Telomerase Reverse Transcriptase Research Articles

TERT promoter mutations in gliomas: Molecular roles in tumorigenesis, metastasis, diagnosis, prognosis, therapeutic targeting, and drug resistance.

Telomerase reverse transcriptase (TERT), a critical player in cellular immortalization, has emerged as a focal point of investigation due to its frequent promoter mutations in various human malignancies. TERT promoter mutations exhibit a significant role in tumorigenesis, fostering unbridled cellular proliferation and survival. This comprehensive review delves into the landscape of TERT promoter mutations and their profound implications in cancer, particularly within the context of gliomas. This article meticulously examines the intricate interplay between TERT promoter mutations and the metastatic cascade, shedding light on their capacity to orchestrate invasive behavior in gliomas. Moreover, this review describes the recent trends in therapeutic targeting of the TERT and dissects the evolving landscape of drug resistance associated with TERT mutations, providing insights into potential therapeutic challenges. In addition, the diagnostic and prognostic implications of TERT promoter mutations in gliomas are scrutinized, unraveling their potential as robust biomarkers. It also discusses the recent advancements in molecular diagnostics, illustrating the promise of TERT mutations as diagnostic tools and prognostic indicators. This review collectively aims to contribute to a deeper understanding of TERT promoter mutations in gliomas, offering a foundation for future research endeavors and paving the way for innovative strategies in glioma management.

Beginning at the ends: telomere and telomere-based cancer therapeutics.

Telomeres, which are situated at the terminal ends of chromosomes, undergo a reduction in length with each cellular division, ultimately reaching a critical threshold that triggers cellular senescence. Cancer cells circumvent this senescence by utilizing telomere maintenance mechanisms (TMMs) that grant them a form of immortality. These mechanisms can be categorized into two primary processes: the reactivation of telomerase reverse transcriptase and the alternative lengthening of telomeres (ALT) pathway, which is dependent on homologous recombination (HR). Various strategies have been developed to inhibit telomerase activation in 85-95% of cancers, including the use of antisense oligonucleotides such as small interfering RNAs and endogenous microRNAs, agents that simulate telomere uncapping, expression modulators, immunotherapeutic vaccines targeting telomerase, reverse transcriptase inhibitors, stabilization of G-quadruplex structures, and gene therapy approaches. Conversely, in the remaining 5-15% of human cancers that rely on ALT, mechanisms involve modifications in the chromatin environment surrounding telomeres, upregulation of TERRA long non-coding RNA, enhanced activation of the ataxia telangiectasia and Rad-3-related protein kinase signaling pathway, increased interactions with nuclear receptors, telomere repositioning driven by HR, and recombination events between non-sister chromatids, all of which present potential targets for therapeutic intervention. Additionally, combinatorial therapy has emerged as a strategy that employs selective agents to simultaneously target both telomerase and ALT, aiming for optimal clinical outcomes. Given the critical role of anti-TMM strategies in cancer treatment, this review provides an overview of the latest insights into the structure and function of telomeres, their involvement in tumorigenesis, and the advancements in TMM-based cancer therapies.

The role of telomere shortening in ambient ozone exposure-related insulin resistance

BackgroundOzone (O3) exposure and telomere shortening are associated with insulin resistance (IR). However, the role of telomere shortening in ambient O3 exposure-related IR is largely unclear. MethodsThe Henan Rural Cohort recruited participants and performed a random forest method to estimate residential O3 concentration. IR was reflected by homeostasis model assessment-IR, quantitative insulin sensitivity check index, triglyceride and glucose index, etc. Generalized linear model, quantile regression model, and mediation effects analysis were utilized to assess the associations of O3 exposure and relative telomere length (RTL) with longitudinal IR markers and their change rates. Furthermore, the role of telomere homeostasis in O3-exposure-induced IR in vivo and in vitro experiments was verified. ResultsO3 exposure was positively associated with longitudinal IR. The proportions of RTL mediated associations between O3 exposure and longitudinal IR markers ranged from 11.92% to 60.36%. O3-exposed mice exhibited a higher glucose load, upregulation of GSK-3β and G-6-Pase expression at mRNA levels, glycogen accumulation reduction, telomere shortening, and decreased telomerase reverse transcriptase activity relative to air-exposed mice. In vitro experiments reveal that overexpression of TERT in HepG2 cells up-regulated G-6-Pase mRNA expression level. ConclusionsImpaired telomere homeostasis may be involved in O3 exposure-related IR via inhibition of glycogen synthesis and acceleration of gluconeogenesis and the specific mechanisms are still further elucidated.

