ABSTRACT
Although oncogene-induced senescence (OIS) is a potent tumor-suppressor mechanism, recent studies revealed that cells could escape from OIS with features of transformed cells. However, the mechanisms that promote OIS escape remain unclear, and evidence of post-senescent cells in human cancers is missing. Here, we unravel the regulatory mechanisms underlying OIS escape using dynamic multidimensional profiling. We demonstrate a critical role for AP1 and POU2F2 transcription factors in escape from OIS and identify senescence-associated chromatin scars (SACSs) as an epigenetic memory of OIS detectable during colorectal cancer progression. POU2F2 levels are already elevated in precancerous lesions and as cells escape from OIS, and its expression and binding activity to cis-regulatory elements are associated with decreased patient survival. Our results support a model in which POU2F2 exploits a precoded enhancer landscape necessary for senescence escape and reveal POU2F2 and SACS gene signatures as valuable biomarkers with diagnostic and prognostic potential.
ABSTRACT
As the global elderly population grows, it is socioeconomically and medically critical to provide diverse and effective means of mitigating the impact of aging on human health. Previous studies showed that the adeno-associated virus (AAV) vector induced overexpression of certain proteins, which can suppress or reverse the effects of aging in animal models. In our study, we sought to determine whether the high-capacity cytomegalovirus vector (CMV) can be an effective and safe gene delivery method for two such protective factors: telomerase reverse transcriptase (TERT) and follistatin (FST). We found that the mouse cytomegalovirus (MCMV) carrying exogenous TERT or FST (MCMVTERT or MCMVFST) extended median lifespan by 41.4% and 32.5%, respectively. We report CMV being used successfully as both an intranasal and injectable gene therapy system to extend longevity. Specifically, this treatment significantly improved glucose tolerance, physical performance, as well as preventing body mass loss and alopecia. Further, telomere shortening associated with aging was ameliorated by TERT and mitochondrial structure deterioration was halted in both treatments. Intranasal and injectable preparations performed equally well in safely and efficiently delivering gene therapy to multiple organs, with long-lasting benefits and without carcinogenicity or unwanted side effects. Translating this research to humans could have significant benefits associated with quality of life and an increased health span.
Subject(s)
Cytomegalovirus Infections , Genetic Therapy , Life Expectancy , Telomerase , Administration, Inhalation , Animals , Follistatin/genetics , Genetic Therapy/adverse effects , Genetic Therapy/methods , Genetic Vectors/genetics , Injections, Intraperitoneal , Mice , Models, Animal , Neoplasms , Telomerase/genetics , Telomerase/metabolismABSTRACT
BACKGROUND: Obesity in adulthood is associated with decreased leucocyte telomere length (LTL), which is associated with cardiovascular disease and diabetes mellitus type 2. The aim of our study was to investigate whether increased body mass index (BMI) is associated with decreased LTL in children and adolescents, and to identify other risk factors of shorter LTL in this population. MATERIALS AND METHODS: A cross-sectional study was conducted among 919 Greek children aged 9-13 years (The Healthy Growth Study). Participants were classified as obese (n = 124), overweight (n = 276) or of normal BMI (n = 519). LTL was determined by monochrome multiplex quantitative real-time polymerase chain reaction. Univariate and multivariable linear regression analyses were applied to determine the predictive factors of LTL. RESULTS: Both overweight and obese children had significantly shorter LTL than their normal-BMI counterparts. Following adjustment for age, sex, total daily energy intake and average weekly physical activity (average total steps per day), increasing weight category was inversely associated with LTL in children and adolescents (ß: -0.110 ± 0.035; P = .002). CONCLUSION: Overweight and obesity in childhood and adolescence are associated with shorter LTL, even following adjustment for potential confounding effects. Therefore, the increased BMI in childhood and adolescence may be associated with accelerated biological ageing and may have an adverse impact on future health in adulthood.
Subject(s)
Aging/metabolism , Leukocytes/metabolism , Pediatric Obesity/metabolism , Telomere/metabolism , Adolescent , Body Mass Index , Case-Control Studies , Child , Female , Greece , Humans , Linear Models , Male , Multiplex Polymerase Chain Reaction , Multivariate Analysis , Real-Time Polymerase Chain ReactionABSTRACT
Objective: Telomeres are specialized nucleoprotein structures located at the ends of chromosomes, which play a crucial role in genomic stability. Telomere shortening has been proposed as a biomarker for the onset of age-related diseases. This study aimed to determine whether restricted or increased intrauterine growth affects leukocyte telomere length (LTL) at birth. Materials and methods: One hundred sixty-five (n = 165) full-term neonates participated in the study. Fetuses were classified as intrauterine growth restriction (IUGR, n = 21), large-for-gestational-age (LGA, n = 15), or appropriate-for-gestational-age (AGA, n = 129), based on customized birth-weight standards. Mixed arteriovenous cord blood samples were collected for isolation of leukocyte DNA. The LTL was measured using multiplex monochrome quantitative real-time PCR and telomeric restriction fragments through Southern blot analysis (terminal restriction fragment [TRF]). Results: Despite differences among groups in birth weight, length and head circumference, LTL did not differ among AGA (6.78 ± 0.58), IUGR (10.54 ± 1.80), and LGA (11.95 ± 2.42) neonates (p = .098). Cord blood IGF-1 and IGFBP-3 concentrations were higher in the LGA group. LTL positively correlated with birth length (r = 0.176, p = .032). Conclusions: Intrauterine growth does not seem to affect LTL at birth. Further studies, comprising a larger sample size of IUGR, LGA, and AGA neonates, are required to determine whether growth at birth influences LTL.