Telomerase Reverse Transcriptase Expression Research Articles

Transcriptional analysis links B cells and TERT expression to favorable prognosis in head and neck cancer.

Telomerase reverse transcriptase (TERT) is a conserved self-tumor antigen overexpressed in ∼85% of tumor cells and is immunogenic in cancer patients. The effect of TERT expression on the regulation of intratumor adaptive immunity has not yet been investigated. We used RNA sequencing data from The Cancer Genome Atlas (TCGA) in 11 solid tumor types to investigate potential interactions between TERT expression, and B and T cell infiltrate in the tumor microenvironment. We found a positive correlation between TERT expression, B and T cells in four cancer types with the strongest association in head and neck squamous cell carcinoma (HSNCC). In HNSCC a Bhigh/TERThigh signature was associated with improved progression-free survival (PFS) (P = 0.0048). This effect was independent of HPV status and not shared in comparable analysis by other conserved tumor antigens (NYESO1, MUC1, MAGE, and CEA). Bhigh/TERThigh HNSCC tumors also harbored evidence of tertiary lymphoid structure (TLS) such as signatures for germinal center (GC) and switched memory B cells, central memory CD4 and effector memory CD8 T cells. Bhigh/TERThigh HNSCC tumors also showed an up-regulation of genes and pathways related to B and T cell activation, proliferation, migration, and cytotoxicity, while factors associated with immunosuppression and cancer cell invasiveness were down-regulated. In summary, our study uncovers a new association between high TERT expression and high B cell infiltrate in HNSCC, suggesting a potential benefit from therapeutic strategies that invigorate intratumor TERT-mediated T-B cooperation.

Association of the Telomerase Reverse Transcriptase rs10069690 Polymorphism with the Risk, Age at Onset and Prognosis of Triple Negative Breast Cancer.

Telomerase reverse transcriptase (TERT) plays a key role in the maintenance of telomere DNA length. The rs10069690 single nucleotide variant, located in intron 4 of TERT, was found to be associated with telomere length and the risk of estrogen receptor-negative but not-positive breast cancer. This study aimed at analysis of the association of rs10069690 genotype and TERT expression with the risk, age at onset, prognosis, and clinically and molecularly relevant subtypes of breast cancer. Accordingly, rs10069690 was genotyped in a hospital-based case-control study of 403 female breast cancer patients and 246 female controls of a Central European (Austrian) study population, and the mRNA levels of TERT were quantified in 106 primary breast tumors using qRT-PCR. We found that in triple-negative breast cancer patients, the minor rs10069690 TT genotype tended to be associated with an increased breast cancer risk (OR, 1.87; 95% CI, 0.75-4.71; p = 0.155) and was significantly associated with 11.7 years younger age at breast cancer onset (p = 0.0002), whereas the CC genotype was associated with a poor brain metastasis-free survival (p = 0.009). Overall, our data show that the rs10069690 CC genotype and a high TERT expression tended to be associated with each other and with a poor prognosis. Our findings indicate a key role of rs10069690 in triple-negative breast cancer.

The impact of moderate endurance exercise on cardiac telomeres and cardiovascular remodeling in obese rats.

Hypercaloric nutrition and physical inactivity cause obesity, a potential driver of myocardial apoptosis and senescence that may accelerate cardiac aging. Although physical activity reduces mortality, its impact on myocardial aging is insufficiently understood. Here we investigated the effects of a hypercaloric high-fat diet (HFD) and regular exercise training on cardiac cells telomeres and histomorphometric indices of cardiac aging. Ninety-six 4-months old female Sprague-Dawley rats were fed for 10 months normal (ND) or a HFD diet. Half of the animals in each group performed 30 min treadmill-running sessions on 5 consecutive days per week. At study end, cardiomyocyte cross-sectional area (CSA), interstitial collagen content, vascular density, apoptotic and senescent cells, relative telomere length (RTL), and expression of telomerase-reverse transcriptase (Tert) as marker of telomere-related senescence and apoptosis were analyzed. Compared to ND, the HFD group developed obesity, higher CSA, lower capillary density and tended to have more apoptotic cardiomyocytes and interstitials cells. Myocardial RTL and the expression of Terf-1 and Terf-2 were comparable in sedentary HFD and ND animals. In the HFD group, regular moderate endurance exercise improved myocardial vascularization, but had no effect on CSA or apoptosis. Notably, the combination of exercise and HFD increased senescence when compared to sedentary ND or HFD, and reduced RTL when compared to exercise ND animals. Exercising HFD animals also showed a trend toward higher Tert expression compared to all other groups. In addition, exercise reduced Terf-1 expression regardless of diet. HFD-induced obesity showed no effects on myocardial telomeres and induced only mild morphologic alterations. Summarized, long-term moderate endurance exercise partially reverses HFD-induced effects but may even trigger cardiac remodeling in the context of obesity.

