Association of OGG1 Ser326Cys polymorphism and pancreatic cancer susceptibility: evidence from a meta-analysis

Genomic instability, DNA damage response and telomere homeostasis in pancreatic cancer

Pancreatic cancer (PC) is becoming one of the most serious health problems at present, but its causes and risk factors are still unclear. One of the drivers in pancreatic carcinogenesis is altered genomic (DNA) integrity with subsequent genomic instability in cancer cells. The latter comprises a) DNA damage response and DNA repair mechanisms, b) DNA replication and mitosis, c) epigenetic regulation, and d) telomere maintenance. In our review we addressed the above aspects in relation to the most abundant and severe form of PC, pancreatic ductal adenocarcinoma (PDAC). In summary, the interactions between the DNA damage response, telomere homeostasis and mitotic regulation are not comprehensively understood at present, including the epigenetic factors entering the trait of genomic stability maintenance. In addition, the complexity of telomere homeostasis in relation to PDAC risk, prognosis and prediction also warrants further investigations.

The relationship between expression level and gene polymorphism of inflammatory factors and sepsis risk

The biomarkers associated with sepsis have not yet been completely elucidated. The objective of the current article is to investigate whether inflammatory factors act as risk factors for sepsis. The study included 320 adult patients with sepsis, which were enrolled as experimental group. In addition, 560 healthy individuals from the same period were selected as the control group. Cytokine expressions were measured using flow cytometry with fluorescence, and gene polymorphisms were analyzed through the PCR-RFLP technique. Significantly higher expression levels of IL-1, IL-6, IL-10, and TNF-α, were detected (p < 0.05). This study also identified specific polymorphisms IL-1B -511 C/T, IL-10 -1082 G/A, IL-6 -174 G/C, and TNF-α -308 G/A, that were significantly associated with an increased risk of sepsis (p < 0.05). The expression levels of IL-1, IL-6, IL-10, and TNF-α are associated with an increased risk of sepsis. Additionally, the polymorphisms IL-1B -511 C/T, IL-6 -174 G/C, IL-10 -1082 G/A, IFN-γ + 874 A/T, and TNF-α -308 G/A are also linked to sepsis risk in the Chinese population.

Quantitative assessment of the associations between ABCA1 gene polymorphism and glaucoma risk, evidence from a meta-analysis

BACKGROUND

The association between polymorphisms in the ATP-binding cassette transporter A1 (ABCA1) gene and the risk of developing glaucoma has yielded conflicting results across various studies. This meta-analysis aims to comprehensively assess whether genetic variations in ABCA1 significantly contribute to the susceptibility to glaucoma.

METHODS

An extensive search was conducted across major databases, including PubMed, EMBASE, and the China National Knowledge Infrastructure (CNKI), covering all publications from the inception of each database through December 2023. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to quantify the strength of the association between ABCA1 polymorphisms and glaucoma risk.

RESULTS

A significant association was observed between ABCA1 gene polymorphisms and glaucoma risk in the overall analysis, as demonstrated by allele contrast (P < .001), homozygote comparison (P < .001), heterozygote comparison (P < .001), recessive genetic model (P = .017), and dominant genetic model (P < .001). Notably, these associations were particularly pronounced in the Asian population, with all models showing statistical significance (P < .05). However, no significant association was detected in Caucasian or mixed populations, suggesting a potential ethnic specificity in the genetic susceptibility to glaucoma conferred by ABCA1 polymorphisms.

CONCLUSIONS

Our findings indicate that ABCA1 polymorphisms may play a role in increasing the risk of glaucoma, specifically within Asian populations. This contrast highlights the importance of considering ethnic background in genetic association studies.

Quantitative assessment of the association between TNF-α gene polymorphisms and angina risk

BACKGROUND

Previous investigations into the correlation between tumor necrosis factor-α (TNF-α) gene polymorphism and susceptibility to angina have produced a range of results. This study aims to clarify the potential significance of TNF-α polymorphism as a contributing factor to the onset of angina.

