Telomerase Reverse Transcriptase Research Articles

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.

Injectable Gene/Fiber‐Plexes Reverse Adipose Niche Senescence via Mito‐TERT Activation by Endogenous Mitochondrial Translocation

AbstractAddressing adipose niche senescence is crucial for preventing obesity‐related aging. Telomerase reverse transcriptase (TERT) is a promising target for gene therapy, but traditional methods lack precision and safety. A novel mitochondrion‐located TERT (mito‐TERT) activating approach is presented by injectable gene/short‐fiber complexes (gene/fiber‐plexes) to safely reverse adipose niche senescence from mitochondrial enhancement. The gene/fiber‐plexes are prepared from polydopamine‐coated short‐fibers to adsorb cationic dendrimers (PAMAM G3, PG3) carrying TERT plasmids and Coenzyme Q10 (CoQ10), termed PG3‐TERT@CoQ10. Upon intraperitoneal injection, the gene/fiber‐plexes adhere to the peritoneum and release PG3‐TERT@CoQ10, precisely targeting the adipose niche. Transient active oxygen scavenging by CoQ10 activates TERT transfection and endogenous mitochondrion translocation sequentially, enhancing mitochondrial function. In vitro and in vivo studies shows that gene/fiber‐plexes effectively targeted visceral adipose tissue, increased mito‐TERT levels and restored mitochondrial function. In an obese mouse model, they restored adipose tissue homeostasis and metabolic stability. RNA sequencing indicated reduced senescence‐related genes and restored cell cycle. This mito‐TERT activation strategy shows great promise for treating premature aging and metabolic diseases linked to adipose tissue senescence.

Effect of obesity and NAFLD on leukocyte telomere length and hTERT gene MNS16A VNTR variant

It is known that telomere length (TL) (evaluated with T/S ratio) is shortened in the presence of obesity. In this study, we aimed to investigate how obesity in adolescents and non-alcoholic liver disease (NAFLD) within the obese group affect TL and the clinical significance of the human telomerase reverse transcriptase (hTERT) gene MNS16A VNTR variant in terms of NAFLD. Adolescents with exogenous obesity and healthy controls (aged 10–19 years) who applied to our adolescent outpatient clinic between May-October 2023 were included in this study. We performed upper abdominal ultrasonography to investigate the presence of NAFLD in adolescents with obesity and divided into two groups: those without hepatosteatosis (obese NAFLD (-)) and those with hepatosteatosis (obese NAFLD (+)). We recorded body weight, height, waist circumference, and blood pressure measurements and measured the T/S ratio (telomere sequence copy number/gene single copy number) by the Quantitative Polymerase Chain Reaction method. The groups were compared using frequentist and Bayesian methods. Eighty-three obese adolescents [63 NAFLD(+) 20 NAFLD(-)] and 69 lean controls were included in the study. Pairwise comparisons revealed that T/S ratio was significantly lower in the obese NAFLD (-) group than the obese NAFLD (+) and the control group (p = 0.025, p = 0.007, respectively). T/S ratio was lower in the LL allele group than in the other alleles (p = 0.022) and slightly higher in the obese group with metabolic syndrome compared to the obese group without metabolic syndrome (p = 0.072). hTERT-MNS16A-VNTR gene variant LL allele had a negative correlation with T/S ratio among the obese adolescent group. Patients with LL alleles had higher ALT, GGT, HOMA-IR, and ALT/AST. Diastolic blood pressure had a significant correlation with the T/S ratio. The T/S ratio was shorter in the obese adolescent group compared to healthy ones but was higher in the NAFLD (+) obese compared to the NAFLD (-) obese. ALT level and ALT/AST ratio were higher, T/S ratio was lower in the hTERT MNS16A VNTR variant LL allele group among obese adolescents. In addition, there was a significant correlation between the T/S ratio and diastolic blood pressure in obese adolescents.

Aged Gut Microbiome Induces Metabolic Impairment and Hallmarks of Vascular and Intestinal Aging in Young Mice.