Imaging telomerase reverse transcriptase expression in oligodendrogliomas using hyperpolarized δ-[1-13C]-gluconolactone.

Telomere maintenance by telomerase reverse transcriptase (TERT) is essential for immortality in most cancers, including oligodendrogliomas. Agents that disrupt telomere maintenance such as the telomere uncapping agent 6-thio-2'-deoxyguanosine (6-thio-dG) are in clinical trials. We previously showed that TERT expression in oligodendrogliomas is associated with upregulation of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway (PPP). We also showed that hyperpolarized δ-[1-13C]-gluconolactone metabolism to 6-phosphogluconate (6-PG) can be used to probe the PPP in glioblastomas. The goal of this study was to determine whether hyperpolarized 13C imaging using δ-[1-13C]-gluconolactone can monitor TERT expression and response to 6-thio-dG in oligodendrogliomas. We examined patient-derived oligodendroglioma cells and orthotopic tumors to assess the link between TERT and hyperpolarized δ-[1-13C]-gluconolactone metabolism. We performed in vivo imaging to assess the ability of hyperpolarized δ-[1-13C]-gluconolactone to report on TERT and response to 6-thio-dG in rats bearing orthotopic oligodendrogliomas in vivo. Doxycycline-inducible TERT silencing abrogated 6-PG production from hyperpolarized δ-[1-13C]-gluconolactone in oligodendroglioma cells, consistent with the loss of G6PD activity. Rescuing TERT expression by doxycycline removal restored G6PD activity and, concomitantly, 6-PG production. 6-PG production from hyperpolarized δ-[1-13C]-gluconolactone demarcated TERT-expressing tumor from surrounding TERT-negative normal brain in vivo. Importantly, 6-thio-dG abrogated 6-PG production at an early timepoint preceding MRI-detectable alterations in rats bearing orthotopic oligodendrogliomas in vivo. These results indicate that hyperpolarized δ-[1-13C]-gluconolactone reports on TERT expression and early response to therapy in oligodendrogliomas. Our studies identify a novel agent for imaging tumor proliferation and treatment response in oligodendroglioma patients.

The TERT Promoter: A Key Player in the Fight for Cancer Cell Immortality

The review describes the role of telomeres and telomerase in tumor progression, as well as various mechanisms of the activation of telomerase reverse transcriptase (TERT) expression in CNS tumors and other cancers. The main mechanism of TERT activation involves acquisition of somatic mutations by the TERT gene promoter (TERTp). The article presents information on the TERTp structure and transcription factors directly interacting with TERTp and regulating its transcription. The prospects of using the mutational status of TERTp as a prognostic marker of CNS malignancies and other tumors with a common profile of TERTp mutations are discussed.

Alternative telomere maintenance mechanism in Alligator sinensis provides insights into aging evolution

Lifespan is a life-history trait that undergoes natural selection. Telomeres are hallmarks of aging, and shortening rate predicts species lifespan, making telomere maintenance mechanisms throughout different lifespans a worthy topic for study. Alligators are suitable for the exploration of anti-aging molecular mechanisms, because they exhibit low or even negligible mortality in adults and no significant telomere shortening. Telomerase reverse transcriptase (TERT) expression is absent in the adult Alligator sinensis, as in humans. Selection analyses on telomere maintenance genes indicated that ATM, FANCE, SAMHD1, HMBOX1, NAT10, and MAP3K4 experienced positive selection on A.sinensis. Repressed pleiotropic ATM kinase in A.sinensis suggests their fitness optimum shift. In ATM downstream, Alternative Lengthening of Telomeres (ALT)-related genes were clustered in a higher expression pattern in A.sinensis, which covers 10-15% of human cancers showing no telomerase activities. In summary, we demonstrated how telomere shortening, telomerase activities, and ALT contributed to anti-aging strategies.

