Association between polymorphisms of ERCC1 and XPD and survival in non-small-cell lung cancer patients treated with cisplatin combination chemotherapy

Genetic polymorphisms as potential pharmacogenetic biomarkers for platinum-based chemotherapy in non-small cell lung cancer

Platinum-based chemotherapy (PBC) is a widely used treatment for various solid tumors, including non-small cell lung cancer (NSCLC). However, its efficacy is often compromised by the emergence of drug resistance in patients. There is growing evidence that genetic variations may influence the susceptibility of NSCLC patients to develop resistance to PBC. Here, we provide a comprehensive overview of the mechanisms underlying platinum drug resistance and highlight the important role that genetic polymorphisms play in this process. This paper discussed the genetic variants that regulate DNA repair, cellular movement, drug transport, metabolic processing, and immune response, with a focus on their effects on response to PBC. The potential applications of these genetic polymorphisms as predictive indicators in clinical practice are explored, as are the challenges associated with their implementation.

Effect of ERCC1 polymorphisms on the response to platinum-based chemotherapy: A systematic review and meta-analysis based on Asian population

BACKGROUND

Platinum-based chemotherapy is one of the most common treatments for many cancers; however, the effect of chemotherapy varies from individual to individual. Excision repair cross complementation group 1 (ERCC1) is widely recognized as a key gene regulating nucleotide excision repair (NER) and is closely associated with platinum response. Many studies have yielded conflicting results regarding whether ERCC1 polymorphisms can affect the response to platinum and overall survival (OS). Therefore, it is necessary to perform a meta-analysis of patients with specific races and cancer types.

METHODS

Eight databases (EMBASE, PubMed, Cochrane Library, Chinese National Knowledge Infrastructure, Scopus, VIP, China Biology Medicine disc and Wanfang databases) were searched. Results were expressed in terms of odds ratios (ORs), hazard ratios (HRs) and 95% CIs.

RESULTS

In this study, rs11615, rs2298881 and rs3212986 SNPs were studied. In the comparison between CT and TT on the response to platinum, esophageal cancer [I2 = 0%, OR = 6.18, 95% CI(1.89,20.23), P = 0.003] and ovarian cancer [I2 = 0%, OR = 4.94, 95% CI(2.21,11.04), P<0.001] showed that the rs11615 CT genotype predicted a better response. In the comparison between CC and TT, ovarian cancer [I2 = 48.0%, OR = 6.15, 95% CI (2.56,14.29), P<0.001] indicated that the CC genotype predicted a better response. In the meta-analysis of OS, the CC genotype was related to longer OS than TT in ovarian cancer [TT vs CC: I2 = 57.7%, HR = 1.71, 95% CI (1.18, 2.49), P<0.001].

CONCLUSION

The ERCC1 rs11615 polymorphism was related to the response to platinum and OS, but the correlation is based on specific cancer types in the Asian population.

Predictive value of ERCC2, ABCC2 and MMP2 of response and long-term survival in locally advanced head and neck cancer patients treated with chemoradiotherapy

PURPOSE

Genetic variants in genes involved in the distribution, metabolism, accumulation or repair of lesions are likely to influence the response of drugs used in the treatment of Head and Neck Cancer (HNC). We examine the effect of 36 SNPs on clinical outcomes in patients with locally advanced HNC who were receiving platinum-based chemoradiotherapy (CRT).

METHODS

These SNPs were genotyped in 110 patients using the iPLEX Gold assay on the MassARRAY method in blood DNA samples and used Kaplan-Meier and Cox regression analyses to compare genotype groups with the survival.

RESULTS

Two SNPs, rs717620 (ABCC2) and rs12934241 (MMP2) were strongly associated with overall survival (OS) and disease-free survival (DFS). At a median follow-up of 64.4 months, the allele A of rs717620 (ABCC2) had an increased risk of disease progression {hazard ratio [HR] = 1.79, p = 0.0018} and death (HR = 2.0, p = 0.00027). ABCC2 was associated with OS after a Bonferroni adjustment for multiple testing. The MMP2 rs12934241-T allele was associated with an increased risk of worse OS and DFS (p = 0.0098 and p = 0.0015, respectively). One SNP of ABCB1 and three SNPs located in the ERCC2 gene showed an association with response in the subgroup of HNC patients treated with definitive CRT.

CONCLUSIONS

Our findings highlight the potential usefulness of SNPs in different genes involved in drug metabolism and repair DNA to predict the response and survival to CRT. ABCC2 is a potential predictor of OS in patients with HNC.

Impact of ERCC1 gene polymorphisms on response to cisplatin based therapy in oral squamous cell carcinoma (OSCC) patients

Background and Objectives

Cisplatin is one of the major drugs that used in the treatment of oral cancer.Excision repair cross-complementation group 1 (ERCC1) is a key DNA repair gene in the nucleotide excision repair pathway which is activated in the repair of intra- and interstrand DNA crosslink caused by platinum-based treatment. The aim of this study was to investigate the association between polymorphisms in ERCC1 (C118T & C8092A) genes and the response to cisplatin-based chemotherapy.

Methods

ERCC1polymorphisms (C118T & C8092A) were studied using PCR-RFLP method from 150 OSCC patients as cases as well as 150 normal tissues from the same patients were collected as controls for this study. Results: Frequencies of ERCC1 C118C, C118T and T118T genotypes were 60%, 28% and 12% in OSCC patients and 78%, 19% and 3% in the controls, respectively. The C118T & T118T genotype had a 1.69 and 4.97 -folds increased risk for OSCC. Frequencies of ERCC1 C8092C, C8092A and A8092A were 78%, 18% and 4% in the OSCC patients and 89%, 10%, amd 1% in the controls, respectively. The C8092A genotype showed a 1.97-fold increased risk for OSCC.

Interpretation & Conclusions

In conclusion, this study highlights the DNA repair gene polymorphisms that might play a role in mediating susceptibility to oral squamous cell carcinoma and cisplatin therapy. Our data suggest that the ERCC1 C118T, T118T and ERCC1 C8092A genotypes are genetic risk factors for Oral squamous cell carcinoma and ERCC1 118 C/T and C8092A polymorphisms have significant influence on clinical outcome.

Genetic polymorphisms of GSTP1, XRCC1, XPC and ERCC1: prediction of clinical outcome of platinum-based chemotherapy in advanced non-small cell lung cancer patients of Bangladesh

Inter-individual genetic makeup can trigger variability in platinum-based chemotherapeutic responses and corresponding adverse drug reactions and toxicities. Exploring the genetic causes behind these inter-individual variabilities in platinum-based chemotherapeutic responses by investigating the effects of GSTP1 (rs1695), XRCC1 (rs25487), XPC (rs2228001) and ERCC1 (rs11615) genetic polymorphisms on toxicity and therapeutic response of this treatment among Bangladeshi advanced non-small cell lung cancer (NSCLC) patients was the aim of this study. 285 Clinically proven either stage IIIB or IV (advanced) NSCLC patients aging not less than 18 years old and receiving platinum-based chemotherapy were recruited to assess the influence of these four single nucleotide polymorphisms (SNPs) on peripheral leukocytes. Toxicity and response were evaluated by multivariate regression analyses using SPSS statistical software (version 17.0). XRCC1 (rs25487) polymorphism was found to act as a predictive factor for not only grade 3 and 4 anemia (p = 0.008), neutropenia (p = 0.010), thrombocytopenia (p = 0.025) and gastrointestinal toxicity (p = 0.002) but also for therapeutic response (p = 0.012) in platinum-based chemotherapy. Although GSTP1 (rs1695) polymorphism might serve as prognostic factor regarding grade 3 or 4 neutropenia, a significant (p = 0.044) improvement in response to platinum-based chemotherapy was observed. However, XPC (rs2228001) and ERCC1 (rs11615) polymorphisms could not establish any significant relation with toxicity or therapeutic response. XRCC1 (rs2228001) and GSTP1 (rs1695) polymorphisms might explain platinum-induced clinical outcomes in terms of both toxicity and therapeutic response variations among Bangladeshi advanced NSCLC patients.

