Association between polymorphisms of XRCC1 and ADPRT genes and ovarian cancer survival with platinum-based chemotherapy in Chinese population

DNA Damage Response Alterations in Ovarian Cancer: From Molecular Mechanisms to Therapeutic Opportunities

The DNA damage response (DDR), a set of signaling pathways for DNA damage detection and repair, maintains genomic stability when cells are exposed to endogenous or exogenous DNA-damaging agents. Alterations in these pathways are strongly associated with cancer development, including ovarian cancer (OC), the most lethal gynecologic malignancy. In OC, failures in the DDR have been related not only to the onset but also to progression and chemoresistance. It is known that approximately half of the most frequent subtype, high-grade serous carcinoma (HGSC), exhibit defects in DNA double-strand break (DSB) repair by homologous recombination (HR), and current evidence indicates that probably all HGSCs harbor a defect in at least one DDR pathway. These defects are not restricted to HGSCs; mutations in ARID1A, which are present in 30% of endometrioid OCs and 50% of clear cell (CC) carcinomas, have also been found to confer deficiencies in DNA repair. Moreover, DDR alterations have been described in a variable percentage of the different OC subtypes. Here, we overview the main DNA repair pathways involved in the maintenance of genome stability and their deregulation in OC. We also recapitulate the preclinical and clinical data supporting the potential of targeting the DDR to fight the disease.

PARP1 Gene Polymorphisms and the Prognosis of Esophageal Cancer Patients from Cixian High-Incidence Region in Northern China

Objective:

Poly (ADP-ribose) polymerase 1 (PARP1), as a key enzyme in the base excision repair pathway, plays a crucial role in tumorigenesis and progression. This study aimed to assess whether polymorphisms of PARP1 gene could be used as predictive biomarkers for the survival of esophageal squamous cell carcinoma (ESCC) patients from Cixian high-incidence region in northern China.

Methods:

In 203 ESCC patients with survival information, PARP1 rs1136410 T/C and rs8679 T/C single nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction ligase detection reaction (PCR-LDR) method. All statistical analyses were performed using the SPSS ver. 22.0 software package (SPSS, Chicago, IL, USA).

Results:

The mean age ± standard deviation of the ESCC patients was 60.4 ± 7.9 years. There was no significant relation of sex, age, smoking status and upper gastrointestinal cancer family history with the survival time of the ESCC patients. The mean survival time of rs1136410 T/T, T/C and C/C genotype carriers were 43.3, 42.3 and 46.6 months, respectively. The rs1136410 was not associated with the survival time of the ESCC patients. For rs8679, the mean survival time of T/T genotype carriers was 43.7 months, which was not significantly different from that of the patients with T/C genotype (42.1 months).

Conclusion:

In Cixian high-incidence region from northern China, rs1136410 and rs8679 SNPs might not be used to predict survival of ESCC patients. There is a need to explore whether other SNPs of PARP1 gene have an effect on prognosis of ESCC patients.

ERCC1, XRCC1, and GSTP1 Polymorphisms and Treatment Outcomes of Advanced Epithelial Ovarian Cancer Patients Treated with Platinum-based Chemotherapy

Objective:

The first line regimen for treating epithelial ovarian cancer (EOC) is platinum-based chemotherapy. Various factors impact its effectiveness including polymorphisms of enzymes in platinum-related metabolism processes.

Methods:

We conducted the study to investigate the association between polymorphisms of ERCC1, XRCC1 and GSTP1, which responsible for platinum’s metabolisms in Thai epithelial ovarian cancer patients.

Results:

Fifty-two patients with advanced epithelial ovarian cancer were enrolled into this study. Genotyping analysis of ERCC1 (C->A, rs3212986), XRCC1 (A->G, rs25487) and GSTP (A->G, rs1695) were performed which variant allele frequencies were found at 35.6%, 28.9% and 10.6%, respectively. Patients with homozygous variant type (A/A) of ERCC1 C8092A had higher rate of platinum-resistance (75% vs 16.7%, p =0.046). In addition, the significant association of GSTP1 polymorphism and grade 2 anemia was found. Patients with A/G genotype of GSTP1 had higher rate of grade 2 anemia (81.8% vs 46.3%, p =0.036).