IL-1 TERT PROMOTER C228T MUTATION IN NEURAL PROGENITORS CONFERS GROWTH ADVANTAGE FOLLOWING TELOMERE SHORTENING IN VIVO

Abstract Heterozygous TERT (Telomerase reverse transcriptase) promoter mutations (TPMs) facilitate TERT expression and are the most frequent mutation in glioblastoma (GBM). A recent analysis revealed this mutation is one of the earliest events in gliomagenesis, however no appropriate human models have been engineered to study the role of this mutation in the initiation of these tumors. To address this, we established GBM models by introducing the heterozygous TPM in human induced pluripotent stem cells (hiPSCs) using a two-step targeting approach in the context of GBM genetic alterations, CDKN2A/B and PTEN deletion, and EGFRvIII overexpression. Orthotopic injection of neuronal precursor cells (NPCs) derived from hiPSCs with TPM into immunodeficient mice did not enhance tumorigenesis compared to TERT promoter wild type (TPW) NPCs at initial in vivo passage which we attribute to relatively long telomeres. We further show that the TPM mutation recruited GA-Binding Protein (GABPA) and engendered low-level TERT expression, resulting in enhanced tumorigenesis upon secondary passage and maintenance of short telomere length as has been reported in human GBM. RNA sequencing of harvested tumors grown as secondary spheres demonstrated upregulated proliferation and mitosis pathway signatures in TPM cells, consistent with their increased in vitro proliferation relative to TPW counterparts. Finally, when secondary TPM and TPW sphere cultures were reinjected into mice, only the TPM led to tumor formation. In summary, our novel GBM model illustrates a growth advantage imparted by heterozygous TPMs in the context of GBM driver mutations relative to isogenic controls, and thereby allows for the identification and validation of TERT promoter-specific vulnerabilities in a genetically accurate background.

TMET-20. TERT ACTS VIA FOXO1 TO ALTER REDOX METABOLISM IN BRAIN TUMORS

Abstract Telomere maintenance is a fundamental hallmark of cancer. Most tumors maintain telomere length via reactivation of telomerase reverse transcriptase (TERT) expression. Identifying imaging biomarkers of TERT can enable non-invasive assessment of tumor proliferation and response to therapy. Deuterium magnetic resonance spectroscopy (DMRS) following administration of 2H-labeled substrates recently emerged as a novel, clinically translatable method of monitoring metabolic activity in vivo. The goal of this study was to delineate metabolic reprogramming associated with TERT expression and to leverage this information for non-invasive imaging of tumor burden and treatment response in gliomas. Our results indicate that TERT expression is associated with elevated levels of the redox metabolite NADH in glioblastomas and oligodendrogliomas. Mechanistically, TERT expression is associated with inhibitory phosphorylation and cytosolic sequestration of FOXO1. FOXO1, in turn, negatively regulates nicotinamide phosphoribosyl transferase (NAMPT), which is the rate-limiting enzyme in NAD+ biosynthesis. As a result, TERT upregulates NAMPT, resulting in elevated steady-state pools of NAD+ and NADH. Concomitantly, FOXO1 negatively regulates the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase, which converts NAD+ to NADH. As a result, TERT upregulates the NADH/NAD+ ratio. Since elevated NADH and NADH/NAD+ ratio drive pyruvate conversion to lactate, we then examined whether DMRS-based imaging of [U-2H]-pyruvate metabolism reports on TERT expression in gliomas. Our results indicate that doxycycline-inducible TERT silencing significantly reduces lactate production from [U-2H]-pyruvate in tumor-bearing mice. Importantly, [U-2H]-pyruvate metabolism to lactate differentiates tumor from normal brain in vivo, including at clinical field strength (3T). Furthermore, [U-2H]-pyruvate reports on early response to treatment with TERT inhibitors or with radiochemotherapy in mice bearing orthotopic patient-derived gliomas at early timepoints before radiographic alterations can be visualized by magnetic resonance imaging. Collectively, our studies integrate a mechanistic understanding of TERT biology with innovative imaging that has the potential to improve assessment of tumor burden and treatment response for glioma patients.

Thyroid carcinoma-featured telomerase activation and telomere maintenance: Biology and translational/clinical significance.