Establishing a Framework for the Clinical Translation of Germline Findings in Precision Oncology

Inherited genetic variation has important implications for cancer screening, early diagnosis, and disease prognosis. A role for germline variation has also been described in shaping the molecular landscape, immune response, microenvironment, and treatment response of individual tumors. However, there is a lack of consensus on the handling and analysis of germline information that extends beyond known or suspected cancer susceptibility in large-scale cancer genomics initiatives. As part of the Personalized OncoGenomics program in British Columbia, we performed whole-genome and transcriptome sequencing in paired tumor and normal tissues from advanced cancer patients to characterize the molecular tumor landscape and identify putative targets for therapy. Overall, our experience supports a multidisciplinary and integrative approach to germline data management. This includes a need for broader definitions and standardized recommendations regarding primary and secondary germline findings in precision oncology. Here, we propose a framework for identifying, evaluating, and returning germline variants of potential clinical significance that may have indications for health management beyond cancer risk reduction or prevention in patients and their families.

Meta-Analysis of ERCC1 Protein Expression and Platinum Chemosensitivity in Non-Small-Cell Lung Cancer

Objective

To carry out the meta-analysis on the relationship between the expression of nucleotide excision repair cross-complementary enzyme 1 (ERCC1) protein and platinum chemosensitivity in patients with advanced non-small-cell lung cancer (NSCLC).

Methods

The literature on the expression of ERCC1 and platinum chemosensitivity in patients with advanced NSCLC was searched in computer, which was published from January 2009 to August 2019 on the databases such as China Journal Full-text Database (CJFD), China National Knowledge Infrastructure (CNKI), Wanfang Database, VIP, PubMed, EMBASE, and others. Stata 15.0 was used for statistical analysis, and ethnicity subgroup analysis was taken.

Results

Finally, 14 studies were included and 1337 patients were involved, of which 697 were ERCC1 positive, with a positive rate of 53.5%. The combined OR was 0.53 (95% CI: 0.30∼0.79; P < 0.01). The results of ethnicity subgroup analysis showed that there was no significant difference, with OR of 0.50 (95% CI: 0.31∼0.82; P=0.001) in Asian population and OR of 0.56 (95% CI: 0.30∼1.07) in Caucasian population.

Conclusion

The sensitivity to platinum chemotherapy in patients with ERCC1 protein negative expression in the middle and late stages of NSCLC is better than that in patients with positive expression, especially in Asian population. There is no correlation in Caucasian population.

Genetic Variations and Cisplatin Nephrotoxicity: A Systematic Review

Background: Nephrotoxicity is a notable adverse effect in cisplatin treated patients characterized by tubular injury and/or increased serum creatinine (SCr) with incidence varying from 20 to 70%. Pharmacogenomics has been shown to identify strongly predictive genetic markers to help determine which patients are more likely to experience, for example, a serious adverse drug reaction or receive optimal benefit through enhanced efficacy. Genetic variations have been reported to influence the risk of cisplatin nephrotoxicity; however, a comprehensive overview is lacking. Methods: A systematic review was performed using Pubmed, Embase and Web of Science on clinical studies that used cisplatin-based chemotherapy as treatment, had available genotyping data, and evaluated nephrotoxicity as an outcome. The quality of reporting was assessed using the STrengthening the REporting of Genetic Association Studies (STREGA) checklist. Results: Twenty-eight eligible studies were included; all were candidate gene studies. Over 300 SNPs across 135 genes were studied; 29 SNPs in 14 genes were significantly associated with cisplatin-induced nephrotoxicity. A variation in SLC22A2 rs316019, a gene involved in platinum uptake by the kidney, was associated with different measures of nephrotoxicity in four independent studies. Further, variants of ERCC1 (rs11615 and rs3212986) and ERCC2 (rs13181), two genes involved in DNA repair, were found to be positively associated with increased risks of nephrotoxicity in two independent studies. Conclusion: Three genes consistently associated with cisplatin-induced nephrotoxicity. Further research is needed to assess the biological mechanism and the clinical value of modifying treatment based on SLCC22A2 and ERCC1/2 genotypes.

The effect of ERCC1 and ERCC2 gene polymorphysims on response to cisplatin based therapy in osteosarcoma patients

Background

Cisplatin is one of the major drugs that used in the treatment of osteosarcoma. Cisplatin exerts its function by making cisplatin-DNA adducts culminating in cellular death. These adducts found to be repaired by nucleotide excision repair (NER) pathway. This study aimed to evaluate if polymorphisms in two main genes in the NER pathway, excision repair cross-complementing group 1 and 2 (ERCC1 and ERCC2) could affect the histological response to cisplatin based chemotherapy or clinical outcomes, particularly, event free survival (EFS) and overall survival (OS) rates.

Method

ERCC1 (C118T (rs11615) and C8092A (rs3212986)) and ERCC2 (A751C (rs171140) and G312A (rs1799793)) polymorphisms were analysed in 44 patients with osteosarcoma, who were treated with cisplatin based neoadjuvant chemotherapy. DNA was extracted from patient’s formalin-fixed paraffin-embedded (FFPE) samples, patient’s genotypes were determined by using polymerase chain reaction-restriction fragment length polymorphism PCR-RFLP assay. The distribution of the patients’ genotype and the allele frequencies were reported. The association between each of these genotypes and many clinical and patho-histological parameters (e.g. EFS, OS and patho-histological response to treatment) was examined. The associations between gender, tumor location, presence of metastasis at diagnosis, histological subtypes, and type of neoadjuvant chemotherapy and between the histological response, EFS and OS rates were also examined.

Results

This study revealed that there was a positive and significant association between ERCC1 C8092 A genotypes and median EFS rate in years; patients who were carriers of C allele (CC & CA) were found to have longer EFS rates than patients with AA genotype (P value = 0.006) and the median EFS rates were respectively as following: 2.04, 0.24 years. As well, both the presence of metastasis and the histological subtype at the time of diagnosis, were able to affect the EFS rate but not the OS. However, there was a positive correlation between OS rate and the patients’ primary response to treatment.

Conclusions

Our results suggested that ERCC1 8092 C allele may play a role as a candidate prognostic marker in patients with osteosarcoma.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0627-4) contains supplementary material, which is available to authorized users.

Pharmacogenetics of platinum-based chemotherapy: impact of DNA repair and folate metabolism gene polymorphisms on prognosis of non-small cell lung cancer patients

Chemotherapy based on platinum compounds is the standard treatment for NSCLC patients with EGFR wild type, and is also used as second line in mutated EGFR patients. Nevertheless, this therapy presents poor clinical outcomes. ERCC1, ERCC2, XRCC1, MDM2, MTHFR, MTR, and SLC19A1 gene polymorphisms may contribute to individual variation in response and survival to platinum-based chemotherapy. The aim of this study was to investigate the influence of these polymorphisms on response and survival of NSCLC patients treated with platinum-based chemotherapy. A retrospective-prospective cohorts study was conducted, including 141 NSCLC patients. Polymorphisms were analyzed by PCR real-time with Taqman® probes. Patients with ERCC1 rs3212986-GG (p = 0.0268; OR = 2.50; CI_95% = 1.12-5.69) and XRCC1 rs25487-GG (p = 0.0161; OR = 2.99; CI_95% = 1.26-7.62) genotype showed significantly better ORR. Cox survival analysis revealed that patients carrying the MDM2 rs1690924-GG genotype (p = 0.0345; HR = 1.99; CI_95% = 1.05-3.80) presented higher risk of death. Furthermore, carriers of MTR rs1805087-A alleles (p = 0.0060; HR = 8.91; CI_95% = 1.87-42.42) and SLC19A1 rs1051266-AA genotype (p = 0.0130; HR = 1.74; CI_95% = 1.12-2.68) showed greater risk of progression. No influence of ERCC1 rs11615, ERCC2 rs13181, ERCC2 rs1799793, XRCC1 rs1799782, MDM2 rs1470383, MTHFR rs1801131, and MTHFR rs1801133 on platinum-based chemotherapy clinical outcomes was found. In conclusion, our results suggest that ERCC1 rs3212986, XRCC1 rs25487, MDM2 rs1690924, MTR rs1805087, and SLC19A1 rs1051266 gene polymorphisms may significantly act as predictive factors in NSCLC patients treated with platinum-based chemotherapy.

