Decreased telomere length in a subgroup of young individuals with bipolar disorders: replication in the FACE-BD cohort and association with the shelterin component POT1.

Bipolar disorder (BD) has been associated with premature cellular aging with shortened telomere length (TL) as compared to the general population. We recently identified a subgroup of young individuals with prematurely shortened TL. The aims of the present study were to replicate this observation in a larger sample and analyze the expression levels of genes associated with age or TL in a subsample of these individuals. TL was measured on peripheral blood DNA using quantitative polymerase chain reaction in a sample of 542 individuals with BD and clustering analyses were performed. Gene expression level of 29 genes, associated with aging or with telomere maintenance, was analyzed in RNA samples from a subsample of 129 individuals. Clustering analyses identified a group of young individuals (mean age 29.64 years), with shorter TL. None of the tested clinical variables were significantly associated with this subgroup. Gene expression level analyses showed significant downregulation of MYC, POT1, and CD27 in the prematurely aged young individuals compared to the young individuals with longer TL. After adjustment only POT1 remained significantly differentially expressed between the two groups of young individuals. This study confirms the existence of a subgroup of young individuals with BD with shortened TL. The observed decrease of POT1 expression level suggests a newly described cellular mechanism in individuals with BD, that may contribute to telomere shortening.

Telomere length is not a useful tool for chronological age estimation in animals.

Telomeres are short repetitive DNA sequences capping the ends of chromosomes. Telomere shortening occurs during cell division and may be accelerated by oxidative damage or ameliorated by telomere maintenance mechanisms. Consequently, telomere length changes with age, which was recently confirmed in a large meta-analysis across vertebrates. However, based on the correlation between telomere length and age, it was concluded that telomere length can be used as a tool for chronological age estimation in animals. Correlation should not be confused with predictability, and the current data and studies suggest that telomeres cannot be used to reliably predict individual chronological age. There are biological reasons for why there is large individual variation in telomere dynamics, which is mainly due to high susceptibility to a wide range of environmental, but also genetic factors, rendering telomeres unfeasible as a tool for age estimation. The use of telomeres for chronological age estimation is largely a misguided effort, but its occasional reappearance in the literature raises concerns that it will mislead resources in wildlife conservation.

Telomere Length Is a Driving Hallmark for Aging-Related Biochemical Hallmarks: Evidence From the Shared Genetic Effect and Causal Inference.

Telomere shortening is an important sign and driving factor of aging, but its association mechanisms and causal effects with other aging-related biochemical hallmarks are largely unknown. This study first performed comprehensive genetic analyses (eg, shared genetic analysis, pleiotropic analysis, and gene enrichment analysis) to detect the underlying molecular mechanisms for the associations between telomere length (TL) and aging-related biochemical hallmarks. Then, further bidirectional Mendelian randomization (MR) analyses investigated the causal effects between TL and other biochemical hallmarks. The genetic correlations were negative between TL and growth differentiation factor-15 (GDF15) (p = .024), C-reactive protein (p = .007), hemoglobin A1c (p = .007), and red blood cell (RBC) (p = .022), but positive between TL and insulin-like growth factor 1 (IGF-1) (p = .002) and white blood cell counts (p = .007). The increased TL has causal effects on the low levels of GDF15 (p = 3.73E-06), sex hormone binding globulin (p = 6.30E-06), testosterone (p = 5.56E-07), fasting insulin (p = 2.67E-05), and RBC (p = 1.54E-05), but the higher levels of IGF-1 (p = 3.24E-07). In conclusion, the observed phenotypic correlations between TL and aging-related biochemical hallmarks may arise from a combination of shared genetic components and causal effects. Telomere length is regarded as a driving hallmark for aging-related biochemical hallmarks.

Significantly shortened telomere length and altered androgen receptor level in cumulus cells from women with polycystic ovary syndrome.

