The TERT promoter mutation incidence is modified by germline TERT rs2736098 and rs2736100 polymorphisms in hepatocellular carcinoma.
ABSTRACT: Telomerase activation via induction of the catalytic component telomerase reverse transcriptase (TERT) plays essential roles in malignant transformation. TERT promoter-activating mutations were recently identified as a novel mechanism to activate telomerase in hepatocellular carcinoma (HCC) and many other malignancies. In addition, single nucleotide polymorphisms (SNPs) in the TERT rs2736098 and rs2736100 are significantly associated with cancer susceptibility. It is currently unclear whether different germline TERT variants modify TERT promoter mutations. Here we analyzed the TERT promoter status and genotyped the TERT SNPs at rs2736098 and rs2736100 in patients with HCC. Thirty percent of HCCs harbored TERT promoter mutations and there was a significant difference in rs2736098 and rs2736100 genotypes between wt and mutant TERT promoter-bearing HCC tumors (P = 0.007 and 0.018, respectively). For rs2736100, the cancer risk genotype CC was significantly associated with a reduced incidence of TERT promoter mutations compared to AA + AC variants [Odds ratio (OR): 0.181, 95% Confidence interval (CI): 0.0543-0.601, P = 0.004]. The rs2736098_CT genotype was significantly associated with the TERT promoter mutation-positive tumors compared to the TT genotype (OR: 5.391, 95% CI: 1.234-23.553, P = 0.025). These differences in genotype distribution did not differ between patients with a wt TERT promoter and controls. The presence of TERT promoter mutations was not associated with clinico-pathological variables. Taken together, the germline TERT genetic background may significantly affect the onset of TERT promoter mutations in HCCs, which provides a better understanding of HCC-related TERT promoter mutations and telomerase regulation in cancer.
Project description:Recurrent somatic mutations in the promoter region of telomerase reverse transcriptase (TERT) gene and in the exon 3 of CTNNB1 gene have been recognized as common events in hepatocellular carcinoma (HCC) with variable frequencies depending on etiology and geographical region. We have analyzed TERT promoter and CTNNB1 gene mutations in 122 cases of hepatitis B (HBV) and hepatitis C (HCV) related HCCs, in 7 cases of cholangiocarcinoma (CC) and hepatocholangiocarcinoma (HCC-CC) as well as in autologous cirrhotic tissues. Overall, 50.4% and 26% of HCC as well as 14.3% and none of CC and HCC-CC were mutated in TERT promoter and in CTNNB1 exon 3, respectively. TERT and CTNNB1 mutations were found more frequently in HCV related (53.6% and 26.4%, respectively) than HBV related (41.7% and 16.7%, respectively) HCCs and coexisted in 57.6% of CTNNB1 mutated tumors. Mutations in TERT and CTNNB1 were not associated with the functional promoter polymorphism rs2853669. No mutations were detected in the 129 non-HCC cirrhotic tissues. In conclusion, mutations in TERT promoter and in CTNNB1 gene represent specific cancer signatures in the pathogenesis of viral related HCC and could be promising early biomarkers as well as targets for tailored therapies.
Project description:AIMS:To investigate the impact of telomerase reverse transcriptase (TERT) gene polymorphism and additional SNP-SNP interaction on non-small cell lung cancer (NSCLC) risk in Chinese population. METHODS:A total of 828 participants (526 males, 302 females), with a mean age of 71.3 ± 15.7 years old, were selected, including 410 NSCLC patients and 418 normal participants. Logistic regression was performed to investigate association between single nucleotide polymorphism (SNP) and NSCLC risk. Generalized multifactor dimensionality reduction (GMDR) was used to analysis the interaction among four SNPs. RESULTS:Non-small cell lung cancer risk was significantly higher in carriers of G allele of the rs2736100 polymorphism than those with TT (TG + GG vs. TT, adjusted OR (95%CI = 1.68 (1.28-2.07). In addition, we also found that NSCLC risk was also significantly higher in carriers of A allele of the rs2736098 polymorphism than those with GG (GA + AA vs. GG, adjusted OR (95%CI) = 1.52 (1.19-1.93). GMDR analysis indicated that there was a significant two-locus model (P = 0.0100) involving rs2736098 and rs2736100, indicating a potential gene-gene interaction between rs2736098 and rs2736100. Overall, the two-locus models had a cross-validation consistency of 10 of 10, and had the testing accuracy of 62.17%. We found that patients with GA or AA of rs2736098 and TG or GG of rs2736100 genotype have the highest NSCLC risk, compared to patients with GG of rs2736098 and TT of rs2736100 genotype, OR (95%CI) was 2.52 (1.68-3.68), after covariates adjustment. CONCLUSIONS:Minor allele of rs2736098 and rs2736100 in TERT gene and interaction between the two SNP were associated with increased risk of NSCLC risk.