Inhibition of the E3 ligase UBR5 stabilizes TERT and protects vascular organoids from oxidative stress

BackgroundExcessive oxidative stress is known to cause endothelial dysfunction and drive cardiovascular diseases (CVD). While telomerase reverse transcriptase (TERT) shows protective effects against oxidative stress in rodents and is associated to human flow-mediated dilation in CVD, its regulatory mechanisms in human vascular systems under pathological oxidative stress require further investigation.MethodsHuman induced pluripotent stem cells (hiPSCs) were used to create vascular organoids (VOs). These VOs and human umbilical vein endothelial cells (HUVECs) were subjected to oxidative stress through both hydrogen peroxide (H2O2) and oxidized low-density lipoprotein (oxLDL) models. The effects of TERT overexpression by inhibition of the ubiquitin protein ligase E3 component N-recognin 5 (UBR5) on reactive oxygen species (ROS)-induced vascular injury and cellular senescence were assessed using neovascular sprouting assays, senescence-associated β-galactosidase (SA-β-Gal) staining, and senescence-associated secretory phenotype (SASP) assays.ResultsROS significantly impaired VO development and endothelial progenitor cell (EPC) angiogenesis, evidenced by reduced neovascular sprouting and increased senescence markers, including elevated SA-β-Gal activity and SASP-related cytokine levels. Overexpression of TERT counteracted these effects, restoring VO development and EPC function. Immunoprecipitation-mass spectrometry identified UBR5 as a critical TERT regulator, facilitating its degradation. Inhibition of UBR5 stabilized TERT, improving VO angiogenic capacity, and reducing SA-β-Gal activity and SASP cytokine levels.ConclusionsInhibiting UBR5 stabilizes TERT, which preserves EPC angiogenic capacity, reduces VO impairment, and delays endothelial cell senescence under oxidative stress. These findings highlight the potential of targeting UBR5 to enhance vascular health in oxidative stress-related conditions.Graphical

Transcription factor AP-4 reactivates telomerase reverse transcriptase independently of genome alteration in non-HBV associated hepatocellular carcinoma

Recurrent genome alterations have been identified in the telomerase reverse transcriptase (TERT) promoter region, a common occurrence in various types of cancer. In addition to epigenetic alterations at the TERT promoter region, the recruitment of transcription factors to this region, which potentially drives the reactivation of TERT gene transcription in human hepatocellular carcinoma (HCC) remains unknown. In this study, using in-silico DNA binding sequence analysis at the TERT promoter and with confirmation with dual luciferase reporter and chromatin immunoprecipitation assays, we found that Transcription Factor AP-4 (TFAP4) physically interacted with the TERT promoter, driving telomerase reactivation. Furthermore, TFAP4 mRNA is upregulated in human HCCs and positively correlates with TERT mRNA expression, according to TCGA-LIHC database, our in-house clinical samples, and HCC cell lines. Interestingly, the knockdown of TFAP4 only suppressed TERT expression levels and telomere length in HCC cells which are not associated with HBV infection. Additionally, we identified that the CCCTC-binding factor (CTCF) physically interacted with the TFAP4 promoter, leading to induced TFAP4 gene transcription in HCC. Clinically, TFAP4 mRNA expression significantly correlated with TERT mRNA expression in alcohol-related HCCs, but not in HBV-associated HCCs, according to TCGA-LIHC cohort. Consistently, ethanol enhanced both TFAP4 and TERT mRNA expression in non-HBV-associated HCC cells but not HBV-associated HCC cells. In conclusion, our findings demonstrate that TFAP4 directly regulates TERT gene transcription via CTCF in non-HBV-associated HCCs. However, its role in regulating telomerase expression or activity through HBV DNA integration in HBV-associated cells might be limited.

H. Pylori-Facilitated TERT/Wnt/β-Catenin Triggers Spasmolytic Polypeptide-Expressing Metaplasia and Oxyntic Atrophy.

Persistent H. pylori infection triggers the repair program of the mucosa, such as spasmolytic polypeptide-expressing metaplasia (SPEM). However, the mechanism underlying the initiation of SPEM in gastric tissues by H. pylori remains unclear. Here, an increase in telomerase reverse transcriptase (TERT) protein expression is observed in chief cells upon infection with cagA-positive H. pylori. Tert knockout significantly ameliorated H. pylori-induced SPEM and single-cell RNA sequencing demonstrated that the Wnt/β-Catenin pathway is suppressed in gastric cells with Tert knockout. Mechanism study revealed that CagA elevated TERT abundance by disrupting the interaction between TERT and its novel E3 ligase, SYVN1. Interestingly, Nitazoxanide effectively relieved SPEM via inhibition of the Wnt/β-Catenin signaling in vivo. This results clarified the mechanism underlying which CagA activated the TERT/Wnt/β-Catenin pathway, thus promoting the dedifferentiation of chief cells and the occurrence of SPEM in gastric mucosa. This highlights a molecular basis for targeting CagA-activated Wnt signaling in chief cells for the treatment of gastric precancerous lesions.

