Capelletti M, Chambers ES, Redig AJ, VanderLaan PA, Costa DB, Imamura Y, Jnne PA. Clin Cancer Res. PMC Hum Genet. Cellular and gene expression responses involved in the rapid growth inhibition of human cancer cells by RNA interference-mediated depletion of telomerase RNA. Cell aging in relation to stress arousal and cardiovascular disease risk factors. A. Mutirangura, P. Supiyaphun, +4 . Effect of comprehensive lifestyle changes on telomerase activity and telomere length in men with biopsy-proven low-risk prostate cancer: 5-year follow-up of a descriptive pilot study. The ciliated protozoan Tetrahymena thermophila normally has constitutive telomerase and can continue to proliferate indefinitely like a cancer cell. Epel ES, Lin J, Wilhelm FH, Wolkowitz OM, Cawthon R, Adler NE, Dolbier C, Mendes WB, Blackburn EH. Weinstein IB. Before The site is secure. An official website of the United States government. Epub 2019 Jun 1. -cancer cells show decreased telomerase activity and the telomeres are shortened. This implies that they have become adapted to their high levels of telomerase. Understanding Ras: it ain't over 'til it's over. which mark DNA damage and dysfunction and found that there is a steady increase with increasing age in humans. Epub 2013 Sep 17. Background Genome-wide association studies (GWAS) have identified genetic susceptibility variants for both leukocyte telomere length (LTL) and lung cancer susceptibility. and transmitted securely. The unexpectedly rapid response to telomerase knockdown prompted us to carry out many controls to rule out possibilities such as targets other than the telomerase RNA being responsible for the effects on cell growth. The .gov means its official. Life extension is the concept of extending the human lifespan, either modestly through improvements in medicine or dramatically by increasing the maximum lifespan beyond its generally-settled limit of 125 years.. Several researchers in the area, along with "life extensionists", "immortalists" or "longevists" (those who wish to achieve longer lives themselves), postulate that future . These cancer cells already had high levels of telomerase, including high levels of the normal wild-type telomerase RNA. Department of Health & Human Services | NIH | National Cancer Institute (NCI)/International, P01CA114046/U.S. Human Rifl protein binds aberrant telomeres and aligns along anaphase midzone microtubules. Rapid down-regulation of genes promoting cell cycle progression and metastasis. official website and that any information you provide is encrypted MeSH Telomerase is commonly expressed in human cancer cells. Nat Rev Cancer. p53 deficiency rescues the adverse effects of telomere loss and cooperates with telomere dysfunction to accelerate carcinogenesis. -, Eisenberg DT. Unable to load your collection due to an error, Unable to load your delegates due to an error, Therapeutic strategies for targeting telomerase Approaches to targeting telomerase include: 1. Ferrara MG, Stefani A, Pilotto S, Carbone C, Vita E, Di Salvatore M, D'Argento E, Sparagna I, Monaca F, Valente G, Vitale A, Piro G, Belluomini L, Milella M, Tortora G, Bria E. Front Oncol. Identification of a specific telomere terminal transferase activity in. Telomerase activity can immortalize cancer cells and about 90% of cancers are characterized by increased telomere activity. An update. Genetic Variants of the TERT Gene and Telomere Length in Obstructive Sleep Apnea. Delay dependent on initial telomere length in the cancer cells? We are very interested in understanding the signaling pathways leading to the apoptosis, which is under active investigation right now. 2019 Nov 15;105(4):861-874. doi: 10.1016/j.ijrobp.2019.08.009. Recently a germline alteration of telomere-telomerase complex has been identified in patients with familial pap-illary thyroid cancer, characterized by short telomeres and increased expression and activity of telomerase compared to patients with sporadic papillary thyroid cancer. Bethesda, MD 20894, Web Policies We found that Kras mutations increased TERT (telomerase reverse transcriptase) mRNA expression and telomerase activity and PMC Search for other works by this author on: Greider CW, Blackburn EH. In humans, telomerase enzyme activity is absent in most normal cells but present in the majority of tumors (4). 30 men with biopsy-diagnosed low-risk prostate cancer were asked to make comprehensive lifestyle changes. Lancet Oncol. -, de Lange T Shelterin: the protein complex that shapes and safeguards human telomeres. Epub 2005 Nov 17. Curr Opin Hematol. Before Front Cell Dev Biol. An official website of the United States government. An intriguing aspect of these results was the rapidity of the cell growth response, which we could now examine and analyze. In contrast to the effects of mutant-template telomerase RNA expression on telomerase RNA knockdown, no telomere shortening or telomere uncapping, or DNA damage response, accompanied the cell growth rate decrease. Suspi- M.P. Mol Cancer Res (2005) 3 (9): 477-482. The significance of telomerase activation and cellular immortalization in human cancer. In contrast, telomerase activity is silenced in most adult somatic cells. Primarily, capping is accomplished through formation of a specific DNA-protein complex at the chromosomal terminus. Another study from the same group further clarified this potential link between telomerase expression and myofibroblast differentiation (18); using the same bleomycin-induced pulmonary fibrosis rat model, they demonstrated that the inhibition of fibroblast telomerase activity led to increased -SMA expression, which represents a marker of . 