Association of TERT Polymorphisms with Clinical Outcome of Non-Small Cell Lung Cancer Patients

Associations of telomerase reverse transcriptase rs10069690 and rs2736100 polymorphisms with papillary thyroid carcinoma

Papillary thyroid carcinoma is one of the most common endocrine malignancies. Telomerase reverse transcriptase rs10069690 and rs2736100 polymorphisms have been studied in thyroid carcinomas with different ethnicity, but the results were inconsistent. Therefore, we evaluated the relationship between rs10069690 and rs2736100 polymorphisms and papillary thyroid carcinoma risk and furtherly investigated the associations of these polymorphisms with stimulated thyroglobulin (sTg) positivity and adverse reactions of I treatment in papillary thyroid carcinoma. Four hundred thirty-six papillary thyroid carcinoma patients and 345 controls of Chinese Han population were included in our study. Rs10069690 and rs2736100 were genotyped using improved multiple ligase detection reactions. Analysis of inheritance model was performed using the unconditional logistic regression. In our study, rs10069690 and rs2736100 were associated with papillary thyroid carcinoma risk, especially in females over 45 years of age (P = 0.002 and P = 0.032, respectively). Rs10069690 was associated with sTg positivity and with an rs10069690-related occurrence risk order of thyroglobulin antibody (Tg-Ab)(+) + Tg(+) > Tg-Ab(+) + sTg(-) > Tg-Ab(-) + sTg(+). Patients with the homozygous TT genotype of rs10069690 had an increased risk of neck discomfort (P = 0.033), while the homozygous CC genotype of rs2736100 had a decreased risk of gastrointestinal toxicity (P = 0.048). Our data demonstrated that rs10069690 and rs2736100 might be bio-indicators related to papillary thyroid carcinoma risk in females over 45 years of age and I treatment-related toxicity. In addition, rs10069690 may be a predictor of bad clinicopathological features and poor prognosis from a serological point of view.

A pharmacogenetics study of platinum-based chemotherapy in lung cancer: ABCG2 polymorphism and its genetic interaction with SLC31A1 are associated with response and survival

Objective: The expression and function of platinum transporters affect drug tissue concentration and therapeutic effects. We had previously characterized functional variant of platinum intake transporter SLC31A1 gene. We aimed to investigate the association of platinum efflux transporter gene ABCG2 polymorphism and combined ABCG2 and SLC31A1 polymorphisms with clinical outcomes of NSCLC patients receiving platinum-based chemotherapy. Methods: We genotyped thirteen tagging and functional SNPs of ABCG2 in 1004 patients, and assessed their association with response, toxicity and survival using unconditional logistic regression and Cox proportional hazards regression analyses respectively. Results: Nonsynonymous rs2231142 (odds ratio [OR] 2.07; 95 % confidence interval [CI] 1.26-3.63), rs1871744 (OR 0.60; 95 % CI 0.42-0.87) and their haplotype and diplotype were associated with objective response. Rs4148157 was associated with shorter overall survival (Log-rank P = 0.002; hazard ratio [HR] 1.22; 95 % CI 1.05-1.42). Furthermore, the combined SLC31A1 rs2233914 and ABCG2 rs1871744 genotype was significantly associated with poor response (OR 0.31; 95 % CI 0.17-0.56; P _interaction = 0.003). And the combined genotypes of the functional rs10759637 of SLC31A1 and the nonsynonymous rs2231142 (Log-rank P = 5.20×10^-5; HR 1.47; 95 % CI 1.19-1.81; P _interaction = 0.007) or linked rs4148157 of ABCG2 were significantly associated with poor survival. Conclusion: This study reveals divergent association of ABCG2 polymorphism with response and survival of NSCLC patients receiving platinum-based chemotherapy, demonstrates the combined effects of functional variants of ABCG2 and SLC31A1 on clinical outcomes, and highlights pharmacogenetic relevance of platinum transporter genes interaction.

Impact of genetic factors on platinum-induced gastrointestinal toxicity

Severe gastrointestinal (GI) toxicity is a common side effect after platinum-based chemotherapy. The incidence and severity of GI toxicity vary among patients with the same chemotherapy. Genetic factors involved in platinum transport, metabolism, detoxification, DNA repair, cell cycle control, and apoptosis pathways may account for the interindividual difference in GI toxicity. The influence of gene polymorphisms in the platinum pathway on GI toxicity has been extensively analyzed. Variations in study sample size, ethnicity, design, treatment schedule, dosing, endpoint definition, and assessment of toxicity make it difficult to precisely interpret the results. Hence, we conducted a review to summarize the most recent pharmacogenomics studies of GI toxicity in platinum-based chemotherapy and identify the most promising avenues for further research.