Telomerase is a ribonucleoprotein complex consisting of a catalytic component telomerase reverse transcriptase (TERT), internal RNA template and other co-factors, and its essential function is to synthesize telomeric DNA, repetitive TTAGGG sequences at the termini of linear chromosomes. Telomerase is silent in normal human follicular thyroid cells, primarily due to the TERT gene being tightly repressed. During the development and progression of thyroid carcinomas (TCs), TERT induction and telomerase activation is in general required to maintain telomere length, thereby conferring TC cells with immortal and aggressive phenotypes. The genomic alterations of the TERT loci including TERT promoter's gain-of-function mutations, copy number gain, fusion and rearrangements, have recently been identified in TCs as mechanisms to induce TERT expression and to activate telomerase. Importantly, numerous studies have consistently shown that TERT promoter mutations and TERT expression occur in all TC subtypes, and are robustly associated with TC malignancy, aggressiveness, treatment failure and poor outcomes. Therefore, the assessment of TERT promoter mutations and TERT expression is highly valuable in TC diagnostics, prognosis, treatment decision, and follow-up design. In addition, the TERT promoter is frequently hypermethylated in TC cells and tumors, which is required to activate TERT transcription and telomerase. Dysregulation of other components in the telomerase complex similarly upregulate telomerase. Moreover, shortened telomeres lead to altered gene expression and metabolism, thereby actively promoting TC aggressiveness. Here we summarize recent findings in TCs to provide the landscape of TC-featured telomere/telomerase biology and discuss underlying implications in TC precision medicine. Mechanistic insights into telomerase activation and TERT induction in TCs are important both biologically and clinically. The TERT gene aberration and expression-based molecular classification of TCs is proposed, and for such a purpose, the standardization of the assay and evaluation system is required. Moreover, the TERT-based system and 2022 WHO TC classification may be combined to improve TC care.

An oncolytic virus as a promising candidate for the treatment of radioresistant oral squamous cell carcinoma

We evaluated the usefulness of an oncolytic virus (Suratadenoturev; OBP-301) against radioresistant oral squamous cell carcinoma. We confirmed the expression of human telomerase reverse transcriptase and the coxsackievirus and adenovirus receptor in cell lines. Also, we examined the potential presence in a patient who has received existing therapy that is amenable to treatment with OBP-301. We evaluated: (1) the antitumor effects of OBP-301 alone and in combination with radiotherapy on radioresistant cell lines, (2) the molecular mechanism underlying the radiosensitizing effect and cell death increased by the combination therapy, and (3) the antitumor effect of the combination therapy invivo using xenograft models (a radioresistant cell line-derived xenograft in mouse and a patient-derived xenograft). Human telomerase reverse transcriptase and the coxsackievirus and adenovirus receptor were expressed in all cell lines. OBP-301 decreased the proliferative activity of these cell lines in a concentration-dependent manner, and significantly enhanced the antitumor effect of irradiation. Phosphorylated STAT3 and its downstream molecules, which correlated with apoptosis and autophagy, showed significant changes in expression after treatment with OBP-301. The combination therapy exerted a significant antitumor effect versus radiotherapy alone in both xenograft models. Combination of OBP-301 with radiotherapy exerts a synergistic effect and may represent a promising treatment for radioresistant oral squamous cell carcinoma.

Telomerase Reverse Transcriptase and Telomerase RNA Component Gene Expression as a Novel Biomarkers for Alzheimer's disease.

Alzheimer's disease (AD) is a neurological, age-related condition that causes cognitive decline and memory loss; it induces dementia in the elderly. Telomerase is a reverse transcriptase ribonucleoprotein that adds nucleotides to the end of DNA. This study aimed to compare human telomerase reverse transcriptase (hTERT) and telomerase RNA component (TERC) expression in different phases of AD and healthy cohorts. Sixty participants were divided into 30 who had dementia and 30 who did not. After collecting blood samples, total RNAs were extracted from the plasma. Screening for hTERT and TERC gene expression was carried out by quantitative reverse transcriptase real-time polymerase chain reaction (RT-qPCR) using the relative quantification method to estimate the expression changes in hTERT and TERC. The RT-qPCR results show that hTERT and TERC gene expression was significantly down-regulated in Alzheimer's patients compared to the health subjects (P-value= <0.0001,0.005), respectively. The area under curve AUC was 0.773 for hTERT and 0.703 for TERC. The Mini-Mental State Examination scores revealed a significant difference between dementia and non-dementia subjects (P=<0.0001). We conclude down-regulations in both hTERT and TERC gene expression in AD patients, which supports our hypothesis that the telomerase expression gene in the blood of AD patients can serve as a non-invasive, early, and novel diagnostic marker of AD.

