Tumor Biol. DOI 10.1007/s13277-014-1959-0
RESEARCH ARTICLE
Association of DNA repair gene polymorphisms with response to chemotherapy and prognosis of gastric cancer in a Chinese population Junkai Li & Xiaoyan Zuo & Xiaoyan Lv & Fanjun Kong & Wen Xu & Shujuan Yang
Received: 9 January 2014 / Accepted: 8 April 2014 # International Society of Oncology and BioMarkers (ISOBM) 2014
Abstract We conducted a study to investigate the role of excision repair cross-complimentary group 1 gene (ERCC1)–xeroderma pigmentosum complementation group F (XPF) gene polymorphisms in response to chemotherapy and clinical outcome of gastric patients. Three SNPs in ERCC1 (rs11615, rs3212986, and rs2298881) and two SNPs in XPF (rs2276465 and rs6498486) were extracted using Tiangen DNA kit (Tiangen Biotech, Beijing, China) according to the manufacturer’s instructions. The median follow-up time was 36.4 months, and ranged from 2–60 months. During the follow-up period, 112 patients died from gastric cancer. Individuals carrying ERCC1 rs11615 AA and XPF rs6498486 CC genotypes were associated with poorer response to chemotherapy when compared with wild-type genotype, with the ORs (95 % CI) of 0.48 (0.25–0.94) and 0.38 (0.14–1.00). In the Cox proportional hazards model, individuals carrying ERCC1 rs11615 GA and AA genotype had 1.91 and 2.66 risk of death when compared with those carrying GG genotype. Patients carrying the XPF rs6498486 AC and CC genotype were associate with 2.17 and 4.91-fold risk of death when compared with wild-type genotype. In conclusion, we found that ERCC1 rs11615 and XPF rs2276465 may substantially contribute to the future design of individualized cancer treatment in gastric cancer patients. J. Li (*) : X. Zuo : F. Kong : W. Xu Department of Oncology, The 456th Hospital of PAL, Jinan 250031, China e-mail: [email protected] X. Lv Department of Radiotherapy, Jinan Military General Hospital, Jinan 250031, China S. Yang Department of Health and Social Behavior, West China School of Public Health, Sichuan University, Chengdu, China
Keywords ERCC1 . XPF . Gastric cancer . Response . Oxaliplatin/5-Fu-survival
Introduction Gastric cancer is the fifth most common malignancy cancer in the world, and it is estimated that almost one million new cases of gastric cancer occurred in 2012 [1]. In China, gastric cancer is the third most common cause of cancer-related deaths, killing approximately 221,478 people in 2012 [1]. Surgery is the main curative treatment for managing early gastric cancer, but majority of gastric cancer patients develop local or distant recurrence with diagnosis [2]. Postoperative adjuvant chemotherapy was confirmed to have an effective role in improving the disease-free and overall survival, but the prognosis of this disease is still poor. 5-Fluorouracil (5-FU) is the main chemotherapeutic agent for managing gastric cancer, and combination chemotherapy with 5-FU has been demonstrated to associate with a significantly improved overall survival [3]. Clinical response to chemotherapy drug is influenced by both genetic and environmental factors. Inter-individual variation in drugmetabolizing enzymes may influence the clinical outcome of this cancer. Therefore, identification of validated prognostic markers can be helpful in the designing of individualized therapy. Nucleotide excision repair (NER) is one of several DNA repair pathways for correcting the abnormal DNA structures that arise from DNA damage, replication errors, and recombination processes [4]. The excision repair crosscomplimentary group 1 gene (ERCC1) encodes a subunit of the NER complex required for the incision step of NER, which forms a heterodimer with the xeroderma pigmentosum complementation group F (XPF) endonuclease to catalyze the 5′ incision during excision of the DNA lesion [5]. The
Tumor Biol.
