AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cel...AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC 50 ) and reversal index (IC 50 in experimental group/IC 50 in control group) were calculated. For HepG2, HepG2/OXA, HepG2/OXA/T, each cell line was divided into a control group, OXA group, OXA + fibroblast growth factor 7 (FGF7) group and OXA + emodin group, and the final concentrations of FGF7, emodin and OXA in each group were 5 ng/mL, 10 μg/mL and 10 μmol/L, respectively. Single-cell gel electrophoresis was conducted to detect DNA damage, and the fibroblast growth factor receptor 2 (FGFR2), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and excision repair cross-complementing gene 1 (ERCC1) protein expression levels in each group were examined by Western blotting. RESULTS: Compared with the IC50 of 120.78 μmol/L in HepG2/OXA cells, the IC 50 decreased to 39.65 μmol/L after treatment with 10 μmol/L emodin; thus, the reversal index was 3.05. Compared with the control group, the tail length and Olive tail length in the OXA group, OXA + FGF7 group and OXA + emodin group were significantly increased, and the differences were statistically significant (P < 0.01). The tail length and Olive tail length were lower in the OXA + FGF7 group than in the OXA group, and this difference was also statistically significant. Compared with the OXA + FGF7 group, the tail extent, the Olive tail moment and the percentage of tail DNA were significantly increased in the OXA + emodin group, and these differences were statistically significant (P < 0.01). In comparison with its parental cell line HepG2, the HepG2/OXA cells demonstrated significantly increased FGFR2, p-ERK1/2 and ERCC1 expression levels, whereas the expression of all three molecules was significantly inhibited in HepG2/ OXA/T cells, in which FGFR2 was silenced by FGFR2 shRNA. In the examined HepG2 cells, the FGFR2, p-ERK1/2 and ERCC1 expression levels demonstrated increasing trends in the OXA group and OXA + FGF7 group. Compared with the OXA group and OXA + FGF7 group, the FGFR2, p-ERK1/2, and ERCC1 expression levels were significantly lower in the OXA + emodin group, and these differences were statistically significant. In the HepG2/OXA/T cell line that was transfected with FGFR2 shRNA, the FGFR2, p-ERK1/2 and ERCC1 expression levels were significantly inhibited, but there were no significant differences in these expression levels among the OXA, OXA + FGF7 and OXA + emodin groups. CONCLUSION: Emodin markedly reversed OXA resistance by enhancing OXA DNA damage in HepG2/OXA cells, and the molecular mechanism was related to the inhibitory effect on ERCC1 expression being mediated by the FGFR2/ERK1/2 signaling pathway.展开更多
AIM： To perform a systematic meta-analysis to in- vestigate the association between X-ray repair crosscomplementing group 1 （XRCC1） polymorphisms and hepatocellular carcinoma （HCC） risk. METHODS： Relevant studie...AIM： To perform a systematic meta-analysis to in- vestigate the association between X-ray repair crosscomplementing group 1 （XRCC1） polymorphisms and hepatocellular carcinoma （HCC） risk. METHODS： Relevant studies extracted from PubMed, Embase, Wanfang, VIP and the Chinese National Knowledge Infrastructure databases up to March 2012 were included in the study. Stata software, version 11.0, was used for the statistical analysis. The odds ratios （ORs） and 95% confidence interval （CI） of the XRCC1 polymorphisms in HCC patients were analyzed and compared with healthy controls. The meta-analysis was performed using fixed-effect or random-effect methods, depending on the absence or presence of significant heterogeneity. RESULTS： Eleven studies with 2075 HCC cases and 2604 controls met our eligibility criteria （four studies, 888 cases and 938 controls for Arg194Trp, four studies, 858 cases and 880 controls for Arg280His, and nine studies, 1845 cases and 2401 controls for Arg399Gln）. The meta-analysis revealed no associations between the Arg194Trp and Arg399GIn polymorphisms of the XRCC1 gene and HCC risk under all contrast models （codominant, dominant and recessive models） in the overall analysis and sensitivity analysis （the studies with controls not in the Hardy-Weinberg equilibrium were excluded）. For XRCC1 Arg280His polymorphism, the overall analysis revealed the significant associa- tion between the His/His genotype and the increased risk of HCC （His/His vs Arg/Arg model, OR： 1.96, 95% CI： 1.03-3.75, P = 0.04）. However, sensitivity analysis showed an altered pattern of result and non-significant association （OR： 2.06, 95% CI： 0.67-6.25, P = 0.20）. The heterogeneity hypothesis test did not reveal any heterogeneity, and Begg＇s and Egger＇s tests did not find any obvious publication bias. CONCLUSION： The XRCC1 Arg194Trp and Arg399GIn polymorphisms are not associated with HCC risk. More rigorous association studies are needed to verify the involvement ofXRCC1 Arg280His polymorphism in HCC susceptibility.展开更多
