Telomere shortening and telomerase activation occur frequently in cases of colorectal carcinoma. In this study, we correlated the clinicopathological parameters with the telomere length in colorectal carcinomas, colonic polyps, and normal colonic tissues. We also investigated whether the telomere length changes reflect the biologic behavior of tumors and different modes of tumor development. Te...

Telomere lengths are tightly regulated within a narrow range in normal human cells. Previous studies have extensively focused on how short telomeres are extended and have demonstrated that telomerase plays a central role in elongating short telomeres. However, much about the molecular mechanisms of regulating excessively long telomeres is unknown. In this report, we demonstrated that the telome...

Background: Chronic Obstructive Pulmonary Disease (COPD) may be associated with accelerated aging. Telomere shortening is a biomarker of aging. Cross-sectional studies describe shorter telomeres in COPD compared with matched controls. No studies have described telomere length trajectory and its relationship with COPD progression. We investigated telomere shortening over time and its relationshi...

Telomere shortening limits the proliferative capacity of human cells, and age-dependent shortening of telomeres occurs in somatic tissues including hematopoietic stem cells (HSCs). It is currently unknown whether genomic and molecular damage that occurs in HSCs induced by telomere shortening is transmitted to the progenitor cells. Here we show that telomere shortening results in DNA damage accu...

Telomere shortening limits proliferative capacity of human cells and age dependent shortening of telomeres occurs in somatic tissues including hematopoietic stem cells (HSCs). It is currently unknown whether genomic and molecular damages occur in HSC induced by telomere shortening are transmitted to the progenitor cells. Here we show that telomere shortening results in DNA damage accumulation a...

Telomeres are transcribed into non-coding TElomeric Repeat containing RNAs (TERRA). We have employed a transcriptionally inducible telomere to investigate how telomere transcription affects telomere function in Saccharomyces cerevisiae. We report that telomere shortening resulting from high levels of telomere transcription stems from a DNA replication-dependent loss of telomere tracts, which ca...

A general branching process model is proposed to describe the shortening of telomeres in eukaryotic chromosomes. The model is flexible and incorporates many special cases to be found in the literature. In particular, we show how telomere shortening can give rise to sigmoidal growth curves, an idea first expressed by Portugal et al. [A computational model for telomere-dependent cell-replicative ...

Telomere studies in carcinomas have been extensively reported for prognostic utility and effective methods for targeting telomerase therapy has been described, but efficacy of telomerase inhibitor remained unknown in sarcoma cells. In this study, we investigated the effects of telomerase inhibitor cationic porphyrin TMPyP4 on telomerase activity, telomere length, cell growth, and apoptosis in o...

Epidemiological studies indicate that exposure to stress during intrauterine life is associated with shorter telomeres in young adulthood, and a correlation between telomere length in early life and lifespan has been suggested. However, empirical studies evaluating these phenomena have not been performed, and the mechanism of stress-induced telomere shortening remains unknown. Since the level o...

Replicative senescence, induced by telomere shortening, exhibits considerable asynchrony and heterogeneity, the origins of which remain unclear. Here, we formally study how telomere shortening mechanisms impact on senescence kinetics and define two regimes of senescence, depending on the initial telomere length variance. We provide analytical solutions to the model, highlighting a non-linear re...