METHODS

A comprehensive review of all corresponding literature was conducted across several major databases, covering their records from inception through to March 2024. Data were synthesized using meta-analysis techniques.

RESULTS

Notable associations were identified in various genetic comparisons: allele contrast (A vs. G: OR=0.77, 95% CI=0.70-0.86, P<0.001), homozygote comparison (AA vs. GG: OR=3.35, 95% CI=2.51-4.48, P<0.001), heterozygote comparison (GA vs. GG: OR=1.69, 95% CI=1.19-2.40, P=0.003), recessive genetic model (AA vs. GG/GA: OR=2.40, 95% CI=1.91-3.03, P<0.001), and dominant genetic model (AA/GA vs. GG: OR=1.84, 95% CI=1.27-2.65, P=0.001). Furthermore, ethnicity-based subgroup analyzes revealed that these associations were especially significant within the Asian population and unstable angina, with all genetic models demonstrating statistical significance (P<0.05).

CONCLUSIONS

TNF-α gene is significantly associated with an increased risk of angina, particularly among the Asian population and unstable angina. This finding underscores the importance of considering genetic factors in the assessment and management of angina risk.

Quantitative assessment of the associations between DNA repair gene XRCC3 Thr241Met polymorphism and pancreatic cancer

BACKGROUND

Prior research exploring the correlation between the XRCC3 Thr241Met polymorphism and the susceptibility to pancreatic cancer has yielded conflicting outcomes. To date, there has been a notable absence of studies examining this polymorphism. The primary aim of the current investigation is to elucidate the potential role of the XRCC3 Thr241Met polymorphism as a risk factor in the development of pancreatic cancer.

METHODS

The comprehensive literature search was meticulously conducted across primary databases, including PubMed, Embase, and CNKI (China National Knowledge Infrastructure), spanning from the inception of each database through January 2024. To synthesize the data, a meta-analysis was performed using either a fixed or random-effects model, as appropriate, to calculate the odds ratios (ORs) and their corresponding 95% confidence intervals (CIs).

RESULTS

The analysis revealed significant associations between the XRCC3 Thr241Met polymorphism and an increased risk of pancreatic cancer. This was evidenced through various genetic model comparisons: allele contrast (T vs. C: OR = 0.77, 95% CI = 0.70-0.86, P < 0.001), homozygote comparison (TT vs. CC: OR = 0.71, 95% CI = 0.58-0.88, P = 0.001), heterozygote comparison (TC vs. CC: OR = 0.67, 95% CI = 0.52-0.87, P = 0.003), and a dominant genetic model (TT/TC vs. CC: OR = 0.68, 95% CI = 0.57-0.81, P < 0.001). Additionally, subgroup analyses based on ethnicity disclosed that these associations were particularly pronounced in the Caucasian population, with all genetic models showing significance (P < 0.05).

CONCLUSIONS

The XRCC3 Thr241Met polymorphism has been identified as contributing to a reduced risk of pancreatic cancer in the Caucasian population. This finding underscores the need for further research to validate and expand upon our conclusions, emphasizing the urgency for continued investigations in this domain.

Genetic polymorphism of IL-18 influences susceptibility to lung cancer in population of eastern China

The association of Interleukin-18 (IL-18) genetic polymorphism with lung cancer risk has yielded inconsistent findings in previous studies. The current research aims to clarify the relationship of IL-18 gene polymorphism with lung cancer susceptibility through experimental investigation and meta-analysis, providing insights for lung cancer prevention and treatment. We conducted a thorough search of major databases from their inception until March 2024. OR and 95%CI were calculated to know the results of meta-analysis. The IL-18 gene polymorphism was detected using the PCR-RFLP method. Significant associations were detected across all genetic models in allele contrast (A vs. C: Odds Ratio [OR] = 1.29, 95% Confidence Interval [CI] = 1.07-1.55, p = 0.006), homozygote comparison (AA vs. CC: OR = 1.87, 95%CI = 1.34-2.62, p < 0.001), recessive genetic model (AA vs. CT/CC: OR = 1.54, 95%CI = 1.08-2.20, p = 0.018), and dominant genetic model (AA/AC vs. CC: OR = 1.41, 95%CI = 1.12-1.78, p = 0.003). Three genotypes (AA, AC, and CC) were identified for the IL-18 -607 C/A polymorphism, with significant associations noted for the AA genotype and A allele (p = 0.018 and 0.005, respectively). This is the first study which investigates this polymorphism with lung cancer in population of eastern China. The IL-18 -607 C/A polymorphism appears to significantly increase the risk of lung cancer in the population of Eastern China. Further research is imperative to validate these findings.