OBJECTIVE: The aim of this study was to investigate the correlation between hormone receptor levels and telomere length (TL) in infertile women with and without polycystic ovary syndrome (PCOS). MATERIALS AND METHODS: This prospective cohort study recruited a total of 431 cumulus oocyte complex (COC) from 88 infertile women between July 2012 and June 2014. The participants were divided into three groups: young age (<38 years, n = 42 and 227 COC), advanced age (≥38 years, n = 33 and 107 COC) and PCOS patients (n = 13 and 97 COC). Cumulus cells were collected from individual follicle during oocyte pick-up, and the mRNA levels of hormone receptors and TL were measured using real-time PCR. RESULTS: The cumulus cells of PCOS patients demonstrated lower mRNA levels of LH receptor (75.57 ± 138.10 vs. 171.07 ± 317.68; p < 0.01) and androgen receptor (1.13 ± 1.52 vs. 4.08 ± 9.57; p < 0.01), as well as a shorter TL (2.39 ± 2.58 vs. 3.96 ± 4.72; p < 0.01) compared to those of the young age group. In the young age group, only androgen receptor mRNA level showed a significant association with TL (rho = 0.148, p = 0.026), while FSH receptor mRNA level was the only factor associated with TL (rho = 0.247, p = 0.015) in PCOS patients. For advanced-aged patients, no significant relationship was observed between hormone receptor mRNA levels and TL. Alternative splicing of androgen receptors was identified in some PCOS patients but not in young age controls. CONCLUSION: The findings suggest that the androgen receptor level and function may be altered in the cumulus cells of PCOS patients, leading to a shorter TL in cumulus cells in PCOS patients.

Ectoparasite presence and brood size manipulation interact to accelerate telomere shortening in nestling jackdaws.

Early-life conditions impact fitness, but whether the combined effect of extrinsic stressors is additive or synergistic is not well known. This is a major knowledge gap because exposure to multiple stressors is frequent. Telomere dynamics may be instrumental when testing how stressors interact because many factors affect telomere shortening, and telomere shortening predicts survival. We evaluated the effect of manipulated brood size and natural infestation by the carnid fly Carnus hemapterus on nestling growth and telomere shortening of wild jackdaws (Corvus monedula). Telomere length, measured in blood using TRF, shortened on average by 264 bp, and on average, Carnus infection induced more telomere shortening. Further analyses showed that in enlarged broods, nestlings' telomeres shortened more when parasitized, while in reduced broods there was no effect of infection on telomere shortening. We conclude that there is a synergistic effect of number of siblings and Carnus infection on telomere shortening rate: blood-sucking parasites may negatively impact telomeres by increasing cell proliferation and/or physiological stress, and coping with infection may be less successful in enlarged broods with increased sibling competition. Larger nestlings had shorter telomeres independent of age, brood manipulation or infection. Growth was independent of infestation but in enlarged broods, nestlings were lighter at fledging. Our findings indicate that (i) evaluating consequences of early-life environmental conditions in isolation may not yield a full picture due to synergistic effects, and (ii) effects of environmental conditions may be cryptic, for example, on telomeres, with fitness consequences expressed beyond the temporal framework of the study.

Early-life telomeres are influenced by environments acting at multiple temporal and spatial scales.

An individual's telomere length early in life may reflect or contribute to key life-history processes sensitive to environmental variation. Yet, the relative importance of genetic and environmental factors in shaping early-life telomere length is not well understood as it requires samples collected from multiple generations with known developmental histories. We used a confirmed pedigree and conducted an animal model analysis of telomere lengths obtained from nestling house sparrows (Passer domesticus) sampled over a span of 22 years. We found significant additive genetic variation for early-life telomere length, but it comprised a small proportion (9%) of the total biological variation. Three sources of environmental variation were important: among cohorts, among-breeding attempts within years, and among nestmates. The magnitude of variation among breeding attempts and among nestmates also differed by cohort, suggesting that interactive effects of environmental factors across time or spatial scales were important, yet we were unable to identify the specific causes of these interactions. The mean amount of precipitation during the breeding season positively predicted telomere length, but neither weather during a given breeding attempt nor date in the breeding season contributed to an offspring's telomere length. At the level of individual nestlings, offspring sex, size and mass at 10 days of age also did not predict telomere length. Environmental effects appear especially important in shaping early-life telomere length in some species, and more focus on how environmental factors that interact across scales may help to explain some of the variation observed among studies.

Telomere length and its association with systemic lupus erythematosus in an Asian population: A Mendelian randomization study.