Project description:Reactivation of telomerase is a critical step in the development of hepatocellular carcinoma (HCC). Here we identified the frequency of mutations in telomerase reverse transcriptase (TERT) promoter was 34% in non-clear cell HCC (NCCHCC, n = 259) and 26.3% in clear cell HCC (CCHCC, n = 57). The mutations were independently associated with poor recurrence-free survival of HCCs. Interestingly immunohistochemical analysis demonstrated a higher positive rate of TERT cytoplasmic localization (95%) than nuclear localization (64%) in HCCs. In NCCHCCs, the mutations correlated with higher TERT nuclear expression and increased telomere-dependent telomerase activity. Higher cytoplasmic expression was found in adjacent tissues compared to tumor tissues, and was associated with tumor well-differentiation and lower level of ?-fetoprotein. NCCHCCs with low nuclear as well as high cytoplasmic expression correlated with better prognosis. In CCHCCs, elevated TERT cytoplasmic expression was observed in CCHCCs harboring mutations. Higher TERT cytoplasmic expression was found in tumor tissues compared to adjacent tissues, and was associated with multiple numbers of tumors and poor prognosis of CCHCCs. In conclusion, mutations in TERT promoter disclose the significance of both nuclear and cytoplasmic TERT in HCC. Cytoplasmic TERT should also be considered when determining prognosis and treatment of HCCs.
Project description:TERT encodes the reverse transcriptase component of telomerase, which adds telomere repeats to chromosome ends, thus enabling cell replication. Telomerase activity is required for cell immortalization. Somatic TERT promoter mutations modifying key transcriptional response elements were recently reported in several cancers, such as melanomas and gliomas.The objectives of the study were: 1) to determine the prevalence of TERT promoter mutations C228T and C250T in different thyroid cancer histological types and cell lines; and 2) to establish the possible association of TERT mutations with mutations of BRAF, RAS, or RET/PTC.TERT promoter was PCR-amplified and sequenced in 42 thyroid cancer cell lines and 183 tumors: 80 papillary thyroid cancers (PTCs), 58 poorly differentiated thyroid cancers (PDTCs), 20 anaplastic thyroid cancers (ATCs), and 25 Hurthle cell cancers (HCCs).TERT promoter mutations were found in 98 of 225 (44%) specimens. TERT promoters C228T and C250T were mutually exclusive. Mutations were present in 18 of 80 PTCs (22.5%), in 40 of 78 (51%) advanced thyroid cancers (ATC + PDTC) (P = 3 × 10(-4) vs PTC), and in widely invasive HCCs (4 of 17), but not in minimally invasive HCCs (0 of 8). TERT promoter mutations were seen more frequently in advanced cancers with BRAF/RAS mutations compared to those that were BRAF/RAS wild-type (ATC + PDTC, 67.3 vs 24.1%; P < 10(-4)), whereas BRAF-mutant PTCs were less likely to have TERT promoter mutations than BRAF wild-type tumors (11.8 vs 50.0%; P = .04).TERT promoter mutations are highly prevalent in advanced thyroid cancers, particularly those harboring BRAF or RAS mutations, whereas PTCs with BRAF or RAS mutations are most often TERT promoter wild type. Acquisition of a TERT promoter mutation could extend survival of BRAF- or RAS-driven clones and enable accumulation of additional genetic defects leading to disease progression.