The Annexin A1 Protein Mimetic Peptide Ac2-26 prevents cellular senescence of CHON-001 chondrocytes against tumor necrosis factor-α via the Nrf2/NF-κB pathway.

Osteoarthritis (OA) is a degenerative joint disorder characterized by progressive cartilage degradation. Excessive oxidative stress (OS), inflammatory responses, extracellular matrix breakdown, and cellular senescence of chondrocytes play crucial roles in the pathological development of OA. Currently, curing OA remains a significant challenge. In this study, we aimed to elucidate the protective effects of Annexin A1 protein Mimetic Peptide (Ac2-26) against tumor necrosis factor-α (TNF-α)-induced damage in CHON-001 chondrocytes by assessing cellular senescence, OS, and the expression levels of matrix metalloproteinase-13 (MMP-13) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4. Our results show that Ac2-26 mitigated the reduction of telomerase activity and the exacerbation of cellular senescence induced by TNF-α in CHON-001 chondrocytes. Treatment with TNF-α led to decreased expression of the human telomerase reverse transcriptase gene and increased expression of the telomeric repeat-binding factor 2 gene, which were reversed by Ac2-26 treatment. The TNF-α-induced increases in the gene and protein expressions of p53 and p16 were restored by Ac2-26 in a dose-dependent manner. Additionally, we found that TNF-α caused elevations in the mRNA and protein levels of MMP-13 and ADAMTS-4, which were reduced by Ac2-26 in a dose-dependent fashion. Furthermore, TNF-α triggered the activation of nuclear factor κ-B (NF-κB) by increasing the levels of phosphorylated NF-κB p65 and the luciferase activity of NF-κB. Notably, Ac2-26 alleviated OS by reducing mitochondrial reactive oxygen species levels and promoting the activation of NF-E2-related factor 2 (Nrf2) in TNF-α-challenged CHON-001 chondrocytes. Silencing Nrf2 abolished the Ac2-26-induced activation of NF-κB and cellular senescence in CHON-001 chondrocytes. Collectively, these findings offer new insights into the potential therapeutic use of Ac2-26 for treating OA.

Maternal infection of SARS-CoV-2 during the first and second trimesters leads to newborn telomere shortening

BackgroundInitial telomere length (TL) in newborns is the major determinant for TL in later life while TL in newborn/early-life predicts long-term health and lifespan. It is important to identify key factors that affect telomere homeostasis throughout embryonic development for precision interventions to maintain optimal TL in fetus/prenatal infants. SARS-CoV-2 has caused a widespread global pandemic of COVID-19, but it remains unclear whether maternal SARS-CoV-2 infection impairs prenatal telomere homeostasis.MethodsWe recruited 413 normally delivered newborns whose mothers were either non-infected or infected with SARS-CoV-2 during different trimesters of pregnancy (otherwise healthy). Telomere length (TL) in cord blood (CB) was assessed using qPCR. CB and maternal blood were analyzed for cytokine levels. Placental senescence was determined using senescence-associated β-galactosidase staining.ResultsControl (non-infected maternal) newborn TL was significantly longer than that from maternal infection (1.568 ± 0.340 vs 1.390 ± 0.350, P = 0.005). Such shorter TL was observed only if maternal infection of SARS-CoV-2 occurred in the first and second trimesters of pregnancy (1.261 ± 0.340 and 1.346 ± 0.353, P < 0.0001 and 0.001, respectively). There were no differences in TL between controls and infection at the third trimester (1.568 ± 0.340 vs 1.565 ± 0.329, P > 0.05). Across the first trimester, there was a positive correlation between newborn TL and gestational weeks with maternal infection, suggesting that the earlier maternal infection occurs, the worse effect is taken on fetal telomere homeostasis. Placental senescence coupled with the downregulated expression of telomerase reverse transcriptase was significantly more frequent from the maternal infection at the first trimester. There were no differences in IL-6, C reactive protein and other cytokine levels in CB and maternal serum or placentas.ConclusionsMaternal SARS-CoV-2 infection at the first and second trimesters leads to significantly shorter TL and earlier infection causes much more severe TL damage. The infection-mediated cell senescence and other histopathological abnormalities result in defective placental function through which fetal telomere homeostasis is impaired. Thus, vaccination against COVID-19 should be done in advance for women who plan pregnancy.

