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Background: Gemcitabine is a widely used cytotoxic drug in the treatment of a number of solid tumors, for instance, lung, pancreatic as well as breast cancer. As a consequence of the progressive genomic instability, the efficiency rates have eventually lowered. Genetic approach targeting one or several genes in drug targeting pathways facilitates substantially more valuable details in explaining the association between variants and also the efficacy of gemcitabine therapy. In addition, several researchers have reported ethnic discrepancies in clinical response to gemcitabine. Thus, the present study was aimed to establish the normative frequencies of genes associated with the metabolic pathway of Gemcitabine (RRM1 -37C>A (rs12806698), RRM1 -524T>C (rs11030918), CDA 79A>C (rs2072671) and CDA 435 C>T (rs1048977) in South Indian healthy population and compared with 1000 genome population. Additionally, the association of these SNPs with the risk of developing lung cancer was also evaluated.Methods: This study was carried out on 184 healthy subjects and 123 lung cancer patients of South Indian origin and genotyping was done using RT-PCR (Real Time Polymerase Chain Reaction). The frequencies of the above polymorphisms were in Hardy-Weinberg equilibrium (p >0 .05).Results: The minor allele frequencies of the SNPs RRM1 -37C>A (rs12806698), RRM1 -524T>C (rs11030918), CDA 79A>C (rs2072671) and CDA -435 C>T (rs1048977) were 31.3, 36.7, 24.5 and 22.0 respectively.Conclusions: There was a significant difference observed between the genotype and allele frequencies of south Indians with the 1000 genome populations. We also found that SNPs of RRM1 were significantly associated with lung cancer risk.
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Background and purpose:Chemotherapy is an alternative treatment option, which could still get a therapeutic effect, when the EGFR-TKI treatment of non-small cell lung cancer failed. Studies have shown that RR, TYMS, ERCC1 and TUBB3 have respectively relationship with chemosensitivity of gemcitabine, pemetrexed, platinum-based drugs and microtubule-based chemotherapy drugs.The expression levels of these molecular markers can predict the sensitivity of these chemotherapy drugs. The patients with RRMI, TS, ERCC1 and TUBB3 higher expression have reduced chemosensitivity, and lower expression have increased sensitivity. The purpose of this study was to explore the sensitivity of tumor cell lines with acquired resistance to geiftinib caused byEGFR-T790M mutation to cisplatin, gemcitabine, pemetrexed, vinorelbine, paclitaxel and docetaxel.Methods:MTT assay was used to detect the IC50 values of cisplatin, gemcitabine, vinorelbine, paclitaxel and docetaxel, pemetrexed to PC9 and PC9/GR cells, and to explore the chemosensitivity of lung adenocarcinoma cells to these chemotherapy drugs; Luminex method was used respectively to detect the expression levels of ERCC1 mRNA, TUBB3 mRNA, TS mRNA, and RRM1 mRNA in PC9 and PC9/GR cells. Western blot was used to detect the protein expression levels of ERCC1, TUBB3, TS and RRM1 in PC9 and PC9/GR cells.Results: The IC50 values of cisplatin, gemcitabine and pemetrexed to PC9/GR cells were signiifcantly higher than those to PC9 cells (P<0.05), while the IC50 values of vinorelbine, paclitaxe and docetaxel to PC9/GR cells were signiifcantly decreased (P<0.05). Luminex method showed the expressions of ERCC1 mRNA, TS mRNA and RRM1 mRNA in PC9/GR cells were signiifcantly increased than those in PC9 cells (P<0.05), while the expression of TUBB3 mRNA was signiifcantly decreased (P<0.05). Western blot method showed the expressions of TUBB3, TS and RRM1 protein in PC9/GR cells were signiifcantly increased than those in PC9 cells (P<0.05), while TUBB3 protein expression in PC9/GR cells was signiifcantly decreased (P<0.05). Western blot method analysis result showed that the expressions of TUBB3, TS and RRM1 protein in PC9/GR cells were significantly increased than those in PC9 cells (P<0.05), while TUBB3 protein expression in PC9/GR cells was signiifcantly decreased (P<0.05). Conclusion:The chemosensitivity of lung adenocarcinoma with EGFR-T790M mutation is changed. It has decreased sensitivity to cisplatin, gemcitabine, pemetrexed and increased sensitivity to vinorelbine, paclitaxel and docetaxel. The reason of the change of chemosensitivity of geiftinib-resistant lung adenocarcinoma cell maybe related to the changes of ERCC1 mRNA, RRM1 mRNA and TS mRNA and their protein expressions.