24 patients had sufficient PBMCs needed for longitudinal analysis. Bookshelf official website and that any information you provide is encrypted -, Morrison SJ, Prowse KR, Ho P, Weissman IL. Thus, Ashwagandha root extract has the anti-aging inducing potential. in patients with breast cancer,4 increased risk of bladder, head and neck, lung, and renal-cell cancers,5 . Telomerase activity analysis was . Telomerase is a critical factor in CAR-T cell replication and overall function, and its abundance diminishes in cell division, aging, and disease.With reduced telomerase activity, CAR-T cells typically die or become aged, non-functional, and non-proliferating (senescent), leading to inhibited CAR-T function and a lack of prolonged cancer . -, Blasco MA. Keshavarz M, Xie K, Schaaf K, Bano D, Ehninger D. Mol Psychiatry. 2022 May 10;11(10):1605. doi: 10.3390/cells11101605. The chromosome ends become progressively shorter, which was predicted eventually to lead, by some unknown mechanism, to cells ceasing to divide. Tieing together loose ends: telomere instability in cancer and aging. 4. Authors have no potential conflicts of interest to disclose. Telomeres and human disease: aging, cancer and beyond. The telomeres consist, first, of a DNA scaffold composed of a tract of very simple repeated DNA sequences. An official website of the United States government. 2013 Aug 22;32(34):4034-42. doi: 10.1038/onc.2012.402. Alternatively, oligonucleotides complementary to the TERC template region can act as competitive telomerase inhibitors. Thus, telomerase represents an attractive target for highly selective cancer therapeutics. In bladder cancer, the promoter mutations correlate with increased TERT expression and telomerase enzymatic activity 21. Reproduced from the Proceedings of the National Academy of Sciences, U.S.A., 2001;98:79827 by copyright permission of the National Academy of Sciences, U.S.A. (5). eCollection 2022. This new gene expression profile defined an interesting signature for telomerase knockdown, marked by diminished expression of 73 genes. Maciejewska N, Olszewski M, Jurasz J, Baginski M, Stasevych M, Zvarych V, Folini M, Zaffaroni N. Cell Death Dis. An example of mutated bases in the telomerase RNA and complementary mutant DNA bases incorporated into telomeric DNA (red A's and T's, respectively) through copying of the mutant telomerase template. cancer cells employ . Recent studies also suggest that telomerase is implicated in tumor . Suppressing the activity of telomerase, a telomeresynthesizing enzyme, and maintaining short telomeres is a protective mechanism against cancer in humans. Telomeres and telomerase in prostatic intraepithelial neoplasia and prostate cancer biology. DNA Southern blot experiments, done to examine the length of the telomeric DNA, showed that there was no bulk shortening of the telomeres. Immunotherapies - Peptide or DNA vaccines supply immunogenic TERT epitopes that stimulate immune responses against telomerase-expressing cancer cells. Telomerase was found to be highly expressed in dimethylhydrazine dihydrochloride (DMH)-induced colorectal cancer in rats, and its high activity was associated with increased TERT expression. We used this organism because it has a large number of telomeres and is a relatively rich source of telomerase. G-quadruplex (G4) stabilizers disrupt telomerase function by blocking the resolution of telomeric G-quadruplex DNA. 2007;21(6):375-85. doi: 10.2165/00063030-200721060-00005. Today, many of those factors are known, including proteins that aid in binding to the telomere and protect it from increased by telomerase activity. Given this finding and the pilot nature of this study, we report these increases in telomerase activity as a significant association rather than inferring causation. We interpret these findings to mean that as the cells grew, with some probability they would die by apoptosis. Thus, the RNA and the protein of telomerase collaborate in the enzymatic action. de Lange T. Shelterin: the protein complex that shapes and safeguards human telomeres. While telomerase activity is detected in cells with high proliferation potential, in somatic cells it is virtually undetected resulting in the overall shortening of telomeres with each cell division. Consecutive Inhibition of Telomerase and Alternative Lengthening Pathway Promotes Hodgkin's Lymphoma Cell Death. . One of the telomerase-specific oncolytic adenovirus . Am J Hum Biol. Tsirpanlis G, Chatzipanagiotou S, Boufidou F, Kordinas V, Alevyzaki F, Zoga M, Kyritsis I, Stamatelou K, Triantafyllis G, Nicolaou C. Am J Nephrol. Telomerase is tightly repressed in the vast majority of normal human somatic cells but becomes activated during cellular immortalization and in cancers. Clin Lung Cancer. The 46 human chromosomes are shown in blue, with the telomeres appearing as white pinpoints. sharing sensitive information, make sure youre on a federal An evolutionary review of human telomere biology: the thrifty telomere