OBJECTIVES: To investigate whether shorter telomere length is a causal risk factor for systemic lupus erythematosus (SLE) in the Asian population. METHODS: We applied the two-sample Mendelian randomization (MR) method to the pooled statistics from a genome-wide association study (GWAS) of 6,707 SLE cases and 16,047 controls. We selected nine single-nucleotide polymorphisms (SNPs) with genome-wide significance as instrumental variables for telomere length. The main analysis was carried out by the random-effects inverse-variance weighted (IVW) method. Horizontal pleiotropy was evaluated by the intercept of MR-Egger regression. RESULTS: A potentially causal relationship between longer genetically predicted telomere length and increased risk of systemic lupus erythematosus (OR = 1.72, 95%CI: 1.21, 2.46, p = 0.01) was observed. The MR-Egger regression demonstrated an intercept proximal to zero (intercept = 0.017, p = 0.69), which does not provide evidence of the presence of horizontal pleiotropy. CONCLUSIONS: Our findings provided evidence supporting a potential causal relationship between longer telomere length and increased risk of systemic lupus erythematosus.

UBQLN1 deficiency mediates telomere shortening and IPF through interacting with RPA1.

Premature telomere shortening is a known factor correlated to idiopathic pulmonary fibrosis (IPF) occurrence, which is a chronic, progressive, age-related disease with high mortality. The etiology of IPF is still unknown. Here, we found that UBQLN1 plays a key role in telomere length maintenance and is potentially relevant to IPF. UBQLN1 involves in DNA replication by interacting with RPA1 and shuttling it off from the replication fork. The deficiency of UBQLN1 retains RPA1 at replication fork, hinders replication and thus causes cell cycle arrest and genome instability. Especially at telomere regions of the genome, where more endogenous replication stress exists because of G rich sequences, UBQLN1 depletion leads to rapid telomere shortening in HeLa cells. It revealed that UBQLN1 depletion also shortens telomere length at mouse lung and accelerates mouse lung fibrosis. In addition, the UBQLN1 expression level in IPF patients is downregulated and correlated to poor prognosis. Altogether, these results uncover a new role of UBQLN1 in ensuring DNA replication and maintaining telomere stability, which may shed light on IPF pathogenesis and prevention.

Is COVID-19 severity associated with telomere length? A systematic review and meta-analysis.

Telomere shortening, a marker of cellular aging, has been linked to hospitalization and the severity of COVID-19. In this systematic review and meta-analysis, the mean difference in telomere length between non-severe and severe COVID-19 individuals was pooled to determine the association between short telomeres and COVID-19 severity. Relevant studies were retrieved through searches conducted in PubMed-Medline, Scopus, EMBASE, Medrxiv, Biorxiv, EuroPMC, and SSRN databases up to November 2022. Selected studies were systematically reviewed and assessed for risk of bias using AXIS tool. The standardized mean difference in telomere length between non-severe and severe COVID-19 was pooled using random-effects model. A total of thirteen studies were included in the review, out of which seven (1332 patients with the severe COVID-19 disease and 6321 patients with non-severe COVID-19) were eligible for meta-analysis. The estimated pooled mean difference in Leukocyte telomere length between severe COVID-19 and non-severe COVID-19 was 0.39 (95% CI - 0.02 to 0.81, I2 = 93.5%) with substantial heterogeneity. Our findings do not provide clear evidence for association of shorter telomere length and severe COVID-19 disease. More extensive studies measuring absolute telomere length with age and gender adjustments are needed to draw definitive conclusions on the potential causal association between telomere shortening and COVID-19 severity.

Maternal depression and child telomere length: The role of genetic sensitivity.

BACKGROUND: The stress of a mother's depression may increasingly tax psychobiological systems that help children with self-regulation, increasing children's allostatic load over time. Some evidence supports children exposed to maternal depression tend to have shorter telomeres and tend to have more somatic and psychological problems. Children having one or more A1 alleles of dopamine receptor 2 (DRD2, rs1800497), tend to have greater sensitivity to maternal depression and could experience more adverse child outcomes that contribute to greater allostatic load. METHODS: Using the Future Families and Child Wellbeing dataset, secondary-data analyses were used to test the effect of repeated exposure to maternal depression during early childhood on children's telomere length during middle childhood moderated by children's DRD2 genotype (N = 2884). RESULTS: Greater maternal depression was not significantly associated with shorter child telomere length and this association was not moderated by DRD2 genotypes while controlling for factors associated with child telomere length. IMPLICATIONS: The effect of maternal depression on children's TL may not be significant in populations from diverse racial-ethnic and family backgrounds during middle childhood. These findings could help further our current understanding psychobiological systems affected by maternal depression that result in adverse child outcomes. LIMITATIONS: Even though this study used a relatively large and diverse sample, replication of DRD2 moderation in even larger samples is an important next step.