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Objective To examine the protein expression levels of ERCC1 and RRM1 in non-small cell lung cancer(NSCLC)and its adjacent tissues in order to identify the the relationship between these expression profiles ,the pathological features and survival time of NSCLC undergoing platinum-containing chemotherapy .Methods The levels of ERCC1 and RRM1 protein expression in 121 NSCLC and adjacent cancer tissue were measured by immunohistochemistry .The relationship between survival time and the expres-sion of these two proteins was used by follow-up study .Results ERCC1 and RRM1 exhibited higher expression in NSCLC cancer compared with normal cancer tissues (P<0 .05) .After receiving platinum-containing chemotherapy postoperatively ,patients with ERCC1 or RRM1 negative expression showed prolonged median overall survival and median time to progression compared with those with positive expression (P<0 .05) .Conclusion The expression of ERCC1 ,RRM1 may have important correlation with the development of lung cancer .ERCC1 or RRM1 of negative protein expression has positive sensitive with platinum .
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Objective The present study presents a meta analysis on the correlation between the expression of ribonucleoside reductase regulatory factor 1(RRM1) and the therapeutic effects of gemcitabine for advanced non-small cell lung cancer (NSCLC). Methods Chinese and English publications were retrieved from the CNKI, WANFANG, PubMed, EMBASE, and ASCO databases with an electronic computer to compare the response rate of the advanced NSCLC patients with different RRM1 expression level (high expression/positive and low expression/negative) to gemcitabine chemotherapy. The Cochrane Collaboration's RevMan 5.0 software was adopted for the analysis. Results Eleven studies, with a total of 515 patients, were identified. The number of patients with high/positive RRM1 protein expression was 235, and the overall efficacy rate was 17.9%. The number of patients with low/negative RRM1 protein expression was 280, and the overall efficacy rate was 44.3%. Heterogeneity test showed no statistical heterogeneity among studies (χ2=10.50, P=0.40, I2=5%). The fixed effect model was adopted for a comprehensive quantitative analysis of the studies, and it showed that the combined odds ratio (OR) was 3.70, with a 95% confidence interval of 2.43 to 5.63, Z=6.11, P<0.00001. Conclusion The patients with low/negative RRM1 expression in advanced NSCLC were more sensitive to gemcitabine chemotherapy compared with patients having high/positive RRM1 expression.
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Objective We analyzed the curative effect of ERCC1 and RRM1 expression on the Neo-adjuvant Chemotherapy of stage Ⅲ NSCLC to investigate the guiding function of ERCC1 and RRM1 expression in chemotherapy regimen containing platinum.Methods Branch DNA-liquid phase chip methods were used to detect ERCC1 and RRM1 expressions before chemotherapy in 80 cases of stage Ⅲ NSCLC confirmed by pathology.All patients received 2 periods Neo-adjuvant Chemotherapy with GP regimen.According to WHO efficacy appraisal standard,the Enhanced Scan of CT showing reaching complete remission or partial remission was effective or stable,otherwise the progression was considered ineffective.Results For the 80 cases of stage Ⅲ NSCLC,the treatment for 20 of the 25 patients with low expressions of both ERCC1 and RRM1 were effective with an effective rate of 80.0％;The treatment for 14 of the 23 patients with low expressed ERCC1 and high expressed RRM1 were effective with an effective rate of 60.9％;The treatment for 10 of the 20 patients with high expressed ERCC1 and low expressed RRM1 were effective with an effective rate of 50.0％;and the treatment for 4 of the 12 patients with both high expression were effective with an effective rate of 33.3％.The difference of effective rates among the four groups had statistical significance ( x2=7.81,P＜0.05 ) with group A having significantly higher rate than the other three groups and group B and group C having significantly higher rate than group D ( P＜0.05 ).Conclusion ERCC1 detection has guiding significance on the regimen selection of NSCLC Neo-adjuvant Chemotherapy.It was worthwhile to use ERCC1 detection widely in the individualized treatment of the stage Ⅲ NSCLC before surgery.