hypothesis and notes on potential adaptive paternal effects. In the current work, we investigated the relationship between genetically predicted LTL and lung . The Chemopreventive Activity of Indonesia Medicinal Plants Targeting on Hallmarks of Cancer. Therefore, Shang Li developed a short-term expression system for mutant-template telomerase RNA (6). In collaboration with Mohammed Kashani-Sabet and his group at University of California, San Francisco, we examined the effect of telomerase RNA knockdown on metastasis in two in vivo models. Telomerase inhibitor BIBR1532 prevents Kras, Figure 5. Although the mouse telomerase RNA component levels were increased 2-fold and correlated well with proliferation markers, activity levels were increased 10-fold, suggesting a second level of regulation in addition to growth regulation . However, development of telomerase inhibitors . Clin Cancer Res. This study is registered on the ClinicalTrials.gov website, number NCT00739791. Telomerase contains an RNA component. Iwama H, Ohyashiki K, Ohyashiki JH, Hayashi S, Yahata N, Ando K, Toyama K, Hoshika A, Takasaki M, Mori M, Shay JW. 30 men with biopsy-diagnosed low-risk prostate cancer were asked to make comprehensive lifestyle changes. That property also makes telomerase a very unusual reverse transcriptase. Careers. Telomerase is by nature a reverse transcriptase by virtue of its action of copying the short RNA template sequence within the telomerase RNA into DNA; an enzyme that copies RNA into DNA is by definition a reverse transcriptase. Cancer Invest. Telomerase play a key role in the maintenance of telomere length and chromosome integrity. The expression of telomerase in various human cancers and its diminished expression in most normal cells suggest that the enzyme might serve as a good target for anticancer drugs. Telomerase therapy is a promising approach to treating age-related diseases. Epub 2012 Sep 10. Telomerase as a therapeutic target in glioblastoma. Bookshelf PBMC telomerase activity in these men increased 29.84% within just 3 months of making significant . Our data suggest that Kras mutations increase telomerase activity and telomere length by activating the RAS/MEK pathway, which contributes to an aggressive phenotype of NSCLC. A popular metaphor for what is involved in capping is that the telomere acts in a way comparable to an aglet, which is the end of a shoelace. Federal government websites often end in .gov or .mil. PMC Biol 1992;225:95160. Kras mutations; chemoresistance; lung cancer; telomerase; telomere. 2. This response does not require the telomeres to shorten. The site is secure. This site needs JavaScript to work properly. Federal government websites often end in .gov or .mil. 2009;6:201205. Before We also showed that a kind of DNA damage response was elicited, as might be predicted because the telomeres were expected to become uncapped. The rapid response of telomerase-positive cancer cells to an abrupt depletion of their telomerase despite the lack of telomere uncapping prompted the hypothesis that these effects were unrelated to telomere maintenance or telomere function. Such a phospho-profile, termed profile II, cannot fully respond to DNA damage; accumulated p53 remains inactive and does not trigger transcription of its target genes upon stimulus, as compared to the standard phospho-profile I. Nosrati M, Li S, Bagheri S, et al. Liutkeviciene R, Mikalauskaite R, Gedvilaite G, Glebauskiene B, Kriauciuniene L, emaitien R. Medicina (Kaunas). Yu GL, Bradley JD, Attardi LD, Blackburn EH. 3). Armando R, Cabrera M, Vilarullo R, Chinestrad P, Maggio J, Paderta C, Lorenzano Menna P, Gomez D, Mengual Gmez D. Oncol Rep. 2022 Nov;48(5):188. doi: 10.3892/or.2022.8403. sharing sensitive information, make sure youre on a federal Cell Senescence Clipboard, Search History, and several other advanced features are temporarily unavailable. Ornish D, Lin J, Chan JM, Epel E, Kemp C, Weidner G, Marlin R, Frenda SJ, Magbanua MJM, Daubenmier J, Estay I, Hills NK, Chainani-Wu N, Carroll PR, Blackburn EH. The Calu-3-KrasG12D xenograft mouse model confirmed that BIBR1532 enhanced the antitumor efficacy of paclitaxel in vivo. Thus, there exists a puzzle that the abundant telomerase activity is apparently not there to make long telomeres. Targeting KRAS in NSCLC: Old Failures and New Options for "Non-G12c" Patients. While increased telomerase activity could bring youth to aging cells and cure premature aging-like diseases, too much of a good thing can be damaging for the individual. Wolkowitz OM, Mellon SH, Lindqvist D, Epel ES, Blackburn EH, Lin J, Reus VI, Burke H, Rosser R, Mahan L, Mackin S, Yang T, Weiner M, Mueller S. Psychiatry Res. . Tornesello ML, Cerasuolo A, Starita N, Tornesello AL, Bonelli P, Tuccillo FM, Buonaguro L, Isaguliants MG, Buonaguro FM. 2020 Feb;60:17-24. doi: 10.1016/j.gde.2020.02.003. Keywords: He X, Qiao Q, Ge N, Nan J, Shen S, Wang Z, Yang Y, Bao G. BMC Cancer. We did these experiments in a manner that made the test of the effects as stringent as possible because we did not include a drug selection step after infecting the cells with the lentiviral vectors. 2003 Nov-Dec;2(6):679-84. These observations lead us to investigate the most efficient means of inhibiting telomerase in cancer cells. 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