Genetic polymorphism of IL-17 influences susceptibility to recurrent pregnancy loss in a Chinese population

The current research aims to investigate the relationship between Interleukin-17 (IL-17) polymorphism and the risk of recurrent pregnancy loss (RPL) within a Chinese population. Totally, 120 patients with RPL were selected and enrolled as the experiment group. Additionally, 210 healthy individuals undergoing routine physical examinations during the same period served as the control group. The IL-17 gene polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism method. The IL-17 rs2275913 polymorphism exhibited 3 genotypes: GG, GA, and AA. Significant associations were observed with the AA genotype and A allele (all P < .05), indicating women with the AA genotype were 2.06 times more likely to experience RPL compared to those with the GG genotype. Similarly, women carrying the A allele faced a 1.63 times higher risk of RPL than those with the G allele. Regarding the IL-17 rs763780 polymorphism, which also presented 3 genotypes (TT, TC, CC), significant associations were noted for the CC genotype and C allele (all P < .05). Women with the CC genotype had a 1.84 times greater risk of suffering from RPL compared to those with the TT genotype, and those with the C allele were 1.51 times more likely to experience RPL than those with the T allele. The IL-17 rs2275913 and rs763780 polymorphisms contribute an increased risk to RPL in the Chinese population. Further studies, with larger sample sizes and more rigorous designs, are necessary to validate or replicate our current results.

Clinical characteristics, HPV involvement, and demographic risk factors in women with cervical intraepithelial neoplasia complicated by vaginal intraepithelial neoplasia

PURPOSE

This study aimed to explore the clinical characteristics and risk factors associated with cervical intraepithelial neoplasia (CIN) when coexisting with vaginal intraepithelial neoplasia (VAIN).

METHODS

We analyzed the clinical data of 212 patients diagnosed with CIN, including 50 patients with concurrent VAIN. The groups were compared to identify distinct clinical features and independent risk factors for the co-occurrence of CIN and VAIN, using logistic regression analysis.

RESULTS

Patients with both CIN and VAIN had a median age of 57, significantly older than the 41-year median age of patients with CIN only (P < 0.05). A higher prevalence of HPV infection (98.0%) was observed in the CIN and VAIN group, with a notable rate of multiple HPV infections (67.3%) compared to the CIN-only group (P < 0.05). Educational levels were significantly lower in the combined CIN and VAIN group (P < 0.05). HPV16, 33, and 52 were identified as significant types for single and multiple infections. Multivariate analysis confirmed age as an independent risk factor for CIN with VAIN (P < 0.05). VAIN3 patients were more likely to exhibit HSIL and ASC-H, whereas VAIN1 cases tended to correspond with ASCUS and LSIL diagnoses.

CONCLUSION

The co-occurrence of CIN and VAIN is significantly influenced by patient age and educational level. The findings advocate for more diligent vaginal examination during colposcopy in older patients, particularly those with multiple HPV infections and cytological abnormalities, to enhance the early detection of vaginal lesions and prevent missed diagnoses and treatments. Additionally, the high prevalence of HPV infection, especially with certain types, underscores the importance of HPV monitoring in this patient population.