Early-life telomere length predicts life-history strategy and reproductive senescence in a threatened wild songbird.

Telomeres are well known for their associations with lifespan and ageing across diverse taxa. Early-life telomere length can be influenced by developmental conditions and has been shown positively affect lifetime reproductive success in a limited number of studies. Whether these effects are caused by a change in lifespan, reproductive rate or perhaps most importantly reproductive senescence is unclear. Using long-term data on female breeding success from a threatened songbird (the hihi, Notiomystis cincta), we show that the early-life telomere length of individuals predicts the presence and rate of future senescence of key reproductive traits: clutch size and hatching success. In contrast, senescence of fledging success is not associated with early-life telomere length, which may be due to the added influence of biparental care at this stage. Early-life telomere length does not predict lifespan or lifetime reproductive success in this species. Females may therefore change their reproductive allocation strategy depending on their early developmental conditions, which we hypothesise are reflected in their early-life telomere length. Our results offer new insights on the role that telomeres play in reproductive senescence and individual fitness and suggest telomere length can be used as a predictor for future life history in threatened species.

Gut-specific telomerase expression counteracts systemic aging in telomerase-deficient zebrafish.

Telomere shortening is a hallmark of aging and is counteracted by telomerase. As in humans, the zebrafish gut is one of the organs with the fastest rate of telomere decline, triggering early tissue dysfunction during normal zebrafish aging and in prematurely aged telomerase mutants. However, whether telomere-dependent aging of an individual organ, the gut, causes systemic aging is unknown. Here we show that tissue-specific telomerase expression in the gut can prevent telomere shortening and rescues premature aging of tert-/-. Induction of telomerase rescues gut senescence and low cell proliferation, while restoring tissue integrity, inflammation and age-dependent microbiota dysbiosis. Averting gut aging causes systemic beneficial impacts, rescuing aging of distant organs such as reproductive and hematopoietic systems. Conclusively, we show that gut-specific telomerase expression extends the lifespan of tert-/- by 40%, while ameliorating natural aging. Our work demonstrates that gut-specific rescue of telomerase expression leading to telomere elongation is sufficient to systemically counteract aging in zebrafish.

Damage-Free Shortening of Telomeres Is a Potential Strategy Supporting Blind Mole-Rat Longevity.

Telomere shortening or loss of shelterin components activates DNA damage response (DDR) pathways, leading to a replicative senescence that is usually coupled with a senescence-associated secretory phenotype (SASP). Recent studies suggested that telomere aberration that activates DDR may occur, irrespective of telomere length or loss of shelterin complex. The blind mole-rat (Spalax) is a subterranean rodent with exceptional longevity, and its cells demonstrate an uncoupling of senescence and SASP inflammatory components. Herein, we evaluated Spalax relative telomere length, telomerase activity, and shelterin expression, along with telomere-associated DNA damage foci (TAFs) levels with cell passage. We show that telomeres shorten in Spalax fibroblasts similar to the process in rats, and that the telomerase activity is lower. Moreover, we found lower DNA damage foci at the telomeres and a decline in the mRNA expression of two shelterin proteins, known as ATM/ATR repressors. Although additional studies are required for understanding the underling mechanism, our present results imply that Spalax genome protection strategies include effective telomere maintenance, preventing early cellular senescence induced by persistent DDR, thereby contributing to its longevity and healthy aging.

Longitudinal telomere dynamics within natural lifespans of a wild bird.

Telomeres, the nucleotide sequences that protect the ends of eukaryotic chromosomes, shorten with each cell division and telomere loss may be influenced by environmental factors. Telomere length (TL) decreases with age in several species, but little is known about the sources of genetic and environmental variation in the change in TL (∆TL) in wild animals. In this study, we tracked changes in TL throughout the natural lifespan (from a few months to almost 9 years) of free-living house sparrows (Passer domesticus) in two different island populations. TL was measured in nestlings and subsequently up to four times during their lifetime. TL generally decreased with age (senescence), but we also observed instances of telomere lengthening within individuals. We found some evidence for selective disappearance of individuals with shorter telomeres through life. Early-life TL positively predicted later-life TL, but the within-individual repeatability in TL was low (9.2%). Using genetic pedigrees, we found a moderate heritability of ∆TL (h2 = 0.21), which was higher than the heritabilities of early-life TL (h2 = 0.14) and later-life TL measurements (h2 = 0.15). Cohort effects explained considerable proportions of variation in early-life TL (60%), later-life TL (53%), and ∆TL (37%), which suggests persistent impacts of the early-life environment on lifelong telomere dynamics. Individual changes in TL were independent of early-life TL. Finally, there was weak evidence for population differences in ∆TL that may be linked to ecological differences in habitat types. Combined, our results show that individual telomere biology is highly dynamic and influenced by both genetic and environmental variation in natural conditions.