Aging, an independent risk factor for cardiometabolic diseases, refers to a progressive deterioration in physiological function, characterized by 12 established hallmarks. Vascular aging is driven by endothelial dysfunction, telomere dysfunction, oxidative stress, and vascular inflammation. This study investigated whether aged gut microbiome promotes vascular aging and metabolic impairment. Fecal microbiome transfer (FMT) was conducted from aged (>75 weeks old) to young C57BL/6 mice (8 weeks old) for 6 weeks. Wire myography was used to evaluate endothelial function in aortas and mesenteric arteries. ROS levels were measured by dihydroethidium (DHE) staining and lucigenin-enhanced chemiluminescence. Vascular and intestinal telomere function, in terms of relative telomere length, telomerase reverse transcriptase expression and telomerase activity, were measured. Systemic inflammation, endotoxemia and intestinal integrity of mice were assessed. Gut microbiome profiles were studied by 16S rRNA sequencing. Some middle-aged mice (40-42 weeks old) were subjected to chronic metformin treatment and exercise training for 4 weeks to evaluate their anti-aging benefits. Six-week FMT impaired glucose homeostasis and caused vascular dysfunction in aortas and mesenteric arteries in young mice. FMT triggered vascular inflammation and oxidative stress, along with declined telomerase activity and shorter telomere length in aortas. Additionally, FMT impaired intestinal integrity, and triggered AMPK inactivation and telomere dysfunction in intestines, potentially attributed to the altered gut microbial profiles. Metformin treatment and moderate exercise improved integrity, AMPK activation and telomere function in mouse intestines. Our data highlight aged microbiome as a mechanism that accelerates intestinal and vascular aging, suggesting the gut-vascular connection as a potential intervention target against cardiovascular aging and complications.

Association between human telomerase reverse transcriptase (hTERT) MNS16A polymorphism and risk of breast cancer.

It is well known that telomerase activity is suppressed in normal human tissues and reactivated in tumors, suggesting that the human telomerase reverse transcriptase (hTERT, MIM: 187270) gene may be involved in carcinogenesis. A polymorphic tandem repeat minisatellite located downstream of exon 16 of hTERT and upstream in the putative promoter region of an antisense hTERT transcript, termed MNS16A, results in a functional polymorphism. Because the association between the MNS16A genetic polymorphism and breast cancer (BC) risk remains an open question, the present case-control study was conducted in Shiraz (Fars Province, Southern Iran). A total of 711 samples were collected, including 362 BC patients and 349 healthy individuals. Genotyping was performed by polymerase chain reaction method. Alleles were determined by classifying DNA amplicons of less than and greater than 300bp as short (S) and long (L) alleles, respectively. Different inheritance models (codominant, dominant, recessive, overdominant genotype models and the allele model) were used to evaluate the association between the MNS16A polymorphism and the risk of BC. No significant association was observed in any of the analyses. It should be noted that the statistical power of the comparisons was low. The present study did not support the association between hTERT MNS16A polymorphism and breast cancer risk. Similar studies in other populations with larger sample sizes are needed to determine the association between the hTERT MNS16A polymorphism and susceptibility to breast cancer.

Examining transfer of TERT to mitochondria under oxidative stress

The primary role of telomerase is the lengthening of telomeres. Nonetheless, emerging evidence highlights additional functions of telomerase outside of the nucleus. Specifically, its catalytic subunit, TERT (Telomerase Reverse Transcriptase), is detected in the cytosol and mitochondria. Several studies have suggested an elevation in TERT concentration within mitochondria in response to oxidative stress. However, the origin of this mitochondrial TERT, whether transported from the nucleus or synthesized de novo, remains uncertain. In this study, we investigate the redistribution of TERT, labeled with a SNAP-tag, in response to oxidative stress using laser scanning fluorescence microscopy. Our findings reveal that, under our experimental conditions, there is no discernible transport of TERT from the nucleus to the mitochondria due to oxidative stress.

TERT promoter mutations and survival outcomes in adult-type granulosa cell tumors

ObjectivesT0 evaluate survival outcomes among patients with adult-type granulosa cell tumors who have telomerase reverse transcriptase (TERT) promoter mutations.MethodsThis is a retrospective cohort study using the MD Anderson Rare Gynecologic...