MMP-3 gene regulates the carcinogenesis and metabolic process of ovarian cancer, evidence from a Chinese population: Observational study and meta-analysis

The current investigation aims to explore the relationship between matrix metalloproteinase-3 (MMP-3) gene polymorphism and ovarian cancer (OC) risk. Two hundred forty pathologically confirmed OC patients and 390 healthy controls participated in the present investigation. Polymerase chain reaction-restriction fragment length polymorphism was applied to investigate the present polymorphism. At the same time, the meta-analysis was also performed to comprehensively explore the relationship. Three genotypes (5A/5A, 5A/6A, and 6A/6A) were observed for MMP-3 gene polymorphism. 6A/6A genotype and 6A allele displayed significant increase in OC patients (all P < .05). Meta-analysis found that no significant results (all P > .05). In conclusion, our results indicate that MMP-3 gene polymorphism contributes increased risk to OC for southern Chinese population. And meta-analysis indicates that MMP-3 gene polymorphism contributes no risk to OC in other populations.

Genetic Polymorphism of Lipoprotein-Associated Phospholipase A2 Influences Susceptibility to Gestational Diabetes Mellitus in Chinese Population

Purpose

This paper aims to study the relationship between lipoprotein-associated phospholipase A2 (Lp-PLA2) and GDM (gestational diabetes mellitus) by detecting Lp-PLA2 level and its gene polymorphism.

Patients and Methods

From January to June 2022, 82 GDM patients treated in our hospital were included as an experimental group, and 89 healthy pregnant women during the same period were selected as the control group. Lp-PLA2 concentration and TG, TC, HDL-C, and LDL-C levels were tested with specialized instruments in clinical laboratories. The PLA2G7 gene polymorphisms (rs1805017, rs1805018, and rs76863441) were detected by fluorescent probe method and sequencing.

Results

Lp-PLA2 concentration was significantly higher in GDM group than control group (P<0.05). Among three polymorphism loci of PLA2G7 gene (rs1805017, rs1805018, and rs76863441) the significant associations were only found in GT genotype of rs76863441 loci (P<0.05).

Conclusion

Pregnant women with high levels of Lp-PLA2 concentration are more likely to develop GDM, especially those with PLA2G7 rs76863441 polymorphism. Lp-PLA2 concentration and PLA2G7 rs1805017 polymorphism may be a novel marker for GDM diagnosis and prediction.

Genetic Polymorphism of NQO1 Influences Susceptibility to Coronary Heart Disease in a Chinese Population: A Cross-Sectional Study and Meta-Anaylsis

Objective

The present study is to explore the association between NQO1 gene polymorphism and coronary heart disease (CHD) risk.

Methods

This research were selected 80 CHD patients as the observation group and 130 healthy people who participated in normal physical examination during the same period as the control group. NQO1 gene polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. In addition, we conducted a meta-analysis to summarize the results of three relevant previously published adult population studies on the association between NQO1 gene polymorphism and coronary heart disease (CHD) risk.

Results

There were three genotypes (CC, CT, and TT) for NQO1 C609T polymorphism. The significant associations were found in TT genotype and T allele (all p<0.05). Specifically, People with the TT genotype have 2.06 times CHD risk as those with the CC genotype. And People with the T allele have 1.62 times CHD risk as those with the C allele. No significant association was found by any genetic models in the meta-analysis (all p >0.05).

Conclusion

NQO1 gene polymorphism increased the CHD risk in a Chinese population. Combined with individual gene polymorphism, the accuracy of risk assessment for CHD can be improved and individualized health education can be provided for CHD patients by nurses.

Structural and Functional Analysis of human lung cancer risk associated hOGG1 variant Ser326Cys in DNA repair gene by molecular dynamics simulation

