Quantitative assessment of common genetic variants on chromosome 5p15 and lung cancer risk

Association between hTERT Polymorphisms and Female Papillary Thyroid Carcinoma

BACKGROUND

A previous genome-wide association study showed that hTERT rs10069690 and rs2736100 polymorphisms were associated with thyroid cancer risk.

OBJECTIVE

This study further investigated the association between increased risk and clinicopathologic characteristics for Papillary Thyroid Carcinoma (PTC) and hTERT polymorphisms rs10069690 or rs2736100 in a Chinese female population.

METHODS

The hTERT genotypes of 276 PTC patients and 345 healthy subjects were determined with regard to SNPs rs10069690 and rs2736100. The association between these SNPs and the risk of PTC and clinicopathologic characteristics was investigated by logistic regression.

RESULTS

We found a significant difference between PTC and rs10069690 (Odds Ratio (OR) = 1.515; P = 0.005), but not between PTC and rs2736100. When the analysis was limited to females, rs10069690 and rs2736100 were both associated with increased risk for PTC in female individuals (OR = 1.647, P = 0.007; OR = 1.339, P = 0.041, respectively). Further haplotype analysis revealed a stimulative effect of haplotypes TC and CA of TERT rs10069690-rs2736100, which increased risk for PTC in female individuals (OR = 1.579, P = 0.014; OR = 0.726, P = 0.025, respectively). Furthermore, the heterozygote A/C of rs2736100 showed significant difference for age (OR = 0.514, P = 0.047).

CONCLUSION

Our finding suggests that hTERT polymorphisms rs10069690 and rs2736100 are associated with increased risk for PTC in Chinese female population and rs2736100 may be related to age. Consistent with US20170360914 and US20170232075, they are expected to be a potential molecular target for anti-cancer therapy.

The TERT rs2736100 polymorphism increases cancer risk: A meta-analysis

Abnormal telomerase activity is implicated in cancer initiation and development. The rs2736100 T > G polymorphism in the telomerase reverse transcriptase (TERT) gene, which encodes the telomerase catalytic subunit, has been associated with increased cancer risk. We conducted a meta-analysis to more precisely assess this association. After a comprehensive literature search of the PubMed and EMBASE databases up to November 1, 2016, 61 articles with 72 studies comprising 108,248 cases and 161,472 controls were included in our meta-analysis. Studies were conducted on various cancer types. The TERT rs2736100 polymorphism was associated with increased overall cancer risk in five genetic models [homozygous model (GG vs. TT): odds ratio (OR) = 1.39, 95% confidence interval (95% CI) = 1.26-1.54, P < 0.001; heterozygous model (TG vs. TT): OR = 1.16, 95% CI = 1.11-1.23, P < 0.001; dominant model (TG + GG vs. TT): OR = 1.23, 95% CI = 1.15-1.31, P < 0.001; recessive model (GG vs. TG + TT): OR = 1.25, 95% CI = 1.16-1.35, P < 0.001; and allele contrast model (G vs. T): OR = 1.17, 95% CI = 1.12-1.23, P < 0.001]. A stratified analysis based on cancer type associated the polymorphism with elevated risk of thyroid cancer, bladder cancer, lung cancer, glioma, myeloproliferative neoplasms, and acute myeloid leukemia. Our results confirm that the TERT rs2736100 polymorphism confers increased overall cancer risk.

CLPTM1L gene rs402710 (C > T) and rs401681 (C > T) polymorphisms associate with decreased cancer risk: a meta-analysis

Cleft lip and palate transmembrane 1-like (CLPTM1L) gene rs402710 (C > T) and rs401681 (C > T) polymorphisms have been widely studied for their potential relation to cancer risk, but studies have produced conflicting results. To systematically evaluate the association between these two polymorphisms and overall cancer risk, we conducted a comprehensive meta-analysis on all relevant articles found in the PubMed and EMBASE databases published prior to May 1, 2017. There were 26 articles with 28 studies, including 30,770 cases and 34,089 controls, for the rs402710 polymorphism and 38 articles with 48 studies, including 67,849 cases and 328,226 controls, for the rs401681 polymorphism. The pooled results indicated that both rs402710 and rs401681 polymorphisms are significantly associated with decreased overall cancer risk. In our stratification analysis, a significant association of the rs402710 polymorphism with lung and bladder cancers was identified among Asian and Caucasian populations in both hospital-based and population-based studies. The rs401681 polymorphism was significantly associated with a decreased risk of lung cancer, bladder cancer, and basal cell carcinoma in Asians and in hospital-based studies. CLPTM1L gene rs402710 and rs401681 polymorphisms thus have a protective association with various types of cancer, especially lung cancer among Asians.

Germline mutations predisposing to non-small cell lung cancer

Lung cancer in multiple first degree relatives had previously been attributed to smoking and to inherited enzymes associated with increased activation of carcinogens in smoke. There was not clear agreement on the significance of the testing methods for lung cancer susceptibility. More recent studies have identified germline mutations associated with lung cancer even in the absence of smoking and other mutations with plausible explanations for their association with lung cancer caused by smoking. At this time, the clinical significance of the various germline mutations for screening and the implications for therapy are not certain. This review summarizes the currently identified germline mutations associated with lung cancer, but this growing area of research will very likely identify further significant mutations as well.

Genetic variations in TERT-CLPTM1L genes and risk of lung cancer in a Chinese population

The objective of the present study was to analyze the relationship between genetic polymorphisms of the rs2736098 locus of the telomerase reverse transcriptase (TERT) gene and the rs401681 locus of the cleft lip and palate transmembrane protein 1 (CLPTM1L) gene and the risk of developing lung cancer in males in Jinzhou. A total of 214 lung cancer patients who were admitted in Jinzhou Medical University were analyzed, and 216 healthy males were selected as controls. Venous blood from all subjects and data on relevant risk factors were collected. DNA was extracted from peripheral blood by the phenol-chloroform method. Real-time fluorescent quantitative PCR (TaqMan real-time PCR) was used for DNA amplification. The genotyping results of the genetic polymorphisms of the TERT rs2736098 and CLPTM1L rs401681 loci were detected. The risk of developing lung cancer in the population with the TERT rs2736098 locus carrying the T allele was 1.614 times that with the TERT rs2736098 locus carrying the C allele after adjustment of the age factor. The risk of developing lung cancer in the population carrying the TT mutant genotype and the CT genotype increased significantly compared with that carrying the CC wild genotype [odds ratio (OR)=1.815, 95% CI=1.132–2.957; OR=2.417, 95% CI=1.158–4.943]. Based on a comparison between the combination of the two mutant genotypes (CT+TT) and the wild homozygous genotype (CC), the mutant genotype increased the risk of developing lung cancer (OR=1.955, 95% CI=1.213–3.157). The risk of developing lung cancer in the population with the CLPTM1L rs401681 locus carrying the T allele was 1.399 times that carrying the C allele (OR=1.343, 95% CI=1.035–1.978). The population with the TERT rs2736098 locus carrying the mutant genotype (CT+TT) was associated with the number of tumors (OR=0.553, 95% CI=0.236–0.928). In conclusion, in males, the TERT rs2736098 and CLPTM1L rs401681 T alleles are the susceptibility factors for developing lung cancer. Individuals, including the smoking population, who carry both the TERT rs2736098 and CLPTM1L rs401681 T alleles are more likely to develop lung cancer.