Excision Repair Cross-complementing Gene Research Articles

Expression of ERCC1, TYMS, RRM1, TUBB3, non-muscle myosin II, myoglobin and MyoD1 in lung adenocarcinoma pleural effusions predicts survival in patients receiving platinum-based chemotherapy.

The association between the expression of excision repair cross‑complementing gene 1 (ERCC1), thymidylate synthase (TYMS), ribonuleotide reductase M1 (RRM1), βIII‑tubulin (TUBB3), non‑muscle myosin II, myoglobin and MyoD1 in metastatic lung adenocarcinoma, and clinical outcomes with platinum‑based chemotherapy treatment is not well‑established. Recently, increasing attention has been focused on the involvement of ERCC1, TYMS, RRM1 and TUBB3 in the development of drug resistance. There has been less research into the role of muscle myosin II, myoglobin and MyoD1 in the pathogenesis of lung cancer, although these genes are known to have important functions within tumor cells. In the current study, malignant pleural effusion from 116 patients with untreated lung adenocarcinoma diagnosed between 2011 and 2012, were collected. The protein expression levels of ERCC1, TYMS, RRM1 and TUBB3 were evaluated with immunocytochemistry and western blot analysis. The expression levels of non‑muscle myosin II, myoglobin and MyoD1 were measured in a subset of 50 patients, treated with platinum‑based chemotherapy. The association of each of these seven factors with one another, as well as with patient survival were analyzed. Immunohistochemistry demonstrated that the percentage of pleural fluid samples from patients with lung adenocarcinoma expressing ERCC1, TYMS, RRM1 and TUBB3 was 37, 36.2, 82.7 and 69.8%, respectively. In the subset of 50 patients in whom the remaining factors were analyzed, the percentage expressing non‑muscle myosin II was 48%, for myoglobin the figure was 40% and for MyoD1 it was 38%. There was a positive correlation between each pair of the above seven molecules with the exception of TYMS and RRM1. Expression of ERCC1, TYMS, TUBB3, non‑muscle myosin II, myoglobin and MyoD1 genes was associated with decreased survival in patients with metastatic lung adenocarcinoma. Expression of ERCC1, TYMS, TUBB3, non‑muscle myosin II, myoglobin and MyoD1 was also associated with decreased survival rates of patients with lung adenocarcinoma treated with platinum‑based chemotherapy. These factors may be used as clinical biomarkers to predict the biological behavior and chemoresistance of tumor cells, and the survival of patients with lung carcinoma.

ERCC1 and the efficacy of cisplatin in patients with resected non-small cell lung cancer.

Excision repair cross-complementing gene 1 (ERCC1) protein is proposed as a predictor for cisplatin efficacy in patients with non-small cell lung cancer (NSCLC). However, recent studies declare that ERCC1 is not associated with the response of platinum-based chemotherapy or clinical outcomes. The purpose of this study is to assess whether ERCC1 expression level is linked to cisplatin sensitivity and clinical outcomes in resected NSCLC patients. Paraffin-embedded cancer samples from 112 patients were used for immunohistochemical staining. Cancer cells isolated from fresh tumor tissues were used to determine the sensitivity to cisplatin by MTT assay. The association between ERCC1 expression and cisplatin sensitivity was tested by Spearman's rho test. The correlation of ERCC1 expression with clinicopathologic parameters was evaluated by the chi-square tests. The relationship between variables and survival was assessed by log-rank test. Overall survival (OS) and disease-free survival (DFS) curves were plotted by the Kaplan-Meier method. Cox proportional hazards model was used for multivariate analysis of survival. ERCC1 expression was significantly correlated with the sensitivity of cisplatin in vitro (p < 0.01, r = 0.37). ERCC1 was not associated with OS (p = 0.17) or DFS (p = 0.13) in patients with resected NSCLC. ERCC1 is not a sensible marker for the choice of treatment in clinical patients with resected NSCLC.

A prospective study of biomarker-guided chemotherapy in patients with non-small cell lung cancer.