Oxidative damaged DNA base lesions are repaired through human 8-oxoguanine DNA glycosylase gene (hOGG1) mediated pathways. A recent report based on the meta-analysis has suggested that the DNA Repair Gene hOGG1 variant Ser326Cys [3p26.2; allele S/C in nucleotide position αHelix2 Ser⇒Cys326] was associated with Lung Cancer risk in Caucasian population will alter the level Zhong et al., 2012. To the best of our knowledge, there has not been any such comprehensive in-silico investigation that validates the functional and structural impact of non-synonymous Lung Cancer Risk Associated Protein Domain (LCRAPD) mutation Ser326Cys (rs1052133) by molecular dynamics (MD) simulation approach following prediction of hOGG1 protein before and after the mutation. Further to the native and mutant protein structures, the amino acid residue and its secondary structure were observed through a solvent accessibility model for protein stability confirmation at the point of mutation. Taken together, this study suggests that the protein functional and structural studies could be a reasonable approach for investigating the impact of nsSNPs in future studies. In addition, 4295 patients samples incorporate with the analysis that genomic data types from cBioPortal. In the result, 4295 cases (91.5%) had alterations in all genes but the frequency of alterations in our targeted hOGG1 gene was shown with and without case alteration in the ratio (Logrank Test P-Value: 0.670) Kaplan-Meier by the number of patients at risk of the survival function.

Genetic Investigation of Polymorphic OGG1 and MUTYH Genes Towards Increased Susceptibility in Lung Adenocarcinoma and its Impact on Overall Survival of Lung Cancer Patients Treated with Platinum Based Chemotherapy

Genes OGG1 and MUTYH are the two primary genes in Base excision repair pathway. OGG1 hydrolyzes the sugar phosphate backbone and remove the damaged base creating abasic site. MUTYH complements OGG1 as it particularly remove adenine mispaired with 8-oxo-G. Both OGG1 and MUTYH act as a check for the mis-incorporation of bases may be due to damages incurred on DNA. DNA isolation for 326 lung cancer cases and 330 controls was followed by genotyping making use of PCR-RFLP. Logistic regression was done to analyze the risk towards lung cancer. Patients were followed through telephonic conversation. Kaplan meier and Cox-regression were used for survival analysis. OGG1 presented a high risk towards lung cancer (CG: OR = 2.44, p = 0.0003; CG + GG: OR = 1.88, p = 0.0093). On the same lines adenocarcinoma for OGG1 were potent risk factors towards lung cancer (CG: OR = 4.72, p = 0.0002; CG + GG: OR = 3.63, p = 0.0018). Single allelic carriers for MUTYH gene imposed a high risk towards overall lung susceptibility and for all the three histology. Stratified analysis for chemotherapeutic drugs revealed administration of Cisplatin/Carboplatin + Pemtrexed for OGG1Ser 326 Cys showed a better survival (MST CG vs. CC: 9.1 vs. 0.56, p = <0.0001; HR =0.051, p = 0.0025). Whereas, MUTYH Gln324His showed a smaller survival for mutant genotype (CC) (MST CC vs. GG: 4.0 vs. 9.4, p = 0.05; HR = 1.75, p = 0.26). Single allelic carriers for both OGG1 and MUTYH were risk factors towards lung cancer. The risk was amplified on combining both OGG1 and MUTYH.

Enhanced mitochondrial DNA repair of the common disease-associated variant, Ser326Cys, of hOGG1 through small molecule intervention

The common oxidatively generated lesion, 8-oxo-7,8-dihydroguanine (8-oxoGua), is removed from DNA by base excision repair. The glycosylase primarily charged with recognition and removal of this lesion is 8-oxoGuaDNA glycosylase 1 (OGG1). When left unrepaired, 8-oxodG alters transcription and is mutagenic. Individuals homozygous for the less active OGG1 allele, Ser326Cys, have increased risk of several cancers. Here, small molecule enhancers of OGG1 were identified and tested for their ability to stimulate DNA repair and protect cells from the environmental hazard paraquat (PQ). PQ-induced mtDNA damage was inversely proportional to the levels of OGG1 expression whereas stimulation of OGG1, in some cases, entirely abolished its cellular effects. The PQ-mediated decline of mitochondrial membrane potential or nuclear condensation were prevented by the OGG1 activators. In addition, in Ogg1-/- mouse embryonic fibroblasts complemented with hOGG1S326C, there was increased cellular and mitochondrial reactive oxygen species compared to their wild type counterparts. Mitochondrial extracts from cells expressing hOGG1S326C were deficient in mitochondrial 8-oxodG incision activity, which was rescued by the OGG1 activators. These data demonstrate that small molecules can stimulate OGG1 activity with consequent cellular protection. Thus, OGG1-activating compounds may be useful in select humans to mitigate the deleterious effects of environmental oxidants and mutagens.