ERCC1-XPF complex is a structure-specific endonuclease essential for the repair of DNA damage by the NER pathway, and plays a role in other key cellular processes, such as DNA interstrand crosslink repair and DNA double-strand break repair [6–8]. Previous studies have showed that ERCC1XPF genetic variation can be a predictive marker for response to chemotherapy and prognosis of various cancers [8–10]. However, only one study conducted in the UK reported the association between ERCC1 and XPF expression and clinical outcome of patients with gastric cancer patients treated with neoadjuvant chemotherapy [11]. We conducted a study to investigate the role of ERCC1XPF gene polymorphisms in response to chemotherapy and clinical outcome of gastric patients. Better understanding of the prognostic markers for gastric cancer can help design individualized therapy, and thus, patients can benefit more from treatment to improve their overall survival and diseasefree survival.
Material and methods Patients A total of 326 consecutive patients who were diagnosed and histopathologically confirmed primary gastric cancer were enrolled from the 456th Hospital of PAL between January 2007 and December 2009. Exclusion criteria were (1) patients had secondary or recurrent tumors, (2) had inadequate organ function, (3) were pregnant, and (4) were breast feeding. Blood samples were obtained from all patients, and a written informed consent was obtained from each patient. The protocol of our study was approved by the Ethic committee of 456th Hospital of PAL. Chemotherapy All gastric cancer patients received chemotherapy as follows: 500 mg/m2 5-FU on days 1 to 5, and 2,500 mg/m2 capecitabine on days 1 to 14. The conjunctive chemotherapy included 25 mg/m2 cisplatin on days 1 to 3, 60 mg/m2 oxaliplatin on days 1 and 8, 75 mg/m2 docetaxel on day 1, or 60 mg/m2 paclitaxel on days 1, 8, and 5. The toxicity assessment was conducted before each cycle. The treatment would not be continued when patient presented progressive disease or experienced unacceptable toxicity. The response to treatment was assessed by World Health Organization (WHO) criteria [12]. Patients who showed complete remission (CR) and partial remission (PR) to chemotherapy were regarded as responders, and those who showed stable disease (SD) and progressive disease (PD) to chemotherapy were considered as non-responders. Overall survival (OS) was calculated at the time of enrolling into study until
death or least known date alive. All the patients were followed up every 4 weeks by telephone. Genotyping Potential ERCC1 and XPF SNPs were selected from the National Center for Biotechnology Information (NCBI) dbSNP database. The inclusion criteria were that minor allele frequencies of SNPs were more than 10 % in Chinese population, and SNPs can affect microRNA binding site activity. Finally, three SNPs in ERCC1 (rs11615, rs3212986, and rs2298881) and two SNPs in XPF (rs2276465 and rs6498486) were selected. Genomic DNA was extracted using Tiangen DNA kit (Tiangen Biotech, Beijing, China) according to the manufacturer’s instructions. Genotyping of ERCC1 (rs11615, rs3212986, and rs2298881) and XPF (rs2276465 and rs6498486) were conducted on a 384-well plate format on the Sequenom MassARRAY platform (Sequenom, San Diego, USA). Sequenom Assay Design 3.1 software (Sequenom®) was performed to design the primers for polymerase chain reaction amplification and single base extension assays. PCR reaction were performed in a total of 25 μL, containing 50 ng of genomic DNA, 0.1-μl dNTP, 1.25-U Taq DNA polymerase, and 21-μl forward and reverse primers. The PCR procedure was conducted with an initial melting step of denaturation at 95 °C for 2 min, followed by 45 cycles of denaturation at 94 °C for 30 s, annealing at 56 °C for 30 s, and 72 °C for 60 s, and a final extension at 72 °C for 5 min. Statistical analysis Continuous variables are expressed as the mean±standard deviation (SD), whereas categorical variables are shown as frequencies and percentages (%). The homozygote for the most frequent allele was considered as reference group. The odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated by unconditional logistic regression analysis and utilized to assess the potential association between ERCC1 (rs11615, rs3212986, and rs2298881) and XPF (rs2276465 and rs6498486) and response to chemotherapy. Log-rank test was conducted to compare survival distributions of different genotypes. The association between genotype and survival was estimated based on the hazard ratios (HRs) and their CIs from a multivariate. All analyses were performed using SPSS version 16.0 statistical software (SPSS; Chicago, IL, USA). A two-sided P value of