Identification of rs2736099 as a novel cis-regulatory variation for TERT and implications for tumorigenesis and cell proliferation.

Lung cancer is a malignant tumor with obvious genetic predisposition. Association studies have proposed that rs2853677, a SNP localizing at intron region of TERT (telomerase reverse transcriptase), is significantly associated with TERT expression, telomere length and eventually lung cancer risk. However, functional genomics work indicates that rs2853677 is not with the ability to alter gene expression. All these facts make us hypothesize that some other genetic variation(s) are in linkage disequilibrium (LD) with rs2853677 and influence TERT expression. LD pattern in rs2853677 nearby region was analyzed based on 1000 genomes data for three representative populations in the world and functional genomics research was performed for this locus. Only one SNP, rs2736099, is in strong LD with rs2853677 in East Asian. Dual-luciferase reporter assay verifies that rs2736099 can regulate gene expression and should be the causal SNP for this disease. Through chromosome conformation capture assay, it is disclosed that the enhancer surrounding rs2736099 can interact with TERT promoter. Through chromatin immunoprecipitation, the transcription factor SP1 (Sp1 transcription factor) is recognized for the chromatin segment spanning rs2736099. Our results provide the missing piece between genetic variation at this locus and lung cancer risk, which is also applied to tumorigenesis in other tissues and cell proliferation.

Monitoring of telomere dynamics in peripheral blood leukocytes in relation to colorectal cancer patients' outcomes.

We investigated the possible associations between leukocyte telomere length, therapy outcomes, and clinicopathological features in patients with colorectal cancer. Additionally, telomerase reverse transcriptase (TERT) expression was evaluated. Telomere length was measured using singleplex qPCR in 478 consecutive leukocyte DNA samples from 198 patients. Blood was drawn at diagnosis prior to any therapy and then at 6-month intervals for 18 months. Following diagnosis, the telomeres gradually shortened during the course of the treatment regardless of the patient’s age. The most pronounced decrease was observed 12 months after the diagnosis (p < 0.0001). Based on tumor localization, the decrease in telomere length one year after the diagnosis followed different trajectories (p = 0.03). In patients treated with adjuvant therapy, telomere length correlated with the time elapsed after completion of therapy (p = 0.03). TERT expression did not correlate with the telomere length; however, it was higher in women than men (1.35-fold, 95% CI 1.11–1.65, p = 0.003) and in smokers than non-smokers (1.27-fold, 95% CI 1.01–1.61, p = 0.04). Leukocyte telomere length declines naturally during aging, but the accelerated shortening observed in our patients was age-independent. Telomere length manifestly reflected chemotherapy impact and could be linked to therapy toxicity.

Exercise regulates shelterin genes and microRNAs implicated in ageing in Thoroughbred horses

Ageing causes a gradual deterioration of bodily functions and telomere degradation. Excessive telomere shortening leads to cellular senescence and decreases tissue vitality. Six proteins, called shelterin, protect telomere integrity and control telomere length through telomerase-dependent mechanisms. Exercise training appears to maintain telomeres in certain somatic cells, although the underlying molecular mechanisms are incompletely understood. Here, we examined the influence of a single bout of vigorous exercise training on leukocyte telomerase reverse transcriptase (TERT) and shelterin gene expression, and the abundance of three microRNAs (miRNAs) implicated in biological ageing (miRNA-143, -223 and -486-5p) in an elite athlete and large animal model, Thoroughbred horses. Gene and miRNA expression were analysed using primer-based and TaqMan Assay qPCR. Leukocyte TRF1, TRF2 and POT1 expression were all significantly increased whilst miR-223 and miR-486-5p were decreased immediately after vigorous exercise (all p < 0.05), and tended to return to baseline levels 24 h after training. Relative to the young horses (~ 3.9 years old), middle-aged horses (~ 14.8 years old) exhibited reduced leukocyte TERT gene expression, and increased POT1 and miR-223 abundance (all p < 0.05). These data demonstrate that genes transcribing key components of the shelterin-telomere complex are influenced by ageing and dynamically regulated by a single bout of vigorous exercise in a large, athletic mammal — Thoroughbred horses. Our findings also implicate TERT and shelterin gene transcripts as potential targets of miR-223 and miR-486-5p, which are modulated by exercise and may have a role in the telomere maintenance and genomic stability associated with long-term aerobic training.