Clinical and Histopathological Features of Thyroid Cancer with TERT Promoter Molecular Alterations in Isolation Versus with Concurrent Molecular Alterations: A Multicenter Retrospective Study

Background/Objectives: Molecular testing of thyroid nodules enables the detection of genetic alterations, which can help assess the risk of malignancy and tumor behavior. While telomerase reverse transcriptase (TERTp) mutations are known to be associated with aggressive disease, their exact prognostic significance when occurring alone or with other molecular alterations remains underreported. Methods: This study examined patients with thyroid cancer treated at two tertiary care hospitals from 2017 to 2024. We compared tumor behavior in patients with TERTp molecular alterations occurring alone and with concurrent molecular alterations. Aggressive histologic subtypes were defined as tall-cell, hobnail, and columnar variants of papillary carcinoma, as well as poorly differentiated and anaplastic carcinoma. High-risk disease was defined according to the 2015 ATA guidelines as gross extrathyroidal extension, lymph node metastasis >3 cm, postoperative elevated serum thyroglobulin, distant metastases, and/or positive resection margins. Statistical analysis was performed to assess differences between groups. Results: 30 patients with TERTp-positive thyroid malignancies were included. TERTp/BRAF V600E was the most prevalent mutation combination (n = 13, 43.3%), followed by TERTp alone (n = 8, 26.7%) and TERTp/RAS (n = 7, 23.4%). TERTp/EIF1AX/GNAS and TERTp/EIF1AX/PIK3CA were the least common combinations (n = 1, 3.3% each). Nodules with TERTp and concurrent mutations were significantly more likely to be classified as high-risk (p = 0.006) and were more frequently associated with aggressive histologic subtypes (p = 0.003) compared to those with TERTp mutations alone, which tended to exhibit more benign behavior. Conclusions: Thyroid carcinomas harboring both TERTp and concurrent molecular alterations are associated with more aggressive features and a higher likelihood of being classified as high-risk. In contrast, TERTp mutations occurring alone do not confer an elevated risk.

TERT promoter mutations contribute to adverse clinical outcomes and poor prognosis in radioiodine refractory differentiated thyroid cancer

Telomerase reverse transcriptase promoter (TERTp) mutations are associated with non-radioiodine avidity. However, the role of these mutations in the clinical outcomes of patients with radioiodine-refractory differentiated thyroid cancer (RAIR-DTC) remains unknown. Herein, we aim to analyze gene mutations and clinical manifestations to verify TERTp’s role in driving disease progression to RAIR-DTC and clinical outcomes. Next-generation sequencing data and clinical data were obtained from 243 patients with DTC. Of the 25 patients with TERTp mutations, 80% (20/25) had RAIR-DTC. RAIR-DTC was significantly less prevalent in patients with BRAFV600E (9/143, 6.3%) than those with both BRAFV600E and TERTp mutations (14/17, 82.4%). Patients with RAIR-DTC harboring both BRAFV600E and TERTp mutations were more likely to have > 3 distant metastatic sites (85.7%, 12/14) than those with BRAFV600E alone (33.3%, 3/9). Only one patient with both BRAFV600E and TERTp mutations had non-RAIR-DTC. The time from initial radioactive iodine therapy to RAIR-DTC diagnosis was significantly shorter in patients with TERTp mutations than in those without. Patients with BRAFV600E and TERTp mutations progressed faster to RAIR-DTC than those with BRAFV600E alone (p < 0.01). Our findings suggest that molecular testing for TERTp and other mutations like BRAFV600E may inform early diagnosis, prognosis, and treatment strategies before progression to RAIR-DTC.