RESEARCH ARTICLE
Association of DNA repair gene polymorphisms with response to chemotherapy and prognosis of gastric cancer in a Chinese population Junkai Li & Xiaoyan Zuo & Xiaoyan Lv & Fanjun Kong & Wen Xu & Shujuan Yang
Received: 9 January 2014 / Accepted: 8 April 2014 # International Society of Oncology and BioMarkers (ISOBM) 2014
Abstract We conducted a study to investigate the role of excision repair cross-complimentary group 1 gene (ERCC1)–xeroderma pigmentosum complementation group F (XPF) gene polymorphisms in response to chemotherapy and clinical outcome of gastric patients. Three SNPs in ERCC1 (rs11615, rs3212986, and rs2298881) and two SNPs in XPF (rs2276465 and rs6498486) were extracted using Tiangen DNA kit (Tiangen Biotech, Beijing, China) according to the manufacturer’s instructions. The median follow-up time was 36.4 months, and ranged from 2–60 months. During the follow-up period, 112 patients died from gastric cancer. Individuals carrying ERCC1 rs11615 AA and XPF rs6498486 CC genotypes were associated with poorer response to chemotherapy when compared with wild-type genotype, with the ORs (95 % CI) of 0.48 (0.25–0.94) and 0.38 (0.14–1.00). In the Cox proportional hazards model, individuals carrying ERCC1 rs11615 GA and AA genotype had 1.91 and 2.66 risk of death when compared with those carrying GG genotype. Patients carrying the XPF rs6498486 AC and CC genotype were associate with 2.17 and 4.91-fold risk of death when compared with wild-type genotype. In conclusion, we found that ERCC1 rs11615 and XPF rs2276465 may substantially contribute to the future design of individualized cancer treatment in gastric cancer patients. J. Li (*) : X. Zuo : F. Kong : W. Xu Department of Oncology, The 456th Hospital of PAL, Jinan 250031, China e-mail: [email protected] X. Lv Department of Radiotherapy, Jinan Military General Hospital, Jinan 250031, China S. Yang Department of Health and Social Behavior, West China School of Public Health, Sichuan University, Chengdu, China
Keywords ERCC1 . XPF . Gastric cancer . Response . Oxaliplatin/5-Fu-survival
Introduction Gastric cancer is the fifth most common malignancy cancer in the world, and it is estimated that almost one million new cases of gastric cancer occurred in 2012 [1]. In China, gastric cancer is the third most common cause of cancer-related deaths, killing approximately 221,478 people in 2012 [1]. Surgery is the main curative treatment for managing early gastric cancer, but majority of gastric cancer patients develop local or distant recurrence with diagnosis [2]. Postoperative adjuvant chemotherapy was confirmed to have an effective role in improving the disease-free and overall survival, but the prognosis of this disease is still poor. 5-Fluorouracil (5-FU) is the main chemotherapeutic agent for managing gastric cancer, and combination chemotherapy with 5-FU has been demonstrated to associate with a significantly improved overall survival [3]. Clinical response to chemotherapy drug is influenced by both genetic and environmental factors. Inter-individual variation in drugmetabolizing enzymes may influence the clinical outcome of this cancer. Therefore, identification of validated prognostic markers can be helpful in the designing of individualized therapy. Nucleotide excision repair (NER) is one of several DNA repair pathways for correcting the abnormal DNA structures that arise from DNA damage, replication errors, and recombination processes [4]. The excision repair crosscomplimentary group 1 gene (ERCC1) encodes a subunit of the NER complex required for the incision step of NER, which forms a heterodimer with the xeroderma pigmentosum complementation group F (XPF) endonuclease to catalyze the 5′ incision during excision of the DNA lesion [5]. The
Tumor Biol.