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We studied the expression of BRCA1, ERCC1, and RRM1 which play an important role in DNA repair systems in breast cancer. Immunohistochemical staining for EGFR, BRCA1, ERCC1, and RRM1 were performed by using a tissue microarray made from 230 breast cancer patients. Patients were classified into luminal A, luminal B, HER-2, and triple negative breast cancer (TNBC) types according to ER, PR, and HER-2 expression. The expression of ERCC1, RRM1, and BRCA1 were correlated (P < 0.05). The expression level of ERCC1 was the lowest in TNBC type (P = 0.031), ERCC1 negativity was more prominent in TNBC and luminal B groups than luminal A and HER-2 groups (P = 0.013). Cases with EGFR overexpression showed high expression of RRM1 and BRCA1 (P = 0.046, and 0.004, respectively). In conclusion, the expression of ERCC1 is particularly lower in TNBCs than other types of breast cancers.
Subject(s)
Adult , Female , Humans , Middle Aged , BRCA1 Protein/genetics , Breast Neoplasms/genetics , DNA Repair , DNA-Binding Proteins/genetics , Disease-Free Survival , Endonucleases/genetics , Gene Expression , Immunohistochemistry , Phenotype , Prognosis , Protein Array Analysis , ErbB Receptors/genetics , Biomarkers, Tumor/genetics , Tumor Suppressor Proteins/geneticsABSTRACT
BACKGROUND: Single nucleotide polymorphisms (SNPs), which consist of a substitution of a single nucleotide pair, are the most abundant form of genetic variations occurring with a frequency of approximately 1 per 1000 base pairs. SNPs by themselves do not cause disease but can predispose humans to disease, modify the extent or severity of the disease or influence the drug response and treatment efficacy. Single nucleotide polymorphisms (SNPs), particularly those within the regulatory regions of the genes often influence the expression levels and can modify the disease. Studies examining the associations between SNP and the disease outcome have provided valuable insight into the disease etiology and potential therapeutic intervention. Traditionally, the genotyping of SNPs has been carried out using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP), which is a low throughput technique not amenable for use in large-scale SNP studies. Recently, TaqMan real-time PCR chemistry was adapted for use in allelic discrimination assays. This study validated the accuracy and utility of real-time PCR technology for SNPs genotyping METHODS: The SNPs in promoter sequence (-37 and -524) of lung cancer suppressor gene, RRM1 (ribonucleotide reductase M1 subunit) with the genomic DNA samples of 89 subjects were genotyped using both real-time PCR and PCR-RFLP. RESULTS: The discordance rates were 2.2% (2 mismatches) in -37 and 16.3% (15 mismatches) in -524. Auto-direct sequencing of all the mismatched samples(17 cases) were in accord with the genotypes read by real-time PCR. In addition, 138 genomic DNAs were genotyped using real-time PCR in a duplicate manner (two separated assays). Ninety-eight percent of the samples showed concordance between the two assays. CONCLUSION: Real-time PCR allelic discrimination assays are amenable to high-throughput genotyping and overcome many of the problematic features associated with PCR-RFLP.