Pharmacogenomics of platinum-based chemotherapy response in NSCLC: a genotyping study and a pooled analysis

Published data showed inconsistent results about associations of extensively studied polymorphisms with platinum-based chemotherapy response. Our study aimed to provide reliable conclusions of these associations by detecting genotypes of the SNPs in a larger sample size and summarizing a comprehensive pooled analysis. 13 SNPs in 8 genes were genotyped in 1024 NSCLC patients by SequenomMassARRAY. 39 published studies and our study were included in meta-analysis. Patients with GA or GG genotypes of XRCC1 G1196 had better response than AA genotype carriers (Genotyping study: OR = 0.72, 95%CI: 0.53-0.96, P = 0.028; Meta-analysis: OR = 0.74, 95%CI: 0.62-0.89, P = 0.001). Patients carrying CT or TT genotypes of XRCC1 C580T could be more sensitive to platinum-based chemotherapy compared to patients with CC genotype (OR = 0.54, 95%CI: 0.37-0.80, P = 0.002). CC genotype of XRCC3 C18067T carriers showed more resistance to platinum-based chemotherapy when compared to those with CT or TT genotypes (OR = 0.69, 95%CI: 0.52-0.91, P = 0.009). Our study indicated that XRCC1 G1196A/C580T and XRCC3 C18067T should be paid attention for personalized platinum-based chemotherapy in NSCLC patients.

Combined effect of ERCC1 and ERCC2 polymorphisms on overall survival in non-squamous non-small-cell lung cancer patients treated with first-line pemetrexed/platinum

OBJECTIVES

Polymorphisms of DNA repair genes may affect DNA repair capacity and the sensitivity of platinum doublets chemotherapy in non-small-cell lung cancer (NSCLC). We prospectively evaluated whether single nucleotide polymorphisms (SNPs) of ERCC1, ERCC2, XRCC1, and XRCC3 were associated with treatment outcome in advanced non-squamous NSCLC patients receiving pemetrexed/platinum as their first-line chemotherapy.

MATERIALS AND METHODS

Genotyping of six SNPs in four DNA repair genes in 58 patients treated with first-line pemetrexed/platinum was performed using TaqMan SNP Genotyping Assays.

RESULTS

The wild-type ERCC1 8092 (C/C) was significantly associated with a better objective response compared to the variant genotypes (C/A + A/A) (48% vs 10%, P = .005). In the multivariate Cox proportional hazards model, we found that individuals with a wild-type genotype of ERCC1 Asn118Asn, ERCC1 C8092A and ERCC2 Asp312Asn had significantly better overall survival (OS) than those with a heterozygous or homozygous variant genotype. On the other hand, the heterozygous variant genotype of ERCC2 Lys751Gln was associated with better OS than that of the wild-type genotype. We further explored the combined effect of SNPs on OS, and found a significant allele/dose-dependent trend toward decreasing OS in patients with an increasing number of unfavorable alleles among four SNPs in ERCC1 and ERCC2. The median OS of patients with two or three unfavorable alleles (30.1 and 30.5 months, respectively) was significantly longer than that of patients with 4 unfavorable alleles (11.8 months, log-rank test for trend, P = .001).

CONCLUSION

A combination of ERCC1 and ERCC2 polymorphisms may predict OS among pemetrexed/platinum treated advanced non-squamous NSCLC patients.

Pharmacogenetics of platinum-based chemotherapy in non-small cell lung cancer: predictive validity of polymorphisms of ERCC1

INTRODUCTION

The efficacy of platinum-based chemotherapy for patients with non-small cell lung cancer (NSCLC) is limited by chemoresistance. Platinum drugs damage DNA by introducing intrastrand and interstrand crosslinks which result in cell death. Excision repair cross-complementing 1 (ERCC1) is a member of the nucleotide excision repair (NER) pathway which erases such defects. Single nucleotide polymorphisms (SNPs) in ERCC1 impair this activity and have been suggested to predict the response to chemotherapy. Area covered: Among the polymorphisms of proteins involved in uptake, metabolism, cytotoxicity and efflux of platinum drugs, codon 118 C/T and C8092A in ERCC1 are the best characterized SNPs studied for their predictive power. Here, the divergent results for studies of these markers in NSCLC are summarized and the reasons for this contradictory data discussed. Expert opinion: Cytotoxicity of platinum compounds comprise complex cellular processes for which DNA repair may not constitute the rate limiting step. These drugs are administered as doublets to histologically diverse patients and, furthermore, the NER pathway in ERCC1 wildtype cohorts may be still impaired by the chemotherapeutics applied. At present, assessment of a limited number of polymorphism in DNA repair proteins is not reliably associated with response to treatment in NSCLC patients.

Association of DNA repair gene polymorphisms with the risk of radiation pneumonitis in lung cancer patients

A total of 149 lung cancer patients were recruited to receive intensity modulated radiation therapy (IMRT). The association of developing radiation pneumonitis (RP) with genetic polymorphism was evaluated. The risks of four polymorphic sites in three DNA repair related genes (ERCC1, rs116615:T354C and rs3212986:C1516A; ERCC2, rs13181:A2251C; XRCC1, rs25487:A1196G) for developing grade ≥ 2 RP were assessed respectively. It was observed that ERCC1 T354C SNP had a significant effect on the development of grade ≥ 2 RP (CT/TT vs. CC, adjusted HR = 0.517, 95% CI, 0.285-0.939; adjusted P = 0.030). It is the first time demonstrating that CT/TT genotype of ERCC1 354 was significantly associated with lower RP risk after radio therapy.

Genetic Polymorphisms and Platinum-based Chemotherapy Treatment Outcomes in Patients with Non-Small Cell Lung Cancer: A Genetic Epidemiology Study Based Meta-analysis

Data regarding genetic polymorphisms and platinum-based chemotherapy (PBC) treatment outcomes in patients with NSCLC are published at a growing pace, but the results are inconsistent. This meta-analysis integrated eligible candidate genes to better evaluate the pharmacogenetics of PBC in NSCLC patients. Relevant studies were retrieved from PubMed, Chinese National Knowledge Infrastructure and WANFANG databases. A total of 111 articles comprising 18,196 subjects were included for this study. The associations of genetic polymorphisms with treatment outcomes of PBC including overall response rate (ORR), overall survival (OS) and progression-free survival (PFS) were determined by analyzing the relative risk (RR), hazard ration (HR), corresponding 95% confidence interval (CI). Eleven polymorphisms in 9 genes, including ERCC1 rs11615 (OS), rs3212986 (ORR), XPA rs1800975 (ORR), XPD rs1052555 (OS, PFS), rs13181 (OS, PFS), XPG rs2296147 (OS), XRCC1 rs1799782 (ORR), XRCC3 rs861539 (ORR), GSTP1 rs1695 (ORR), MTHFR rs1801133 (ORR) and MDR1 rs1045642 (ORR), were found significantly associated with PBC treatment outcomes. These variants were mainly involved in DNA repair (EXCC1, XPA, XPD, XPG, XRCC1 and XRCC3), drug influx and efflux (MDR1), metabolism and detoxification (GSTP1) and DNA synthesis (MTHFR), and might be considered as potential prognostic biomarkers for assessing objective response and progression risk in NSCLC patients receiving platinum-based regimens.