ERCC1-XPF complex is a structure-specific endonuclease essential for the repair of DNA damage by the NER pathway, and plays a role in other key cellular processes, such as DNA interstrand crosslink repair and DNA double-strand break repair [6–8]. Previous studies have showed that ERCC1XPF genetic variation can be a predictive marker for response to chemotherapy and prognosis of various cancers [8–10]. However, only one study conducted in the UK reported the association between ERCC1 and XPF expression and clinical outcome of patients with gastric cancer patients treated with neoadjuvant chemotherapy [11]. We conducted a study to investigate the role of ERCC1XPF gene polymorphisms in response to chemotherapy and clinical outcome of gastric patients. Better understanding of the prognostic markers for gastric cancer can help design individualized therapy, and thus, patients can benefit more from treatment to improve their overall survival and diseasefree survival.
Material and methods Patients A total of 326 consecutive patients who were diagnosed and histopathologically confirmed primary gastric cancer were enrolled from the 456th Hospital of PAL between January 2007 and December 2009. Exclusion criteria were (1) patients had secondary or recurrent tumors, (2) had inadequate organ function, (3) were pregnant, and (4) were breast feeding. Blood samples were obtained from all patients, and a written informed consent was obtained from each patient. The protocol of our study was approved by the Ethic committee of 456th Hospital of PAL. Chemotherapy All gastric cancer patients received chemotherapy as follows: 500 mg/m2 5-FU on days 1 to 5, and 2,500 mg/m2 capecitabine on days 1 to 14. The conjunctive chemotherapy included 25 mg/m2 cisplatin on days 1 to 3, 60 mg/m2 oxaliplatin on days 1 and 8, 75 mg/m2 docetaxel on day 1, or 60 mg/m2 paclitaxel on days 1, 8, and 5. The toxicity assessment was conducted before each cycle. The treatment would not be continued when patient presented progressive disease or experienced unacceptable toxicity. The response to treatment was assessed by World Health Organization (WHO) criteria [12]. Patients who showed complete remission (CR) and partial remission (PR) to chemotherapy were regarded as responders, and those who showed stable disease (SD) and progressive disease (PD) to chemotherapy were considered as non-responders. Overall survival (OS) was calculated at the time of enrolling into study until
death or least known date alive. All the patients were followed up every 4 weeks by telephone. Genotyping Potential ERCC1 and XPF SNPs were selected from the National Center for Biotechnology Information (NCBI) dbSNP database. The inclusion criteria were that minor allele frequencies of SNPs were more than 10 % in Chinese population, and SNPs can affect microRNA binding site activity. Finally, three SNPs in ERCC1 (rs11615, rs3212986, and rs2298881) and two SNPs in XPF (rs2276465 and rs6498486) were selected. Genomic DNA was extracted using Tiangen DNA kit (Tiangen Biotech, Beijing, China) according to the manufacturer’s instructions. Genotyping of ERCC1 (rs11615, rs3212986, and rs2298881) and XPF (rs2276465 and rs6498486) were conducted on a 384-well plate format on the Sequenom MassARRAY platform (Sequenom, San Diego, USA). Sequenom Assay Design 3.1 software (Sequenom®) was performed to design the primers for polymerase chain reaction amplification and single base extension assays. PCR reaction were performed in a total of 25 μL, containing 50 ng of genomic DNA, 0.1-μl dNTP, 1.25-U Taq DNA polymerase, and 21-μl forward and reverse primers. The PCR procedure was conducted with an initial melting step of denaturation at 95 °C for 2 min, followed by 45 cycles of denaturation at 94 °C for 30 s, annealing at 56 °C for 30 s, and 72 °C for 60 s, and a final extension at 72 °C for 5 min. Statistical analysis Continuous variables are expressed as the mean±standard deviation (SD), whereas categorical variables are shown as frequencies and percentages (%). The homozygote for the most frequent allele was considered as reference group. The odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated by unconditional logistic regression analysis and utilized to assess the potential association between ERCC1 (rs11615, rs3212986, and rs2298881) and XPF (rs2276465 and rs6498486) and response to chemotherapy. Log-rank test was conducted to compare survival distributions of different genotypes. The association between genotype and survival was estimated based on the hazard ratios (HRs) and their CIs from a multivariate. All analyses were performed using SPSS version 16.0 statistical software (SPSS; Chicago, IL, USA). A two-sided P value of
