Association of the Telomerase Reverse Transcriptase rs10069690 Polymorphism with the Risk, Age at Onset and Prognosis of Triple Negative Breast Cancer

Telomere length and TERT polymorphisms as biomarkers in asbestos-related diseases

BACKGROUND

Asbestos exposure has been proposed as a risk factor for shorter telomere length. The aim of our study was to investigate whether telomere length in leukocytes and hTERT genetic polymorphisms may serve as potential biomarkers for the risk of developing asbestos-related diseases and as biomarkers of progression and chemotherapy response rate in malignant mesothelioma (MM).

SUBJECTS AND METHODS

We conducted two retrospective studies. In the first study, a case-control study, telomere length and hTERT polymorphisms were determined in patients with MM, subjects with pleural plaques and controls without the asbestos related disease, who were occupationally exposed to asbestos. In the second study, a longitudinal observational study, telomere length was also determined in samples from MM patients before and after chemotherapy. Telomere length was determined by monochromatic multiplex quantitative polymerase chain reaction (PCR), while competitive allele-specific PCR was used to genotype hTERT rs10069690, rs2736100 and rs2736098. Logistic regression and survival analysis were used in statistical analysis.

RESULTS

Patients with MM had shorter telomere length than subjects with pleural plaques (p < 0.001). After adjustment for age, rs2736098 CT, and rs10069690 TT and CT+TT genotypes were significantly associated with a higher risk of MM (padj = 0.023; padj = 0.026 and padj = 0.017), while rs2736100 AA and CA+AA genotypes conferred to a lower risk for MM compared to all other subjects (padj = 0.017, and padj = 0.026). Telomere length was not associated with a response to chemotherapy (p > 0.05) or time to disease progression (p > 0.05). Carriers of one or two polymorphic rs10069690 T alleles had a good response to chemotherapy (p = 0.039, and p = 0.048), these associations remained statistically significant after adjustment for age (padj = 0.019; padj = 0.017). Carriers of two polymorphic rs2736100 A alleles had a longer time to disease progression (p = 0.038).

CONCLUSIONS

Shorter telomere length and hTERT polymorphisms may serve as a biomarker for the risk of developing MM. Additionally, rs10069690 and rs2736100 polymorphisms, but not telomere length, were associated with a chemotherapy response or MM progression.

The Contribution of Tissue Inhibitor of Metalloproteinase-2 Genotypes to Breast Cancer Risk in Taiwan

Tissue inhibitor of metalloproteinase-2 (TIMP-2) is an endogenous inhibitor of matrix metalloproteinase-2 and is highly expressed in breast cancer (BC) cases at diagnosis. However, the genetic investigations for the association of TIMP-2 genotypes with BC risk are rather limited. In this study, contribution of TIMP-2 rs8179090, rs4789936, rs2009196 and rs7342880 genotypes to BC risk was examined among Taiwan's BC population. TIMP-2 genotypic profiles were revealed among 1232 BC cases and 1232 controls about their contribution to BC using a PCR-based RFLP methodology. The TIMP-2 rs8179090 homozygous variant CC genotype was significantly higher in BC cases than controls (odds ratio (OR) = 2.76, 95% confidence interval (95%CI) = 1.78-4.28, p = 0.0001). Allelic analysis showed that C allele carriers have increased risk for BC (OR = 1.39, 95%CI = 1.20-1.62, p = 0.0001). Genotypic together with allelic analysis showed that TIMP-2 rs4789936, rs2009196 or rs7342880 were not associated with BC risk. Stratification analysis showed that TIMP-2 rs8179090 genotypes were significantly associated with BC risk among younger (≤55) aged women, not among those of an elder (>55) age. Last, rs8179090 genotypes were also associated with triple negative BC. This study sheds light into the etiology of BC in Taiwanese women. Rs8179090 may be incorporated into polygenic risk scores and risk prediction models, which could aid in stratifying individuals for targeted breast cancer screening.