Angiotensin-(1–7) Restores Microcirculation Profiles in Acute Pancreatitis

The aim of this study was to investigate whether angiotensin (Ang)-(1-7)-mediated restoration of pancreatic microcirculation profiles and endothelial injury is associated with the expression of telomerase reverse transcriptase (TERT). Wild-type, TERT transgene, and TERT knockdown mice were used in this study, and acute pancreatitis model was induced by intraperitoneal injection of cerulein and lipopolysaccharide (LPS). Pancreatitis was confirmed by histopathology and serum amylase levels. Pancreatic microcirculation function was assessed by laser Doppler. Endothelial injury model was established by exposing endothelial cells to LPS. Proinflammatory cytokines were detected using enzyme-linked immunosorbent assay, endothelial permeability was detected using transwell assay, and mitochondrial dysfunction and mitochondrial reactive oxygen species (mtROS) were determined by performing confocal microscopy. The effects of Ang-(1-7) in the treatment of pancreatic microcirculation dysfunction were associated with TERT expression. In addition, Ang-(1-7) protected against endothelial cell lesions via inhibiting the increase in endothelial cell permeability and release of proinflammatory cytokines in a TERT-dependent manner. Furthermore, TERT was involved in Ang-(1-7)-mediated attenuation of mitochondrial dysfunction and mtROS in LPS-induced endothelial cells. Angiotensin-(1-7) restores pancreatic microcirculation profiles and reverses endothelial injury by inhibiting mtROS production and mitochondrial dysfunction in a TERT-dependent manner.

Selected Articles from This Issue

MOXR0916 is an agonist antibody that targets the OX40 receptor. Ligation of OX40 provides costimulatory signals to effector T cells and functional inhibition of regulatory T cells. Here, Kim and colleagues demonstrated the safety of MOXR0916 in patients with solid tumors with no dose-limiting toxicities observed. Serial tumor biopsies demonstrated limited evidence of immune activation in a heterogeneous population. Minimal antitumor activity was observed in indication-specific expansion cohorts enrolled at the recommended dose of 300 mg every 3 weeks selected based on projected tumor OX40 receptor saturation. Therefore, clinical proof-of-concept for OX40 agonism was not demonstrated by this phase I study. Whether combination with established agents with complementary mechanisms of action, such as anti-PD-L1, or whether an alternative approach to targeting the OX40 receptor can achieve more compelling efficacy remains to be determined.Outcomes for patients with locally recurrent head and neck squamous cell carcinoma (HNSCC) remain poor. Although salvage surgery is currently the standard of care, surgery fails to achieve disease control in more than half of patients. To date, no adjuvant therapy has been shown to provide survival benefit after salvage resection. Here, Leddon and colleagues report the results of a phase II open-labeled trial of adjuvant nivolumab after salvage resection for recurrent HNSCC. They found that adjuvant nivolumab was well tolerated. Two-year disease-free survival after following adjuvant nivolumab was 71.4%, which is significantly longer than a historical control sample with similar baseline characteristics. Further study in randomized controlled trials is warranted to establish clinical efficacy.Telomere maintenance is essential for uncontrolled tumor proliferation. Most tumors maintain telomere length via reactivation of telomerase reverse transcriptase (TERT) expression. Identifying clinically translatable imaging biomarkers of TERT has the potential to enable noninvasive assessment of tumor proliferation and response to therapy. Batsios and colleagues utilized deuterium metabolic imaging following administration of deuterated pyruvate to noninvasively monitor TERT expression in tumor-bearing mice in vivo. Importantly, lactate production from deuterated pyruvate is a biomarker of early response to therapy, prior to anatomical alterations, thereby providing clinicians with a novel tool for assessment of tumor proliferation and treatment response in cancer.Perineural invasion (PNI) occurs frequently in oral squamous cell carcinoma. However, diagnostic criteria of PNI vary and its role as an independent predictor of prognosis has not been established. Schmitd and colleagues reveal that PNI is an important predictor of prognosis among patients with no lymph node metastasis. Moreover, patients with nerves closer to the tumor have poor outcomes even if diagnosed as PNI-negative using current criteria. Consistent with clinical findings, spatial transcriptomic analysis of nerves in sections of human tumors shows a gradient of gene expression that is dependent on nerve-tumor distance. Together, these findings support broadening the definition of PNI to make it more clinically relevant. Moreover, the transcriptomic data reveal an injury response to the tumor; mechanisms involved in response to stress and growth are upregulated in nerves proximal to cancer. Understanding how these mechanisms contribute to clinical outcomes is crucial for developing new treatment strategies that reduce tumor recurrence.