Association between TERT gene polymorphisms (rs2736100 and rs2736109) and breast cancer risk in the Iranian population: A case-control study

BackgroundThe level of hormones and genetic predispositions increase the risk of breast cancer. Genetic variations in the genes of the telomere pathway, which can influence the activity of telomerase, may be decisive for the development of breast cancer. Due to a lack of studies on TERT gene polymorphisms (rs2736100 and rs2736109) in the Iranian population, in this study we investigated the association of these polymorphisms with breast cancer in the Iranian population. Patients & methodsA total of 300 individuals participated in this research, which included 150 breast cancer patients and 150 healthy controls. Participants' blood samples were collected before the beginning of treatment. The RFLP-PCR procedure was used for the genotyping of TERT gene rs2736109 and rs2736100 polymorphisms. ResultsThere are statistically significant differences in the age of menarche and the age of menopause (P-value <0.05). For rs2736100, the frequency of TT genotype in the case and control groups was 22.7 % and 16.7 %, respectively. However, these differences were not statistically significant (P-value >0.05). For rs2736109, the frequency of the AA genotype was lower in the case group (12.0 % vs. 19.3 %). These differences reach a statistically significant level (P-value = 0.012). Individuals carrying AA genotype have a lower risk of suffering from breast cancer (odds ratio = 0.403, 95 % CI: 0.196–0.827). ConclusionOur findings suggest that the rs27326109 polymorphism in the TERT gene is associated with a decreased risk of breast cancer. Also this study reveals that age of menarche and age of menopause are associated with risk of this disease.

TERT mutations and aggressive histopathologic characteristics of radioiodine-refractory papillary thyroid cancer.

Radioiodine (RI) ablation following thyroid-stimulating hormone suppression is an effective treatment for papillary thyroid cancer (PTC), typically leading to favorable outcomes. However, RI-refractory tumors exhibit aggressive behavior and poor prognoses. Recent studies highlight the role of genetic abnormalities in PTC signaling pathways, including the activation of telomerase reverse transcriptase (TERT), and the correlation of mutations with adverse outcomes. This study analyzed mutations in BRAF V600E and the TERT-promoter genes, comparing clinicopathological features between RI-refractory and RI-responsive PTCs. Among 82 RI-refractory patients, formalin-fixed, paraffin-embedded tissues from initial surgeries were available for 26. Another 89 without distant metastasis over 5 years formed a matched RI-responsive control group. Histopathologically, RI-refractory PTCs showed increased frequencies of small tumor clusters without fibrovascular cores, hobnail features, and a high height-to-width ratio of tumor cells. These tumors were more likely to exhibit necrosis, mitosis, lymph node metastasis, extrathyroidal extension, and involvement of resection margins. TERT-promoter mutations were statistically significantly associated with these aggressive clinicopathologic features. Immunohistochemically, decreased expression of sodium iodide symporter and thyroglobulin stimulating hormone receptor proteins was common in RI-refractory PTCs, along with lower levels of oncogenic proteins such as vascular endothelial cell growth factor, vascular endothelial cell growth factor receptor 2, and nuclear factor kappa-light-chain-enhancer of activated B cells. Total loss of PTEN expression was occasionally observed. In contrast, all cases tested positive for cytoplasmic β-catenin. RI-refractory PTCs are linked to TERT mutations and exhibit specific aggressive histopathologic features, particularly in tumor centers.

Immortalized mammosphere-derived epithelial cells retain a bioactive secretome with antimicrobial, regenerative, and immunomodulatory properties

BackgroundThe secretome of primary bovine mammosphere-derived epithelial cells (MDECs) has been shown to exert antimicrobial, regenerative, and immunomodulatory properties in vitro, which warrants its study as a potential biologic treatment with the potential to be translated to human medicine. Currently, the use of the MDEC secretome as a therapy is constrained by the limited life span of primary cell cultures and the decrease of secretome potency over cell passages.MethodsTo address these limitations, early-passage bovine MDECs were immortalized using hTERT, a human telomerase reverse transcriptase. The primary and immortal MDECs were compared morphologically, transcriptomically, and phenotypically. The functional properties and proteomic profiles of the secretome of both cell lines were evaluated and compared. All experiments were performed with both low and high passage cell cultures.ResultsWe confirmed through in vitro experiments that the secretome of immortalized MDECs, unlike that of primary cells, maintained antimicrobial and pro-migratory properties over passages, while pro-angiogenic effects of the secretome from both primary and immortalized MDECs were lost when the cells reached high passage. The secretome from primary and immortalized MDECs, at low and high passages exerted immunomodulatory effects on neutrophils in vitro.ConclusionsHigh passage immortalized MDECs retain a bioactive secretome with antimicrobial, regenerative, and immunomodulatory properties, suggesting they may serve as a consistent cell source for therapeutic use.