Evaluation of Prediction of Polymorphisms of DNA Repair Genes on the Efficacy of Platinum-Based Chemotherapy in Patients With Non-Small Cell Lung Cancer: A Network Meta-Analysis

This network meta-analysis (NMA) was conducted to compare the predictive value of 14 SNPs in eight DNA repair genes on the efficacy of platinum-based chemotherapy in patients with non-small cell lung cancer (NSCLC). These included ERCC1 (rs11615, rs3212986, rs3212948), XRCC1 (rs25487, rs25489, rs1799782), XPD (rs13181, rs1799793), XPG (rs1047768, rs17655), XPA (rs1800975), XRCC3 (rs861539), APE1 (rs3136820), and RRM1 (rs1042858). The PubMed and Cochrane library databases were reviewed from their inception to February 2017 and studies which met our inclusion criteria were included in our investigation. This network meta-analysis combines direct and indirect evidence to assess the predictive value of 14 SNPs in eight DNA repair genes on the efficacy of platinum-based chemotherapy in NSCLC. We evaluated the predictive value through the use of the odd ratios (OR) and drawing surface under the cumulative ranking curves (SUCRA). A total of 26 eligible cohort studies were enrolled in this NMA. The pairwise meta-analysis indicated that in terms of overall response ratio (ORR), ERCC1 (rs11615), XRCC1 (rs25487, rs1799782), and XPD (rs13181) polymorphisms are associated with the efficacy of platinum-based chemotherapy in NSCLC. The result of this NMA suggests that there is no significant difference in predictive value of 8 DNA repair genes on the efficacy of platinum-based chemotherapy in NSCLC patients. The rank of SUCRA values of the 14 SNPs in the eight DNA repair genes were: XPD (rs1799793)→ERCC1 (rs3212986)→XPA(rs1800975)→ERCC1(rs3212948)→XRCC1(rs25487)→XRCC3(rs861539)→APE1(rs3136820)→ERCC1(rs11615)→XRCC1(rs1799782)→RRM1(rs1042858)→XPD(rs13181)→XPG (rs1047768)→XPG(rs17655)→XRCC1(rs25489). ERCC1(rs11615), XRCC1(rs25487, rs1799782) and XPD(rs13181) polymorphisms were better predictors in evaluating the efficacy of platinum-based chemotherapy in NSCLC patients. J. Cell. Biochem. 118: 4782-4791, 2017. © 2017 Wiley Periodicals, Inc.

Metformin Triggers Autophagy to Attenuate Drug-Induced Apoptosis in NSCLC Cells, with Minor Effects on Tumors of Diabetic Patients

The biologic plausibility of an association between type 2 diabetes mellitus (T2D) and lung cancer has received increasing attention, but the results of investigations remain largely inconclusive. In the present study we investigated the influence of the anti-diabetic drug metformin on the cytotoxic effects of EGFR targeted therapy and chemotherapy in 7 non-small cell lung cancer (NSCLC) cell lines and a cohort of lung cancer patients with/without T2D. In vitro cell viability assays indicated that metformin didn't potentiate the growth inhibitory effects of erlotinib at different doses in cell lines that are of distinct genetic background. EGFR downstream signaling evaluation further demonstrated that metformin, at its IC₅₀ value, modified apoptosis caused in erlotinib or chemotherapeutic agent-treated cells via AKT activation and the inhibition of caspase 3 and PARP cleavages. These regulations were driven independently from EGFR, LKB1, KRAS, PTEN and p53 status. Metformin triggered autophagy (LC3B expression) was identified to interplay with apoptosis to attenuate the drug effect and postpone cancer cell death. In the retrospective study of 8 NSCLC patients, the administration of metformin did not induce statistically significant changes as assessed by immunohistochemical staining of pERK, pAKT and cleaved PARP. Consequently, the application of metformin for T2D NSCLC patients receiving chemo or EGFR targeted therapy should be considered with caution.

Association between XRCC1 and ERCC1 single-nucleotide polymorphisms and the efficacy of concurrent radiochemotherapy in patients with esophageal squamous cell carcinoma

The aim of the present study was to investigate the association between single-nucleotide polymorphisms (SNPs) in X-ray repair cross-complementing 1–399 (XRCC1-399) or excision repair cross-complementation group 1–118 (ERCC1-118) and the short-term efficacy of radiochemotherapy, tumor metastasis and relapse, as well as the survival time in patients with esophageal squamous cell carcinoma (ESCC). TaqMan probe-based quantitative polymerase chain reaction (qPCR) was conducted to examine the levels of XRCC1-399 and ERCC1-118 SNPs in the peripheral blood of 50 patients with pathologically confirmed ESCC. In addition, the associations between different genotypes and short-term therapeutic efficacy [the complete remission (CR) rate], tumor metastasis and relapse, as well as the survival time following concurrent radiochemotherapy, were determined. A total of 50 ESCC patients who received concurrent radiochemotherapy were enrolled. It was found that the short-term therapeutic efficacy (CR rate) was higher in the group of patients carrying the homozygous mutation of XRCC1-399 (A/A genotype) than in the group of patients without the XRCC1-399 mutation (G/G genotype). In addition, the CR rate was significantly increased in patients carrying one or two ERCC1-118 C alleles (C/C or C/T genotype) compared with patients lacking the C allele (T/T genotype). The differences were statistically significant (A/A vs. G/G, P=0.014; TT vs. C/T+C/C, P=0.040). During the follow-up period, the group of patients carrying the homozygous mutation of XRCC1-399 (A/A genotype) exhibited a markedly reduced risk of metastasis and relapse compared with the group of patients carrying non-mutated XRCC1-399 (G/G genotype; P=0.031). By contrast, ERCC1-118 SNP was not associated with the risk of metastasis and recurrence (P>0.05). The combined results of univariate and multivariate Cox regression analysis showed that the SNP in ERCC1-118 was closely associated with survival time. The mean survival time was significantly prolonged in patients carrying 1 or 2 C alleles (C/C or C/T genotype) compared with patients lacking the C allele (T/T genotype) [T/T vs. C/C, HR=12.96, 95% confidence interval (CI)=3.08–54.61, P<0.001; TT vs. C/T+C/C, HR=11.71, 95% CI=3.06–44.83, P<0.001]. However, XRCC1-399SNP had no effect on survival time (P>0.05). XRCCl-399 SNP was associated with the short-term therapeutic efficacy (the CR rate) and tumor metastasis/relapse in ESCC patients who received the docetaxel plus cisplatin (TP) regimen-based concurrent radiochemotherapy. By contrast, ERCC1-118 SNP was significantly associated with the short-term therapeutic efficacy (the CR rate) and survival time in ESCC patients who received TP regimen-based concurrent radiochemotherapy.

Single nucleotide polymorphisms in DNA repair genes and putative cancer risk

Single nucleotide polymorphisms (SNPs) are the most frequent type of genetic alterations between individuals. An SNP located within the coding sequence of a gene may lead to an amino acid substitution and in turn might alter protein function. Such a change in protein sequence could be functionally relevant and therefore might be associated with susceptibility to human diseases, such as cancer. DNA repair mechanisms are known to play an important role in cancer development, as shown in various human cancer syndromes, which arise due to mutations in DNA repair genes. This leads to the question whether subtle genetic changes such as SNPs in DNA repair genes may contribute to cancer susceptibility. In numerous epidemiological studies, efforts have been made to associate specific SNPs in DNA repair genes with altered DNA repair and cancer. The present review describes some of the common and most extensively studied SNPs in DNA repair genes and discusses whether they are functionally relevant and subsequently increase the likelihood that cancer will develop.

A meta-analysis identifies ERCC1 gene polymorphism as a predictor of better patient response to treatment with radiochemotherapy

PURPOSE

This meta-analysis aimed to evaluate whether an association exists between the ERCC1 rs11615 (C>T) polymorphism and patient response to platinum-based chemotherapy and radiation-based chemotherapy.