Peripartum depression symptom trajectories, telomere length and genotype, and adverse childhood experiences

BackgroundAs a biological marker for cellular senescence, telomere length (TL) has been linked to a variety of psychiatric disorders and adverse childhood experiences (ACE), though only preliminarily to peripartum depression (PPD). The present study sought to examine the association between TL and PPD, assessing the moderating role of ACE and genetic polymorphic variations related with the telomere machinery.MethodsAdversity was self-reported, likewise were depressive symptoms evaluated at pregnancy week 17 and 32, as well as six-weeks and six-months postpartum. TL was assessed by use of qPCR in blood samples collected during delivery from females with antenatal depression resolving postpartum, females with depression persisting to postpartum, and healthy controls. Twenty haplotype-tagging Single Nucleotide Polymorphisms in the Telomerase Reverse Transcriptase (TERT) and three in the Telomerase RNA Component (TERC) genes were genotyped.ResultsTL was negatively correlated with severity of PPD symptoms at pregnancy week 32 and postpartum week 6. PPD was associated with shorter TL. Lastly, ACE, but not the TERT/TERC genotype, moderated the TL-trajectory association; with increasing ACE, individuals with persistent PPD symptoms had shorter TL, whereas the opposite pattern (longer TL) was observed in the controls.ConclusionsThe findings contribute to further understanding of PPD underpinnings, suggesting a negative relationship with TL.

Human pancreatic islet-derived stromal cells reveal combined features of mesenchymal stromal cells and pancreatic stellate cells.

Mesenchymal stromal cells (MSCs) are recognized for their potential in regenerative medicine, attributed to their multipotent differentiation capabilities and immunomodulatory properties. Despite this potential, the classification and detailed characterization of MSCs, especially those derived from specific tissues like the pancreas, remains challenging leading to a proliferation of terminology in the literature. This study aims to address these challenges by providing a thorough characterization of human pancreatic islets-derived mesenchymal stromal cells (hPD-MSCs). hPD-MSCs were isolated from donor islets using enzymatic digestion, immortalized through lentiviral transduction of human telomerase reverse transcriptase (hTERT). Cells were characterized by immunostaining, flow cytometry and multilineage differentiation potential into adipogenic and osteogenic lineages. Further a transcriptomic analysis was done to compare the gene expression profiles of hPD-MSCs with other mesenchymal cells. We show that hPD-MSCs express the classical MSC features, including morphological characteristics, surface markers expression (CD90, CD73, CD105, CD44, and CD106) and the ability to differentiate into both adipogenic and osteogenic lineages. Furthermore, transcriptomic analysis revealed distinct gene expression profiles, showing notable similarities between hPD-MSCs and pancreatic stellate cells (PSCs). The study also identified specific genes that distinguish hPD-MSCs from MSCs of other origins, including genes associated with pancreatic function (e.g., ISL1) and neural development (e.g., NPTX1, ZNF804A). A novel gene with an unknown function (ENSG00000286190) was also discovered. This study enhances the understanding of hPD-MSCs, demonstrating their unique characteristics and potential applications in therapeutic strategies. The identification of specific gene expression profiles differentiates hPD-MSCs from other mesenchymal cells and opens new avenues for research into their role in pancreatic function and neural development.