Molecular profiling reveals novel therapeutic targets and clonal evolution in ovarian clear cell carcinoma

BackgroundOvarian clear cell carcinoma (OCCC) has a disproportionately high incidence among women in East Asia. Patients diagnosed with OCCC tend to experience worse clinical outcomes than those with high-grade serous carcinoma (HGSC) at advanced stages. The unfavorable prognosis of OCCC can be partly attributed to its frequent resistance to conventional chemotherapy. Within a precision medicine framework, we sought to provide a comprehensive molecular characterization of OCCC using whole-exome sequencing to uncover potential molecular targets that may inform novel therapeutic strategies.MethodsWe performed whole-exome sequencing analysis on tumor-normal paired samples from 102 OCCC patients. This comprehensive genomic characterization of a substantial cohort of OCCC specimens was coupled with an analysis of clonal progression.ResultsOn analyzing 102 OCCC samples, ARID1A (67%) and PIK3CA (49%) emerged as the most frequently mutated driver genes. We identified tier 1 or 2 clinically actionable molecular targets in 40% of cases. This included DNA mismatch repair deficiency (n = 1), as well as BRCA2 (n = 1), PIK3CA (n = 36), KRASG12C (n = 1), and ATM (n = 4) mutations. Furthermore, 45% of OCCC samples displayed ARID1A biallelic loss. Interestingly, we identified previously unreported mutations in the 5’ untranslated region of the TERT gene that harbored an adverse prognostic significance. Clock-like mutational processes and activated APOBECs were major drivers of somatic point mutations. Mutations arising from DNA mismatch repair deficiency were uncommon. Reconstruction of clonal evolution revealed that early genetic events likely driving tumorigenesis included mutations in the ARID1A, PIK3CA, TERT, KRAS, and TP53 genes.ConclusionsOur study provides a comprehensive characterization of the genomic landscape and clonal evolution in OCCC within a substantial cohort. These findings unveil potentially actionable molecular alterations that could be leveraged to develop targeted therapies.

Effects of Glutamine or Glucose Deprivation on Inflammation and Tight Junction Disruption in Yak Rumen Epithelial Cells.

Yak is a special free-ranging cattle breed in the plateau areas of Qinghai and Tibet. Pasture withering in cold-season pastures results in energy deficiency in yaks, which undermines the rumen epithelial barrier. However, the leading factor causing rumen epithelial injury remains unknown. Glutamine (Gln), a conditionally essential amino acid, is insufficient under pathological conditions. Glucose (GLU) is an important energy source. Thus, we explored the effects of Gln or GLU deprivation on the barrier function of yak rumen epithelial cells and investigated the underlying mechanisms, as well as the differences in rumen epithelial barrier function between Gln deprivation (Gln-D) and GLU deprivation (GLU-D). In previous work, we constructed the yak rumen epithelial cells (YRECs) line by transferring the human telomerase reverse transcriptase gene (hTERT) and simian virus 40 large T antigen (SV40T) into primary YRECs. The YRECs were exposed to normal, Gln-D, GLU-D, and serum replacement (SR) media for 6, 12, and 24 h. Our data displayed that cell viability and tight junction protein expression in the SR group were not significantly changed compared to the normal group. Whereas, compared with the SR group, Gln-D treated for more than 12 h reduced cell viability and proliferation, and GLU-D treated for more than 12 h damaged the cell morphology and reduced cell viability and proliferation. The cell proliferation and cell viability were decreased more in GLU-D than in Gln-D. In addition, Gln-D treated for more than 12 h disrupted YREC cellular partially tight junctions by inducing oxidative stress and inflammation, and GLU-D treated for more than 12 h disrupted YREC cellular tight junctions by inducing apoptosis, oxidative stress, and inflammation. Compared with Gln-D, GLU-D more significantly induced cell injury and reduced tight junction protein levels. Our results provided evidence that GLU-D induced damage through the p38 mitogen-activated protein kinase (p38 MAPK)/c-junN-terminal kinase (JNK) signaling pathway, which was more serious than Gln-D treated for more than 12 h.