Transcriptional modulation of inflammation, and aging in Indian obese adults following a 12-week yoga-based lifestyle intervention: A randomized controlled trial.

IntroductionObesity is one of the major global problems in today's world, both in children, and the adult age group. Current evidence suggests obesity alters the expression of various genes related to oxidative stress, inflammation, and aging. In recent times complementary therapy like yoga-based lifestyle intervention (YBLI) is used as an adjunct therapy to modern medicine. This study examines the efficacy of 12 weeks of yoga-based lifestyle intervention with standard care (SC) on the expression of genes related to oxidative stress, inflammation, and aging in obese adults.MethodsThis was a two-arm parallel randomized control trial implemented at Integral Health Clinic (IHC), an outpatient facility that regularly conducted YBLI programs for the prevention of lifestyle diseases like obesity and diabetes in the Department of Physiology, All India Institute of Medical Sciences (AIIMS), New Delhi. Blood samples at baseline and weeks 2,4, and 12 were collected from 72 adults (male n = 21; female n = 51) of age 20–45 years with a body–mass index (BMI) of 25–35 kg/m2 who were randomized to receive either a 12-week SC (n = 36) or YBLI (n = 36). SC included recommendations for the management of obesity as per Indian guidelines including a low-calorie individualized diet and physical activity. Asana (physical postures), pranayama (breathing exercises), and meditation were all part of the YBLI. Primary outcomes were relative fold change in the expression of genes associated with oxidative stress [Nuclear factor-kappa B (NF-Kappa B)], inflammation [Tumor necrosis factor-α (TNFα), interleukin-6 (IL-6)], and aging [human telomerase reverse transcriptase (TERT)] in peripheral blood mononuclear cells between the two groups at week-12.ResultsThere were no significant changes in fold change of TERT, IL-6, and NF-kappa B between the groups at week 12. The relative fold change of TERT was significantly greater in the YBLI group (p = <0.0001) vs the SC group at 2 weeks. The relative fold change of TNF α was significantly lower at week 12 in YBLI though the change was not continuous and reliable. Within both groups, TERT expression was significantly increased at week 2 though the change was greater in the YBLI group (p < 0.0001). TNF α gene expression was significantly lower at weeks 2 and 4, compared to baseline level, in the SC group but it increased at week 12.ConclusionThe results while did not confirm our hypothesis, are important to share with the scientific society, to be able to improve prospective study designs and find optimal time/intervention/biological marker settings for this highly important scientific field. The results are suggestive of a positive impact of YBLI and SC on the fold change of aging-related TERT gene in obesity, though the benefit was not evident till week 12. However, the results should be evaluated with caution and in light of other published studies. To better understand the positive effects of YBLI on oxidative stress, inflammation, and aging-related gene expression in obesity, larger studies are recommended.

PPARγ activation inhibits PDGF-induced pulmonary artery smooth muscle cell proliferation and migration by modulating TERT.

Vascular remodeling is a significant feature of pulmonary artery hypertension (PAH), and is characterized by abnormal proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs). Telomerase reverse transcriptase (TERT), as a determining factor for controlling telomerase activity, has been proven to be associated with cell proliferation. This study aims to explore whether TERT mediates the proliferation and migration of PASMCs and the underlying molecular mechanism. Primary PASMCs from Sprague-Dawley (SD) rats were used in this experiment. Cell proliferation and migration were evaluated by Cell Counting Kit-8, EdU incorporation assay and transwell assay, respectively. Telomerase activity was assessed with a rat TE ELISA kit. Small interfering RNA (siRNA) transfection was conducted to silence c-MYC expression. The protein levels of p-Akt, c-MYC, PPARγ and TERT were determined through western blotting. Our work demonstrates that PDGF upregulated TERT expression and telomerase activation by activating Akt and upregulating of c-MYC in PASMCs. Inhibition of Akt with LY294002, knockdown of c-MYC by siRNA or suppression of telomerase activity with BIBR1532 repressed PDGF-induced PASMC proliferation and migration. Furthermore, activation of peroxisome proliferator-activated receptor γ (PPARγ) with pioglitazone suppressed PDGF-induced TERT expression and telomerase activation, leading to inhibition of PASMC proliferation and migration.