Background：Conflicting results about the association between expression level of excision repair cross-complementation group 1 （ERCC1） and clinical outcome in patients with colorectal cancer （CRC） receiving chemo...Background：Conflicting results about the association between expression level of excision repair cross-complementation group 1 （ERCC1） and clinical outcome in patients with colorectal cancer （CRC） receiving chemotherapy have been reported.Thus,we searched the available articles and performed the meta-analysis to elucidate the prognostic role of ERCC1 expression in patients with CRC.Methods：A thorough literature search using PubMed （Medline）,Embase,Cochrane Library,Web of Science databases,and Chinese Science Citation Database was conducted to obtain the relevant studies.Pooled hazard ratios （HRs） or odds ratios （ORs） with 95% confidence intervals （CIs） were calculated to estimate the results.Results：A total of 11 studies were finally enrolled in this meta-analysis.Compared with patients with lower ERCC1 expression,patients with higher ERCC1 expression tended to have unfavorable overall survival （OS） （HR =2.325,95% CI：1.720-3.143,P 〈 0.001）,progression-free survival （PFS） （HR =1.917,95% CI：1.366-2.691,P 〈 0.001） and poor response to chemotherapy （OR =0.491,95% CI：0.243-0.990,P =0.047）.Subgroup analyses by treatment setting,ethnicity,HR extraction,detection methods,survival analysis,and study design demonstrated that our results were robust.Conclusions：ERCC1 expression may be taken as an effective prognostic factor predicting the response to chemotherapy,OS,and PFS.Further studies with better study design and longer follow-up are warranted in order to gain a deeper understanding of ERCC 1＇s prognostic value.展开更多
Background Several studies have evaluated the association between polymorphisms of encoding excision repair cross complementation group 1 （ERCC1） enzyme and lung cancer risk in diverse populations but with conflicti...Background Several studies have evaluated the association between polymorphisms of encoding excision repair cross complementation group 1 （ERCC1） enzyme and lung cancer risk in diverse populations but with conflicting results.By pooling the relatively small samples in each study, it is possible to perform a meta-analysis of the evidence by rigorous methods.Methods Embase, Ovid, Medline and Chinese National Knowledge Infrastructure were searched. Additional studies were identified from references in original studies or review articles. Articles meeting the inclusion criteria were reviewed systematically, and the reported data were aggregated using the statistical techniques of meta-analysis.Results We found 3810 cases with lung cancer and 4332 controls from seven eligible studies. T19007C polymorphism showed no significant effect on lung cancer risk （C allele vs. T allele： odds ratio （OR）=0.91, 95% confidence interval （CI）=0.80-1.04; CC vs. TT： OR=0.76, 95% CI=0.56-1.02; CC vs. （CT＋TT）： OR=0.96, 95% CI=-0.84-1.10）. Similarly,there was no significant main effects for T19007C polymorphism on lung cancer risk when stratified analyses by ethnicity （Chinese or Caucasian）. No significant association was found between C8092A polymorphism （3060 patients and 2729 controls） and the risk of lung cancer （A allele vs. C allele： OR=1.03, 95% CI=0.95-1.11; AA vs. CC： OR=1.08, 95% CI=-0.88-1.33; AA vs. （AC＋CC）： OR=1.08, 95% CI=-0.88-1.31）.Conclusion We found little evidence of an association between the T1900C or C8092A polymorphisms of ERCC 1 and the risk of lung cancer in Caucasian or Han Chinese people.展开更多
Fluorodeoxyglucose positron emission tomography/conlputed tomography （FDG PET/CT） is widely applied in non-small cell lung cancer （NSCLC）. The standardized uptake value （SUV）, a semi-quantitative index, plays an...Fluorodeoxyglucose positron emission tomography/conlputed tomography （FDG PET/CT） is widely applied in non-small cell lung cancer （NSCLC）. The standardized uptake value （SUV）, a semi-quantitative index, plays an essential role in NSCLC tbr diagnosis, staging, and efficacy evaklation. It has been px3posed that the SUV of tumors may correlate with the presence or absence of chemotherapy resistance-associated biomarkers based on studies that have displayed a close correlation between SUV and the expression levels of excision repair cross-complementary Group 1 （ERCC 1 ）1~1 and Tp53-induced glycolysis and apoptosis regulator.121 FDG avidity of NSCLC and ERCC 1 and ribonucleotide reductase subunit M 1 （RRM 1 ） levels have not been as extensively investigated. Based on these findings, we looked tbr correlations among metabolic parameters （SUVm,,. metabolic tumor volume [MTV], and total lesion glycolysis [TLG]） and ERCC1 and RRM1 expression in patients with NSCLC, to investigate whether FDG uptake reflects the presence or absence ofchemoresistance proteins （ERCC1 and RRM 1 ） within tumor cells.展开更多
