Exercise, Telomeres, and Cancer: "The Exercise-Telomere Hypothesis"

Kaempferol: Paving the path for advanced treatments in aging-related diseases

Aging-related diseases (ARDs) are a major global health concern, and the development of effective therapies is urgently needed. Kaempferol, a flavonoid found in several plants, has emerged as a promising candidate for ameliorating ARDs. This comprehensive review examines Kaempferol's chemical properties, safety profile, and pharmacokinetics, and highlights its potential therapeutic utility against ARDs. Kaempferol's therapeutic potential is underpinned by its distinctive chemical structure, which confers antioxidative and anti-inflammatory properties. Kaempferol counteracts reactive oxygen species (ROS) and modulates crucial cellular pathways, thereby combating oxidative stress and inflammation, hallmarks of ARDs. Kaempferol's low toxicity and wide safety margins, as demonstrated by preclinical and clinical studies, further substantiate its therapeutic potential. Compelling evidence supports Kaempferol's substantial potential in addressing ARDs through several mechanisms, notably anti-inflammatory, antioxidant, and anti-apoptotic actions. Kaempferol exhibits a versatile neuroprotective effect by modulating various proinflammatory signaling pathways, including NF-kB, p38MAPK, AKT, and the β-catenin cascade. Additionally, it hinders the formation and aggregation of beta-amyloid protein and regulates brain-derived neurotrophic factors. In terms of its anticancer potential, kaempferol acts through diverse pathways, inducing apoptosis, arresting the cell cycle at the G2/M phase, suppressing epithelial-mesenchymal transition (EMT)-related markers, and affecting the phosphoinositide 3-kinase/protein kinase B signaling pathways. Subsequent studies should focus on refining dosage regimens, exploring innovative delivery systems, and conducting comprehensive clinical trials to translate these findings into effective therapeutic applications.

Unraveling the "golden ratio": a pilot study investigating acute-to-chronic workload ratio in breast cancer patients undergoing active treatment

Training load monitoring is a common practice in sports medicine for supporting athletes' health and performance. Despite progress in exercise oncology research for breast cancer patients, training load monitoring is underutilized. This study retrospectively investigated the relationship between maintained training load within a defined range and physical and health outcomes of ten breast cancer patients during active anticancer treatment who underwent a 12-week exercise program. Intervention consisted of endurance and resistance training, three times a week, with each session lasting 30-45 min. Assessments were conducted at baseline, 6 and 12 weeks after enrollment, evaluating physical function (6-min walk test-6MWT, and sit-to-stand), muscle strength, body composition, sleep quality (Pittsburgh Sleep Quality Index-Pittsburgh Sleep Quality Index), quality of life (EORTC-QLQ-C30), heart rate variability and physical activity levels (International Physical Activity Questionnaire-International Physical Activity Questionnaire). The Physiological Cost Index/Energy Expenditure Index (PCI/EEI) was estimated using the 6MWT and Heart rate. Training load monitoring was performed by session rating of perceived exertion (sRPE, relative intensity multiplying with session duration). Acute-to-Chronic Workload Ratio (ACWR) (7:28, rolling average) was calculated accordingly. Analyses were performed within-subjects across time points and between-subjects, comparing those who maintained from weeks 6-12 an ACWR of 0.8-1.3 with those who did not. Adherence rates were similar between groups. Physical function improved in the total sample with large effect sizes (Δ6MWT = 56.5 m [95%CI: 6-100 m], effect size [w] = 0.52, p = 0.006; ΔSit-to-Stand = 1.5 [95%CI: 1-5], effect size [w] = 0.681, p < 0.001), demonstrating greater changes in patients with higher ACWR. Sleep quality improvements were higher in the appropriate ACWR group (p = 0.016). A positive correlation was demonstrated between global health status and 6MWT change from baseline to 12 weeks (ρ = 0.689, p = 0.04). Despite a small sample size, patients maintaining sufficient relative training load presented greater physical fitness and sleep quality improvements. Thus, training load monitoring may enhance exercise program benefits in breast cancer patients under active treatment.