EXTH-68. EPIGENETIC EDITING BY MRNA-BASED CRISPROFF ENABLES FLEXIBLE AND DURABLE TARGETING OF GLIOBLASTOMA DRIVERS MGMT AND TERT

Abstract Alterations in cis-regulatory elements, such as hypomethylation of the O-6-methylguanine-DNA methyltransferase (MGMT) promoter and activating mutations within the telomerase reverse transcriptase (TERT) promoter, are pervasive drivers of glioblastoma (GBM) tumorigenesis that are challenging to target. CRISPRoff is an engineered CRISPR/Cas9 system that can potently and heritably silence cis-regulatory elements through DNA methylation. Here, we develop an mRNA-based CRISPRoff platform to target the MGMT and TERT promoters in GBM, and we establish proof-of-principal in vivo targeting through lipid nanoparticles (LNP). Epigenetic editing in GBM cells and primary GBM organoids was performed using either electroporation or LNP encapsulation of CRISPRoff mRNA and sgRNAs. Target gene silencing and functional phenotypes were assessed by bisulfite sequencing, RT-qPCR, RNA-seq, western blot, cell viability/apoptosis, and telomere restriction fragment assays. In vivo efficacy was demonstrated using intracranial GBM xenografts, first through transplantation of cells with CRISPRoff delivered ex vivo, then with direct delivery of LNPs using convection enhanced delivery (CED) coupled with immunofluorescence/ immunohistochemistry. CRISPRoff targeting of MGMT promoter resulted in &amp;gt;99% reduction in MGMT expression in MGMT unmethylated primary GBM organoids, inducing up to 150-fold sensitization to temozolomide. Temozolomide sensitization was retained after intracrania transplantation, and silencing was durable in clonally isolated GBM cells continuously passaged for over 8 months after transient delivery of CRISPRoff. CRISPRoff targeting of the TERT promoter in primary GBM cultures harboring the G228A TERT promoter mutation silenced TERT expression by up to 99%, overcoming constitutive activation of TERT, and induced telomere shortening sufficient for complete replicative senescence. CED of mRNAs encapsulated by LNPs based on cKK-E12 or Lipid A9 resulted in tumor-selective uptake of mRNA transcripts, establishing a foundation for direct delivery of CRISPRoff in vivo bypassing the blood-brain-barrier. In summary, we establish a flexible and durable epigenetic editing system against multiple regulatory elements driving GBM, leveraging LNPs with potential for in vivo application.

CTNI-73. ASSESSMENT OF MOLECULAR ALTERATIONS IN NEWLY DIAGNOSED GBM MGMT-UNMETHYLATED PATIENTS TREATED WITH VAL-083

Abstract Glioblastoma (GBM) commonly features molecular alterations in the TERT, EGFR, PTEN, and TP53 genes, which contributes to uncontrolled cell growth, evasion of apoptosis, and enhanced tumor cell survival. VAL-083 is a bi-functional DNA-targeting agent which rapidly induces inter-strand DNA cross-links at N7 and O6-guanine inducing double-strand breaks causing cell death independently of MGMT DNA repair and DNA mismatch repair deficiency. VAL-083 was evaluated in an open-label, biomarker-driven, phase 2 trial in MGMT-unmethylated, bevacizumab-naïve GBM patients. The molecular profile of tumors from a newly diagnosed GBM patient subgroup who received VAL-083 alone after chemo-radiation with concurrent TMZ, was determined in order to correlate with clinical outcomes. Thirty-four (34/36, 94.4%) patients who received 30 mg/m2 VAL-083 (days 1-3 of 21-day cycle) had available next-generation sequencing data on their primary tissue. Patient median age was 54.8 years (5-95pth: 29.8-66.0), median KPS was 90 (5-95pth: 80-100) and 58.8% were males. The median number of cycles of VAL-083 was 7.5 (5-95pth: 1-12). There were 5 dose reductions due to toxicity. The median time to progression (PFS) and overall survival (OS) were 9.2 mo (95%CI: 7.6-10.2) and 16.5 mo (95%CI: 13.3-19.0), respectively. The mean number of molecular alterations was 3.9 (5-95pth 1-8). Six (17.6%) patients had gene fusions. The most common molecular alterations were TERT promoter (91.2%), EGFR amplification (amp) (52.9%), PTEN (50.0%), EGFR (20.6%), and TP53 (20.6%). Additional alterations (in ≥2 patients; 6%) included EGFR-EGFR (EGFRvIII), BRCA2, CDKN2A/B, CDK4/6 amp, MDM2/4 amp, NF1, NOTCH1, PIK3R1 and RB1. While TP53 mutations showed a trend as predictors for time to progression (P 0.027), this was not observed with OS. None of the molecular alterations were predictors of number of treatment cycles or dose reductions. No specific molecular alterations were identified that predicted either improved or poorer patient outcome, during treatment with VAL-083. Clinicaltrials.gov identifier: NCT02717962.

TERT Gene Mutation in Gliomas Cross-Linked With (NTRK, PDL1, ALK, IDH, P53, EGFR, HER2): A Integrative Review TERT Gene Mutation in Gliomas.