METHODS

Publications were selected from PubMed and MEDLINE. A meta-analysis was conducted to determine the association between genetic polymorphisms and response to platinum-based chemotherapy and radiation-based chemotherapy by checking the odds ratios (ORs) and 95 % confidence intervals (CIs).

RESULTS

In our overall analysis, the ERCC1 rs11615 (C>T) polymorphism was not associated with response to platinum-based chemotherapy in five comparison models. In the subgroup analyses by ethnicity, the ERCC1 rs11615 (C>T) polymorphism was shown to be significantly associated with objective response in Caucasian patients treated with platinum-based chemotherapy in the recessive model (TT vs.

CT/CC

OR 0.696, 95 % CI 0.508-0.954, heterogeneity = 0.330), but the association was not observed in the Asian population. The C allele was significantly associated with better response to radiochemotherapy in the recessive model comparison (TT vs.

CC/CT

OR 0.724, 95 % CI 0.585-0.869, heterogeneity = 0.008). Subgroup analysis by cancer type revealed that the C allele of ERCC1 rs11615 predicted a better response in esophageal cancers in two comparison models (T vs. C: OR 0.756, 95 % CI 0.648-0.880, heterogeneity = 0.653; TT vs.

TC/CC

OR 0.457, 95 % CI 0.306-0.684, heterogeneity = 0.723). Stratified analysis by ethnicity showed a better response in Caucasians in allelic comparison model (T vs. C: OR 0.895, 95 % CI 0.819-0.977, heterogeneity = 0.095).

CONCLUSION

Together, our results suggest that the ERCC1 rs11615 (C>T) polymorphism was associated with therapeutic response in Caucasian patients and C allele of ERCC1 rs11615 could represent a genetic molecular marker to predict better patient response to radiochemotherapy in recessive model. However, larger prospective randomized trials will be required.

Cisplatin resistance and opportunities for precision medicine

Cisplatin is one of the most commonly used chemotherapy drugs, treating a wide range of cancer types. Unfortunately, many cancers initially respond to platinum treatment but when the tumor returns, drug resistance frequently occurs. Resistance to cisplatin is attributed to three molecular mechanisms: increased DNA repair, altered cellular accumulation, and increased drug inactivation. The use of precision medicine to make informed decisions on a patient's cisplatin resistance status and predicting the tumor response would allow the clinician to tailor the chemotherapy program based on the biology of the disease. In this review, key biomarkers of each molecular mechanism will be discussed along with the current clinical research. Additionally, known polymorphisms for each biomarker will be discussed in relation to their influence on cisplatin resistance.

A Significant Statistical Advancement on the Predictive Values of ERCC1 Polymorphisms for Clinical Outcomes of Platinum-Based Chemotherapy in Non-Small Cell Lung Cancer: An Updated Meta-Analysis

Background. There is no definitive conclusion so far on the predictive values of ERCC1 polymorphisms for clinical outcomes of platinum-based chemotherapy in non-small cell lung cancer (NSCLC). We updated this meta-analysis with an expectation to obtain some statistical advancement on this issue. Methods. Relevant studies were identified by searching MEDLINE, EMBASE databases from inception to April 2015. Primary outcomes included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). All analyses were performed using the Review Manager version 5.3 and the Stata version 12.0. Results. A total of 33 studies including 5373 patients were identified. ERCC1 C118T and C8092A could predict both ORR and OS for platinum-based chemotherapy in Asian NSCLC patients (CT + TT versus CC, ORR: OR = 0.80, 95% CI = 0.67–0.94; OS: HR = 1.24, 95% CI = 1.01–1.53) (CA + AA versus CC, ORR: OR = 0.76, 95% CI = 0.60–0.96; OS: HR = 1.37, 95% CI = 1.06–1.75). Conclusions. Current evidence strongly indicated the prospect of ERCC1 C118T and C8092A as predictive biomarkers for platinum-based chemotherapy in Asian NSCLC patients. However, the results should be interpreted with caution and large prospective studies are still required to further investigate these findings.

Value of detection of molecules associated with drug sensitivity in individualized chemoembolization for hepatocellular carcinoma

AIM: To investigate the value of detection of molecules associated with drug sensitivity in preventive transcatheter arterial chemoembolization (TACE) for patients with hepatocellular carcinoma (HCC) after hepatectomy.

METHODS: A total of 92 patients with HCC receiving preventive TACE within three months after hepatectomy were divided into an observation group (n = 50) and a control group (n = 42). In the observation group, chemotheraputic agents were selected based on the detection of molecules associated with drug sensitivity, while chemotheraputic agents were chosen empirically in the control group. The one-year recurrence rate, side effects of TACE and disease-free survival time were compared between the two groups.

RESULTS: The one-year recurrence rate in the observation group was lower than that of the control group (χ² = 4.422, P = 0.035). The difference in disease-free survival time between the two groups was of statistical significance (t = 3.081, P = 0.003). The disease-free survival curve of the observation group differed from that of the control group (χ² = 5.99, P = 0.014). The incidence rates of nausea, emesis, diarrhea, and leukopenia in the observation group after TACE were significantly lower than those of the control group (P < 0.05). The difference in the incidence rate of fever after TACE had no statistical difference between the two groups (χ² = 0.091, P = 0.763).

CONCLUSION: Selection of chemotheraputic agents based on detection of molecules can delay recurrence, prolong disease-free survival time and reduce the incidence of side effects after TACE in patients with HCC after hepatectomy.

Glutathione S-Transferase Gene Polymorphisms and Treatment Outcome in Cervical Cancer Patients under Concomitant Chemoradiation

Purpose

Cisplatin based concomitant chemoradiation (CRT) is the standard treatment for locally advanced cervical cancer (CC). Glutathione S-transferase (GST), a phase II antioxidant enzyme is induced by oxidative stress generated by drugs and reactive oxidants. The present study was undertaken to evaluate the association of GSTM1, T1 and P1 polymorphisms with the outcome of CRT treatment in CC patients.

Methods

A total of 227 cervical cancer patients with stages IIB-IIIB treated with the same chemoradiotherapy regimen were enrolled and genotyped for GSTM1, T1 and P1 gene polymorphisms by multiplex polymerase chain reaction (mPCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). Overall survival was evaluated using Kaplan-Meier survival function and Cox proportional hazards model. All data were analyzed using SPSS (version 21.0).

Results

Stratified analysis showed that GSTM1 null (M1-) genotype was associated with a significantly better survival among patients with stage IIB cervical cancer (log-rank P = 0.004) than cases with stage IIIA/IIIB. Death and recurrence were significantly higher in patients with GSTM1 present genotype (M1+) (P = 0.037 and P = 0.003 respectively) and those with M1- showed reduced hazard of death with an adjusted hazard ratio ‘HR’ of 0.47 (95% CI, 0.269–0.802, P = 0.006). Women with M1- genotype as well as in combination with GSTT1 null (T1-), GSTP1 (AG+GG) and GSTT1 null/GSTP1 (AG+GG) showed better survival and also reduced risk of death (HR = 0.31, P = 0.016; HR = 0.45, P = 0.013; HR = 0.31, P = 0.02 respectively).

Conclusions

To the best of our knowledge, this is the first study to correlate the association of GSTM1, T1 and P1 gene polymorphisms with treatment outcome of CRT treated CC patients. Our results suggested that individuals with GSTM1 null genotype and in combination with GSTT1 null and GSTP1 (AG+GG) had a survival advantage. Such genetic studies may provide prognostic information in CRT treated CC patients.