Differential Effects of Very-Low-Volume Exercise Modalities on Telomere Length, Inflammation, and Cardiometabolic Health in Obese Metabolic Syndrome Patients: A Subanalysis from Two Randomized Controlled Trials

Oxidative stress (OS) and inflammation are features of metabolic syndrome (MetS) that can contribute to the shortening of telomere length (TL), a marker of cellular ageing. Research indicates that exercise can positively influence MetS-associated conditions and TL. However, the effects of low-volume exercise types on TL are still unknown. We investigated the impact of very-low-volume high-intensity interval training (LV-HIIT), one-set resistance training (1-RT), and whole-body electromyostimulation (WB-EMS) on TL, inflammation, and cardiometabolic indices in 167 MetS patients. Data were derived from two randomized controlled trials where patients were allocated to an exercise group (2 sessions/week, for 12 weeks) or a control group. All groups received standard-care nutritional weight loss counselling. TL was determined as the T/S ratio (telomere to single-copy gene amount). All groups significantly reduced body weight (p < 0.05), but the T/S-ratio (p < 0.001) only increased with LV-HIIT. OS-related inflammatory markers (C-reactive protein, interleukin-6, and lipopolysaccharide-binding protein) only decreased (p < 0.05) following LV-HIIT. The MetS severity z-score improved with LV-HIIT (p < 0.001) and 1-RT (p = 0.014) but not with WB-EMS. In conclusion, very-low-volume exercise modalities have differential effects on telomeres, inflammation, and cardiometabolic health. Only LV-HIIT but not strength-based low-volume exercise increased TL in MetS patients, presumably due to superior effects on OS-related inflammatory markers.

A systematic review evaluating the effectiveness of exercise training on physical condition in prostate cancer patients undergoing androgen deprivation therapy

Background

Androgen deprivation therapy (ADT) is an effective prostate cancer (PCa) treatment strategy that can curb the development or progression of the disease. This review aimed to examine and summarize available systematic reviews/meta-analyses (SRs/MAs) of exercise training on physical condition of PCa patients undergoing ADT.

Methods

A comprehensive search of 8 databases was conducted for relevant literature published before April 25, 2022 with the language restrictions of Chinese and English. Two reviewers independently assessed the methodological quality, risk of bias, reporting quality, and evidence quality of the included SRs/MAs using a range of evaluation tools, including A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2, Risk of Bias in Systematic Reviews (ROBIS), the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), and Grades of Recommendations, Assessment, Development and Evaluation (GRADE).

Results

This review included 8 SRs/MAs which included a total of 94 studies. Ultimately, A total of 51 outcomes was included, regarding 11 different outcome categories. The AMSTAR-2 tool showed that 3 SRs/MAs had moderate methodological quality, 4 SRs/MAs had very low quality, and the remaining 1 had low quality. According to the ROBIS scale, 3 SRs/MAs had a high risk of bias. The PRISMA checklist showed that the primary reporting faults were protocol registration and funding source. The GRADE system was used to analyze the evidence quality of the 51 outcomes, and no high-quality evidence was found. However, moderate-quality evidence indicated that exercise training may improve body composition [by lowering body fat mass (BFM) and body fat rate (BFR)], muscular strength, and quality of life (QoL) in PCa patients undergoing ADT. Low-quality evidence demonstrated that exercise training could improve such symptoms as fatigue, depression, sexual function, and cardiometabolic changes.

Conclusions

Available evidence suggests that exercise training may be used as an adjuvant treatment for PCa patients undergoing ADT to improve several aspects of general health. Studies with more rigorous designs and larger sample sizes are needed to support our findings with more robust evidence.

Three Tiers to biological escape velocity: The quest to outwit aging

As longevity companies emerge with new products and the fields of anti-aging research develop new cutting-edge therapies, three distinct classes of longevity methodologies emerge. This discussion finds that there are three clear classes (Tiers) of longevity systems that are currently under development, and all three will be paramount to achieve biological escape velocity (where tissues can be repaired faster than aging can damage them). These classes are referred to as Tier 1, Tier 2, and Tier 3 treatments and are described in detail below. These three Tiers are required for easy identification for pharmaceutical companies and research companies to determine the type of therapy they may choose to deliver being noninvasive, invasive, time consuming, or simple end user products. Specific targets and goals need to be defined clearly from an early perspective in the development of these technologies for future precision medicines. This allows consumers of future anti-aging technologies to consider which Tier a particular therapy may be, delivering a more informed choice.