8078 TERT Positive Thyroid Nodule in the Setting of Metastatic Melanoma

Abstract Disclosure: E. Langnas: None. S. Chao: None. K.M. Gomes: None. A. Bhan: None. Metastatic disease to the thyroid gland is uncommon with a reported incidence of up to 4% in post-surgical specimens. Lung cancer is the most common primary tumor site in autopsy series. Clinically, renal cell carcinoma is the most common primary tumor site. Metastatic melanoma to the thyroid gland is clinically rare, however, in autopsy series, it has been reported with incidence of up to 39%. A 61-year-old man presented to the endocrinology clinic for an incidentally detected thyroid nodule. He had recently presented with a chronic cough, prompting a chest x-ray that revealed pulmonary nodules. Subsequent computed tomography (CT) showed numerous bilateral lung nodules measuring up to 2.5 cm and an incidental thyroid nodule. Ultrasound of the thyroid identified a 2.7 cm mixed cystic-solid right thyroid nodule. No risk factors for thyroid cancer were identified. His TSH was 3.51uIU (0.45 - 5.33 uIU/mL). The thyroid nodule was biopsied, and pathology revealed atypical spindle cells with irregular nuclear membranes and scattered histiocytes. A further review with cytopathology suggested non-thyroidal origin of the cells. Molecular testing with AFIRMA reported a telomerase reverse transcriptase (TERT) promoter mutation at C228T. The sequencing was negative for TERT C250T, BRAF, RET, PETC1, PTC3 and MTC. Due to concerns about metastatic disease, a positron-emission tomography (PET)-CT was conducted, revealing hypermetabolic lesions in numerous bilateral lung nodules, right thyroid nodule, porta hepatis lymph node, and a soft tissue nodule within the greater curvature of the gastric body. Subsequent biopsies of the right lung and gastric body confirmed the diagnosis of metastatic melanoma. On further questioning, it was found that the patient had a history of a skin lesion on his back that was excised several years ago with pathology reporting tumoral melanosis. Malignant melanoma has a poor prognosis due to high recurrence and metastatic rates. In melanoma, TERT promoter mutations are the most common mutations in noncoding regulatory regions. TERT C228T mutations and C250T mutations are seen in malignant melanoma and studies have shown that TERT promoter mutations are associated with aggressive clinical behavior. These TERT promoter mutations can also be seen in various other cancers including primary thyroid cancers with a similar association with more aggressive thyroid tumor characteristics. Our case describes a patient with a thyroid nodule and molecular testing noting a TERT promoter mutation. Both primary thyroid cancer and metastatic disease to the thyroid should be considered in these cases. This case also highlights the importance of obtaining a thorough history of prior malignancy in patients with thyroid nodules to assess the risk of metastatic disease. Presentation: 6/1/2024

The Evaluation of the Genetic Polymorphisms of TERT (rs2736100) and MUC5B (rs35705950) in Idiopathic Pulmonary Fibrotic patients

Background: Polymorphisms of the TERT and MUC5B genes have been consistently associated with idiopathic pulmonary fibrosis (IPF) in recent genome-wide genetic studies. In Iraq, we did not find research on the role of these polymorphisms in respiratory disorders, so we conducted this study to evaluate the genetic polymorphisms of TERT (rs2736100) and MUC5B (rs35705950) in IPF patients in Iraq. Method: The current study was a case-control study that included 70 patients who were diagnosed with IPF, in addition to, 70 healthy control groups who had no history or clinical evidence of IPF or asthma. blood samples from participants were obtained for DNA extraction, and T-ARMS-PCR was used to determine genetic polymorphisms of TERT (rs2736100) and MUC5B (rs35705950). Result: Current study showed that the mutant/minor homogenous genotype AA and allele A of TERT (rs2736100) appeared at a higher rate in patients (47% and 87% respectively) compared to control (38.5% and 53% respectively), as this indicator appeared as an effective factor (EF = 0.139 and 0.242 respectively), while the wild/major homogenous genotype CC and allele C were appeared in control at a rate of 38.5% and 50% respectively and in patients at rate 23% and 50% respectively. The results of MUC5B (rs35705950) G/T polymorphism showed that the mutant/minor TT genotype and T allele were associated with the occurrence of the disease (EF = 0.177 and 0.192 respectively) while the wild /major GG genotype and G allele appeared as a protective factor (PF= 0.243 and 0.375 respectively) for the control group. Moreover, most of the smoking patients were carriers of the mutant homogenous genotypes of TERT (rs2736100) and MUC5B (rs35705950). Conclusion: TERT (rs2736100) and MUC5B (rs35705950) polymorphisms are significantly associated with IPF, especially among smokers patients.

Cell Senescence and the Genetics of Melanoma Development.