Identification of gene markers in the development of smoking-induced lung cancer

Lung cancer is a malignant tumor with high mortality in both women and men. To study the mechanisms of smoking-induced lung cancer, we analyzed microarray of GSE4115. GSE4115 was downloaded from Gene Expression Omnibus including 78 and 85 bronchial epithelium tissue samples separately from smokers with and without lung cancer. Limma package in R was used to screen differentially expressed genes (DEGs). Hierarchical cluster analysis for DEGs was conducted using orange software and visualized by distance map. Using DAVID software, functional and pathway enrichment analyses separately were conducted for the DEGs. And protein-protein interaction (PPI) network was constructed using Cytoscape software. Then, the pathscores of enriched pathways were calculated. Besides, functional features were screened and optimized using the recursive feature elimination (RFE) method. Additionally, the support vector machine (SVM) method was used to train model. Total 1923 DEGs were identified between the two groups. Hierarchical cluster analysis indicated that there were differences in gene level between the two groups. And SVM analysis indicated that the five features had potential diagnostic value. Importantly, MAPK1 (degree=30), SRC (degree=29), SMAD4 (degree=23), EEF1A1 (degree=21), TRAF2 (degree=21) and PLCG1 (degree=20) had higher degrees in the PPI network of the DEGs. They might be involved in smoking-induced lung cancer by interacting with each other (e.g. MAPK1-SMAD4, SMAD4-EEF1A1 and SRC-PLCG1). MAPK1, SRC, SMAD4, EEF1A1, TRAF2 and PLCG1 might be responsible for the development of smoking-induced lung cancer.

Predictive Value of Ercc1 and Xpd Polymorphisms for Clinical Outcomes of Patients Receiving Neoadjuvant Therapy: A Prisma-Compliant Meta-Analysis

Excision repair cross complementing 1 (ERCC1) and xeroderma pigmentosum group D (XPD) play important roles in the nucleotide excision repair (NER) pathway. The correlation between ERCC1 polymorphisms (rs11615 and rs3212986) and XPD polymorphisms (rs13181 and rs1799793) with the response rate and overall survival of cancer patients who accept neoadjuvant therapy has been extensively investigated. However, the results are inconclusive. In this study, we performed a meta-analysis to determine the strength of this correlation. A comprehensive literature search was conducted in Medline, PubMed, and Embase up to February 2015. A review of all titles and abstracts was performed by 2 of the authors to screen the articles based on the eligibility criteria. Clinical trials, observational studies, and epidemiological studies describing ERCC polymorphisms and neoadjuvant treatment were considered for review. The response rate was analyzed using pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Overall survival was assessed using the hazard ratio (HR) with corresponding 95% confidence intervals. In the present meta-analysis, we demonstrated that the ERCC1 rs3212986 polymorphism was significantly correlated with the response rate of esophageal cancer patients to neoadjuvant therapy (OR =  .49, 95% CI = 0.31-0.76, heterogeneity P = 0.480). Furthermore, a considerable correlation was observed between ERCC1 rs11615 and the response rate of esophageal cancer patients to neoadjuvant therapy (OR = 0.228, 95% CI = 0.125-0.418, heterogeneity P = 0.291). No correlation was observed in the meta-analysis of overall survival. The individual studies included in our study differed in their patient selection and therapeutic protocols, which might lead to some bias in the results. These findings indicate that the ERCC1 rs11615 and ERCC1 rs312986 polymorphisms may be candidate pharmacogenomic factors capable of predicting the response rate of esophageal cancer patients who accept neoadjuvant therapy. Further studies are warranted.

XRCC1 and ERCC1 polymorphisms are related to susceptibility and survival of colorectal cancer in the Chinese population

Excision repair cross complementing group 1 (ERCC1) and X-ray repair cross-complementing groups 1 (XRCC1) are DNA repair enzymes. Polymorphisms in DNA repair genes may be important factors affecting cancer susceptibility, prognosis and therapy outcome. The purpose of this study was to investigate the correlation of ERCC1 and XRCC1 polymorphisms with colorectal cancer (CRC) risk, and explore the effect of polymorphisms on event-free, overall survival and oxaliplatin-based therapy in CRC patients. Genotyping was examined with the iMLDR technique. An unconditional logistic regression model was used to estimate the association of certain polymorphisms with CRC risk. The Kaplan-Meier method, log-rank test and Cox regression model were employed to evaluate the effects of polymorphisms on survival analysis. Results showed that Trp/Trp genotype of XRCC1 Arg194Trp and AA genotype of ERCC1 rs2336219 have a significantly increased risk of CRC; Trp allele of XRCC1 Arg194Trp and CC genotype of ERCC1 rs735482 were associated with lower response to oxaliplatin-based chemotherapy, a shorter survival and a higher risk of relapse or metastasis. 194Trp/280Arg/399Arg haplotype was associated with a significant resistance, and the ERCC1 protein expression was statistically higher in tumours with rs735482 CC genotype than with AA genotype. Our studies indicate that XRCC1 and ERCC1 polymorphisms probably affect susceptibility, chemotherapy response and survival of CRC patients.

ERCC1 SNPs as Potential Predictive Biomarkers in Non-Small Cell Lung Cancer Patients Treated With Platinum-Based Chemotherapy

Polymorphisms in ERCC1, XPD, and XRCC1 were examined for (a) association with the clinical outcome of 107 non-small cell lung cancer patients receiving front-line platinum-based chemotherapy, and (b) correlation with the ERCC1 mRNA levels of 176 chemo-naive primary tumors. The ERCC1-C8092 allele and the number of ERCC1 polymorphic variants (C8092A and Asn118Asn) were associated with progression-free survival. In non-squamous histology, tumoral ERCC1 mRNA levels were lower in patients homozygous for ERCC1-C8092 as compared with the patients carrying the A allele (p = .024). These findings merit investigation in larger cohorts of patients treated with uniform regimens.

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.

ERCC1 and personalized medicine in lung cancer

Excision repair cross-complementing group 1 (ERCC1) is known to be a key player in nucleotide excision repair (NER) pathway. Its prognostic or predictive relevance has been extensively investigated in cancer patients including non-small-cell lung cancer. However, several questions should be addressed before its clinical application as biomarker for patient classification or guiding platinum treatment.

The role of DNA repair pathways in cisplatin resistant lung cancer

Platinum chemotherapeutic agents such as cisplatin are currently used in the treatment of various malignancies such as lung cancer. However, their efficacy is significantly hindered by the development of resistance during treatment. While a number of factors have been reported that contribute to the onset of this resistance phenotype, alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating this phenomenon. The mode of action of cisplatin has been linked to its ability to crosslink purine bases on the DNA, thereby interfering with DNA repair mechanisms and inducing DNA damage. Following DNA damage, cells respond by activating a DNA-damage response that either leads to repair of the lesion by the cell thereby promoting resistance to the drug, or cell death via activation of the apoptotic response. Therefore, DNA repair is a vital target to improving cancer therapy and reduce the resistance of tumour cells to DNA damaging agents currently used in the treatment of cancer patients. To date, despite the numerous findings that differential expression of components of the various DNA repair pathways correlate with response to cisplatin, translation of such findings in the clinical setting are still warranted. The identification of alterations in specific proteins and pathways that contribute to these unique DNA repair pathways in cisplatin resistant cancer cells may potentially lead to a renewed interest in the development of rational novel therapies for cisplatin resistant cancers, in particular, lung cancer.

What's your poison? Impact of individual repair capacity on the outcomes of genotoxic therapies in cancer. Part II - information content and validity of biomarkers for individual repair capacity in the assessment of outcomes of anticancer therapy

The individual variance in the efficiency of repair of damage induced by genotoxic therapies may be an important factor in the assessment of eligibility for different anticancer treatments, the outcomes of various treatments and the therapy-associated complications, including acute and delayed toxicity and acquired drug resistance. The second part of this paper analyses the currently available information about the possibilities of using experimentally obtained knowledge about individual repair capacity for the purposes of personalised medicine and healthcare.