AIM To investigate the interactions of the DNA repair gene excision repair cross complementing group 5(ERCC5) and the metabolic gene glutathione S-transferase pi 1(GSTP1) and their effects on atrophic gastritis(AG) an...AIM To investigate the interactions of the DNA repair gene excision repair cross complementing group 5(ERCC5) and the metabolic gene glutathione S-transferase pi 1(GSTP1) and their effects on atrophic gastritis(AG) and gastric cancer(GC) risk.METHODS Seven ERCC5 single nucleotide polymorphisms(SNPs)(rs1047768, rs2094258, rs2228959, rs4150291, rs4150383, rs751402, and rs873601) and GSTP1 SNP rs1695 were detected using the Sequenom MassA RRAY platform in 450 GC patients, 634 AG cases, and 621 healthy control subjects in a Chinese population.RESULTS Two pairwise combinations(ERCC5 rs2094258 and rs873601 with GSTP1 rs1695) influenced AG risk(P_(interaction) = 0.008 and 0.043, respectively), and the ERCC5 rs2094258-GSTP1 rs1695 SNP pair demonstrated an antagonistic effect, while ERCC5 rs873601-GSTP1 rs1695 showed a synergistic effect on AG risk OR = 0.51 and 1.79, respectively). No pairwise combinations were observed in relation to GC risk. There were no cumulative effects among the pairwise interactions(ERCC5 rs2094258 and rs873601 with GSTP1 rs1695) on AG susceptibility(P_(trend) > 0.05). When the modification effect of Helicobacter pylori(H. pylori) infection was evaluated, the cumulative effect of one of the aforementioned pairwise interactions(ERCC5 rs873601-GSTP1 rs1695) was associated with an increased AG risk in the case of negative H. pylori status(P_(trend)= 0.043).CONCLUSION There is a multifarious interaction between the DNA repair gene ERCC5 SNPs(rs2094258 and rs873601) and the metabolic gene GSTP1 rs1695, which may form the basis for various inter-individual susceptibilities to AG.展开更多
Objective： To estimate the relationship between genetic polymorphisms of X-ray repair cross- complementing group 1 （XRCC1） and the susceptibility to childhood acute lymphoblastic leukemia （ALL）. Methods： Relevan...Objective： To estimate the relationship between genetic polymorphisms of X-ray repair cross- complementing group 1 （XRCC1） and the susceptibility to childhood acute lymphoblastic leukemia （ALL）. Methods： Relevant case-control studies were enrolled in the meta-analysis. We applied Rev Man 4.2 software to pool raw data and test studies＇ heterogeneity and to calculate the incorporated odds ratio （OR） and 95% confidence interval （95% CI）. Results： Our data showed that the OR for the Gln allele of the Arg399Gln polymorphism, compared with the Arg allele, was 1.35 （95% CI, 1.16-1.57; P〈0.0001） for childhood ALL patients. Similarly, the homozygous genotype Gln/Gln and heterozygous genotype Arg/Gln both significantly increased the risk of childhood ALL compared with the wild genotype Arg/Arg （OR =1.58; 95% CI, 1.13-2.21; P=0.008; OR =1.51; 95% CI, 1.21-1.87; P=0.0002）. The dominant model of Arg399Gln was associated with childhood ALL risk （OR =1.54; 95% CI, 1.25-1.89; P〈0.0001）. The ethnic subgroup analysis demonstrated that the Gln allele in all five ethnic groups was prone to be a risk factor for childhood ALL just with different degrees of correlation while Arg194Trp SNP showed a protective or risk factor or irrelevant thing in different races. Conclusions： XRCC1 399 polymorphism may increase the risk of childhood ALL. Different ethnic groups with some gene polymorphism have different disease risks.展开更多
基金Supported by National Natural Sciences Foundation of China,No. 81001067the Ministry of Science and Technology International Cooperation Project, No. 2010DFA31870the AstraZeneca Special Research Foundation for Targeted Therapy of the Wu Jieping Medical Foundation, No. 320.6700.09068