Sex-specific interventions to prevent and manage frailty

There is growing interest in interventions that delay, slow, and even reverse frailty. In this narrative review, we explore the evidence on exercise, nutrition, medication optimisation and social support interventions for frailty and consider how these relate to underlying frailty pathophysiology. We also consider pathophysiological mechanisms underpinning sex differences in frailty before evaluating the limited evidence for sex-specific frailty interventions that is currently available. Through this review of the literature, we generate a list of potential sex-specific interventions for frailty. While individual-level recommendations are certainly important, future work should turn the focus towards population-level interventions that take into account sex differences in frailty, including changes to healthcare and socioeconomic systems, as well as changes to the built environment to promote healthy behaviours.

Panic disorder aging characteristics: The role of telomerase reverse transcriptase gene and brain function

Panic disorder (PD) causes serious functional damage and disability and accelerates the process of individual aging. The pathological basis of PD is the same as that of age-related diseases, which is proposed as a new viewpoint in recent years. Memory decline and social functional impairment are common manifestations of accelerated aging in PD. The function of telomerase reverse transcriptase (TERT) and telomere length (TL) is abnormal in patients with aging and PD. However, the molecular mechanism behind remains unclear. The purpose of this study was to explore the relationship between TERT gene expression (including DNA methylation) and the changes in PD aging characteristics (memory and social function). By TERT gene knockout mice, we found that loss of TERT attenuated the acquisition of recent fear memory during contextual fear conditioning. This study reported that a significantly lower methylation level of human TERT (hTERT) gene was detected in PD patients compared with healthy control and particularly decreased CpG methylation in the promoter region of hTERT was associated with the clinical characteristics in PD. Regional homogeneity (ReHo) analysis showed that the methylation of hTERT (cg1295648) influenced social function of PD patients through moderating the function of the left postcentral gyrus (PCG). This indicates that the hTERT gene may play an important role in the pathological basis of PD aging and may become a biological marker for evaluating PD aging. These findings provide multidimensional evidence for the underlying genetic and pathological mechanisms of PD.

Aging clocks & mortality timers, methylation, glycomic, telomeric and more. A window to measuring biological age

As humans age multiple forms of biological decay ensue, and many aspects of human biology can be measured to determine how far biological machinery has drifted from homeostasis. Research has led to aging clocks being developed that claim to predict biological age as opposed to chronological age. Aging could be regarded as a measured loss of homeostatic biological equilibrium that augments biological decay in fully developed tissues. Measuring aspects of how far various elements of biology have drifted from a youthful state may allow us to make determinations on a subject's health but also make informed predictions on their biological age. As we see across human physiology, many facets that maintain human health taper off such as nicotinamide adenine dinucleotide, glutathione, catalase, super oxide dismutase, and more. Extracellular vesicle density also tapers off during age combined with epigenetic drift, telomere attrition, and stem cell exhaustion, whilst genomic instability and biological insults from environment and lifestyle factors increase. Measuring these types of biomarkers with aging clocks may allow subjects to understand their own health more accurately and enable subjects to better focus on their efforts in the pursuit of longevity and, in addition, allow healthcare practitioners to deliver better health advice.

Association between Physical Activity and Telomere Length in Women with Breast Cancer: A Systematic Review

The association between physical activity and telomere length (TL) has been continuously reported. However, the interplay of physical activity and TL among women with breast cancer has not been elucidated. Thus, the purpose of this systematic review was to synthesize the evidence for the association of physical activity with TL in women with breast cancer. Systematic searches were conducted to identify quantified studies using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and Clinical Trials.gov. Five studies were included in this systematic review. Three of the five studies reported that physical activity has a significant relationship in delaying TL shortening, but others observed no association between physical activity and TL in breast cancer survivors. Although the heterogeneous studies acted as limitations in drawing clear conclusions, physical activity strategies show encouraging impacts in delaying TL shortening. To understand the effects of physical activity on TL shortening in breast cancer survivors, further studies are needed considering the tissue site, treatments for breast cancer, DNA extraction methods, and tools for measuring physical activity.