Replication of results of a genome-wide association study on lung cancer survival in a Korean population

Recently, a genome-wide association study (GWAS) identified single nucleotide polymorphisms (SNPs) that may influence the prognosis of early-stage non-small cell lung cancer (NSCLC) in Caucasians. We attempted to replicate the impact of genetic variants identified in the GWAS on lung cancer survival in a Korean population. A total of 363 patients with surgically resected NSCLCs were enrolled, and 12 SNPs were genotyped using the SEQUENOM MassARRAY iPLEX assay, TaqMan assay, or a polymerase chain reaction-restriction fragment length polymorphism analysis. The association between genotypes and overall survival (OS) was analyzed. Among the 12 SNPs, the rs6034368T>C was associated with OS. Patients with the rs6034368C allele showed a better OS than the patients with the rs6034368T allele (adjusted hazard ratio = 0.72, confidence interval = 0.56-0.93, P = 0.01). The rs12446308A>G had an effect on OS, but it was marginally significant (under a codominant model, adjusted hazard ratio = 1.85, confidence interval = 0.98-3.47, P = 0.06). We identified that the rs6034368T>C was associated with survival in early-stage NSCLC in a Korean population.

The association between the ERCC1/2 polymorphisms and the clinical outcomes of the platinum-based chemotherapy in non-small cell lung cancer (NSCLC): a systematic review and meta-analysis

The relationship between the ERCC1/2 single nucleotide polymorphisms (SNPs) and the clinical outcomes of the platinum-based chemotherapy in the non-small cell lung cancer (NSCLC) is still inconsistent and inconclusive despite extensive investigations have been conducted to address this question. In this meta-analysis, we aim to further explore the prognostic value of the ERCC1/2 SNPs in NSCLC by analyzing all currently available evidences. Relevant studies were searched in PubMed, Embase, and China National Knowledge Infrastructure. The inclusion criteria were platinum-based chemotherapy in NSCLC patients and evaluation of clinical outcomes in relation to the ERCC1 C118T, ERCC1 C8092A, ERCC2 Asp312Asn, and ERCC2 Lys751Gln. Clinical outcomes analyzed in this study included the overall response rate, overall survival (OS), and progression-free survival (PFS). Odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) were calculated to examine the risk or hazard associated with each SNP. A total of 46 studies including 9,407 NSCLC patients were qualified for this meta-analysis. For ERCC1 C118T, the T allele was associated with a poor OS (HR = 1.35, 95% CI = 1.04-1.75); for ERCC2 Asp312Asn, the Asn variant was linked to an unfavorable OS (HR = 2.07, 95% CI = 1.11-3.88); and for ERCC2 Lys751Gln, patients with the Gln variant have a worse OS (HR = 1.22, 95% CI = 1.05-1.41) and PFS (HR = 1.35, 95% CI = 1.07-1.71). In addition, the main findings of the ERCC1/2 SNPs on chemotherapy toxicity were also summarized. This meta-analysis suggested that the ERCC1 C118T, ERCC2 Asp312Asn, and Lys751Gln may be useful biomarkers to predict the clinical outcomes of the platinum-based chemotherapy in NSCLC patients.

Polymorphisms in XPD gene could predict clinical outcome of platinum-based chemotherapy for non-small cell lung cancer patients: a meta-analysis of 24 studies

OBJECTIVE

Xeroderma pigmentosum group D (XPD) is an essential gene involved in the nucleotide excision repair (NER) pathway. Two commonly studied single nucleotide polymorphisms (SNPs) of XPD (Lys751Gln, A>C, rs13181; Asp312Asn, G>A, rs1799793) are implicated in the modulation of DNA repair capacity, thus related to the responses to platinum-based chemotherapy. Here we performed a meta-analysis to better evaluate the association between the two XPD SNPs and clinical outcome of platinum-based chemotherapy in non-small cell lung cancer (NSCLC) patients.

METHODS

A comprehensive search of PubMed database was conducted to identify relevant articles. Primary outcomes included objective response (i.e., complete response + partial response vs. stable disease + progressive disease), progression-free survival (PFS) and overall survival (OS). The pooled and 95% confidence intervals (CIs) of ORs (odds ratios) and HRs (hazard ratios) were estimated using the fixed or random effect model.

RESULTS

Twenty-four studies were eligible according to the inclusion criteria. None of the XPD Lys751Gln/Asp312Asn polymorphisms was associated with objective response, PFS or OS in NSCLC patients treated with platinum drugs. However, in stratified analysis by ethnicity, the XPD Lys751Gln (A>C) polymorphism was not significantly associated with increased response in Caucasians (OR=1.35, 95%CI=1.0-1.83, P=0.122 for heterogeneity) but was associated with decreased PFS in Asians (HR=1.39, 95%CI=1.07-1.81, P=0.879 for heterogeneity). Furthermore, a statistically significant difference existed in the estimates of effect between the two ethnicities (P=0.014 for TR; P<0.001 for PFS).

CONCLUSIONS

XPD Lys751Gln (A>C) may have inverse predictive and prognostic role in platinum-based treatment of NSCLC according to different ethnicities. Further studies are needed to validate our findings.

Identification of HOXB8 and KLK11 expression levels as potential biomarkers to predict the effects of FOLFOX4 chemotherapy

AIM

To measure global gene expression in primary advanced colorectal cancer patients who have undergone fluorouracil, leucovorin and oxaliplatin (FOLFOX4) chemotherapy and screen valuable biomarkers to predict the effects of chemotherapy.

MATERIALS & METHODS

Samples from primary advanced colorectal cancer patients were collected. The effects of chemotherapy were evaluated, and patients were divided into an experimental group and a control group. Cancerous tissue gene expression profiles were detected by chip technology. Valuable biomarkers were screened by bioinformatic analysis. Immunohistochemical analysis was performed to characterize the pattern of HOXB8 and KLK11 expression. HOXB8 and KLK11 signal probe values were analyzed using receiver operating characteristic analysis.

RESULTS

There were differentially expressed genes in the two groups. HOXB8 and KLK11 proteins were observed in the nucleus and on the outside of the cancer cells, respectively. Their prediction accuracies were 79.9 and 76.7%, respectively.

CONCLUSION

HOXB8 and KLK11 may be classified as valuable biomarkers, as they can predict the effects of FOLFOX4 chemotherapy in primary advanced colorectal cancer patients.

Methylenetetrahydrofolate reductase C677T polymorphism predicts response and time to progression to gemcitabine-based chemotherapy for advanced non-small cell lung cancer in a Chinese Han population

OBJECTIVE

The aim of this study was to evaluate the association between the methylenetetrahydrofolate reductase (MTHFR) C677T excision repair cross-complementation group 1 (ERCC1) genetic polymorphisms and the clinical efficacy of gemcitabine-based chemotherapy in advanced non-small cell lung cancer (NSCLC).

METHODS

A total of 135 chemonaive patients with unresectable advanced NSCLC were treated with gemcitabine/platinum regimens. The polymorphisms of MTHFR C677T, ERCC1 C8092A, and ERCC1 C118T were genotyped using the TaqMan methods.

RESULTS

The overall response rate was 28.9%. Patients with MTHFR CC genotype had a higher rate of objective response than patients with variant genotype (TT or CT) (41.2% versus 19.1%, P=0.01). Median time to progression (TTP) of patients with MTHFR CC genotype was longer than that of patients with variant genotype (7.6 months versus 5.0 months, P=0.003). No significant associations were obtained between ERCC1 C118T and C8092A polymorphisms and both response and survival.

CONCLUSIONS

Our data suggest the value of MTHFR C677T polymorphism as a possible predictive marker of response and TTP in advanced NSCLC patients treated with gemcitabine/platinum.

Predictive value of XPD polymorphisms on platinum-based chemotherapy in non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The correlation between xeroderma pigmentosum group D (XPD) polymorphisms (Lys751Gln and Asp312Asn) and clinical outcomes of non-small cell lung cancer (NSCLC) patients, who received platinum-based chemotherapy (Pt-chemotherapy), is still inconclusive. This meta-analysis was aimed to systematically review published evidence and ascertain the exact role of XPD polymorphisms.

METHODS

Databases of MEDLINE and EMBASE were searched up to April 2013 to identify eligible studies. A rigorous quality assessment of eligible studies was conducted according the Newcastle-Ottawa Quality Assessment Scales. The relationship between XPD polymorphisms and response to Pt-chemotherapy and survival was analyzed.

