Association between the OGG1 Ser326Cys Polymorphism and Cancer Risk: Evidence from 152 Case-Control Studies

BER genes expression in oral and pre-oral cancer: Combinatorial approach to propose potential biomarker

OBJECTIVE

DNA repair genes and their variants have been found to alter the risk of oral cancer.

METHOD

The level of expression of XRCC3, NBS1, and OGG1 genes among 20 cases of oral cancer, 6 pre-oral cancer, and 50 healthy control subjects was measured with RT-PCR. All the subjects were also genotyped for XRCC3 rs861539 C>T, NBS1 rs1805794 C>G, and OGG1 rs1052133 C>G polymorphisms by the PCR-RFLP method; their genotypes were correlated with their level of expression. Further, a localized fold structure analysis of the mRNA sequence surrounding the studied SNPs was performed with RNAfold.

RESULTS

Results showed increased expression of XRCC3, NBS1, and OGG1 transcripts among oral cancer (4.49 fold, 3.45 fold, and 3.27 fold) as well as pre-oral cancer (3.04 fold, 5.32 fold, and 1.74 fold) as compared to control subjects. The transcript level of OGG1 was found to be significantly increased (6.68 fold, p-value 0.009) with the GG genotype compared to the CC genotype. The C>T polymorphism of XRCC3 and the C>G polymorphism of OGG1 result in an apparent change in its mRNA secondary structure. Folding energy with the C allele for XRCC3 C>T polymorphism was lower than that of the T allele (MFE C vs T: -50.20 kcal/mol vs -48.70 kcal/mol). In the case of OGG1 C>G polymorphism MFE for the C allele was higher (-23.30 kcal/mole) than with the G allele (-24.80 kcal/mol).

CONCLUSION

Our results showed elevated levels of XRCC3, NBS1, and OGG1 both in oral cancer and pre-oral cancer conditions, which indicates their role as prospective biomarkers of oral cancer and pre-cancerous lesions. SNPs in these genes alter their level of expression, possibly by altering the secondary structure of their transcript. However, due to the small sample size our study can only provide a suggestive conclusion and warned future study with large sample size to verify our findings.

Association of buccal micronucleus cytome assay (BMNCyt) biomarkers with inorganic element concentration and genetic polymorphisms in welders

Welding fumes are classified as carcinogenic to humans. The aim of the present study was to measure buccal micronucleus cytome assay biomarkers and to evaluate their association with inorganic elements and genetic polymorphisms (XRCC1, OGG1, XRCC3, GSTM1, and GSTT1) in welders (n = 98) and control individuals (n = 100). Higher levels of DNA damage and cell death were observed in the exposed group. Also, a significant correlation between the frequency of micronuclei and Na, Si, Cl, Ti, Cr, Zn and Mg concentrations. The formation of micronuclei, binucleated cells, cell death was associated with polymorphisms in repair pathways. The OGG1Ser326Cys and XRCC3 241Thr/Met genotypes were associated with cell death. Individuals with GSTM1 null genotype had a higher frequency of micronuclei. These results demonstrate that the deleterious effects of exposure to welding fumes are exacerbated by lifestyle habits, and genetic polymorphisms can influence DNA damage and cell death.

Assessment of hOGG1 Genetic Polymorphism (rs1052133) and DNA Damage in Radiation-Exposed Workers

OBJECTIVE

The aim of this study was to assess the effect of radiation exposure, human 8-oxoguanine DNA N-glycosylase-1 (hOGG1) exon 7 genetic polymorphism and confounding factors on DNA damage response.

METHODS

Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and alkaline Comet assay method were applied to determine the hOGG1 genetic polymorphisms and DNA damage response. A total of 80 participants were enrolled in this study, consisting of 40 radiation-exposed workers as a case group and 40 non-radiation workers as a control group.

RESULT

The genotypes frequencies for controls were Ser/Ser (35%), Ser/Cys (32.5%), and Cys/Cys (32.5%), with frequencies of alleles being 326Ser (0.52) and 326Cys (0.48), whereas the genotypes frequencies for radiation-exposed workers (cases group) were Ser/Ser (17.5%), Ser/Cys (57.5%), and Cys/Cys (25%), with frequencies of alleles being 326Ser (0.46) and 326Cys (0.54). The results indicated that DNA damage response were not significantly higher in the exposed workers than in controls (22.55 ± 6.02 versus 21.72 ± 7.14; P=0.58). The time of exposure has a significantly negative correlation with comet tail length value among radiation workers. In addition, it was found that the DNA damage response was strongly associated with age and time of exposure with a decrease of 0.6 percent (P-value: 0.008) and 0.58 percent (P-value: 0.009), respectively. Whereas gender, smoking habit, and equivalent dose were not correlated with DNA damage.

