Potential maximum life span of humans is estimated around 115-120 years by Cutler. His estimate agrees with an earlier observation by Buffon who claimed that animals tended to live six times the period needed to complete their growth. As humans reach their skeletal maturity at approximately 20 years. Life span has not changed throughout recorded history. Life expectany, the actual average survival for certain given population has increased thanks to social, economic and medical advances. There are two basic levels of biological explanations on aging: macrobiological and microbiological. Macrobiological explanation includes homeostasis, immune system, endocrine, lifestyle, nutrition and environment. Microbiological explanation includes cellular clock theory, free radical theory and metabolic theory with nutrition and antioxidants. Recent advances of genetics opened new era on telomere and telemorase. Gene therapy is applied mainly at the laboratory or limited as local use under investigation. Although the results are encouraging at the laboratory, application for clinical purpose will need tremendous thorough trial and errors.
Aging ; Animals ; Antioxidants ; Genetic Therapy ; Genetics ; Homeostasis ; Humans ; Immune System ; Life Style ; Telomere

Short telomeres are known as one of the risk factors for human cancers. The present study was conducted to evaluate the association between 6 polymorphisms, which were related with short telomere length in the Korean population, and lung cancer risk using 1,100 cases and 1,096 controls. Among the 6 polymorphisms, TERT rs2853669 was significantly associated with increased lung cancer risk under a recessive model (odds ratio [OR]=1.38, 95% confidence interval [CI]=1.05-1.81, P=0.02). The effect of rs2853669 on lung cancer risk was significant in younger individuals (OR=1.73, 95% CI=1.18-2.54, P=0.005) and adenocarcinoma (OR=1.50, 95% CI=1.07-2.07, P=0.02). Our results suggest that a common functional promoter polymorphism, TERT rs2853669, may influence both telomere length and lung cancer risk in the Korean population.
Adenocarcinoma/epidemiology/*genetics ; Case-Control Studies ; Female ; Gene Frequency/genetics ; Genetic Association Studies ; Genetic Predisposition to Disease ; Humans ; Lung Neoplasms/epidemiology/*genetics ; Male ; Middle Aged ; Polymorphism, Single Nucleotide/*genetics ; Promoter Regions, Genetic/*genetics ; Republic of Korea/epidemiology ; Telomerase/*genetics ; Telomere/physiology ; Telomere Homeostasis/*genetics

BACKGROUND/AIMS: A number of genome-wide and candidate gene association studies have identified polymorphisms associated with telomere length in Caucasian populations. This study was conducted to determine the impacts of 17 polymorphisms identified in Caucasians on telomere length in a Korean population. METHODS: Ninety-four healthy individuals were enrolled in this study. Relative telomere length of chromosomes from peripheral blood samples was measured using quantitative polymerase chain reaction. RESULTS: Two polymorphisms, rs10936599 of MYNN and rs412658 of ZNF676, were found to be associated w ith telomere length (under dominant model, p = 0.04; under recessive model, p = 0.001). Three polymorphisms, rs2853669, rs7705526, and rs2736108, at the TERT locus were also associated with telomere length (under recessive model, p = 0.01, p = 0.02, and p = 0.01, respectively). The genotypes of the five polymorphisms associated with short telomere length were considered bad genotypes; telomere length was significantly decreased with increasing number of bad genotypes (p= 1.7 x 10(-5)). CONCLUSIONS: We have identified polymorphisms associated with telomere length in a Korean population.
Adult ; Aged ; Asian Continental Ancestry Group/*genetics ; Case-Control Studies ; DNA-Binding Proteins/genetics ; Female ; Genome-Wide Association Study ; Genotype ; Humans ; Kruppel-Like Transcription Factors/genetics ; Male ; Middle Aged ; Phenotype ; *Polymorphism, Single Nucleotide ; Republic of Korea ; Telomerase/genetics ; Telomere/*genetics/metabolism ; *Telomere Homeostasis ; Zinc Fingers

Human telomerase reverse transcriptase (hTERT) plays a central role in telomere lengthening for continuous cell proliferation, but it remains unclear how extracellular cues regulate telomerase lengthening of telomeres. Here we report that the cytokine bone morphogenetic protein-7 (BMP7) induces the hTERT gene repression in a BMPRII receptor- and Smad3-dependent manner in human breast cancer cells. Chonic exposure of human breast cancer cells to BMP7 results in short telomeres, cell senescence and apoptosis. Mutation of the BMPRII receptor, but not TGFbRII, ACTRIIA or ACTRIIB receptor, inhibits BMP7-induced repression of the hTERT gene promoter activity, leading to increased telomerase activity, lengthened telomeres and continued cell proliferation. Expression of hTERT prevents BMP7-induced breast cancer cell senescence and apoptosis. Thus, our data suggest that BMP7 induces breast cancer cell aging by a mechanism involving BMPRII receptor- and Smad3-mediated repression of the hTERT gene.
Actin-Related Protein 2 ; genetics ; metabolism ; Activin Receptors, Type II ; genetics ; metabolism ; Bone Morphogenetic Protein 7 ; genetics ; metabolism ; Bone Morphogenetic Protein Receptors, Type II ; genetics ; metabolism ; Breast Neoplasms ; genetics ; metabolism ; Cellular Senescence ; Female ; HeLa Cells ; Humans ; MCF-7 Cells ; Neoplasm Proteins ; genetics ; metabolism ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Receptor, Transforming Growth Factor-beta Type II ; Receptors, Transforming Growth Factor beta ; genetics ; metabolism ; Smad3 Protein ; genetics ; metabolism ; Telomerase ; genetics ; metabolism ; Telomere Homeostasis

Werner syndrome (WS) is a premature aging disorder that mainly affects tissues derived from mesoderm. We have recently developed a novel human WS model using WRN-deficient human mesenchymal stem cells (MSCs). This model recapitulates many phenotypic features of WS. Based on a screen of a number of chemicals, here we found that Vitamin C exerts most efficient rescue for many features in premature aging as shown in WRN-deficient MSCs, including cell growth arrest, increased reactive oxygen species levels, telomere attrition, excessive secretion of inflammatory factors, as well as disorganization of nuclear lamina and heterochromatin. Moreover, Vitamin C restores in vivo viability of MSCs in a mouse model. RNA sequencing analysis indicates that Vitamin C alters the expression of a series of genes involved in chromatin condensation, cell cycle regulation, DNA replication, and DNA damage repair pathways in WRN-deficient MSCs. Our results identify Vitamin C as a rejuvenating factor for WS MSCs, which holds the potential of being applied as a novel type of treatment of WS.
Animals ; Ascorbic Acid ; pharmacology ; Cell Cycle Checkpoints ; drug effects ; Cell Line ; Cellular Senescence ; drug effects ; DNA Damage ; DNA Repair ; drug effects ; DNA Replication ; drug effects ; Disease Models, Animal ; Heterochromatin ; metabolism ; pathology ; Humans ; Mesenchymal Stem Cells ; metabolism ; pathology ; Mice ; Nuclear Lamina ; metabolism ; pathology ; Reactive Oxygen Species ; metabolism ; Telomere Homeostasis ; drug effects ; Werner Syndrome ; drug therapy ; genetics ; metabolism