RESULTS

A total of 22 eligible studies were included and analyzed in this meta-analysis. The overall analysis suggested that the XPD Lys751Gln polymorphism was not associated with response to Pt-chemotherapy or survival. However, the XPD 312Asn allele was significantly associated with poor response to Pt-chemotherapy compared with the Asp312 allele (Asn vs. Asp: OR = 0.435, 95% CI: 0.261-0.726). Additionally, the variant genotype of XPD Asp312Asn polymorphism was associated with favorable survival in Caucasian (AspAsn vs. AspAsp: HR = 0.781, 95% CI: 0.619-0.986) but unfavorable survival in Asian (AspAsn+AsnAsn vs. AspAsp: HR = 1.550, 95% CI: 1.038-2.315).

CONCLUSIONS

These results suggest that XPD Asp312Asn polymorphism may function as a predictive biomarker on platinum-based chemotherapy in NSCLC and further studies are warranted.

Phase II study of satraplatin and prednisone in patients with metastatic castration-resistant prostate cancer: a pharmacogenetic assessment of outcome and toxicity

BACKGROUND

We assessed the effect of excision repair cross-complementing group 1 (ERCC1) and x-ray cross-complementing group 1 (XRCC1) gene polymorphisms on treatment outcomes with satraplatin and prednisone in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel-based therapy.

PATIENTS AND METHODS

Twenty-four patients were enrolled in this single arm study. The primary objective was to determine if the presence of ERCC1 Asn118Asn (N118N, 500C>T, rs11615) and XRCC1 Arg399Gln (R399Q, 1301G>A, rs25487) genetic variants might be associated with an impact on progression-free survival (PFS); secondary objectives included overall response, survival, and toxicity.

RESULTS

After population stratification by race, white patients carrying heterozygous or variant genotypes at the ERCC1 C>T locus had a >3-fold longer median PFS (5.8 vs. 1.8 months; 2P = .18, adjusted) and 5-fold longer median overall survival (OS) (15.7 vs. 3.2 months; 2P = .010, adjusted) than did patients carrying only wild-type alleles. For the XRCC1 G>A variant, without regard to race, patients carrying the wild-type GG alleles had a longer PFS (9.3 months) than those carrying GA or AA alleles (2.7 months; 2P = .02). Similarly, those carrying GG alleles did not reach median OS, whereas those carrying GA or AA alleles had a median OS of 9.6 months (2P = .12, adjusted). Multivariable analysis by using Cox proportional hazards modeling demonstrated that only XRCC1 was associated with PFS.

CONCLUSIONS

To our knowledge, this is the first prospective study to date in patients with metastatic castration-resistant prostate cancer that describes predictive germline polymorphisms of ERCC1 and XRCC1 for assessing the clinical activity of satraplatin.

Predictive effect of XPA and XPD polymorphisms on survival of advanced NSCLC patients treated with platinum-based chemotherapy: a three-dimensional (3-D), polyacrylamide gel-based DNA microarray method

Platinum-based chemotherapy is a primary treatment for patients with advanced non-small cell lung cancer (NSCLC). Considering individual differences, an effective and convenient method is urgently needed to identify the sensitivity of individual patient to platinum based regimen. Genetic variants in DNA repair genes are presumed to represent important determinants of drug efficacy. Our previous studies have demonstrated the involvement of xeroderma pigmentosum group A (XPA) codon23 and xeroderma pigmentosum group D (XPD) codon751 single-nucleotide polymorphisms (SNPs) in clinical response to platinum based chemotherapy in advanced NSCLC patients. Thus, a follow-up study was carried out to investigate the relevance of these genotypes and survival of the cohort (n = 115). The three-dimensional (3-D), polyacrylamide gel-based DNA microarray method was used to assess the genotypes of XPA and XPD in peripheral lymphocytes. Log-rank test revealed that the variant genotypes of XPA23 (A/G+G/G) were associated with significantly longer progression- free survival (PFS) (6.0 m vs. 10.6 m, log-rank P = 0.001) and overall survival (OS) (11.2 m vs. 20.8 m, log-rank P = 0.001). In Cox proportional hazards model, the hazard ratio (HR) for death in patients with G allele was 0.65 (P = 0.049). While no significant differences were observed in PFS or OS according to XPD Lys751Gln genotypes (log-rank P > 0.05). In combination with our previous short-term clinical results, this study further confirmed that by detecting the SNPs in blood cells, XPA A23G polymorphic variants might be a promising biomarker in predicting a favor prognosis of NSCLC patients and be helpful towards designing individualized treatments.

ERCC1 and ERCC2 haplotype modulates induced BPDE-DNA adducts in primary cultured lymphocytes

Background

Benzo[a]pyrene(B[a]P), and its ultimate metabolite Benzo[a]pyrene 7,8-diol 9,10-epoxide (BPDE), are classic DNA damaging carcinogens. DNA damage caused by BPDE is normally repaired by Nucleotide Excision Repair (NER), of which ERCC1 and ERCC2/XPD exert an indispensable role. Genetic variations in ERCC1 and ERCC2 have been related to DNA repair efficiency. In this study we used lymphocytes from healthy individuals to show that polymorphisms in ERCC1 and ERCC2 are directly associated with decreased DNA repair efficiency.

Methods

ERCC1 (rs3212986 and rs11615) and ERCC2 (rs13181, rs1799793 and rs238406) were genotyped in 818 healthy Han individuals from the northeast of China. BPDE induced DNA adducts in lymphocytes were assessed by high performance liquid chromatography (HPLC) in 282 randomly selected participants. The effect of ERCC1 rs3212986 and ERCC2 rs238406 on DNA damage caused by B[a]P was assessed with a modified comet assay.

Results

We found that the variant genotypes of ERCC1 rs3212986 and ERCC2 rs238406 were associated with the high levels of BPDE-DNA adducts. Especially ERCC1 rs3212986 A-allele variant was significantly associated with the high BPDE-DNA adducts. Haplotype analysis showed that the ERCC1 haplotype AC (OR = 2.36, 95% CI = 1.84–2.97), ERCC2 haplotype AGA (OR = 1.51, 95% CI = 1.06–2.15) and haplotype block AGAAC (OR = 5.28, 95% CI = 2.95–9.43), AGCAC (OR = 1.35 95% CI = 1.13–1.60) were linked with high BPDE-DNA adducts. In addition, we found that the combined minor alleles of ERCC1 rs3212986 and ERCC2 rs238406 were associated with a reduced DNA repair capacity.

Conclusions

Our results suggest that the variant genotypes of ERCC1 rs3212986 and ERCC2 rs238406 are associated with decreased repair efficiency of BPDE induced DNA damage, and may be predictive for an individual’s DNA repair capacity in response to environmental carcinogens.

Pharmacogenetics of conventional chemotherapy in non-small-cell lung cancer: a changing landscape?

Pharmacogenetics might be used to select patients who may benefit from specific chemotherapy that best matches the individual and tumor genetic profile, thus allowing maximum activity and minimal toxicity. Even if most studies in non-small-cell lung cancer yielded contradictory results, several potential biomarkers for sensitivity/resistance to platinum compounds, gemcitabine, taxanes and pemetrexed have been proposed. However, these markers need to be validated within larger prospective randomized trials of customized chemotherapy in homogeneous populations. Other critical points include the optimization/standardization of technical procedures, and further studies to unravel the extremely complex regulation of gene function. From this perspective, the evaluation of key factors influencing genotype-phenotype relationships, such as miRNAs, and functional studies to clarify pharmacokinetic/pharmacodynamic interactions, are fundamental for the pharmacogenetic optimization of cancer chemotherapy. Finally, limitation of the traditional pharmacogenetic approach relying only on candidate genes suspected of affecting drug response is now being overcome by the use of novel genome-wide studies.