CONCLUSION

The single-nucleotide polymorphism of hOGG1 exon 7 (rs1052133) demonstrated no association with the extent of DNA damage in radiation-exposed workers.

Rare POLN mutations confer risk for familial nasopharyngeal carcinoma through weakened Epstein-Barr virus lytic replication

BACKGROUND

Nasopharyngeal carcinoma (NPC) exhibits significant familial aggregation; however, its susceptibility genes are largely unknown. Thus, this study aimed to identify germline mutations that might contribute to the risk of familial NPC, and explore their biological functions.

METHODS

Whole-exome sequencing was performed in 13 NPC pedigrees with multiple cases. Mutations co-segregated with disease status were further validated in a cohort composed of 563 probands from independent families, 2,953 sporadic cases, and 3,175 healthy controls. Experimental studies were used to explore the functions of susceptibility genes and their disease-related mutations.

FINDINGS

The three rare missense mutations in POLN (DNA polymerase nu) gene, P577L, R303Q, and F545C, were associated with familial NPC risk (5/576 [0·87%] in cases vs. 2/3374 [0·059%] in healthy controls with an adjusted OR of 44·84 [95% CI:3·91-514·34, p = 2·25 × 10^-3]). POLN was involved in Epstein-Barr virus (EBV) lytic replication in NPC cells in vitro. POLN promoted viral DNA replication, immediate-early and late lytic gene expression, and progeny viral particle production, ultimately affecting the proliferation of host cells. The three mutations were located in two pivotal functional domains and were predicted to alter the protein stability of POLN in silico. Further assays demonstrated that POLN carrying any of the three mutations displayed reduced protein stability and decreased expression levels, thereby impairing its ability to promote complete EBV lytic replication and facilitate cell survival.

INTERPRETATION

We identified a susceptibility gene POLN for familial NPC and elucidated its function.

FUNDING

This study was funded by the National Key Research and Development Program of China (2021YFC2500400); the National Key Research and Development Program of China (2020YFC1316902); the Basic and Applied Basic Research Foundation of Guangdong Province, China (2021B1515420007); the National Natural Science Foundation of China (81973131); the National Natural Science Foundation of China (82003520); the National Natural Science Foundation of China (81903395).

The effects of voluntary complex and regular wheel running exercises on the levels of 8-oxoguanine DNA glycosylase, semaphorin 3B, H2O2, and apoptosis in the hippocampus of diabetic rats

PURPOSE

One of the most frequent complications associated with diabetes mellitus is apoptosis within the brain which can lead to cognitive disorders. Exercise is considered the best non-pharmacological approach to reduce the severity and extent of cell death through poorly-understood mechanisms. The aim of this study was to investigate the effects of voluntary complex and regular wheel running on the levels of 8-oxoguanine DNA glycosylase (OGG₁ ), semaphorin 3B (sema3B), hydrogen peroxide (H₂ O₂ ), and apoptosis in the hippocampus of diabetic rats.

METHODS

48 Wistar male rats were randomly divided into 6 groups: healthy control (C), diabetes control (D), regular wheel running + diabetes (RWD), complex wheel running + diabetes (CWD), healthy regular wheel running (RW), and healthy complex wheel running (CW). The diabetic rat model was produced by intraperitoneal injection of streptozotocin (STZ). The protocol encompassed a 4-week voluntary running training regimen on regular and complex wheel running apparatus. The rats were sacrificed 48 hr after the last training session. To measure the protein concentrations within the hippocampus, ELISA has been utilized. One-way ANOVA was used to compare the groups.

RESULTS

There were no significant differences in OGG1 protein levels between the groups. H₂ O₂ level in the D group was significantly higher than the C group (p = .002), while this in RWD and CWD groups was considerably lower than the D group (p = .002 and p = .003, respectively). In the D group, the levels of apoptosis and Sema3B were significantly (p = .001 and p = .007, respectively) higher than C, RWD (p = .001, p = .0001, respectively), and CWD groups (p = .001, p = .006, respectively). Nevertheless, there were not any significant differences between RWD and CWD groups.

CONCLUSION

The increased levels of Sema3B, H2O2, and apoptosis within the hippocampus associated with diabetes could be noticeably restored by both types of voluntary wheel running protocols.