Recent advancements in glioma treatment are largely driven by the identification of genetic alterations, which enhance diagnostic precision and prognostic assessments, and unveil potential therapeutic targets. TERT promoter mutations, in particular, are associated with a poorer prognosis and aggressive clinical behavior. This study explores the genetic interplay between TERT and other genes (ntrk, pdl1, alk, idh, p53, egfr, her2) in brain tumors through an integrative literature review. This method synthesizes evidence from selected articles spanning 2014 to 2023. The review identified 65 articles based on defined inclusion criteria, out of which 14 were analyzed in depth. Findings reveal that TERT, TP53, and IDH1 are the most frequently mutated genes in gliomas. The prognosis of glioma patients can be refined through the combined analysis of IDH and TERT mutations. Additionally, PD-L1 expression levels are associated with prognosis and may influence treatment responses, particularly, in immunotherapy. The study underscores the importance of molecular diagnostics, such as Next-Generation Sequencing (NGS), in detecting key genetic mutations. These advancements have paved the way for new therapeutic strategies and better patient outcomes. The findings highlight the crucial role of genetic markers in glioma treatment and prognosis, advocating for continued research to enhance clinical applications and patient care. The use of NGS is indispensable in identifying biomarkers associated with mutations in the TERT gene.

The role of genetic and epigenetic modifications as potential biomarkers in the diagnosis and prognosis of thyroid cancer.

Thyroid cancer (TC) is the most common endocrine cancer, which contributes to more than 43,600 deaths and 586,000 cases worldwide every year. Among the TC types, PTC and FTC comprise 90% of all TCs. Genetic modifications in genes are responsible for encoding proteins of mitogen-associated protein kinase cascade, which is closely related with numerous cellular mechanisms, including controlling programmed cell death, differentiation, proliferation, gene expression, as well as in genes encoding the PI3K (phosphatidylinositol 3-kinase)/protein kinase B (AKT) cascade, which has contribution in controlling cell motility, adhesion, survival, and glucose metabolism, have been associated with the TC pathogenesis. Various genetic modifications including BRAF mutations, RAS mutations, RET mutations, paired-box gene 8/peroxisome proliferator-activated receptor-gamma fusion oncogene, RET/PTC rearrangements, telomerase reverse transcriptase mutations, neurotrophic tyrosine receptor kinase fusion genes, TP53 mutations, and eukaryotic translation initiation factor 1A X-linked mutations can effectively serve as potential biomarkers in both diagnosis and prognosis of TC. On the other hand, epigenetic modifications can lead to aberrant functions or suppression of a range of signalling cascades, which can ultimately result in cancer. Various studies have observed the link between epigenetic modification and multiple cancers including TC. It has been reported that several epigenetic alterations including histone modifications, aberrant DNA methylation, and epigenetic modulations of non-coding RNAs can play significant roles as potential biomarkers in the diagnosis and prognosis of TC. Therefore, a good understanding regarding the genetic and epigenetic modifications is not only essential for the diagnosis and prognosis of TC, but also for the development of novel therapeutics. In this review, most of the major TC-related genetic and epigenetic modifications and their potential as biomarkers for TC diagnosis and prognosis have been extensively discussed.

Mapping the evolving trend of research on leukocyte telomere length: a text-mining study

BackgroundSubstantial evidence indicates that measuring leukocyte telomere length (LTL) is a useful tool that may be considered as a valuable biomarker of individual biological age, correlating with numerous chronic disorders. However, to date, there has been a lack of in-depth understanding regarding the current landscape and forthcoming developments in the LTL field. Therefore, this study aimed to utilize bibliometric methods to summarize the knowledge structure, current focus, and emerging directions in this field.MethodScientific publications on LTL spanning the period from 2000 to 2022 were acquired from the Web of Science Core Collection database. Several bibliometric tools including CiteSpace, VOSviewer, and an online website were utilized for bibliometric analysis. The primary evaluations encompassed investigating the major contributors and their collaborative relationships among countries/regions, institutions, and authors, conducting co-citation analyses of authors, journals, as well as reference, examining reference bursts, as well as performing co-occurrence analyses of keywords.ResultsThere are 1818 papers with 66,668 citations identified. Both the annual publication and citation counts on LTL exhibited significant upward trends. The United States emerged as the most prominent contributor, as evidenced by the greatest volume of papers and the highest H-index value. University of California San Francisco and Aviv A were identified as the most productive institution and author in this domain, respectively. Reference analysis revealed that longitudinal study and mendelian randomization study are the most concerned research method in this field recently. Keywords analysis showed that the most concerned diseases in LTL fields were aging, inflammation, cardiovascular diseases, endocrine diseases, neurological and psychiatric diseases, and cancers. In addition, the following research directions such as “COPD”, “mendelian randomization”, “adiposity”, “colorectal cancer”, “National Health and Nutrition Examination Survey (NHNES)”, “telomerase reverse transcriptase”, “pregnancy” have garnered increasing attention in recent times and hold the potential to evolve into research foci in the foreseeable future.ConclusionThis is the first bibliometric study that provides comprehensive overview of LTL research. The findings of this study could become valuable references for investigators to explore and address the current and emerging challenges in LTL research.