Cutaneous malignant melanoma is an aggressive skin cancer with an approximate lifetime risk of 1 in 38 in the UK. While exposure to ultraviolet radiation is a key environmental risk factor for melanoma, up to ~10% of patients report a family history of melanoma, and ~1% have a strong family history. The understanding of causal mutations in melanoma has been critical to the development of novel targeted therapies that have contributed to improved outcomes for late-stage patients. Here, we review current knowledge of the genes affected by familial melanoma mutations and their partial overlap with driver genes commonly mutated in sporadic melanoma development. One theme linking a set of susceptibility loci/genes is the regulation of skin pigmentation and suntanning. The largest functional set of susceptibility variants, typically with high penetrance, includes CDKN2A, RB1, and telomerase reverse transcriptase (TERT) mutations, associated with attenuation of cell senescence. We discuss the mechanisms of action of these gene sets in the biology and progression of nevi and melanoma.

DCas9-HDAC8-EGFP fusion enables epigenetic editing of breast cancer cells by H3K9 deacetylation

Epigenetic editing is thriving as a robust tool for manipulating transcriptional regulation and cell fate. Despite its regulatory role in gene downregulation, epigenetic editing with histone deacetylation has been sparsely studied, especially in the context of cancer. In this current study, we have reconstructed a dCas9-HDAC8-EGFP fusion to perform histone deacetylation on the promoter of the ESR1, TERT and CDKN1C genes for the first time in breast cancer cell lines MCF-7 and MDA-MB-231 as well as in HEK293T cells. Our results demonstrated that dCas9-HDAC8-EGFP in combination with appropriate gRNAs were able to downregulate the expression of the ESR1, TERT and CDKN1C genes transcriptionally by specifically depleting the H3K9ac level on the recruitment loci. The addition of histone deacetylase inhibitors was found to neutralize the outcomes of dCas9-HDAC8-EGFP-induced epigenetic editing. Furthermore, we observed a significant downregulation of full length ERα expression in epigenetically edited MCF-7 cells with consequential alteration in cellular response toward estradiol and tamoxifen treatment due to dCas9-HDAC8-EGFP mediated epigenetic editing of the ESR1 gene. Overall, dCas9-HDAC8-EGFP is a novel circuit that enabled downregulation of crucial genes with cellular outcome in breast cancer cells by preferentially inducing H3K9 deacetylation of specific promoter regions.

TERT Expression and Clinical Outcome in Pulmonary Carcinoids.

The clinical course of pulmonary carcinoids ranges from indolent to fatal disease, suggesting that specific molecular alterations drive progression toward the fully malignant state. A similar spectrum of clinical phenotypes occurs in pediatric neuroblastoma, in which activation of telomerase reverse transcriptase (TERT) is decisive in determining the course of disease. We therefore investigated whether TERT expression defines the clinical fate of patients with pulmonary carcinoid. TERT expression was examined by RNA sequencing in a test cohort and a validation cohort of pulmonary carcinoids (n = 88 and n = 105, respectively). A natural TERT expression cutoff was determined in the test cohort on the basis of the distribution of TERT expression, and its prognostic value was assessed by Kaplan-Meier survival estimates and multivariable analyses. Telomerase activity was validated by telomere repeat amplification protocol assay. Similar to neuroblastoma, TERT expression exhibited a bimodal distribution in pulmonary carcinoids, separating tumors into TERT-high and TERT-low subgroups. A natural TERT cutoff discriminated unfavorable from favorable clinical courses with high accuracy both in the test cohort (5-year overall survival [OS], 0.547 ± 0.132 v 1.0; P < .001) and the validation cohort (5-year OS, 0.788 ± 0.063 v 0.913 ± 0.048; P < .001). In line with these findings, telomerase activity was largely absent in TERT-low tumors, whereas it was readily detectable in TERT-high carcinoids. In multivariable analysis considering TERT expression, histology (typical v atypical carcinoid), and stage (≤IIA v ≥IIB), high TERT expression was an independent prognostic marker for poor survival, with a hazard ratio of 5.243 (95% CI, 1.943 to 14.148; P = .001). Our data demonstrate that high TERT expression defines clinically aggressive pulmonary carcinoids with fatal outcome, similar to neuroblastoma, indicating that activation of TERT may be a defining feature of lethal cancers.

