Association between XRCC1 polymorphisms and laryngeal cancer susceptibility in a Chinese sample population

Assessment on the influence of TLR4 and DNA repair genes in laryngeal cancer susceptibility: a selective examination in a Romanian case control study

Background: Tumor characterization through the study of molecular biology has become an invaluable tool in understanding cancer development and evolution due to its relationship with chromosomal mutations, alterations or aberrations. The purpose of this study was to investigate the involvement of genes such as TLR-4 and DNA repair pathways (XRCC1 and XPD) in laryngeal cancer susceptibility in a Romanian population. Method: We performed a case-control study on 157 laryngeal cancer patients and 101 healthy controls. Genetic testing was carried out using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism. Results: We identified the Gln allele of the XPDLys751Gln polymorphism as an individual risk factor in laryngeal cancer development (Gln vs Lys, adjusted OR=1.65, 95%CI=1.13–2.40, P=0.008). Subjects with the mutant homozygote variant (Gln/Gln) had a two fold increase in cancer risk (adjusted OR=2.18, 95%CI=1.06–4.47, p=0.028) when compared to the reference wild type genotype (Lys/Lys). Stratification by sex and age, identified males under 62 years as the most susceptible group with an almost three fold risk (adjusted OR=2.94, 95%CI=1.31–6.59, p=0.007) for the dominant model (Lys/Gln+Gln/Gln). No associations were found for TLR-4Thr399Ile, XRCC1Arg194Trp and XRCC1Arg399Gln. Conclusion: The results of the study show that the XPDLys751Gln polymorphism may be among other independent risk factors for developing laryngeal cancer where as TLR-4Thr399Ile, XRCC1Arg194Trp and XRCC1 Arg399Gln show no such association. However, we consider the relative small number of the subjects selected for this analyses a possible limitation towards the real influence the obtain results may pertain in laryngeal cancer evolution.

The impacts of genetic polymorphisms in genes of base excision repair pathway on the efficacy and acute toxicities of (chemo)radiotherapy in patients with nasopharyngeal carcinoma

Purpose

To explore whether polymorphisms in base excision repair (BER) pathway genes are predictors of (chemo)radiotherapy outcome in patients with nasopharyngeal carcinoma (NPC).

Methods

We genotyped five potentially functional single nucleotide polymorphisms (SNPs) of three genes in the BER pathway in 174 NPC patients who were treated with (chemo)radiotherapy. Sequenom MassArray was used for SNPs analysis. The efficacy at the end of radiotherapy and at 3 months after radiotherapy was evaluated by Response Evaluation Criteria in Solid Tumors (RECIST). Acute radiation toxicity was scored using Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer (RTOG/EORTC) acute radiation morbidity scoring criteria. Logistic regression was employed to assess the multivariate analyses.

Results

We found that the wide genotype GG of X-ray repair cross-complementing 1 (XRCC1) rs25489 (GG vs GA: OR=3.833, 95%CI=1.512-9.714, P=0.005; GG vs GA+AA: OR=3.610, 95%CI=1.496-8.713, P=0.004) and the wide genotype CC of 8-oxoguanine DNA glycosylase (OGG1) rs1052133 (CC vs GG: OR=0.263, 95%CI=0.073-0.951, P=0.042; CC vs CG+GG: OR=0.454, 95%CI=0.195-1.053, P=0.066) were positively and negatively associated with primary tumor efficacy at the end of radiotherapy, respectively. By contrast, no association was found between BER gene polymorphisms and the treatment outcomes at 3 months post-treatment or the treatment-related acute toxicities.

Conclusions

The SNPs of the BER genes may act as biomarkers for the curative effect of (chemo)radiotherapy. Further study with long-time follow-up and large population is needed for accurate assessment.