Comparison qPCR study for selecting a valid single copy gene for measuring absolute telomere length.

Telomere shortening is a well-known biomarker for biological aging. A previous review of the methods used to measure telomere length (TL) noted how challenging it is to compare results from different studies using diverse methodological techniques. The most commonly used high throughput method for measuring average TL is the quantitative PCR (qPCR) method, where there are two protocols available; the relative TL and the absolute TL (aTL) method. All qPCR methods have similarities in that they use two different primer sets to measure the telomere repeat sequence (TTAGGG)n and a single copy gene region to calculate the average TL, (T/S) ratio. The difference between the relative TL and the aTL assay lies with the introduction of duplex oligomer standards to identify TL in kilobase pairs rather than using the traditional relative TL, T/S ratio method. Problems were noted using 36B4 (RPLP0), which was originally used as a suitable single copy gene qPCR assay. A previous aTL publication attempted to replace the 36B4 (RPLP0) single copy gene using the Interferon beta 1 gene (IFNB1) but results showed a lack of agreement with the TL results when compared to the DNAmTL assay. Here, we compare the two single copy gene assays previously used for the aTL assay and offer an alternative IFNB1 single copy gene assay without non-specific priming amplification to provide more consistent diploid copy number determination and a more robust and reproducible assay for measuring absolute TL.

Shorter telomere length and suicidal ideation in familial bipolar disorder.

Bipolar Disorder (BD) has recently been related to a process of accelerated aging, with shortened leukocyte telomere length (LTL) in this population. It has also been observed that the suicide rate in BD patients is higher than in the general population, and more recently the telomere length variation has been described as shorter in suicide completers compared with control subjects. Objectives The aim of the present study was to investigate if there is an association between LTL and BD in families where two or more members have BD including clinical symptomatology variables, along with suicide behavior. Methods Telomere length and single copy gene ratio (T/S ratio) was measured using quantitative polymerase chain reaction in a sample of 143 relatives from 22 families, of which 60 had BD. The statistical analysis was performed with a polygenic mixed model. Results LTL was associated with suicidal ideation (p = 0.02) as that there is an interaction between suicidal ideation and course of the disorder (p = 0.02). The estimated heritability for LTL in these families was 0.68. In addition, covariates that relate to severity of disease, i.e. suicidal ideation and course of the disorder, showed an association with shorter LTL in BD patients. No difference in LTL between BD patients and healthy relatives was observed. Conclusion LTL are shorter in subjects with familial BD suggesting that stress related sub-phenotypes possibly accelerate the process of cellular aging and correlate with disease severity and suicidal ideation.

Parental Genetics Communicate with Intrauterine Environment to Reprogram Newborn Telomeres and Immunity.

Telomeres, markers for cellular senescence, have been found substantially influenced by parental inheritance. It is well known that genomic stability is preserved by the DNA repair mechanism through telomerase. This study aimed to determine the association between parents−newborn telomere length (TL) and telomerase gene (TERT), highlighting DNA repair combined with TL/TERT polymorphism and immunosenescence of the triad. The mother−father−newborn triad blood samples (n = 312) were collected from Ziauddin Hospitals, Pakistan, between September 2021 and June 2022. The telomere length (T/S ratio) was quantified by qPCR, polymorphism was identified by Sanger sequencing, and immunosenescence by flow cytometry. The linear regression was applied to TL and gene association. The newborns had longest TL (2.51 ± 2.87) and strong positive association (R = 0.25, p ≤ 0.0001) (transgenerational health effects) with mothers' TL (1.6 ± 2.00). Maternal demographics­socioeconomic status, education, and occupation­showed significant effects on TL of newborns (p < 0.015, 0.034, 0.04, respectively). The TERT risk genotype CC (rs2736100) was predominant in the triad (0.6, 0.5, 0.65, respectively) with a strong positive association with newborn TL (ß = 2.91, <0.0011). Further analysis highlighted the expression of KLRG 1+ in T-cells with shorter TL but less frequent among newborns. The study concludes that TERT, parental TL, antenatal maternal health, and immunity have a significantly positive effect on the repair of newborn TL.