Purpose To assess the therapeutic value of biomarker-guided chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).MethodsEighty-five NSCLC patients at stage IIIb or IV were divided into two groups based on the feasibility of biomarker analysis. Group A included patients with biomarker data (n = 41); Group B were patients without biomarker results (n = 44). Tumor samples obtained by fiberoptic bronchoscopy and computerized tomography-guided needle biopsy were analyzed by immunohistochemistry for intratumoral level of excision repair cross-complementing gene 1 (ERCC1), ribonucleotide reductase M1 (RRM1), and β-tubulin III. Chemotherapy regimens in Group A were determined according to the status of molecular signatures, whereas a standard gemcitabine plus cisplatin regimen was used for Group B. Tumor response, patient survival, and adverse effects were monitored for both groups.ResultsThe overall response rate, defined as complete response plus partial response, was 56.1 % for Group A, significantly higher than that in Group B (31.8 %; P = 0.024). The median progression-free survival (PFS) time was 5.2 months for Group A, significantly longer than that of Group B (4.1 months; P = 0.026). The 1-year survival rate of Group A was 65.9 %, significantly higher than that of Group B (40.9 %; P = 0.021), whereas the median overall survival times were 13.5 versus 12.5 months for Groups A and B, respectively (P = 0.483). The adverse effects in the two groups were essentially the same.ConclusionsBiomarker-tailored chemotherapy based on ERCC1, RRM1, and β-tubulin III expression showed significantly increased response rate, median PFS time, and 1-year survival rate in patients with NSCLC.

ERCC1 siRNA ameliorates drug resistance to cisplatin in gastric carcinoma cell lines

The present study examined the effects of cisplatin (DDP) on gastric carcinoma cells by inhibiting the expression of excision repair cross-complementing 1 (ERCC1) using RNA interference (RNAi). mRNA and protein expression of ERCC1 were measured in various gastric carcinoma cell lines using reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis. Cells were treated with different concentrations of DDP and the cell viability was measured using an MTT assay. The correlation between the expression of the ERCC1 gene and the resistance to DDP in the cells was determined. The specific ERCC1 small interfering RNA (siRNA) was synthesized and then transfected into SGC-7901/DDP cells. Alterations in intracellular ERCC1 mRNA expression and protein levels were detected using RT-PCR and western blot analysis, the number of apoptotic cells were measured using flow-cytometry and the cell viability was measured using an MTT assay. The gene expression of ERCC1 correlated with the resistance to DDP of the cells. mRNA expression of ERCC1 was significantly reduced 24 h following transfection of ERCC1 siRNA compared with the mock control group. In addition, the number of apoptotic cells was increased and cell viability was significantly decreased in the ERCC1 siRNA-transfected group compared with the mock control group, suggesting that the sensitivity of SGC-7901/DDP cells to DDP had significantly increased. Cells transfected with siRNA1, siRNA2 and siRNA3 were significantly more sensitive to DPP (161, 381 and 249%, respectively) compared with the mock controls (P<0.05). The results of the present study showed that drug resistance to DDP in gastric carcinoma is correlated with increased expression of ERCC1; therefore, inhibition of ERCC1 by siRNA may ameliorate resistance to DDP in gastric carcinoma.

PEITC reverse multi‐drug resistance of human gastric cancer SGC7901/DDP cell line

Gastric cancer is one of the leading causes of cancer death in the world and nearly all patients who respond initially to cisplatin later develop drug resistance, indicating multi-drug resistance is an essential aspect of the failure of treatment. Phenethyl isothiocyanate (PEITC) has been implicated in inhibiting metastasis of several types of human cancer. However, the effect and potential mechanism of PEITC reversed multi-drug resistance of human gastric cancer is not fully clear. We have identified the role of PEITC in multi-drug resistance reversal of human gastric cancer SGC7901/DDP cell line. PEITC inhibited cisplatin-resistant human SGC7901/DDP cell growth in a dose-dependent manner, causing increased apoptosis, ROS generation, glutathione depletion, accumulation of Rhodamine-123, decreased expression of P-glycoprotein and cell cycle arrest. mRNA and protein expression of the multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), survivin, and Mad2 was decreased, and phosphorylation of Akt and transcriptional activation of NF-κB were suppressed. PEITC may be useful as the therapeutic strategy for overcoming multi-drug resistance through suppressing the PI3K-Akt pathway in human gastric cancer.