Telomere Attrition With Concomitant hTERT Overexpression Involved in the Progression of Gastric Cancer May Have Prognostic and Clinical Implications in High-Risk Population Group From North India.

Genetic instabilities exacerbated by the dysfunction of telomeres can lead to the development of cancer. Nearly 90% of all human malignancies are linked with telomere dysregulation and overexpression of telomerase, an enzyme that catalyzes the synthesis of telomeric DNA repeats at the ends of chromosomes. The burden of gastric cancer continues to inflict a deterring impact on the global health scenario, accounting for over one million new cases in 2020. The disease is asymptomatic in its early stages of progression, which is attributed to the poor prognosis and overall surge in mortality rate worldwide. Exploiting telomere physiology can provide extensive mechanistic insight into telomere-associated gastric cancer progression and its use as a target in a variety of therapeutic interventions. In this study, we aimed to evaluate the clinical implications of c-Myc, human telomerase reverse transcriptase (hTERT) expression, and telomere length in patients with gastric cancer. A total of 57 gastric cancer cases and adjacent controls were included in the study. RT-PCR and immunohistochemistry were used to assess the expression levels of c-Myc and hTERT. The relative telomere length was measured by MMQPCR using the Cawthon method. Our results indicated that the shorter telomere and increased hTERT expression were associated with gastric cancer progression. The study also highlighted the role of short telomeres and increased expression of hTERT in gastric cancer progression and its association with various etiological risk factors, transcriptional activators, and overall survival among the ethnic Kashmiri population of North India.

Abstract 2302: The pan-cancer regulator of the mutant TERT promoter and a new model of the GABP-TERT axis

Abstract Ninety percent of human tumors reactivate telomerase reverse transcriptase (TERT) to achieve cellular immortality. The route to immortality found in over 50 cancer types is mutation of the TERT promoter (TERTp) mutations. Studies in glioblastoma have shown the two most common TERTp mutations, G228A and G250A, reactivate TERT expression through de novo E26 transformation specific (ETS) site generation that, in tandem with a native TERTp ETS site, recruits the tetrameric GA-binding protein (GABP) complex formed by two GABP alpha (GABPA) subunits and two tetramer specific GABPB1 (B1) subunits, GABPB1L (B1L). While ten additional TERTp mutations have been described across cancer types, functional studies have been limited to select mutations and cancer types. We found that each de novo ETS motif generating TERTp mutation increases TERTp transcriptional activity in a GABP-dependent manner. Furthermore, our pan-cancer analysis demonstrated selective enrichment of GABPA at the mutant TERTp across 14 cancer types and further determined that this recruitment is necessary for TERT expression. Prior investigations found that CRISPR-cas9 mediated mutagenesis of the B1 ninth exon, specific to B1L, reduces TERT transcriptional activity in a TERTp-mutation dependent manner. We explored B1L targeting in the reversal of tumor cell immortality in several cancers. We found that the B1 dimer restricted isoform, GABPB1S (B1S), is consistently and significantly increased following B1L reduction, which we determined to be the consequence of a disengagement of a GABP tetramer mediated negative feedback loop acting on the B1 promoter. Interestingly, this upregulated B1S expression enables GABP dimer binding and activation of the mutant TERTp thereby compensating for B1L loss. Indeed, knockout of B1L and B1S together resulted in a near complete elimination of GABPA TERTp recruitment and a striking reduction in TERT expression, leading to telomere shortening and ultimately resulting in tumor cell death and senescence. This data identifies GABP as the master regulator of the mutant TERTp across cancer type and de novo ETS mutation type and suggests a new model of the GABP-TERT axis involving both the GABP tetramer, and the GABP dimer. Citation Format: Nicholas O. Stevers, Carter Barger, Olivia Lenzo, Chibo Hong, Katarzyna Soczek, Samuel H. Wu, Andrew M. McKinney, Abigail Suwala, Jennifer A. Doudna, Joseph F. Costello. The pan-cancer regulator of the mutant TERT promoter and a new model of the GABP-TERT axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2302.