Analysis of telomere length variation and Shelterin complex subunit gene expression changes in ethanol-exposed human embryonic stem cells

Prognostic significance of dysregulation of shelterin complex and its correlation with telomere length and cytogenetics in multiple myeloma

BACKGROUND

MM (multiple myeloma) is a bone marrow disease with the accumulation of malignant plasma cells characterized by the neoplastic transformation of differentiated B cells. The onset and progression of cancer are greatly influenced by telomere dysfunction. We aimed to study the biomarker potential and prognostic significance of shelterin complex and hTERT. Telomere length and gene expression were measured using real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and these results were further correlated with clinical parameters.

RESULTS

Our study showed increased expression of all genes in complex, hTERT, and TL in MM (n = 72) in comparison with controls (n = 31). TRF2 (P = 0.025) and hTERT (P = 0.0002) displayed significant association among cytogenetic analysis. The receiver operative curve showed POT1 and RAP1 with a greater area under the curve (AUC). RAP1 (P = 0.020) and hTERT (P = 0.037) displayed to be independent prognostic markers for overall survival. Clinical parameters and genes were observed to be significantly correlated.

CONCLUSION

Our study findings showed variation in telomere-associated genes and suggest the participation of these genes as prognostic markers in MM. These results all together highlight the evaluation and role of genes involved in telomeric alteration and TL, providing the opportunity to study new therapeutic approaches in patients with MM.

The telomere regulatory gene POT1 responds to stress and predicts performance in nature: Implications for telomeres and life history evolution

Telomeres are emerging as correlates of fitness-related traits and may be important mediators of ecologically relevant variation in life history strategies. Growing evidence suggests that telomere dynamics can be more predictive of performance than length itself, but very little work considers how telomere regulatory mechanisms respond to environmental challenges or influence performance in nature. Here, we combine observational and experimental data sets from free-living tree swallows (Tachycineta bicolor) to assess how performance is predicted by the telomere regulatory gene POT1, which encodes a shelterin protein that sterically blocks telomerase from repairing the telomere. First, we show that lower POT1 gene expression in the blood was associated with higher female quality, that is, earlier breeding and heavier body mass. We next challenged mothers with an immune stressor (lipopolysaccharide injection) that led to "sickness" in mothers and 24 h of food restriction in their offspring. While POT1 did not respond to maternal injection, females with lower constitutive POT1 gene expression were better able to maintain feeding rates following treatment. Maternal injection also generated a 1-day stressor for chicks, which responded with lower POT1 gene expression and elongated telomeres. Other putatively stress-responsive mechanisms (i.e., glucocorticoids, antioxidants) showed marginal responses in stress-exposed chicks. Model comparisons indicated that POT1 mRNA abundance was a largely better predictor of performance than telomere dynamics, indicating that telomere regulators may be powerful modulators of variation in life history strategies.