Genetic polymorphism of SLC31A1 is associated with clinical outcomes of platinum-based chemotherapy in non-small-cell lung cancer patients through modulating microRNA-mediated regulation

SLC31A1 is the major transporter for platinum drug intake, its expression correlates with drug disposition and response. In 1004 Chinese NSCLC patients with platinum-based chemotherapy, we investigated the association between SLC31A1 polymorphisms and clinical outcomes. Heterozygotes of rs10759637 at 3′UTR was associated with severe thrombocytopenia (odds ratio [OR]: 2.69; P = 0.012) and shorter overall survival (hazard ratio [HR]: 1.24; P = 0.005). Variant homozygote of rs2233914 was correlated with longer overall survival (hazard ratio [HR]: 0.73; P = 0.008). Haplotype and diplotype of these linked SNPs were associated with hematologic toxicities. In stratification analyses, rs10759637 and rs2233914 consistently correlated with overall survival in specific subgroups such as men, smoker, patients older than 58 years, or with ECOG PS 0-1, or with squamous cell carcinoma. rs10759637 could change the local structure of 3′UTR harboring putative binding sites for hsa-miR-29, whose transfection into 16HBE cells resulted in remarkable suppression of gene expression. The rs10759637 variant significantly correlated with lowered luciferase activity in reporter assays and decreased expression of SLC31A1 transcript in tumorous tissues. The study thereby identified functional polymorphism of SLC31A1 that modulates miRNA-3′UTR interaction and gene expression as potential pharmacogenetic biomarker for clinical outcomes of platinum-based chemotherapy in NSCLC patients.

Genetic variants of genes in the Notch signaling pathway predict overall survival of non-small cell lung cancer patients in the PLCO study

The Notch signaling pathway has been shown to have biological significance and therapeutic application in non-small cell lung cancer (NSCLC). We hypothesize that genetic variants of genes in the Notch signaling pathway are associated with overall survival (OS) of NSCLC patients. To test this hypothesis, we performed multivariate Cox proportional hazards regression analysis to evaluate associations of 19,571 single nucleotide polymorphisms (SNPs) in 132 Notch pathway genes with OS of 1,185 NSCLC patients available from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. We found that five potentially functional tagSNPs in four genes (i.e., ADAM12 rs10794069 A > G, DTX1 rs1732793 G > A, TLE1 rs199731120 C > CA, TLE1 rs35970494 T > TC and E2F3 rs3806116 G > T) were associated with a poor OS, with a variant-allele attributed hazards ratio (HR) of 1.27 [95% confidence interval (95% CI) = 1.13–1.42, P = 3.62E-05], 1.30 (1.14–1.49, 8.16E-05), 1.40 (1.16–1.68, 3.47E-04), 1.27 (1.11–1.44, 3.38E-04), and 1.21 (1.09–1.33, 2.56E-04), respectively. Combined analysis of these five risk genotypes revealed that the genetic score 0–5 was associated with the adjusted HR in a dose-response manner (P_trend = 3.44E-13); individuals with 2–5 risk genotypes had an adjusted HR of 1.56 (1.34–1.82, 1.46E-08), compared with those with 0–1 risk genotypes. Larger studies are needed to validate our findings.

A TERT-CLPTM1 locus polymorphism (rs401681) is associated with EGFR mutation in non-small cell lung cancer

Telomere length is associated with lung carcinogenesis, and recent studies have focused on telomere-maintaining genes and their polymorphisms. Cancer susceptibility of the rs401681 polymorphism, located in the TERT-CLPTM1L locus, has been studied in many cancers. We examined the clinicopathological and prognostic value of rs401681 variants in lung cancer. The relationship between rs401681 variants and telomere length was analyzed in 134 non-small cell lung cancers (NSCLCs). The rs401681 polymorphism had the following genotype frequencies: C/C in 52.2% of the samples, C/T in 30.6%, and T/T in 17.2%. The T allele showed a strong correlation with EGFR mutation (p=0.037). Telomeres in the tumor samples were 3.26-fold longer, on average, than telomeres in matched normal samples (SD=0.48), and there were no differences in telomere length according to rs401681 polymorphism. Smoking was associated with telomere shortening (p=0.01). Survival analysis showed no prognostic value for rs401681 polymorphisms or telomere length in NSCLC. These results suggested that the rs401681 polymorphism contributes to lung carcinogenesis only in patients harboring an EGFR mutation. However, the polymorphism was not associated with survival; therefore, further comprehensive analysis should be performed.