文摘AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC 50 ) and reversal index (IC 50 in experimental group/IC 50 in control group) were calculated. For HepG2, HepG2/OXA, HepG2/OXA/T, each cell line was divided into a control group, OXA group, OXA + fibroblast growth factor 7 (FGF7) group and OXA + emodin group, and the final concentrations of FGF7, emodin and OXA in each group were 5 ng/mL, 10 μg/mL and 10 μmol/L, respectively. Single-cell gel electrophoresis was conducted to detect DNA damage, and the fibroblast growth factor receptor 2 (FGFR2), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and excision repair cross-complementing gene 1 (ERCC1) protein expression levels in each group were examined by Western blotting. RESULTS: Compared with the IC50 of 120.78 μmol/L in HepG2/OXA cells, the IC 50 decreased to 39.65 μmol/L after treatment with 10 μmol/L emodin; thus, the reversal index was 3.05. Compared with the control group, the tail length and Olive tail length in the OXA group, OXA + FGF7 group and OXA + emodin group were significantly increased, and the differences were statistically significant (P < 0.01). The tail length and Olive tail length were lower in the OXA + FGF7 group than in the OXA group, and this difference was also statistically significant. Compared with the OXA + FGF7 group, the tail extent, the Olive tail moment and the percentage of tail DNA were significantly increased in the OXA + emodin group, and these differences were statistically significant (P < 0.01). In comparison with its parental cell line HepG2, the HepG2/OXA cells demonstrated significantly increased FGFR2, p-ERK1/2 and ERCC1 expression levels, whereas the expression of all three molecules was significantly inhibited in HepG2/ OXA/T cells, in which FGFR2 was silenced by FGFR2 shRNA. In the examined HepG2 cells, the FGFR2, p-ERK1/2 and ERCC1 expression levels demonstrated increasing trends in the OXA group and OXA + FGF7 group. Compared with the OXA group and OXA + FGF7 group, the FGFR2, p-ERK1/2, and ERCC1 expression levels were significantly lower in the OXA + emodin group, and these differences were statistically significant. In the HepG2/OXA/T cell line that was transfected with FGFR2 shRNA, the FGFR2, p-ERK1/2 and ERCC1 expression levels were significantly inhibited, but there were no significant differences in these expression levels among the OXA, OXA + FGF7 and OXA + emodin groups. CONCLUSION: Emodin markedly reversed OXA resistance by enhancing OXA DNA damage in HepG2/OXA cells, and the molecular mechanism was related to the inhibitory effect on ERCC1 expression being mediated by the FGFR2/ERK1/2 signaling pathway.
基金Supported by International Science and Technology Cooperation Program of the Ministry of Science and Technology,No.010S2012ZR0058the National Basic Research Program of China,No. 2012CB526706+2 种基金the Innovation Program of Shanghai Municipal Education Commission,No.13ZZ060the Fund of Shanghai Municipal Health Bureau,No. 2008Y077the Special Program for Military Medicine,No. 2010JS15
文摘AIM： To perform a systematic meta-analysis to in- vestigate the association between X-ray repair crosscomplementing group 1 （XRCC1） polymorphisms and hepatocellular carcinoma （HCC） risk. METHODS： Relevant studies extracted from PubMed, Embase, Wanfang, VIP and the Chinese National Knowledge Infrastructure databases up to March 2012 were included in the study. Stata software, version 11.0, was used for the statistical analysis. The odds ratios （ORs） and 95% confidence interval （CI） of the XRCC1 polymorphisms in HCC patients were analyzed and compared with healthy controls. The meta-analysis was performed using fixed-effect or random-effect methods, depending on the absence or presence of significant heterogeneity. RESULTS： Eleven studies with 2075 HCC cases and 2604 controls met our eligibility criteria （four studies, 888 cases and 938 controls for Arg194Trp, four studies, 858 cases and 880 controls for Arg280His, and nine studies, 1845 cases and 2401 controls for Arg399Gln）. The meta-analysis revealed no associations between the Arg194Trp and Arg399GIn polymorphisms of the XRCC1 gene and HCC risk under all contrast models （codominant, dominant and recessive models） in the overall analysis and sensitivity analysis （the studies with controls not in the Hardy-Weinberg equilibrium were excluded）. For XRCC1 Arg280His polymorphism, the overall analysis revealed the significant associa- tion between the His/His genotype and the increased risk of HCC （His/His vs Arg/Arg model, OR： 1.96, 95% CI： 1.03-3.75, P = 0.04）. However, sensitivity analysis showed an altered pattern of result and non-significant association （OR： 2.06, 95% CI： 0.67-6.25, P = 0.20）. The heterogeneity hypothesis test did not reveal any heterogeneity, and Begg＇s and Egger＇s tests did not find any obvious publication bias. CONCLUSION： The XRCC1 Arg194Trp and Arg399GIn polymorphisms are not associated with HCC risk. More rigorous association studies are needed to verify the involvement ofXRCC1 Arg280His polymorphism in HCC susceptibility.