Project description:Telomerase reverse transcriptase gene (TERT) promoter mutations are identified in many malignancies but not in hematological malignancies. Here we analyzed TERT and protection of telomeres 1 gene (POT1) mutations, and four different TERT SNVs in 226 acute myeloid leukemia (AML) patients and 806 healthy individuals in a case referent design, where also overall survival was assessed. A significant association for increased risk of AML was found for TERT SNVs, rs2853669 (OR = 2.45, p = 0.00015) and rs2736100 (OR = 1.5, p = 0.03). The overall survival for patients with CC genotype of rs2853669 was significantly shorter compared to those with TT or TC genotypes (p = 0.036 and 0.029 respectively). The influence of TERT rs2853669 CC on survival was confirmed in multivariable Cox regression analysis as an independent risk biomarker in addition to high risk group, higher age and treatment. No hot spot TERT promoter mutations at -228C > T or -250C > T or POT1 mutations could be identified in this AML cohort. We show that rs2853669 CC may be a risk factor for the development of AML that may also be used as a prognostic marker to identify high risk normal karyotype-AML (NK-AML) patients, for treatment guidance.
Project description:Telomerase reverse transcriptase (<i>TERT</i>) mutation is the most frequent genetic alteration in hepatocellular carcinoma (HCC). Our aims were to investigate whether <i>TERT</i> mutations can be detected in circulating cell-free DNA (cfDNA) of patients with HCC and/or cirrhosis and characterize clinical parameters associated with these mutations. We retrieved data on <i>TERT</i> C228T and C250T promoter mutations in 196 HCCs from The Cancer Genome Atlas. We measured these <i>TERT</i> mutations in plasma cfDNA in 218 patients with HCC and 81 patients with cirrhosis without imaging evidence of HCC. The prevalence of <i>TERT</i> mutations in The Cancer Genome Atlas HCC specimens was 44.4%. <i>TERT</i> mutations were detected with similar prevalence (47.7%) in plasma cfDNAs from 218 patients with HCC. <i>TERT</i> mutations, either within the HCC or in cfDNA, were associated with male sex, hepatitis C virus (HCV), alcoholic cirrhosis, family history of cancer, and poor prognosis. The high prevalence of <i>TERT</i> mutations in HCCs in male patients with cirrhosis caused by HCV and/or alcohol was confirmed in an independent set of HCCs (86.6%). Finally, <i>TERT</i> mutations were detected in cfDNA of 7 out of 81 (8.6%) patients with cirrhosis without imaging evidence of HCC, including 5 male patients with cirrhosis due to HCV and/or alcohol. Genes involved in xenobiotic and alcohol metabolism were enriched in HCCs with <i>TERT</i> mutations, and vitamin K2 was identified as an upstream regulator. <i>Conclusion</i>: <i>TERT</i> mutations are detectable in plasma cfDNA. Long-term imaging surveillance of patients with cirrhosis with cfDNA TERT mutations without evidence of HCC is required to assess their potential as early biomarkers of HCC. (<i>Hepatology Communications</i> 2018;2:718-731).