Conclusions:

Genetic polymorphisms of ERCC1, and GSTP1 might be useful biomarkers for prediction of clinical benefit and toxicities of platinum-based chemotherapy in Thai epithelial ovarian cancer patients.

DNA Repair and Ovarian Carcinogenesis: Impact on Risk, Prognosis and Therapy Outcome

There is ample evidence for the essential involvement of DNA repair and DNA damage response in the onset of solid malignancies, including ovarian cancer. Indeed, high-penetrance germline mutations in DNA repair genes are important players in familial cancers: BRCA1, BRCA2 mutations or mismatch repair, and polymerase deficiency in colorectal, breast, and ovarian cancers. Recently, some molecular hallmarks (e.g., TP53, KRAS, BRAF, RAD51C/D or PTEN mutations) of ovarian carcinomas were identified. The manuscript overviews the role of DNA repair machinery in ovarian cancer, its risk, prognosis, and therapy outcome. We have attempted to expose molecular hallmarks of ovarian cancer with a focus on DNA repair system and scrutinized genetic, epigenetic, functional, and protein alterations in individual DNA repair pathways (homologous recombination, non-homologous end-joining, DNA mismatch repair, base- and nucleotide-excision repair, and direct repair). We suggest that lack of knowledge particularly in non-homologous end joining repair pathway and the interplay between DNA repair pathways needs to be confronted. The most important genes of the DNA repair system are emphasized and their targeting in ovarian cancer will deserve further attention. The function of those genes, as well as the functional status of the entire DNA repair pathways, should be investigated in detail in the near future.

Efficient Single-Strand Break Repair Requires Binding to Both Poly(ADP-Ribose) and DNA by the Central BRCT Domain of XRCC1

XRCC1 accelerates repair of DNA single-strand breaks by acting as a scaffold protein for the recruitment of Polβ, LigIIIα, and end-processing factors, such as PNKP and APTX. XRCC1 itself is recruited to DNA damage through interaction of its central BRCT domain with poly(ADP-ribose) chains generated by PARP1 or PARP2. XRCC1 is believed to interact directly with DNA at sites of damage, but the molecular basis for this interaction within XRCC1 remains unclear. We now show that the central BRCT domain simultaneously mediates interaction of XRCC1 with poly(ADP-ribose) and DNA, through separate and non-overlapping binding sites on opposite faces of the domain. Mutation of residues within the DNA binding site, which includes the site of a common disease-associated human polymorphism, affects DNA binding of this XRCC1 domain in vitro and impairs XRCC1 recruitment and retention at DNA damage and repair of single-strand breaks in vivo.

XRCC1 polymorphism and overall survival in ovarian cancer patients treated with platinum-based chemotherapy: A systematic review and MOOSE-compliant meta-analysis

OBJECTIVES

Although platinum-based chemotherapy is widely used for advanced ovarian cancer (OC), genetic polymorphisms can influence the chemotherapeutic response. This study investigated the association between XRCC1 polymorphisms Arg194Trp, Arg280His, and Arg399Gln, and overall survival (OS) in OC patients who received platinum-based chemotherapy.

METHODS

We systematically searched PubMed, Embase, the Cochrane library, Chinese National Knowledge Infrastructure, Wanfang, and Weipu databases for relevant studies from inception to October, 2017. OS was calculated using a random-effects model. Sensitivity, subgroup, and publication bias analyses were also performed.

RESULTS

Five studies involving 1159 OC patients were included. When compared with 194ArgArg, 194TrpTrp (hazard ratio [HR] 1.09, 95% confidence interval [CI] 0.71-1.69, P = .69) and 194TrpArg (HR 1.00, 95% CI 0.78-1.28, P = .98) carriers were not associated with OS. Similarly, compared with 280ArgArg carriers, neither 280HisHis (HR 1.39, 95% CI 0.82 to -2.34, P = .22) nor 280HisArg (HR 0.98, 95% CI 0.73 to -1.31, P = .90) affected OS. Furthermore, there were no significant differences in OS between 399GlnGln (HR 1.00, 95% CI 0.46-2.16, P > .99), 399GlnArg (HR 1.05, 95% CI 0.81-1.37, P = .70), and 399ArgArg. Finally, subgroup analysis suggested that 399GlnGln significantly decreased OS when the percentage of III or IV cases was >80.0% (HR 1.79, 95% CI 1.22-2.62, P = .003), while OS was increased when this percentage was <80.0% (HR 0.47, 95% CI 0.28-0.79, P = .004).