文摘Background：Conflicting results about the association between expression level of excision repair cross-complementation group 1 （ERCC1） and clinical outcome in patients with colorectal cancer （CRC） receiving chemotherapy have been reported.Thus,we searched the available articles and performed the meta-analysis to elucidate the prognostic role of ERCC1 expression in patients with CRC.Methods：A thorough literature search using PubMed （Medline）,Embase,Cochrane Library,Web of Science databases,and Chinese Science Citation Database was conducted to obtain the relevant studies.Pooled hazard ratios （HRs） or odds ratios （ORs） with 95% confidence intervals （CIs） were calculated to estimate the results.Results：A total of 11 studies were finally enrolled in this meta-analysis.Compared with patients with lower ERCC1 expression,patients with higher ERCC1 expression tended to have unfavorable overall survival （OS） （HR =2.325,95% CI：1.720-3.143,P 〈 0.001）,progression-free survival （PFS） （HR =1.917,95% CI：1.366-2.691,P 〈 0.001） and poor response to chemotherapy （OR =0.491,95% CI：0.243-0.990,P =0.047）.Subgroup analyses by treatment setting,ethnicity,HR extraction,detection methods,survival analysis,and study design demonstrated that our results were robust.Conclusions：ERCC1 expression may be taken as an effective prognostic factor predicting the response to chemotherapy,OS,and PFS.Further studies with better study design and longer follow-up are warranted in order to gain a deeper understanding of ERCC 1＇s prognostic value.
文摘Background Several studies have evaluated the association between polymorphisms of encoding excision repair cross complementation group 1 （ERCC1） enzyme and lung cancer risk in diverse populations but with conflicting results.By pooling the relatively small samples in each study, it is possible to perform a meta-analysis of the evidence by rigorous methods.Methods Embase, Ovid, Medline and Chinese National Knowledge Infrastructure were searched. Additional studies were identified from references in original studies or review articles. Articles meeting the inclusion criteria were reviewed systematically, and the reported data were aggregated using the statistical techniques of meta-analysis.Results We found 3810 cases with lung cancer and 4332 controls from seven eligible studies. T19007C polymorphism showed no significant effect on lung cancer risk （C allele vs. T allele： odds ratio （OR）=0.91, 95% confidence interval （CI）=0.80-1.04; CC vs. TT： OR=0.76, 95% CI=0.56-1.02; CC vs. （CT＋TT）： OR=0.96, 95% CI=-0.84-1.10）. Similarly,there was no significant main effects for T19007C polymorphism on lung cancer risk when stratified analyses by ethnicity （Chinese or Caucasian）. No significant association was found between C8092A polymorphism （3060 patients and 2729 controls） and the risk of lung cancer （A allele vs. C allele： OR=1.03, 95% CI=0.95-1.11; AA vs. CC： OR=1.08, 95% CI=-0.88-1.33; AA vs. （AC＋CC）： OR=1.08, 95% CI=-0.88-1.31）.Conclusion We found little evidence of an association between the T1900C or C8092A polymorphisms of ERCC 1 and the risk of lung cancer in Caucasian or Han Chinese people.