Co-expression analysis identifies networks of miRNAs implicated in biological ageing and modulated by short-term interval training

Exercise training seems to promote healthy biological ageing partly by inducing telomere maintenance, yet the molecular mechanisms are not fully understood. Recent studies have emphasised the importance of microRNAs (miRNAs) in ageing and their ability to mirror pathophysiological alterations associated with age-related diseases. We examined the association between aerobic fitness and leukocyte telomere length before determining the influence of vigorous exercise training on the regulation of leukocyte miRNA networks. Telomere length was positively correlated to aerobic fitness (r = 0.32, p = 0.02). 104 miRNAs were differentially expressed after six weeks of thrice-weekly sprint interval training (SIT) in healthy men (q < 0.05). Gene co-expression analysis (WGCNA) detected biologically meaningful miRNA networks, five of which were significantly correlated with pre-SIT and post-SIT expression profiles (p < 0.001) and telomere length. Enrichment analysis revealed that the immune response, T cell differentiation and lipid metabolism associated miRNAs clusters were significantly down-regulated after SIT. Using data acquired from the Gene Expression Omnibus (GEO), we also identified two co-expressed miRNAs families that were modulated by exercise training in previous investigations. Collectively, our findings highlight the miRNA networks implicated in exercise adaptations and telomere regulation, and suggest that SIT may attenuate biological ageing through the control of the let-7 and miR-320 miRNA families.

Dietary pattern and telomere length in preschool children in a middle-income country

Telomere length (TL) has been associated with lifestyle and dietary pattern. However, the available evidence on this association in children is scarce, especially in low- and middle-income countries (LMICs). Therefore, this study aimed to evaluate the association of dietary pattern and leukocyte TL (LTL) in preschool children, Sabzevar, Iran (2017). This cross-sectional study was based on 187 preschool children (aged 5 to 7) recruited from 27 kindergartens. Nutrition information including amounts of consumed dairy products, meat and processed meat products, nuts and seeds, white bread and refined grains, fruits, vegetables, simple sugars, fats and drinks was obtained through a questionnaire. Linear mixed-effects models were fitted with polymerase chain reaction (PCR) plate ID and kindergartens as random effects to estimate the association of each food group consumption with LTL, controlled for relevant covariates. Higher consumption of dairy products and sugar was associated with shorter LTL (β = -0.180, 95% confidence interval [CI]: -0.276, -0.085, P value <0.001 and β = -0.139, 95% CI: -0.193, -0.086, P value <0.001, respectively). An increase in consumption of fish, nuts and seeds, coloured fruits, green leafy vegetables, cruciferous vegetables and olive was significantly associated with the increase in relative LTL. The associations for the consumption of legumes, other fruits, yellow and orange vegetables, red meat, egg, white bread and refined grains, solid and liquid fats, processed meats, potato chips, carbonated drinks, tea (black) and soft drinks groups were not statistically significant. Our findings showed that there was an association between the consumption of certain food groups with LTL.

Physical activity advice in the UK bowel cancer screening setting: qualitative healthcare professional perspectives

Providing physical activity advice in the bowel cancer screening setting could help to reduce the risk of cancer and cardiometabolic disease in older adults. This study investigated the views of healthcare professionals (HCPs) regarding the provision of physical activity advice as part of the UK Bowel Cancer Screening Programme. A purposive sample of HCPs (aged 22-63 years, with 1-26 years of experience) from four bowel cancer screening disciplines (four endoscopists, four colorectal surgeons, four staff nurses and four specialist screening practitioners) were recruited from a large National Health Service gastroenterology unit. Data collection used individual interviews and focus groups, with topics being guided by an a priori topic guide. All interviews and focus groups were audio-recorded and transcribed verbatim. Three key themes, which contextualize the views and perceptions of HCPs recruited to the study, emerged from the framework analysis: (i) appraisal of the concept; (ii) perceived barriers to implementation; (iii) steps to implementation. While the general concept was viewed positively, there were differences of opinion and a range of perceived barriers were revealed. Ideas for effective implementation were also presented, taking into consideration the need for time efficiencies and importance of optimizing effectiveness. This qualitative study provided important insights into the perceptions of HCPs regarding the provision of physical activity advice in the bowel cancer screening setting, and yielded novel ideas for effective implementation.

Potential of Naturally Derived Compounds in Telomerase and Telomere Modulation in Skin Senescence and Aging

Proper functioning of cells-their ability to divide, differentiate, and regenerate-is dictated by genomic stability. The main factors contributing to this stability are the telomeric ends that cap chromosomes. Telomere biology and telomerase activity have been of interest to scientists in various medical science fields for years, including the study of both cancer and of senescence and aging. All these processes are accompanied by telomere-length modulation. Maintaining the key levels of telomerase component (hTERT) expression and telomerase activity that provide optimal telomere length as well as some nontelomeric functions represents a promising step in advanced anti-aging strategies, especially in dermocosmetics. Some known naturally derived compounds contribute significantly to telomere and telomerase metabolism. However, before they can be safely used, it is necessary to assess their mechanisms of action and potential side effects. This paper focuses on the metabolic potential of natural compounds to modulate telomerase and telomere biology and thus prevent senescence and skin aging.