TERT-CLPTM1 locus polymorphism (rs401681) is associated with the prognosis of hepatocellular carcinoma

Telomere length is associated with the development of hepatocellular carcinoma (HCC), and recent studies have focused on the genetic alteration or polymorphism in telomere-maintaining genes. We examined the clinicopathologic and prognostic value of rs401681 polymorphism, located in the TERT-CLPTM1L locus, in HCC. The relationship between rs401681 variants and telomere length was also analyzed in 156 HCC patients. The rs401681 polymorphism had the following genotype frequencies: C/C in 51.3% of the samples, C/T in 39.7%, and T/T in 9.0%. Telomeres in the tumor samples were 4.04-fold longer, on average, than the telomeres in matched normal samples (SD =1.32), and there were no differences in telomere length according to rs401681 polymorphism (p=0.802). Our results indicate that the rs401681 C allele was significantly associated with increased T and International Union for Cancer Control stages (p<0.01). Univariate and multivariate survival analyses showed that HCC with C allele had poorer prognosis (p<0.01). In conclusion, our findings suggest that rs401681 is a possible prognostic biomarker for HCC patients.

The associations of TERT-CLPTM1L variants and TERT mRNA expression with the prognosis of early stage non-small cell lung cancer

Lung cancer is the leading cause of cancer-related death in the world. Several genome-wide association studies (GWAS) have identified TERT-CLPTM1L as plausible causative locus for lung cancer development. This study aimed to investigate the associations of genetic variations in TERT-CLPTM1L and the expression level of TERT with the survival of early stage non-small cell lung cancer (NSCLC) patients. We selected three single-nucleotide polymorphisms of TERT-CLPTM1L (rs2853669, rs2736108 and rs31490) and genotyped in 140 early stage NSCLC patients by TaqMan assay. Associations between these variations and survival outcome of early stage NSCLC patients were further investigated. We also used TCGA data to evaluate the associations of TERT messenger RNA (mRNA) expression and survival outcome of early stage NSCLC patients. Survival analysis showed that, compared with early NSCLC patients carrying TERT rs2853669 TT+TC genotypes, patients with rs2853669 CC genotype had significantly longer median survival time (MST=102.2 vs 52.4 months; log-rank P=0.028) and lower death risk [hazard ratio (HR) with 95% confidence interval (CI))=0.38(0.17-0.82), P=0.014]. Early NSCLC patients carrying TERT rs2736108 AA genotype had significantly shorter MST (MST=29.0 vs 63.3 months; log-rank P=0.020) and increased death risk [HR (95% CI)=2.22(1.01-5.80), P=0.046], when compared with patients carrying rs2736108 GG genotypes. TCGA data revealed that early NSCLC patients with higher expression level of TERT mRNA in lung tumor tissues had a longer MST and decreased death risk than those with low expression level of TERT mRNA [MST=54.4 vs 49.0 months; log-rank P=0.041; adjusted HR (95% CI)=0.68(0.50-0.94)]. These findings may add potential evidence to understand the prognostic value of TERT and provide a new prospect of individualized prevention and treatment for early stage NSCLC.

Systematic Review of Genetic Variation in Chromosome 5p15.33 and Telomere Length as Predictive and Prognostic Biomarkers for Lung Cancer

Lung cancer remains the leading cause of cancer mortality worldwide. Known histomolecular characteristics and genomic profiles provide limited insight into factors influencing patient outcomes. Telomere length (TL) is important for genomic integrity and has been a growing area of interest as agents targeting telomerase are being evaluated. Chromosome 5p15.33, an established cancer susceptibility locus, contains a telomerase-regulatory gene, TERT, and CLPTM1L, a gene associated with cisplatin-induced apoptosis. This review offers a summary of the clinical utility of 5p15.33 polymorphisms and TL. A total of 621 abstracts were screened, and 14 studies (7 for 5p15.33, 7 for TL) were reviewed. Endpoints included overall survival (OS), progression-free survival (PFS), therapy response, and toxicity. Of the 23 genetic variants identified, significant associations with OS and/or PFS were reported for rs401681 (CLPTM1L), rs4975616 (TERT-CLPTM1L), and rs2736109 (TERT). Both shorter and longer TL, in tumor and blood, was linked to OS and PFS. Overall, consistent evidence across multiple studies of 5p15.33 polymorphisms and TL was lacking. Despite the potential to become useful prognostic biomarkers in lung cancer, the limited number of reports and their methodologic limitations highlight the need for larger, carefully designed studies with clinically defined subpopulations and higher resolution genetic analyses. Cancer Epidemiol Biomarkers Prev; 25(12); 1537-49. ©2016 AACR.