Association of the hOGG1 Ser326Cys polymorphism with gynecologic cancer susceptibility: a meta-analysis

The association between the hOGG1 Ser326Cys polymorphism and gynecologic cancer susceptibility is inconclusive. We performed a comprehensive meta-analysis to precisely estimate of the impact of the hOGG1 Ser326Cys polymorphism on gynecologic cancer susceptibility. Electronic databases including PubMed, Embase, WanFang, and the China National Knowledge Infrastructure were searched for relevant studies. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were determined to assess the strength of the association. Fourteen studies with 2712 cases and 3638 controls were included in the final meta-analysis. The pooled analysis yielded a significant association between the hOGG1 Ser326Cys polymorphism and overall gynecologic cancer susceptibility (dominant model: OR = 1.16, 95% CI = 1.03–1.30, P=0.017). A significantly higher gynecologic cancer risk was found for the European population (homozygous model: OR = 2.17, 95% CI = 1.80–2.61, P<0.001; recessive model: OR = 2.11, 95% CI = 1.41–3.17, P<0.001; dominant model: OR = 1.29, 95% CI = 1.12–1.48, P<0.001; and allele model: OR = 1.40, 95% CI = 1.13–1.74, P=0.002), but not in the Asian population. The stratified analysis by cancer type revealed endometrial cancer was significantly associated with the hOGG1 Ser326Cys polymorphism (dominant model: OR = 1.29, 95% CI = 1.09–1.54, P=0.003; and allele model: OR = 1.28, 95% CI = 1.02–1.60, P=0.031). In conclusion, the hOGG1 Ser326Cys polymorphism was associated with higher overall gynecologic cancer susceptibility, especially for endometrial cancer in the European population.

Association Between the hOGG1 1245C>G (rs1052133) Polymorphism and Susceptibility to Colorectal Cancer: a Meta-analysis Based on 7010 Cases and 10,674 Controls

BACKGROUND

The 1245C>G (rs1052133) polymorphism of human 8-oxoguanine DNA glycosylase 1 (hOGG1) gene has been indicated to be correlated with colorectal (CRC) susceptibility, but studies have yielded conflicting results. Thus, the present meta-analysis was performed to derive a more precise estimation between hOGG1 1245C>G polymorphism and CRC risk.

METHODS

Data were collected from several electronic databases such as PubMed, EMBASE, and Google Scholar databases, with the last search up to September 01, 2020. Pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the strength of the association.

RESULTS

A total of 24 case-control studies with 7010 CRC cases and 10,674 controls were selected. Pooled data showed that the hOGG1 1245C>G polymorphism was significantly associated with CRC risk under three genetic models, i.e., homozygote (GG vs. CC: OR = 1.229, 95% CI 1.031-1.465, p = 0.022); heterozygote (GC vs. CC: OR = 1.142, 95% CI 1.008-1.294, p = 0.037); and dominant (GG+GC vs. CC: OR = 1.162, 95% CI 1.034-1.304, p = 0.011). When stratified analysis by ethnicity, a significant association of the hOGG1 1245C>G polymorphism with risk of CRC was found in the Caucasians, but not in Asians. Moreover, there were significant associations between hOGG1 1245C>G polymorphism and CRC by PCR-RFLP and hospital-based subgroups.

CONCLUSIONS

Inconsistent with the previous meta-analysis, these meta-analysis results revealed that the hOGG1 1245C>G polymorphism might be associated with an increased risk of CRC, especially in Caucasians.

Comprehensive analysis of the correlation between base-excision repair gene SNPs and esophageal squamous cell carcinoma risk in a Chinese Han population

This study sought to assess the relationship between single nucleotide polymorphisms (SNPs) affecting DNA base-excision repair (BER) genes and esophageal squamous cell carcinoma (ESCC) risk in a Han Chinese population. Genes screened for such SNPs included 8-oxoguanine DNA glycosylase (OGG1), apurinic/apyrimidinic endonuclease 1 (APE1) and X-ray repair cross-complementing group 1 protein (XRCC1). Blood samples that had been collected in a prospective manner were used for DNA extraction, with all DNA samples then being subjected to PCR-restriction fragment length polymorphism genotyping for BER gene SNPs, including APE1 Asp148Glu and -141T/G, OGG1 Ser326Cys, and XRCC1 Arg399Gln. The relationship between these SNPs and ESCC risk was then assessed, with the comparability of the case and control groups being enhanced via propensity score matching (PSM). This study initially included 642 healthy controls and 321 ESCC patients, with PSM optimization leading to a final analyzed total of 311 matched subjects per group (311 total). Factors associated with elevated ESCC risk in this analysis included advanced age, being male and smoking. We further identified that the XRCC1 399 Gln/Gln genotype was associated with a significant reduction in ESCC risk prior to propensity matching (odds ratio=0.48; 95% CI: 0.23-1.00; P<0.05), although this did not remain true following matching. For the remaining analyzed SNPs, no significant associations between genotype and ESCC risk were detected prior to or following propensity matching. A multivariate analysis incorporating patient age, sex, smoking status and drinking status failed to detect any relationship between the four tested genotypes and ESCC risk. In conclusion, being male, a smoker or of advanced age was associated with an elevated ESCC risk. However, we did not detect any significant relationship between ESCC risk and BER polymorphisms in XRCC1, OGG1, APE1 or the APE1 promoter region in a Han Chinese population.