Mitochondrial Oxidative Stress and Cardiac Dysfunction in TERT Knockout Mice

Abstract Background Heart failure (HF) is a major cause of hospitalization in the elderly, with its incidence increasing due to aging and associated risk factors like hypertension, diabetes, and myocardial fibrosis. Aging-related myocardial fibrosis, characterized by alterations in the extracellular matrix and myocardial structure, impairs cardiac function. Mitochondrial oxidative stress plays a pivotal role in cardiac electrical and structural remodeling, necessitating a deeper understanding of its involvement in aging-related heart failure. Purpose The purpose of this study is to investigate the mechanisms of aging-related ventricular electrical and structural remodeling by constructing an aging mouse model. This research aims to provide potential therapeutic targets for heart failure associated with aging. Methods We developed a third-generation homozygous telomerase reverse transcriptase (TERT) knockout mouse model. Comparing third-generation homozygous TERT knockout mice (F3 group) with age-matched wild-type males (WT group). The study encompassed blood pressure measurement, electrocardiographic analysis, echocardiography, ELISA for cardiac biomarkers, ventricular tissue electrophysiology, fibrosis assessment through staining, transcriptomic profiling via RNA-seq, and electron microscopy of ventricular mitochondria. Results Compared to the WT group, the F3 group demonstrated increased P53 and P16 protein expression. Decreased LVEF and FS, along with increased interventricular septum thickness, left ventricular diameter, and left ventricular volume. Elevated serum NT-pro-BNP and troponin I (cTnI) levels, with prolonged QRS duration. Decreased left and right ventricular conduction velocity, accompanied by increased conduction dispersion. Notable elevation in COLI, TGFβ, and α-SMA gene transcription and protein expression in ventricular tissue. Significant differences in mitochondrial oxidative stress signal pathways via RNA-seq analysis. Elevated serum MDA levels and decreased SOD levels, with up-regulated Mn-SOD gene transcription and protein expression, and down-regulated MFN2 and Drp1 gene transcription and protein expression in ventricular tissue. Electron microscopy revealed mitochondrial abnormalities such as loose arrangement, decreased number, swelling, vacuolation, and myofilament disintegration or breakage in the F3 group. Conclusion Third-generation TERT-/- senescent mice exhibit notable cardiac impairments, including electrical remodeling, structural changes, and mitochondrial dysfunction. These findings suggest a potential link between mitochondrial oxidative stress and aging-related heart failure, indicating novel therapeutic opportunities targeting mitochondrial dysfunction for managing such conditions.

The mechanism of NF-κB-TERT feedback regulation of granulosa cell apoptosis in PCOS rats.

Patients with Polycystic ovary syndrome (PCOS) have chronic low-grade ovarian inflammation. Inflammation can cause telomere dysfunction, and telomere and telomerase complex are also involved in regulating inflammation. However, the specific mechanisms of inflammatory signaling feedback and telomere-telomerase mutual regulation remain to be discovered. This study elucidates the role of Nuclear factor kappa-B (NF-κB)-Telomerase reverse transcriptase (TERT) feedback in PCOS granulosa cell apoptosis. Using letrozole and a high-fat diet, a PCOS rat model was established, along with a Lipopolysaccharide (LPS) -treated KGN cell inflammation model was established. NF-κB and TERT inhibitors (BAY 11-7082 and BIBR1532) were then administered to LPS-induced KGN cells. PCOS rats displayed disrupted estrous cycles, increased weight, elevated serum testosterone, cystic follicles, granulosa cell layer thinning, and reduced corpora lutea count (P are all less than 0.05). In PCOS rat ovaries, NF-κB, Interleukin-6 (IL-6), Tumor Necrosis Factor α (TNF-α), TERT, Bax, and Caspase-3 exhibited notable upregulation, while Bcl-2 decreased, with telomere elongation (P are all less than 0.05). There were significant correlations among NF-κB-related inflammatory factors, TERT and apoptotic factors, and they were positively correlated with Bax and Caspase-3, and negatively correlated with Bcl-2 (P are all less than 0.05). LPS-treated KGN cells demonstrated increased expression of inflammatory and pro-apoptotic factors, later restored post-treatment with NF-κB and TERT inhibitors (P are all less than 0.05). In conclusion, TERT may induce granulosa cell apoptosis by participating in the regulation of the NF-κB signaling pathway, thereby mediating the chronic inflammatory response of PCOS through downstream inflammatory factors IL-6 and TNF-α.