Cancer prevention through weight control-where are we in 2020?

Growing data from epidemiological studies highlight the association between excess body fat and cancer incidence, but good indicative evidence demonstrates that intentional weight loss, as well as increasing physical activity, offers much promise as a cost-effective approach for reducing the cancer burden. However, clear gaps remain in our understanding of how changes in body fat or levels of physical activity are mechanistically linked to cancer, and the magnitude of their impact on cancer risk. It is important to investigate the causal link between programmes that successfully achieve short-term modest weight loss followed by weight-loss maintenance and cancer incidence. The longer-term impact of weight loss and duration of overweight and obesity on risk reduction also need to be fully considered in trial design. These gaps in knowledge need to be urgently addressed to expedite the development and implementation of future cancer-control strategies. Comprehensive approaches to trial design, Mendelian randomisation studies and data-linkage opportunities offer real possibilities to tackle current research gaps. In this paper, we set out the case for why non-pharmacological weight-management trials are urgently needed to support cancer-risk reduction and help control the growing global burden of cancer.

Physical Activity and Breast Cancer: A Case-Control Study in Southern Brazil

Physical inactivity is one of the greatest public health challenges in the 21st century. More than five million deaths a year are caused by lack of physical activity (PA) around the world. Despite its relevance to public health, about one-third of the world's adults do not meet current PA recommendations for health benefits. Thus, the aim of the present study was to investigate the association between lifetime PA and risk of breast cancer. A case-control study was conducted between November 2016 and June 2017. The cases were recruited from all cancer centers in the city of Pelotas in southern Brazil. Each case was age-matched (±5 years) with a neighborhood control enrolled based on nearby addresses of the cases. Overall, 230 cases and 231 controls were included. Lifetime leisure-time PA may decrease the odds of breast cancer (adjusted OR = 0.44; 95%CI 0.23-0.86) in the comparison between the most active with the least active quartile. PA was associated with a reduction in the odds of breast cancer. Future studies should aim at understanding the physiological pathways that could explain how an active lifestyle influences this disease, helping in the establishment of volume and intensities necessary to obtain the benefits.

The effect of long-term ultra-endurance exercise and SOD2 genotype on telomere shortening with age

Habitual ultra-endurance exercise seems to promote telomere length maintenance, especially at older ages. In addition, the beneficial effect of ultra-endurance training on biological aging is higher in ultra-trail runners who have been engaged to ultra-endurance training during many years. Finally, and for the first time, this study shows that the SOD2 rs4880 polymorphism has a significant impact on telomere length, as well as on acute inflammatory response to a 107-km trail race.

No effect of the endurance training status on senescence despite reduced inflammation in skeletal muscle of older individuals

The aim of the present study was to determine if the training status decreases inflammation, slows down senescence, and preserves telomere health in skeletal muscle in older compared with younger subjects, with a specific focus on satellite cells. Analyses were conducted on skeletal muscle and cultured satellite cells from vastus lateralis biopsies (n = 34) of male volunteers divided into four groups: young sedentary (YS), young trained cyclists (YT), old sedentary (OS), and old trained cyclists (OT). The senescence state and inflammatory profile were evaluated by telomere dysfunction-induced foci (TIF) quantification, senescence-associated β-galactosidase (SA-β-Gal) staining, and quantitative (q)RT-PCR. Independently of the endurance training status, TIF levels (+35%, P < 0.001) and the percentage of SA-β-Gal-positive cells (+30%, P < 0.05) were higher in cultured satellite cells of older compared with younger subjects. p16 (4- to 5-fold) and p21 (2-fold) mRNA levels in skeletal muscle were higher with age but unchanged by the training status. Aging induced higher CD68 mRNA levels in human skeletal muscle (+102%, P = 0.009). Independently of age, both trained groups had lower IL-8 mRNA levels (-70%, P = 0.011) and tended to have lower TNF-α mRNA levels (-40%, P = 0.10) compared with the sedentary subjects. All together, we found that the endurance training status did not slow down senescence in skeletal muscle and satellite cells in older compared with younger subjects despite reduced inflammation in skeletal muscle. These findings highlight that the link between senescence and inflammation can be disrupted in skeletal muscle.