CONCLUSIONS

This study indicated that XRCC1 Arg194Trp, Arg280His, and Arg399Gln did not affect OS after platinum-based chemotherapy in OC patients. However, disease status could affect the relationship between Arg399Gln and OS in these patients.

Genetic variants as ovarian cancer first-line treatment hallmarks: A systematic review and meta-analysis

BACKGROUND

The potential predictive value of genetic polymorphisms in ovarian cancer first-line treatment is inconsistently reported. We aimed to review ovarian cancer pharmacogenetic studies to update and summarize the available data and to provide directions for further research.

METHODS

A systematic review followed by a meta-analysis was conducted on cohort studies assessing the involvement of genetic polymorphisms in ovarian cancer first-line treatment response retrieved through a MEDLINE database search by November 2016. Studies were pooled and summary estimates and 95% confidence intervals (CI) were calculated using random or fixed-effects models as appropriate.

RESULTS

One hundred and forty-two studies gathering 106871 patients were included. Combined data suggested that GSTM1-null genotype patients have a lower risk of death compared to GSTM1-wt carriers, specifically in advanced stages (hazard ratio (HR), 0.68; 95% CI, 0.48-0.97) and when submitted to platinum-based chemotherapy (aHR, 0.61; 95% CI, 0.39-0.94). ERCC1 rs11615 and rs3212886 might have also a significant impact in treatment outcome (aHR, 0.67; 95% CI, 0.51-0.89; aHR, 1.28; 95% CI, 1.01-1.63, respectively). Moreover, ERCC2 rs13181 and rs1799793 showed a distinct ethnic behavior (Asians: aHR, 1.41; 95% CI, 0.80-2.49; aHR, 1.07; 95% CI, 0.62-1.86; Caucasians: aHR, 0.10; 95% CI, 0.01-0.96; aHR, 0.18; 95% CI, 0.05-0.68, respectively).

CONCLUSION(S)

The definition of integrative predictive models should encompass genetic information, especially regarding GSTM1 homozygous deletion. Justifying additional pharmacogenetic investigation are variants in ERCC1 and ERCC2, which highlight the DNA Repair ability to ovarian cancer prognosis. Further knowledge could aid to understand platinum-treatment failure and to tailor chemotherapy strategies.

XRCC1 mediated the development of cervival cancer through a novel Sp1/Krox-20 swich

Cervical cancer is the second leading cause of mortality among women. Impairment of the base excision repair (BER) pathway is one of the major causes of the initiation and progression of cervical cancer. However, whether the polymorphisms of the BER pathway components (i.e., HOGG1, XRCC1, ADPRT, and APE1) can affect the risk of cervical cancer remains unknown. Herein, we applied a hospital-based case-control study covering two independent cohorts and a subsequent functional assay to determine the roles of the single nucleotide polymorphisms (SNPs) of the BER pathway genes in cervical cancer. Results indicated that the XRCC1 rs3213245 (-77TC) TT genotype was associated with an increased risk of cervical cancer. The immunohistochemistry assay showed that XRCC1 protein expression levels were upregulated in cervical cancer patients with the XRCC1 rs3213245 CC genotype compared with the CT or TT genotypes. Further, results from ChIP assay showed that Sp1 could bind to the −77 site and that the rs3213245 C genotype promoted the binding of Sp1 to the XRCC1 promoter. Moreover, ChIP/Re-ChIP assays revealed that transcription factor Krox-20 was recruited to the XRCC1 rs3213245 mutation region and regulated the transcription of the XRCC1 gene by interacting with Sp1, ultimately mediated cervical cancer development. In summary, the findings indicated that the functional XRCC1 SNP rs3213245 was associated with the risk of cervical cancer based on the Sp1/Krox-20 switch.