Influence of Two DNA Repair Pathway Polymorphisms in Colorectal Cancer Risk in Southwest Iran

Objective:

X-ray cross-complementing group 1 (XRCC1) and 8 Oxo guanine DNA-glycosylase 1 (OGG1) genes are implicated in the repair of single-stranded breaks (SSBRs) and base excision repair (BER) pathways. Common polymorphisms in DNA repair genes are supposed to decrease the capability of DNA repair and cause genetic instability. This study was designed to investigate the association between XRCC1 (rs25487) and OGG1 (rs1052133) polymorphisms and susceptibility to colorectal cancer (CRC) in the Ahvaz city, south-west Iran.

Methods:

This case- control study comprised 150 patients and 150 controls that were selected from 2 educational hospitals in Ahvaz. They were matched for age and gender, and their genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results:

Our results indicate that the frequency of the Gln (A) allele of XRCC1 (rs25487) is significantly higher in colorectal cancer patients, compare to controls (p = 0.01, OR: 1.54, 95% CI 1.9–13.3). Significant increased risk of cancer was observed in XRCC1 (rs25487) genotypes (p = 0.001 OR: 5.3, 95% CI 1.9–14.2 for Gln / Gln), while no association was found between OGG1 (rs1052133) and colorectal cancer risk (p = 0.6).

Conclusion:

Our study suggests that XRCC1 (rs25487) polymorphism might be associated with an increasing risk of CRC in Ahvaz. It also demonstrates positive correlation between the XRCC1 (rs25487) genotypes and demographic characteristics, such as smoking and increased age in patients and control groups.

Systematic Review: Genetic Associations for Prognostic Factors of Urinary Bladder Cancer

INTRODUCTION

Many germline associations have been reported for urinary bladder cancer (UBC) outcomes and prognostic characteristics. It is unclear whether there are overlapping genetic patterns for various prognostic endpoints. We aimed to review contemporary literature on genetic associations with UBC prognostic outcomes and to identify potential overlap in reported genes.

METHODS

EMBASE, MEDLINE, and PubMed databases were queried for relevant articles in English language without date restrictions. The initial search identified 1346 articles. After exclusions, 112 studies have been summarized. Cumulatively, 316 single-nucleotide polymorphisms (SNPs) were reported across prognostic outcomes (recurrence, progression, death) and characteristics (tumor stage, grade, size, age, risk group). There were considerable differences between studied outcomes in the context of genetic associations. The most commonly reported SNPs were located in OGG1, TP53, and MDM2. For outcomes with the highest number of reported associations (ie, recurrence and death), functional enrichment annotation yields different terms, potentially indicating separate biological mechanisms.

CONCLUSIONS

Our study suggests that all UBC prognostic outcomes may have different biological origins with limited overlap. Further validation of these observations is essential to target a phenotype that could best predict patient outcome and advance current management practices.

Urinary 8-hydroxydeoxyguanosine in relation to XRCC1 rs25487 G/A (Arg399Gln) and OGG1 rs1052133 C/G (Ser326Cys) DNA repair genes polymorphisms in patients with chronic hepatitis C and related hepatocellular carcinoma

Background and aim: DNA repair represents a protective mechanism against cell injury and cancer. 8-hydroxy-deoxyguanosine (8-OHdG) is the main ROS-induced DNA mutation. The current study aimed to evaluate urinary 8-OHdG levels in patients with chronic hepatitis C virus (HCV) and its related hepatocellular (HCC) and correlate its level to XRCC1 rs25487 G/A and OGG1 rs1052133 C/G gene polymorphisms.