Telomerase inhibition decreases esophageal squamous carcinoma cell migration and invasion

Telomerase has been shown to be associated with a variety of cancer types. To elucidate the role of telomerase in esophageal squamous carcinoma (ESCC), tissue samples from 100 patients with ESCC, and paired paracancerous tissues from 75 of these patients, were collected for use in the present study. Using immunohistochemical analysis, the expression of telomerase reverse transcriptase (hTERT) in the cytoplasm of ESCC cells was revealed to be significantly higher compared with that in paracancerous tissues, and no significant difference was observed between hTERT expression in the nucleus of ESCC and paracancerous tissue cells. Combined analysis revealed that the cytoplasmic hTERT-positive rate of patients with ESCC was significantly associated with pathological grade, N stage and Tumor-Node-Metastasis (TNM) stage; these data support the association between hTERT expression and poor patient prognosis. In vitro experiments demonstrated that hTERT knockdown does not inhibit the proliferation of ESCC Kyse410 or Kyse520 cells, but inhibits their migration and invasion abilities. These findings indicate that hTERT expression is associated with ESCC metastasis. Interestingly, decreased colony-formation ability was observed in Kyse410 cells, but not in Kyse520 cells. Collectively, the results of the present study suggest that hTERT may serve as a potential therapeutic target for ESCC.

Telomerase: Key regulator of inflammation and cancer

The telomerase holoenzyme, which has a highly conserved role in maintaining telomere length, has long been regarded as a high-profile target in cancer therapy due to the high dependency of the majority of cancer cells on constitutive and elevated telomerase activity for sustained proliferation and immortality. In this review, we present the salient findings in the telomerase field with special focus on the association of telomerase with inflammation and cancer. The elucidation of extra-telomeric roles of telomerase in inflammation, reactive oxygen species (ROS) generation, and cancer development further complicated the design of anti-telomerase therapy. Of note, the discovery of the unique mechanism that underlies reactivation of the dormant telomerase reverse transcriptase TERT promoter in somatic cells not only enhanced our understanding of the critical role of TERT in carcinogenesis but also opens up new intervention ideas that enable the differential targeting of cancer cells only. Despite significant effort invested in developing telomerase-targeted therapeutics, devising efficacious cancer-specific telomerase/TERT inhibitors remains an uphill task. The latest discoveries of the telomere-independent functionalities of telomerase in inflammation and cancer can help illuminate the path of developing specific anti-telomerase/TERT therapeutics against cancer cells.

Does Physical Activity Regulate Prostate Carcinogenesis and Prostate Cancer Outcomes? A Narrative Review

Background: Prostate cancer (PCa) represents a common disease in men aged >65 years. The role of physical activity (PA) in patients at risk or diagnosed with PCa represents an evolving issue. We aimed to summarize available evidences about the impact of PA on the pathophysiology and clinical outcomes of PCa. Methods: We performed a narrative review. Evidences about the role of PA in elderly patients in terms of PCa biology, epidemiology, oncological and functional outcomes, as well as in terms of impact on the outcomes of androgen deprivation therapy (ADT) were summarized. Results: Potential pathophysiological pathways hypothesized to explain the benefits of PA in terms of prostate carcinogenesis include circulating levels of Insulin-like growth factor-1 (IGF-1), oxidative stress, systemic inflammation, sex hormones, and myokines. Clinically, emerging evidences support the hypothesis that PA is associated with decreased PCa risk, improved PCa-related survival, improved functional outcomes, and reduced ADT-related adverse events.

Shortened Leukocyte Telomere Length Associates with an Increased Prevalence of Chronic Health Conditions among Survivors of Childhood Cancer: A Report from the St. Jude Lifetime Cohort

PURPOSE

We aimed to analyze and compare leukocyte telomere length (LTL) and age-dependent LTL attrition between childhood cancer survivors and noncancer controls, and to evaluate the associations of LTL with treatment exposures, chronic health conditions (CHC), and health behaviors among survivors.

EXPERIMENTAL DESIGN

We included 2,427 survivors and 293 noncancer controls of European ancestry, drawn from the participants in St. Jude Lifetime Cohort Study (SJLIFE), a retrospective hospital-based study with prospective follow-up (2007-2016). Common nonneoplastic CHCs (59 types) and subsequent malignant neoplasms (5 types) were clinically assessed. LTL was measured with whole-genome sequencing data.

