Genetic variations associated with telomere length affect the risk of gastric carcinoma

Association of telomerase reverse transcriptase gene rs10069690 variant with cancer risk: an updated meta-analysis

OBJECTIVE

Existing evidence suggests telomerase activation is a crucial step in tumorigenesis. The telomerase reverse transcriptase (TERT), encoded by the human TERT gene, is critical for telomerase expression. The TERT rs10069690 (C > T) variant was identified to be associated with the risk of cancer, however, there have been inconsistent results. Therefore, we performed a comprehensive meta-analysis aiming to clarify the association between this variant and cancer susceptibility.

METHODS

We conducted literature search in PubMed, EMbase, MEDLINE and Cochrane Library up to April 30, 2024. Overall, there are 55 studies involving 334,196 patients with cancer and 741,187 controls included in the present study. All statistical analyses were performed by STATA software (version 11.0).

RESULTS

The pooled results showed a significant association between rs10069690 and an increased risk of cancer under allele model (OR = 1.10, 95% CI: 1.07-1.13, P < 0.001), especially in European and Asian populations. When stratified by cancer types, this variant was associated with elevated risk of breast cancer (OR = 1.11, 95% CI: 1.07-1.15, P < 0.001), ovarian cancer (OR = 1.14, 95% CI: 1.10-1.19, P < 0.001), lung cancer (OR = 1.20, 95% CI: 1.07-1.35, P = 0.003), thyroid cancer (OR = 1.23, 95% CI: 1.15-1.32, P < 0.001), gastric cancer (OR = 1.31, 95% CI: 1.19-1.45, P < 0.001), and renal cell carcinoma (OR = 1.29, 95% CI: 1.07-1.55, P = 0.007), while decreased risk was found for hepatocellular carcinoma, prostate cancer and pancreatic cancer. Our results also indicated that this variant was significantly associated with solid cancer (OR = 1.11, 95% CI: 1.07-1.14, P < 0.001), but not with hematological tumor.

CONCLUSION

This systematic meta-analysis demonstrated that the TERT rs10069690 variant was a risk factor for cancer. However, the effects of this variant may vary in different types of cancer and differ across ethnic populations.

Parental telomeres implications on immune senescence of newborns

Telomere, the biological chronometer, and its effect on the immune system considerably varies among individuals. During pregnancy, multiple risk factors affect telomere reprogramming during fetal life which can lead to health disparities in newborns. These changes may cause a long-term impact on the telomere genetics of the newborn and become a reason for lifelong health implications and immune senescence. Therefore, telomere shortening in parents due to genetic variation may act as a hallmark of immune senescence and aging in their newborns.

Role of telomere length in human carcinogenesis (Review)

Cancer is considered the most important clinical, social and economic issue regarding cause‑specific disability‑adjusted life years among all human pathologies. Exogenous, endogenous and individual factors, including genetic predisposition, participate in cancer triggering. Telomeres are specific DNA structures positioned at the end of chromosomes and consist of repetitive nucleotide sequences, which, together with shelterin proteins, facilitate the maintenance of chromosome stability, while protecting them from genomic erosion. Even though the connection between telomere status and carcinogenesis has been identified, the absence of a universal or even a cancer‑specific trend renders consent even more complex. It is indicative that both short and long telomere lengths have been associated with a high risk of cancer incidence. When evaluating risk associations between cancer and telomere length, a disparity appears to emerge. Even though shorter telomeres have been adopted as a marker of poorer health status and an older biological age, longer telomeres due to increased cell growth potential are associated with the acquirement of cancer‑initiating somatic mutations. Therefore, the present review aimed to comprehensively present the multifaceted pattern of telomere length and cancer incidence association.

Association between telomere length and mitochondrial copy number and cancer risk in humans: A meta-analysis on more than 300,000 individuals

In the last decades the association of leukocyte telomere length (LTL) and mitochondrial copy number (mtDNAcn) with cancer risk has been the focus of many reports, however the relation is not yet completely understood. A meta-analysis of 112 studies including 64,184 cancer cases and 278,641 controls that analysed LTL and mtDNAcn in relation to cancer risk has been conducted to further our understanding of the topic. Stratified analyses for tumor type were also performed. Overall, no association was observed for all cancer combined neither for LTL nor mtDNAcn. Significant associations were detected for these biomarkers and specific cancer type; however, a large degree of heterogeneity was present, even within the same tumor type. Alternatives approaches based on polymorphic variants, such as polygenic risk scores and mendelian randomization, could be adopted to unravel the causal correlation of telomere length and mitochondrial copy number with cancer risk.