INSR gene polymorphisms correlate with sensitivity to platinum-based chemotherapy and prognosis in patients with epithelial ovarian cancer

This study aimed to investigate the correlation between INSR gene polymorphisms on platinum-based chemotherapy sensitivity and prognosis in epithelial ovarian cancer (EOC). A total of 339 EOC patients receiving postoperative chemotherapy were recruited for the study. Tag single-nucleotide polymorphism of INSR gene was screened from HapMap combined with available literature. Frequency distribution of genotypes and alleles in INSR gene was sequenced by ABI3100-Avant. Compared with CC+GC genotype, INSR rs2252673 GG genotype and rs3745546 CC genotype showed less platinum-based chemotherapy sensitivity in EOC patients (odds ratio (OR)=0.269, 95% confidence interval (CI)=0.159~0.456; OR=0.445, 95% CI=0.214~0.926, respectively), as well as serous EOC patients (OR=0.083, 95% CI=0.024~0.278; OR=0.235, 95%CI=0.053~1.041, respectively). The clinical characteristics including age, clinical stage, histological grade and residual lesion size were significantly related with chemosensitivity to platinum drugs and mortality in EOC patients. According to Kaplan-Meier curve, compared with CC+GC genotype, rs2252673 GG genotype showed significantly decreased survival rate in EOC patients (P<0.05). Cox regression model indicated that rs2252673, age and clinical stage were independent risk factors for the prognosis in EOC (all P<0.05). These findings indicate that INSR rs2252673 and rs3745546 polymorphisms were associated with sensitivity to platinum-based chemotherapy in EOC patients and rs2252673 polymorphism may be an independent risk factor for EOC prognosis.

Polymorphism in XRCC1 gene modulates survival and clinical outcomes of advanced North Indian lung cancer patients treated with platinum-based doublet chemotherapy

Survival in lung cancer patients is genetically determined. Single nucleotide polymorphisms (SNPs) in DNA repair genes are observed to play a critical role in survival as DNA repair itself can behave as double-edged sword. We aim to explore the association of DNA repair gene XRCC1 in survival and clinical outcomes for North Indian population. Blood sample from patients diagnosed with lung cancer was taken. DNA isolation and genotyping were performed for the SNPs of XRCC1 gene. Further, patients were followed up through telephonic conversation after every 2 months for 3 years. Statistical analysis was carried out using Kaplan-Meier to determine the median survival time (MST) and Cox proportional regression model to determine the hazards ratio. Further, logistic regression was used to calculate to calculate the objective response. The mutant genotype for XRCC1 399 is observed to have a better survival (MST = 9.6). Histological stratification did not reveal any association for any SNP except for SCLC subtype in XRCC1 632 with an increased death rate (HR 3.08, p = 0.02). On stratification according to chemotherapy regimen administered; cisplatin/carboplatin + docetaxel was observed to increase survival for XRCC1 399 mutant genotype (AA) (HR 0.26, p = 0.05). Cisplatin/carboplatin + irinotecan increased survival in both heterozygotes (GA) and combined variants (GA + AA) (HR 0.22, p = 0.014; HR 0.23, p = 0.012). The polymorphic variants within the XRCC1 gene have found to play an important role in overall survival of lung cancer patients undergoing specific chemotherapy regimen.

Single nucleotide polymorphisms (SNPs) of hOGG1 and XRCC1 DNA repair genes and the risk of ovarian cancer in Polish women

The aim of this study was to determine single nucleotide polymorphisms in hOGG1 (Ser326Cys (rs13181)) and XRCC1 (Arg194Trp (rs1799782)) genes, respectively, and to identify the correlation between them and the overall risk, grading and staging of ovarian cancer in Polish women. Our study comprised 720 patients diagnosed with ovarian cancer and 720 healthy controls. The genotype analysis of hOGG1 and XRCC1 polymorphisms was performed using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (PCR-RFLP). Odds ratios (OR) and 95 % confidence intervals (CI) for each genotype and allele were calculated. Results revealed an association between hOGG1 Ser326Cys polymorphism and the incidence of ovarian cancer. Variant Cys allele of hOGG1 increased the overall cancer risk (OR 2.89; 95 % CI 2.47-3.38; p < .0001). Moreover, ovarian cancer grading remained in a relationship with both analysed polymorphisms; G1 tumours presented increased frequencies of hOGG1 Cys/Cys homozygotes (OR 18.33; 95 % CI 9.38-35.81; p < .0001) and XRCC1 Trp/Trp homozygotes (OR 20.50; 95 % CI 10.17-41.32; p < .0001). Furthermore, G1 ovarian cancers displayed an overrepresentation of Cys and Trp allele. In conclusion, hOGG1 Ser326Cys and XRCC1 Arg194Trp polymorphisms may be regarded as risk factors of ovarian cancer.