Reversing Effect of Sorcin in the Drug Resistance of Human Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is one of the most common cancers originating in the nasopharynx, and chemoresistance is an essential aspect of NPC chemotherapy failure. Sorcin has been implicated in multidrug resistance (MDR) of many types of human tumor. However, the effect and mechanism of Sorcin in MDR of human NPC is not fully clear. In this report, we silenced Sorcin in human NPC CNE2/DDP cells, and explored the role of Sorcin in MDR reversal. The results showed an increased cytotoxicity of cisplatin and intracellular accumulation of Rhodamine-123 and glutathione depletion in Sorcin silencing CNE2/DDP cells. We also found a decreased messenger RNA and protein expression of multidrug resistance gene (MDR1), multidrug resistance-associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), glutathione S-transferase-π (GST-n), RhoE, Bcl-2, and Survivin in Sorcin silencing CNE2/DDP cells. The increased expression of PTEN and decreased expression of p-Akt and NF-κB suggested that the key cellular signaling pathways were triggered by Sorcin silencing. We concluded that Sorcin silencing would contribute to establish a potent target point for MDR reversal.

Fluorodeoxyglucose positron emission tomography and chemotherapy-related tumor marker expression in non-small cell lung cancer

BackgroundThe chemotherapy resistance of non-small cell lung cancer (NSCLC) remains a clinic challenge and is closely associated with several biomarkers including epidermal growth factor receptor (EGFR) ( Drugs 72(Suppl 1):28–36, 012.), p53 ( Med Sci Monit 11(6):HY11–HY20, 2005.) and excision repair cross complementing gene 1 (ERCC1) ( J Thorac Oncol 8(5):582–586, 2013.). Fluorodeoxyglucose positron emission tomography (FDG–PET) is the best non-invasive surrogate for tumor biology with the maximal standardized uptake values (SUVmax) being the most important paradigm. However, there are limited data correlating FDG-PET with the chemotherapy resistant tumor markers. The purpose of this study was to determine the correlation of chemotherapy related tumor marker expression with FDG–PET SUVmax in NSCLC.MethodsFDG–PET SUVmax was calculated in chemotherapy naïve patients with NSCLC (n = 62) and immunohistochemical analysis was performed for EGFR, p53 or ERCC1 on the intraoperative NSCLC tissues. Each tumor marker was assessed independently by two pathologists using common grading criteria. The SUVmax difference based on the histologic characteristics, gender, differentiation, grading and age as well as correlation analysis among these parameters were performed. Multiple stepwise regression analysis was further performed to determine the primary predictor for SUVmax and the receiver operating characteristics (ROC) curve analysis was performed to detect the optimized sensitivity and specificity for SUVmax in suggesting chemotherapy resistant tumor markers.ResultsThe significant tumor type (P = 0.045), differentiation (P = 0.021), p53 (P = 0.000) or ERCC1 (P = 0.033) positivity dependent differences of SUVmax values were observed. The tumor differentiation is significantly correlated with SUVmax (R = -0.327), tumor size (R = -0.286), grading (R = -0.499), gender (R = 0.286) as well as the expression levels for p53 (R = -0.605) and ERCC1 (R = -0.644). The expression level of p53 is significantly correlated with SUVmax (R = 0.508) and grading (R = 0.321). Furthermore, multiple stepwise regression analysis revealed that p53 expression was the primary predictor for SUVmax. When the cut-off value of SUVmax was set at 5.15 in the ROC curve analysis, the sensitivity and specificity of SUVmax in suggesting p53 positive NSCLC were 79.5% and 47.8%, respectively.ConclusionThe current study suggests that SUVmax of primary tumor on FDG-PET might be a simple and good non-invasive method for predicting p53-related chemotherapy resistance in NSCLC when we set the cu-off value of SUVmax at 5.15.

Polymorphisms of ERCC1 gene and outcomes in epithelial ovarian cancer patients with platinum-based chemotherapy