Unravelling the role of telomere shortening with ageing and their potential association with diabetes, cancer, and related lifestyle factors.

Telomeres are often considered as the 'ageing clock' that determines the lifespan at the cellular level, forming the ends of a chromosome, which shorten each time the cell divides itself to the point where they become so short the cell is unable to divide itself further. Telomere length alteration is often linked with lifestyle factors such as age, obesity, exposure to pesticides and pollution, depression, unhealthy diet, lack of exercise, and stress. The current review discusses the mechanism of telomere shortening in relation to ageing and lifestyle factors in general and its association with chronic diseases like diabetes which may influence the health and lifespan of an individual by increasing telomere shortening. Accelerated or excessive telomere shortening is also associated with the early onset of age-related disorders globally and, hence, reduced lifespan of individuals. Upregulated Telomerase activity and reactivation of telomeres is observed in > 70 % of cancer patients by TERT point mutations, rearrangements, DNA amplifications, and transcript fusions, making it a useful marker in diagnosis and prognosis of various cancers. The study presents a systematic review of the unregulated Telomere activity with progression of various cancer and extrapolation of suitable pathways and prognostic information correlated with mRNA levels of TERT, which are critical among thymic epithelial tumors (TETs). In most cancers, unlimited proliferation is due to the reactivation of reverse transcriptase gene TERT. All these observations are comprehensively presented in the paper and might be useful for researchers working in the field of telomere dynamics and finding the correlation of age shortening with mRNA expression profiling.

Telomere is shortened in patients with irritable bowel syndrome in the Chinese population.

BACKGROUND AND AIM: Telomere shortening is an accepted indicator of aging. Many studies have investigated an association between leukocyte telomere length (LTL) and psychiatric disorders. Mental or psychological factors could be an important cause of irritable bowel syndrome (IBS). However, there are currently few research evaluating correlations between LTL and IBS. METHODS: We examined associations between LTL and IBS using quantitative polymerase chain reaction in independent cohorts, including 205 patients with IBS and 189 healthy controls. Furthermore, we examined whether mental or psychological factors, types of IBS, duration of IBS and antidepressants had an association with LTL in patients with IBS. RESULTS: Among total samples, patients with IBS presented shorter LTL when compared to healthy controls (P < 0.0001). Moreover, in subgroup analyses of patients with IBS, not only the LTL in patients with IBS caused by mental or psychological factors was shorter (P < 0.0001), but also in patients with IBS that were caused by other factors (P = 0.0082). Furthermore, LTL in patients with IBS who had taken antidepressants for more than 1 month was longer than that in patients with IBS who did not take antidepressants or took for less than 1 month (P < 0.0001). CONCLUSIONS: This is the first study to describe the relationship between LTL and IBS. This study showed significantly shorter telomeres in patients with IBS. Our findings suggest that LTL may hold the potential to serve as a predictor of IBS diagnosis.

Telomeres, the loop tying cancer to organismal life-histories.

Recent developments in telomere and cancer evolutionary ecology demonstrate a very complex relationship between the need of tissue repair and controlling the emergence of abnormally proliferating cells. The trade-off is balanced by natural and sexual selection and mediated via both intrinsic and environmental factors. Here, we explore the effects of telomere-cancer dynamics on life history traits and strategies as well as on the cumulative effects of genetic and environmental factors. We show that telomere-cancer dynamics constitute an incredibly complex and multifaceted process. From research to date, it appears that the relationship between telomere length and cancer risk is likely nonlinear with good evidence that both (too) long and (too) short telomeres can be associated with increased cancer risk. The ability and propensity of organisms to respond to the interplay of telomere dynamics and oncogenic processes, depends on the combination of its tissue environments, life history strategies, environmental challenges (i.e., extreme climatic conditions), pressure by predators and pollution, as well as its evolutionary history. Consequently, precise interpretation of telomere-cancer dynamics requires integrative and multidisciplinary approaches. Finally, incorporating information on telomere dynamics and the expression of tumour suppressor genes and oncogenes could potentially provide the synergistic overview that could lay the foundations to study telomere-cancer dynamics at ecosystem levels.