RESULTS

After adjusting for age at DNA sampling, gender, genetic risk score based on 9 SNPs known to be associated with telomere length, and eigenvectors, LTL among survivors was significantly shorter both overall [adjusted mean (AM) = 6.20 kb; SE = 0.03 kb] and across diagnoses than controls (AM = 6.69 kb; SE = 0.07 kb). Among survivors, specific treatment exposures associated with shorter LTL included chest or abdominal irradiation, glucocorticoid, and vincristine chemotherapies. Significant negative associations of LTL with 14 different CHCs, and a positive association with subsequent thyroid cancer occurring out of irradiation field were identified. Health behaviors were significantly associated with LTL among survivors aged 18 to 35 years (P _trend = 0.03).

CONCLUSIONS

LTL is significantly shorter among childhood cancer survivors than noncancer controls, and is associated with CHCs and health behaviors, suggesting LTL as an aging biomarker may be a potential mechanistic target for future intervention studies designed to prevent or delay onset of CHCs in childhood cancer survivors.See related commentary by Walsh, p. 2281.

The Relationship between Telomere Length and Cancer Mortality: Data from the 1999-2002 National Healthy and Nutrition Examination Survey (NHANES)

OBJECTIVES

The association between telomeres length (TL) and cancer mortality is uncertain. We tested the hypotheses that long TL are associated with reduced cancer mortality.

DESIGN

Prospective cohort study.

SETTING

the National Health and Nutrition Survey (NHANES, 1999-2002).

PARTICIPANTS

The analytic sample included adults (n = 7183) who had TL measurements.

MEASUREMENTS

DNA was obtained via blood samples. Telomere length was assessed using the quantitative polymerase chain reaction method.

RESULTS

During follow-up (0.08-12.7 person-years, median = 9.5 years), we observed 195 participants had cancer as causes of death. TL was negatively corelated with age, body mass index (BMI), systolic blood pressure (SBP), C-reactive protein (CRP), race, diabetes, hypertension, cardiovascular diseases (CVD) and cancer mortality, conversely, positively corelated with alcohol use, but not related to diastolic blood pressure (DBP) and smoking. Kaplan-Meier analysis revealed that TL was significantly associated with cancer mortality (log-rank, P <0.001).

CONCLUSIONS

Our study expands upon previous evidence of a relationship between TL and cancer mortality. TL may be a useful tool for evaluating risk of cancer mortality in American adults.

Associations of sperm telomere length with semen parameters, clinical outcomes and lifestyle factors in human normozoospermic samples

BACKGROUND

Many studies have demonstrated that lifestyle factors can affect sperm quality and fertility. Sperm telomere length (STL) has been reported as potential biomarker or sperm quality. However, no studies have investigated how lifestyle factors can affect STL and associated clinical outcomes.

OBJECTIVES

The purpose of this manuscript is to investigate any association between STL with lifestyle factors, semen parameters and clinical outcomes.

MATERIALS AND METHODS

Sperm telomere length was measured using real-time PCR in normozoospermic male partners (n = 66) of couples undergoing ART treatment. Each participant also completed a detailed questionnaire about general lifestyle. Linear regression univariate analysis and ANCOVA were performed to respectively determine correlations between STL and study parameters or identify statistically significant differences in STL while controlling for age, BMI and other factors.

RESULTS

Using a linear regression model, STL is positively correlated with in vitro fertilization success (n = 65, r = 0.37, P = .004) but not with embryo cleavage rates and post-implantation clinical outcomes including gestational age-adjusted birth weight. No associations were observed between STL and sperm count, concentration or progressive motility. We further found that STL did not associate age, BMI, health or lifestyle factors.

DISCUSSION

In somatic cells, the rate of telomere shortening is influenced by a number of lifestyle factors such as smoking, diet and occupation. However, little is known about how lifestyle factors affect STL and subsequently reproductive outcome. Out data suggest that STL might have an important role mechanistically for fertilization rate regardless of sperm parameters and lifestyle factors.

CONCLUSION

The results of this study demonstrate that STL is associated with in vitro fertilization rates, but not with semen parameters nor lifestyle factors. Further investigations are warranted to identify the potential variation of STL overtime to clarify its significance as a potential biomarker in ART.