To explore the relationship among single nucleotide polymorphism (SNP) of excision repair cross-complementing 1(ERCC1) gene, chemotherapy sensitivity and clinical outcomes of epithelial ovarian cancer (EOC) patients treated with platinum. Six tag single nucleotide polymorphisms (tagSNP;rs11615, rs3212986, rs735482, rs3212955, rs12610134 and rs3212958) were chose from ERCC1 gene. The genotypes of 6 tagSNP were determined by Snapshot method in 220 EOC patients. Primary clinical outcomes parameter contained EOC patients' responses to platinum-based chemotherapy, progression-free survival (PFS) and overall survival (OS) were analysed. The rs11615 C/T SNP of ERCC1, CC, CT and TT genotype frequencies were 53.1%, 45.6%, 1.4% in responders to platinum-based chemotherapy, while 52.0%, 35.6%, 12.3% in non-responders, respectively, in which there was significant difference between the two groups (P = 0.002) . Compared with the patients with CC genotype, the patients carrying TT genotype had a significantly poor response to platinum-based chemotherapy (OR = 6.22, 95%CI:1.12-34.42). Similarly, the genotypes frequencies distribution of rs11615 C/T SNP of ERCC1 was different between the recurrence and non-recurrence group, death and survival group (all P < 0.05). Kaplan-Meier survival analysis showed that the genotypes frequencies distribution of rs11615 C/T SNP of ERCC1 was associated with PFS and OS (P < 0.01) of EOC patients. Cox's multivariate analysis suggested that patients with TT genotype had a shorter PFS (HR = 2.19, 95%CI:1.14-4.22, P = 0.009) and OS (HR = 2.22, 95%CI:1.06-4.64, P = 0.021) compared with those carrying CC genotype [adjusting for age, International Federation of Gynecology and Obstetrics (FIGO) stage, pathological type, grade and tumor residual size]. The genotypes frequencies distribution of rs3212986, rs735482, rs3212955, rs12610134 and rs3212958 SNP of ERCC1 did not show the significant difference between the responders to platinum-based chemotherapy and non-responders. The other 5 tagSNP may not be associated with the PFS and OS of EOC patients (all P > 0.05). The rs11615 SNP of ERCC1 may become a valuable prognostic biomarker for EOC patients treated with platinum-based chemotherapy.

Impact of excision repair cross-complementing gene 1 (ERCC1) on the outcomes of patients with advanced gastric cancer: correlative study in Japan Clinical Oncology Group Trial JCOG9912

BackgroundSince the best chemotherapy regimen for each patient with advanced gastric cancer is uncertain, we aimed to identify molecular prognostic or predictive biomarkers from biopsy specimens in JCOG9912, a randomized phase III trial for advanced gastric cancer. Patients and methodsEndoscopic biopsy specimens from primary lesions were collected in 445 of 704 randomized patients in JCOG9912. We measured the mRNA expression of excision repair cross-complementing group 1 (ERCC1), thymidylate synthase, dihydropyrimidine dehydrogenase, and five other genes, then, categorized them into low and high groups relative to the median, and examined whether gene expression was associated with efficacy end point. ResultsMultivariate analyses showed that high ERCC1 expression [HR 1.37; 95% confidence interval (CI) 1.08–1.75; P = 0.010], performance status ≥1 (HR 1.45; 95% CI 1.13–1.86; P = 0.004), and number of metastatic sites ≥2 (HR 1.66; 95% CI 1.28–1.86; P < 0.001) were associated with a poor prognosis, and recurrent disease (versus unresectable; HR 0.75; 95% CI 0.56–1.00; P = 0.049) was associated with a favorable prognosis. None of these molecular factors were a predictive marker for choosing irinotecan plus cisplatin or 5-fluorouracil rather than S-1. ConclusionThese correlative analyses suggest that ERCC1 is an independent prognostic factor for overall survival in the first-line treatment of gastric cancer. Clinical Trial NumberC000000062, www.umin.ac.jp.

Differential expression and prognostic value of ERCC1 and thymidylate synthase in resected gastric adenocarcinoma

Excision repair cross-complementing gene-1 (ERCC1) and thymidylate synthase (TS) are key regulatory enzymes whose expression patterns are associated with overall survival (OS) in several malignancies. Their expression patterns and prognostic value in resected gastric adenocarcinoma (GAC) are not known. In total, 109 patients who underwent resection for GAC between January 2000 and June 2011 had tissue available for analysis. The primary objective was to assess for the differential expression of ERCC1 and TS using immunohistochemistry. The secondary objective was to assess for the association between OS and the expression of ERCC1 and TS. The median follow-up was 21.2 months, and the median OS was 28.8 months. Resected GAC exhibited differential expression of ERCC1 (high expression, 23%; n = 25) and TS (high expression, 43%; n = 47). ERCC1 and TS expression were not associated with OS. In a subset analysis of patients who received chemotherapy (n = 73), high ERCC1 expression was associated with decreased OS (16.7 months vs 53.8 months; P = 0.03). After controlling for known adverse pathologic features, high ERCC1 expression persisted as a negative prognostic factor in multivariate Cox regression analysis (hazard ratio, 2.5; 95% confidence interval, 1.03-6.0; P = .04). Conversely, in patients who underwent resection only (n = 35), high ERCC1 expression demonstrated a trend toward improved OS (40.4 months vs 12.7 months; P = .10); a positive prognostic influence also was present on multivariate analysis (hazard ratio, 0.20; 95% confidence interval, 0.04-0.86; P = .03). Resected GAC exhibited differential expression of TS and ERCC1. Among all patients, ERCC1 and TS expression levels were not associated with OS. High ERCC1 tumor expression was associated with decreased OS in the patients who received chemotherapy but was associated with increased OS in those who underwent surgery alone. ERCC1 expression had prognostic value in resected gastric cancer, and further investigation is warranted.