Materials and methods: Urinary 8-OHdG assays were performed using HPLC technique, and XRCC1 rs25487 G/A and OGG1 rs1052133 C/G gene polymorphisms were analyzed by PCR using confronting two-pair primer method (PCR-CTPP) in 200 subjects allocated into 50 chronic HCV patients, 50 HCV-related HCC patients, and 100 controls.

Results: There were significantly increased urinary 8-OHdG levels in HCV-related HCC and chronic HCV patients when compared with the controls (P<0.05 for all). Urinary 8-OHdG was associated with the tumor spread. Regarding, XRCC1 (Arg399Gln), AA (Gln/Gln) genotype and A-allele were more frequent in HCC and chronic HCV patients than in the controls (P<0.05). ORs (95%CI) using the dominant and the recessive genetic models were; 2.1 (1.1–4.1), P=0.032 and 1.9 (1–3.6), P=0.043 respectively. For OGG1 (Ser326Cys), GG (Cys/Cys) genotype and G-allele were increased significantly in chronic HCV and HCC patients compared to the controls (P<0.05). ORs (95%CI) under the dominant and the recessive genetic models were; 2.1 (1.1–4.1), P=0.032 and 1.9 (1–3.8), P=0.049 respectively. Additionally, XRCC1 (AA) and OGG1 (GG) genotypes had significantly increased urinary 8-OHdG levels among patients (P<0.05).

Conclusions: XRCC1 (AA) and OGG1 (GG) could be considered as possible genotypic risk factors for HCV- related HCC development which were associated with significantly high urinary 8-hydroxy-deoxyguanosine levels, thus urinary 8-OHdG could be considered as non-invasive marker in follow-up chronic HCV progression into HCC.

TISSUE EXPRESION OF THE GENES MUTYH AND OGG1 IN PATIENTS WITH SPORADIC COLORECTAL CANCER

BACKGROUND

MTUYH and OGG1 genes have importance in the base excision repair systems of oxidized DNA bases. Modification of the tissue expression of these genes is related to the increased risk of developing colorectal cancer.

AIM

To evaluate the tissue expression of MUTYH and OGG1 comparing normal and neoplastic tissues of patients with sporadic colorectal cancer and to correlate it with clinical and histopathological variables.

METHOD

MUTYH and OGG1 tissue expression was quantified by RT-PCR in patients with colorectal cancer and the values were compared in normal and neoplastic tissues. MUTYH and OGG1 expression was measured and normalized to the constitutive 18S gene. The level of expression of both genes was correlated with the variables: age, gender, tumor location, size of the tumor, histological type, degree of cell differentiation, invasion depth in the intestinal wall, angiolymphatic infiltration, lymph node involvement and TNM staging.

RESULTS

Was found downregulation of both genes in neoplastic when compared to normal tissue. There was downregulation of the MUTYH in larger tumors and in patients with angiolymphatic invasion. Tumors with more advanced TNM stages (III and IV) presented downregulation of both genes when compared to those with earlier stages (I and II).

CONCLUSION

The MUTYH and OGG1 genes present downregulation in the more advanced stages of colorectal cancer.

DNA repair genes polymorphisms and genetic susceptibility to Philadelphia-negative myeloproliferative neoplasms in a Portuguese population: The role of base excision repair genes polymorphisms

The role of base excision repair (BER) genes in Philadelphia-negative (PN)-myeloproliferative neoplasms (MPNs) susceptibility was evaluated by genotyping eight polymorphisms [apurinic/apyrimidinic endodeoxyribonuclease 1, mutY DNA glycosylase, earlier mutY homolog (E. coli) (MUTYH), 8-oxoguanine DNA glycosylase 1, poly (ADP-ribose) polymerase (PARP) 1, PARP4 and X-ray repair cross-complementing 1 (XRCC1)] in a case-control study involving 133 Caucasian Portuguese patients. The results did not reveal a correlation between individual BER polymorphisms and PN-MPNs when considered as a whole. However, stratification for essential thrombocythaemia revealed i) borderline effect/tendency to increased risk when carrying at least one variant allele for XRCC1_399 single-nucleotide polymorphism (SNP); ii) decreased risk for Janus kinase 2-positive patients carrying at least one variant allele for XRCC1_399 SNP; and iii) decreased risk in females carrying at least one variant allele for MUTYH SNP. Combination of alleles demonstrated an increased risk to PN-MPNs for one specific haplogroup. These findings may provide evidence for gene variants in susceptibility to MPNs. Indeed, common variants in DNA repair genes may hamper the capacity to repair DNA, thus increasing cancer susceptibility.