An Overview of Genetic Changes and Risk of Pancreatic Ductal Adenocarcinoma

The pancreatic carcinoma is a leading cause of death in cancer carriers worldwide. The early diagnostic is difficult due to late stage during diagnosis, lack of characteristic symptoms and also multifactor basis. In cancer development take part both, environmental and genetic factors, alone or in conjunction with each other. The nonspecific biomarkers of cancers are a reason for the search for more accurate factors which allow for fast and personalized diagnostics. Some of cancers have identified molecular (metabolic, biochemical or genetic) markers but in most cases the only clue is patient`s interview and abnormal levels of organ functions markers. Possible genetic basis of cancer suggests to widen studies on connection between environmental factors with both, nuclear and mitochondrial, genes changes.

Association between OGG1 Ser326Cys polymorphism and risk of upper aero-digestive tract and gastrointestinal cancers: a meta-analysis

Cancers of the upper aero-digestive and gastrointestinal tract are one of the major causes of mortality around the world. DNA repair genes play a vital role in preventing carcinogenesis by maintaining genomic integrity. Polymorphisms in the nucleotide sequence of DNA repair genes are often reported to be associated with an increased risk for different cancers. The OGG1 gene encodes the enzyme 8-oxoguanine DNA glycosylase which removes oxidatively damaged bases of DNA. Several studies report that the OGG1 Ser326Cys polymorphism increases the risk for cancers of the upper aero-digestive and gastrointestinal tract. However, other studies provide evidence that such an association does not exist. A meta-analysis to assess the role of OGG1 Ser326Cys polymorphism in the cancers of the upper aero-digestive and gastrointestinal tract was therefore undertaken in order to resolve this ambiguity. Seventeen studies were recruited for this meta-analysis after screening 58 articles with a total of 5533 cases and 6834 controls for which the odds ratio with 95 % confidence interval was calculated. Begg’s funnel test and Egger’s test were performed for calculating publication bias. Our study reveals an association between OGG1 Ser326Cys polymorphism and cancer susceptibility of the upper aero-digestive and gastrointestinal tract (CG + GG vs CC; odds ratio, OR 1.22; 95 % CI 1.05–1.41; GG vs CG + CC; OR 1.36; 95 % CI 1.09–1.70; GG vs CC; OR 1.46; 95 % CI 1.12–1.92). Subgroup analysis based on cancer types and ethnicity also revealed the association of OGG1 Ser326Cys polymorphism to the risk for upper aero-digestive and gastrointestinal tract cancers among both the Asian and the Caucasian populations. No risk was however observed for smoking habits and OGG1 Ser326Cys polymorphism. In conclusion, OGG1 Ser326Cys polymorphism may be associated with the increased risk for aero-digestive tract and gastro-intestinal cancers in both Asian and Caucasian populations.

Effects of physical exercise training in DNA damage and repair activity in humans with different genetic polymorphisms of hOGG1 (Ser326Cys)

The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8-oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty-two healthy Caucasian men (40-74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild-type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG-sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG-sensitive sites) and repair activity (OGG1) between genotype groups (in the pre-training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG-sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism.