Project description:BACKGROUND:Reactivation of telomerase reverse transcriptase (TERT) is an important event in cancer. Two hotspot mutations in the TERT promoter region, c.-124C > T (C228T) and c.-146C > T (C250T), occur in various cancer types including thyroid cancer. They generate de novo binding sites for E-twenty-six (ETS) transcription factors causing increased TERT transcription. The aim of this study was to search for novel TERT promoter mutations and additional mechanisms of TERT activation in thyroid cancer. METHODS:We studied 198 papillary thyroid carcinomas (PTCs), 34 follicular thyroid carcinomas (FTCs), 40 Hürthle cell carcinomas (HCCs), 14 poorly differentiated/anaplastic thyroid carcinomas (PDTC/ATC), and 15 medullary thyroid carcinomas (MTCs) for mutations in an -424 bp to +64 bp region of TERT. The luciferase reporter assay was used to functionally characterize the identified alterations. Copy number variations (CNVs) in the TERT region were analyzed using TaqMan copy number assay and validated with fluorescence in situ hybridization (FISH). RESULTS:We detected the hotspot c.-124C > T and c.-146C > T mutations in 7% PTC, 18% FTC, 25% HCC, and 86% PDTC/ATC. One PTC carried a c.-124C > A mutation. Furthermore, we identified two novel mutations resulting in the formation of de novo ETS-binding motifs: c.-332C > T in one MTC and c.-104_-83dup in one PTC. These genetic alterations, as well as other detected mutations, led to a significant increase in TERT promoter activity when assayed using luciferase reporter system. In addition, 5% of thyroid tumors were found to have ?3 copies of TERT. CONCLUSIONS:This study confirms the increased prevalence of TERT promoter mutations and CNV in advanced thyroid cancers and describes novel functional alterations in the TERT gene promoter, including a point mutation and small duplication. These mutations, as well as TERT copy number alterations, may represent an additional mechanism of TERT activation in thyroid cancer.
Project description: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.
Project description:The chromosome 5p15.33 TERT-CLPTM1L region has been identified by genome-wide association studies as a susceptibility locus of multiple malignancies. However, the involvement of this locus in esophageal squamous cell carcinoma (ESCC) development is still largely unclear. We fine-mapped the TERT-CLPTM1L region through genotyping 15 haplotype-tagging single nucleotide polymorphisms (htSNPs) using a two stage case-control strategy. After analyzing 2098 ESCC patients and frequency-matched 2150 unaffected controls, we found that rs2853691, rs2736100 and rs451360 genetic polymorphisms are significantly associated with ESCC risk in Chinese (all P<0.05). Reporter gene assays indicated that the ESCC susceptibility SNP rs2736100 locating in a potential TERT intronic promoter has a genotype-specific effect on TERT expression. Similarly, the CLPTM1L rs451360 SNP also showed allelic impacts on gene expression. After measuring TERT and CLPTM1L expression in sixty-six pairs of esophageal cancer and normal tissues, we observed that the rs2736100 G risk allele carriers showed elevated oncogene TERT expression. Also, subjects with the rs451360 protective T allele had much lower oncogene CLPTM1L expression than those with G allele in tissue specimens. Results of these analyses underline the complexity of genetic regulation of telomere biology and further support the important role of telomerase in carcinogenesis. Our data also support the involvement of CLPTM1L in ESCC susceptibility.
Project description:OBJECTIVE:Benign prostatic hyperplasia (BPH) is an age-related disease, occurring in >70% of men of age >60. Because telomeres and telomerase play a key role in aging and age-related diseases, and certain telomerase gene single nucleotide polymorphisms (SNPs) are shown to be associated with the susceptibility to age-related diseases, we wanted to determine the relationship between BPH and leukocyte telomere length (LTL) and telomere length-related single nucleotide polymorphisms (SNPs) of the telomerase holoenzyme genes. METHODS:Peripheral blood was collected from both BPH patients and age-matched healthy male controls and genomic DNA was extracted. rs2736100 and rs2736098 at the TERT and rs12696304 at the TERC locus were analysed using pre-designed TaqMan SNP genotyping assay kits. LTL was determined using qPCR. RESULTS:Patients with BPH had significantly shorter LTL (1.231 ± 0.532 vs 0.899 ± 0.322, P < 0.001). The genotyping results show similar frequencies in rs2736100, rs2736098 and rs12696304 between healthy and BPH individuals. CONCLUSIONS:Shorter telomeres but not telomerase SNPs at the TERT and TERC loci, are associated with BPH. Short telomeres may promote senescence of a fraction of prostatic epithelial cells, while senescent cells in turn facilitate epithelial and stromal cell proliferation by the senescence-associated secretory phenotype mechanism, thereby eventually leading to BPH development.