Subject(s)
Humans , Base Pairing , Chemistry , Discrimination, Psychological , DNA , Genes, Suppressor , Genetic Variation , Genotype , Lung Neoplasms , Lung , Oxidoreductases , Polymorphism, Single Nucleotide , Real-Time Polymerase Chain Reaction , Regulatory Sequences, Nucleic Acid , Treatment OutcomeABSTRACT
Objective: To investigated the expressions of ERCC1, RRM1 and BRCA1 (members of DNA repair gene family) in patients with non-small cell lung cancer (NSCLC) as well as their clinical prognostic significance. Methods: Expression levels of ERCC1, RRM1 and BRCA1 were detected by real-time PCR method in 32 NSCLC patients and 16 cases of adjacent normal lung tissues. Wilcoxon signed-rank test, Wilcoxon rank sum test, rank correlation, Kaplan-Meier survival curve, and COX multivariate regression analysis were used for statistical analysis. Results: The expression levels of ERCC1, RRM1 and BRCA1 were significantly higher in lung cancer tissues than that in adjacent normal lung tissues. There were significant correlations between intratumoral expression of ERCC1, RRM1, and BRCA1. RRM1 expression level was significantly higher in lung squamous cell carcinomas compared with lung adenocarcinomas but had no difference between different clinical stages. The expression of ERCC1 and BRCA1 had no difference between different pathological classification and clinical TNM stages. The patients with high expression of RRM1 and BRCA1 had significant longer survival time than those with low expression of RRM1 and BRCA1. COX multivariate regression analysis showed that expression of RRM1 was an independent prognostic factor for NSCLC. Conclusion: The expression levels of ERCCI, RRM1, and BRCA1 are significantly higher in lung cancer tissues than that of adjacent normal lung tissues. The patients with high expression of RRM1 and BRCA1 had significant longer survival time than those with low expression of RRM1 and BRCA1. RRM1 and BRCA1 mRNA expressions can be used to predict prognosis of NSCLC.
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BACKGROUND: LOH11A is a region with frequent allele loss (>75%) in lung cancer that is located on the centromeric part of chromosome 11p15.5. Clinical and cell biological studies suggest that this region contains a gene associated with metastatic tumor spread. RRM1 encoding the M1 subunit of ribonucleotide reductase, which is an enzyme that catalyses the rate-limiting step in deoxyribonucleotide synthesis, is located in the LOH11A region. METHODS: Polymorphisms were found at nucleotide position (-)37 (C/A) and (-)524 (C/T) from the beginning of exon 1 of the RRM1 gene that might regulate the expression of RRM1. We studied the polymorphisms in 127 Korean individuals (66 lung cancer and 61 normal controls) and compared with those of 140 American patients with lung cancer. RESULTS: CC, AC and AA were found at the (-)37 position in 64(50.4%), 55(43.3%), and 8(6.3%) out of 127 Korean individuals (66 cancer, 61 non-cancer patients), respectively. There was a similar frequency of allele A at (-)37 in the American(27.9%) and Korean population(28.0%). CC, CT and TT was found at the (-)524 position in 24(18.9%), 44(34.6%), and 59(46.5%) out of the 127 Korean individuals, respectively. There was a similar frequency of allele C at (-)524 in the American(34.6%) and Korean population(36.2%).There was no difference in the frequency of the (-)37 and (-)524 genotypes between the cancer and non-cancer group. However there was a significant correlation of the genotypes between (-)37 and (-)524 (p<0.001), which suggests the possible coordination of these polymorphisms in the regulation of the promoter activity of the RRM1 gene. CONCLUSION: RRM1 promoter polymorphisms were not found to be significant risk factors for lung cancer. However, a further study of the promoter activity and expression of the RRM1 gene according to the pattern of the polymorphism will be needed.
Subject(s)
Humans , Alleles , Catalysis , Exons , Genes, vif , Genotype , Lung Neoplasms , Lung , Ribonucleotide Reductases , Risk FactorsABSTRACT
Gemcitabine is important pyrimidine antimetabolites drug. Ribonucleotide reductase is oneof its targets whose overexpression has been observed in several gemcitabine- resistant cell lines. Meanwhile,the NSCLC patients with high RRM1 expression levels have a relatively poor survival when treated with gem-citabine. To this day, the relationship between RRM1 expression levels in peripheral blood mononuclear cellsand gemcitabine is still uncertain and it deserves further research.