Can pharmacogenetics explain efficacy and safety of cisplatin pharmacotherapy?

Several recent pharmacogenetic studies have investigated the variability in both outcome and toxicity in cisplatin-based therapies. These studies have focused on the genetic variability of therapeutic targets that could affect cisplatin response and toxicity in diverse type of cancer including lung, gastric, ovarian, testicular, and esophageal cancer. In this review, we seek to update the reader in this area of investigation, focusing primarily on DNA reparation enzymes and cisplatin metabolism through Glutathione S-Transferases (GSTs). Current evidence indicates a potential application of pharmacogenetics in therapeutic schemes in which cisplatin is the cornerstone of these treatments. Therefore, a collaborative effort is required to study these molecular characteristics in order to generate a genetic panel with clinical utility.

TCRP1 contributes to cisplatin resistance by preventing Pol β degradation in lung cancer cells

Cisplatin (DDP) is the first-line chemotherapy drug widely used for the treatment of lung cancer patients, whereas the majority of cancer patients will eventually show resistance to DDP. The mechanisms responsible for DDP resistance are not fully understood. Tongue cancer resistance-associated protein 1 (TCRP1) gene was recently cloned and reported to specially mediate DDP resistance in human oral squamous cell carcinoma (OSCC) cells. However, the mechanisms of TCRP1-mediated DDP resistance are far from clear, and whether TCRP1 participates in DDP resistance in lung cancer cells remains unknown. Here, we show that TCRP1 contributes to DDP resistance in lung cancer cells. Knockdown of TCRP1 sensitizes the cells to DDP and increases the DDP-induced DNA damage. We have identified that Pol β is associated with DDP resistance, and Pol β knockdown delays the repair of DDP-induced DNA damage in A549/DDP cells. We find TCRP1 interacts with Pol β in lung cancer cells. Moreover, TCRP1 knockdown decreases the level of Pol β and increases the level of its ubiquitination. These results suggest that TCRP1 contributes to DDP resistance through the prevention of Pol β degradation in lung cancer cells. These findings provide new insights into chemoresistance and may contribute to prevention and reversal of DDP resistance in treatment of lung cancer in the future.

Clinicopathological and functional significance of XRCC1 expression in ovarian cancer

X-ray repair cross-complementing gene 1 (XRCC1) is essential for DNA base excision repair, single strand break repair and nucleotide excision repair. We investigated clinicopathological and functional significance of XRCC1 expression in ovarian cancers. XRCC1 protein expression was evaluated in 195 consecutive human ovarian cancers and correlated with clinicopathological variables and survival outcomes. Functional preclinical studies were conducted in a panel of XRCC1 deficient and proficient Chinese hamster and Human cancer cells for cisplatin chemosensitivity. Clonogenic assay, neutral COMET assay, γH2AX immunocytochemistry and flow cytometric analyses were performed in cells. In ovarian cancer, 48% of the tumors were positive for XRCC1 expression and significantly associated with higher stage (p = 0.006), serous type tumors (p = 0.008), suboptimal de-bulking (p = 0.004) and platinum resistance (p < 0.0001). Positive XRCC1 had twofold increase of risk of death (p = 0.007) and progression (p < 0.0001). In the multivariate Cox model, XRCC1 expression was independently associated with cancer specific [p = 0.038] and progression free survival [p = 0.003]. Preclinically, XRCC1 negative cells were sensitive to cisplatin compared to XRCC1 positive cells. Sensitivity to cisplatin in XRCC1 negative cells was associated with accumulation of DNA double strand breaks and G2/M cell cycle arrest. XRCC1 expression is associated with adverse clinicopathological and survival outcomes in patients. Preclinical data provides mechanistic functional evidence for cisplatin sensitivity in XRCC1 negative cells. XRCC1 is a promising predictive biomarker in ovarian cancer.