Astragalus polysaccharide ameliorates bone marrow haematopoietic failure in mice with aplastic anaemia via the Hippo/TERT signalling pathway

ObjectiveTo study the effects of astragalus polysaccharide (APS) on aplastic anaemia (AA) in mice through modulation of the upstream and downstream effectors of the Hippo pathway. Further, we investigated the underlying mechanisms of APS in the treatment of AA to provide possible therapeutic strategies and drugs for clinical use. MethodsBALB/c mice were subjected to 4 Gy X-ray irradiation and subsequently injected with lymphocytes from DBA/2 donor mice by using the tail vein to establish an AA mouse model. Next BALB/c mice were randomly divided into five groups: control (untreated), AA (model), and three APS remedy groups - LA (low-dose APS, 200 mg/kg), MA (medium-dose APS, 400 mg/kg), and HA (high-dose APS, 800 mg/kg). The mice were sacrificed after 14 d of continuous gavage with different doses of APS or saline, and the bone marrow, spleen and liver were obtained. The haematopoietic condition, apoptosis levels, and the expression of Large Tumour Suppressor 1/2 (LATS 1/2), transcriptional co-activator of activation (TCA) Yes-associated protein (YesAP), transcriptional enhancer of adherence domain (TEAD) protein, and Telomerase Reverse Transcriptase (TERT), were analysed. ResultsCompared with control mice, mice in the AA group exhibited a reduction in peripheral blood cell counts, a significant decrease in the haematopoietic area, increased adipocyte infiltration, and overall haematopoietic failure, mirroring the clinical presentation of AA; After 14 days of treatment with different doses of APS, the APS-treated group, in comparison to the untreated AA group, showed an increase in peripheral blood cell counts (P < 0.05), an expansionof the haematopoietic area in the bone marrow, restoration of haematopoietic function (P < 0.05), and a marked reduction in adipocyte infiltration within the bone marrow(P < 0.05). Cell infiltration into the bone marrow was also reduced. Further experiments revealed that the expression levels of TERT, LATS 1/2, YAP, and TEAD were elevated in the treated mice (P < 0.05). ConclusionX-ray irradiation combined with T-lymphocyte infusion successfully established an AA mouse model, and APS administration modulated the expression of TERT and the Hippo pathway effectors LATS 1/2, YAP, and TEAD, which are implicated in the pathogenesis of AA. This modulation resulted in the restoration of bone marrow haematopoietic function in AA mice, suggesting APS as a promising therapeutic agent for the treatment of AA.

TERT upregulation promotes cell proliferation via degradation of p21 and increases carcinogenic potential.

Telomerase reverse transcriptase (TERT) gene aberration is detectable in >80% of cases with hepatocellular carcinoma (HCC). TERT reactivation is essential for cellular immortalization because it stabilizes telomere length, although the role of TERT in hepatocarcinogenesis remains unelucidated. To elucidate the significance of aberrant TERT expression in hepatocytes in inflammation-associated hepatocarcinogenesis, we generated Alb-Cre;TertTg mice, which overexpress TERT in the liver and examined their phenotype during chronic inflammation. Based on transcriptome data from the liver tissue of Alb-Cre;TertTg mice, we examined the role of TERT in hepatocarcinogenesis in vitro. We also evaluated the relationship between TERT and cell-cycle-related molecules, including p21, in HCC samples. The liver tumor development rate was increased by TERT overexpression during chronic inflammation, especially in the absence of p53 function. Gene set enrichment analysis of liver tissues revealed that gene sets related to TNF-NFκB signaling, cell cycle, and apoptosis were upregulated in Alb-Cre;TertTg liver. A luciferase reporter assay and immunoprecipitation revealed that TERT interacted with NFκB p65 and enhanced NFκB promoter activity. On the other hand, TERT formed protein complexes with p21, cyclin A2, and cyclin E and promoted ubiquitin-mediated degradation of p21, specifically in the G1 phase. In the clinical HCC samples, TERT was highly expressed but p21 was conversely downregulated, and TERT expression was associated with the upregulation of molecules related to the cell cycle. Taken together, the aberrant upregulation of TERT increased NFκB promoter activity and promoted cell cycle progression via p21 ubiquitination, leading to hepatocarcinogenesis. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.