OGG1 Mutations and Risk of Female Breast Cancer: Meta-Analysis and Experimental Data

In first part of this study association between OGG1 polymorphisms and breast cancer susceptibility was explored by meta-analysis. Second part of the study involved 925 subjects, used for mutational analysis of OGG1 gene using PCR-SSCP and sequencing. Fifteen mutations were observed, which included five intronic mutations, four splice site mutations, two 3'UTR mutations, three missense mutations, and a nonsense mutation. Significantly (p < 0.001) increased (~29 fold) breast cancer risk was associated with a splice site variant g.9800972T>G and 3'UTR variant g.9798848G>A. Among intronic mutations, highest (~15 fold) increase in breast cancer risk was associated with g.9793680G>A (p < 0.009). Similarly ~14-fold increased risk was associated with Val159Gly (p < 0.01), ~17-fold with Gly221Arg (p < 0.005), and ~18-fold with Ser326Cys (p < 0.004) in breast cancer patients compared with controls, whereas analysis of nonsense mutation showed that ~13-fold (p < 0.01) increased breast cancer risk was associated with Trp375STOP in patients compared to controls. In conclusion, a significant association was observed between OGG1 germ line mutations and breast cancer risk. These findings provide evidence that OGG1 may prove to be a good candidate of better diagnosis, treatment, and prevention of breast cancer.

Association between OGG1 gene single nucleotide polymorphisms and risk of pancreatic cancer in Chinese

Previous studies have suggested that the 8-oxoguanine DNA glycosylase gene (OGG1) has potentially influenced the risk of pancreatic cancer. The objective of this study was to assess the association between single nucleotide polymorphisms (SNPs) of OGG1 gene and risk of pancreatic cancer. A case-control study has been conducted in 370 pancreatic cancer patients and 395 healthy controls. Genotypes were determined using the polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. The association analysis was evaluated by the unconditional logistic regression test. Our data suggested that the distributions of alleles and genotypes were statistically different between pancreatic cancer patients and healthy controls. The c.307G>C SNP was associated with the decreased risk of pancreatic cancer (C vs. G: OR 0.73, 95 % CI 0.59-0.91, P = 0.006). As for c.828A>G SNP, the significantly decreased risk of pancreatic cancer was detected (G vs. A: OR 0.74, 95 % CI 0.59-0.92, P = 0.006). The allele C of c.307G>C and allele G of c.828A>G SNPs might be associated with a protection from pancreatic cancer. Findings from this study indicate that OGG1 SNPs are associated with pancreatic cancer risk in Chinese Han population and could be useful molecular biomarkers for assessing the risk of pancreatic cancer.

Lack of association of XRCC1 rs1799782 genetic polymorphism with risk of pancreatic cancer: a meta-analysis

Emerging evidence suggests that genetic polymorphisms in X-ray repair cross-complementation group 1 (XRCC1) gene could be associated with pancreatic cancer risk. However, previous published studies on the association between XRCC1 rs1799782 genetic polymorphism and pancreatic cancer risk reported inconsistent results. For better understanding of the effects of XRCC1 rs1799782 genetic polymorphism on pancreatic cancer risk, we conducted a meta-analysis of previous published studies by calculating the pooled odds ratio (OR) with a 95% confidence interval (95% CI). A total of five eligible studies with 1,144 pancreatic cancer cases and 2,925 controls were eventually enrolled. Overall, we found that the XRCC1 rs1799782 genetic polymorphism was not associated with pancreatic cancer risk in total population under all genetic models (TT vs. CC: OR = 1.11, 95% CI 0.76-1.63, P = 0.583; CT vs. CC: OR = 1.39, 95% CI 0.92-2.10, P = 0.118; TT/CT vs. CC: OR = 1.39, 95% CI 0.92-2.10, P = 0.121; TT vs.

CT/CC

OR = 1.07, 95% CI 0.73-1.55, P = 0.743; T vs. C: OR = 1.31, 95% CI 0.93-1.86, P = 0.125). In the subgroup analysis based on ethnicity, there was no statistically significant association between XRCC1 rs1799782 genetic polymorphism and pancreatic cancer risk in Asians/Caucasians under all genetic models (all P values > 0.05). No publication bias was detected in this study. Our meta-analysis suggests that the XRCC1 rs1799782 genetic polymorphism is not significantly associated with pancreatic cancer risk. Considering the limited sample size and ethnicity enrolled in this meta-analysis, further larger scaled studies are needed to provide a more precise estimation on the association.