文摘Fluorodeoxyglucose positron emission tomography/conlputed tomography （FDG PET/CT） is widely applied in non-small cell lung cancer （NSCLC）. The standardized uptake value （SUV）, a semi-quantitative index, plays an essential role in NSCLC tbr diagnosis, staging, and efficacy evaklation. It has been px3posed that the SUV of tumors may correlate with the presence or absence of chemotherapy resistance-associated biomarkers based on studies that have displayed a close correlation between SUV and the expression levels of excision repair cross-complementary Group 1 （ERCC 1 ）1~1 and Tp53-induced glycolysis and apoptosis regulator.121 FDG avidity of NSCLC and ERCC 1 and ribonucleotide reductase subunit M 1 （RRM 1 ） levels have not been as extensively investigated. Based on these findings, we looked tbr correlations among metabolic parameters （SUVm,,. metabolic tumor volume [MTV], and total lesion glycolysis [TLG]） and ERCC1 and RRM1 expression in patients with NSCLC, to investigate whether FDG uptake reflects the presence or absence ofchemoresistance proteins （ERCC1 and RRM 1 ） within tumor cells.
基金Supported by the National Science and Technology Support Program,No.2015BAI13B07
文摘AIM To investigate the interactions of the DNA repair gene excision repair cross complementing group 5(ERCC5) and the metabolic gene glutathione S-transferase pi 1(GSTP1) and their effects on atrophic gastritis(AG) and gastric cancer(GC) risk.METHODS Seven ERCC5 single nucleotide polymorphisms(SNPs)(rs1047768, rs2094258, rs2228959, rs4150291, rs4150383, rs751402, and rs873601) and GSTP1 SNP rs1695 were detected using the Sequenom MassA RRAY platform in 450 GC patients, 634 AG cases, and 621 healthy control subjects in a Chinese population.RESULTS Two pairwise combinations(ERCC5 rs2094258 and rs873601 with GSTP1 rs1695) influenced AG risk(P_(interaction) = 0.008 and 0.043, respectively), and the ERCC5 rs2094258-GSTP1 rs1695 SNP pair demonstrated an antagonistic effect, while ERCC5 rs873601-GSTP1 rs1695 showed a synergistic effect on AG risk OR = 0.51 and 1.79, respectively). No pairwise combinations were observed in relation to GC risk. There were no cumulative effects among the pairwise interactions(ERCC5 rs2094258 and rs873601 with GSTP1 rs1695) on AG susceptibility(P_(trend) > 0.05). When the modification effect of Helicobacter pylori(H. pylori) infection was evaluated, the cumulative effect of one of the aforementioned pairwise interactions(ERCC5 rs873601-GSTP1 rs1695) was associated with an increased AG risk in the case of negative H. pylori status(P_(trend)= 0.043).CONCLUSION There is a multifarious interaction between the DNA repair gene ERCC5 SNPs(rs2094258 and rs873601) and the metabolic gene GSTP1 rs1695, which may form the basis for various inter-individual susceptibilities to AG.
文摘Objective： To estimate the relationship between genetic polymorphisms of X-ray repair cross- complementing group 1 （XRCC1） and the susceptibility to childhood acute lymphoblastic leukemia （ALL）. Methods： Relevant case-control studies were enrolled in the meta-analysis. We applied Rev Man 4.2 software to pool raw data and test studies＇ heterogeneity and to calculate the incorporated odds ratio （OR） and 95% confidence interval （95% CI）. Results： Our data showed that the OR for the Gln allele of the Arg399Gln polymorphism, compared with the Arg allele, was 1.35 （95% CI, 1.16-1.57; P〈0.0001） for childhood ALL patients. Similarly, the homozygous genotype Gln/Gln and heterozygous genotype Arg/Gln both significantly increased the risk of childhood ALL compared with the wild genotype Arg/Arg （OR =1.58; 95% CI, 1.13-2.21; P=0.008; OR =1.51; 95% CI, 1.21-1.87; P=0.0002）. The dominant model of Arg399Gln was associated with childhood ALL risk （OR =1.54; 95% CI, 1.25-1.89; P〈0.0001）. The ethnic subgroup analysis demonstrated that the Gln allele in all five ethnic groups was prone to be a risk factor for childhood ALL just with different degrees of correlation while Arg194Trp SNP showed a protective or risk factor or irrelevant thing in different races. Conclusions： XRCC1 399 polymorphism may increase the risk of childhood ALL. Different ethnic groups with some gene polymorphism have different disease risks.