ERCC1 predicts outcome in patients with gastric cancer treated with adjuvant cisplatin-based chemotherapy

Adjuvant chemotherapy is gaining an increasing role in resectable gastric cancer. Customizing chemotherapy on the basis of chemosensitivity may improve outcome, and putative predictive molecular markers have been mostly evaluated in Asian patients. We profiled key DNA and damage signaling factors and correlated them with outcome, in a European cohort. Formalin-fixed tumor samples obtained from surgical specimens of patients treated with adjuvant cisplatin-based chemotherapy for gastric cancer were analyzed. Immunohistochemistry (IHC) was performed to analyze excision repair cross-complementing gene 1 (ERCC1) and thymidylate synthase (TS) expression, and p53 mutations were detected with direct sequencing. Among the 68 patient recruited, the median age was 69 (range 30-74), and UICC stage was III in 44 patients (65 %). With a median follow-up of 40.5 months, disease-free and overall survival were 18.0 (95 % CI 13.4-22.76) and 56 months (95 % CI 44.87-67.13), respectively. ERCC1 score was 0 in 14 out 67 (21 %) cases, 1 in 19 (28 %), 2 in 20 (30 %) and 3 in 14 cases (21 %). Longer overall survival (p = 0.04) was found in patients categorized as ERCC1 negative by IHC according to median score. TS score was 0 in 16 out 67 (24 %) cases, 1 in 27 (40 %), 2 in 16 (24 %) and 3 in 8 cases (12 %). Mutations of p53 were found in 21 out 66 (32 %) cases. Neither TS nor p53 were found to correlate with outcome. Excision repair cross-complementing gene 1 by IHC might predict patients more likely to benefit from adjuvant cisplatin-based chemotherapy in curatively resected gastric cancer. In patients exhibiting ERCC1 positive tumors, alternative regimens should be evaluated.

Reply to an analysis of human equilibrative nucleoside transporter‐1, ribonucleoside reductase subunit M1, ribonucleoside reductase subunit M2, and excision repair cross‐complementing gene‐1 expression in patients with resected pancreas adenocarcinoma: Implications for adjuvant treatment

BACKGROUND Tumor overexpression of excision repair cross-complementing gene-1 (ERCC1) may be associated with decreased survival in patients with pancreas adenocarcinoma (PAC). Human equilibrative nucleoside transporter-1 (hENT1) and ribonucleoside reductase subunits M1 and M2 (RRM1 and RRM2) are integral to cellular transport and DNA synthesis and are implicated as poor prognostic factors in other malignancies. To the authors's knowledge, their role in PAC is not defined. METHODS A prospective database was used to randomly select 95 patients who underwent pancreaticoduodenectomy for PAC between January 2000 and October 2008. Immunohistochemical analysis was performed on tumor samples for hENT1, RRM1 and RRM2, and ERCC1. Main outcomes were recurrence-free survival (RFS) and overall survival (OS). RESULTS The median follow-up, RFS, and OS were 49 months, 10.6 months, and 15.5 months, respectively. The median tumor size was 3 cm. Approximately 26% of patients had positive microscopic margins, 61% had lymph node involvement, and 88% and 45% had perineural and lymphovascular invasion, respectively. High tumor expression of hENT1, RRM1, RRM2, and ERCC1 was present in 85%, 40%, 17%, and 16%, respectively, of patients. High hENT1 expression was associated with reduced RFS (9.5 months vs 44.5 months; P = .029), but not with OS. RRM1 expression was not associated with survival. High RRM2 expression was associated with reduced RFS (6.9 months vs 16.0 months; P < .0001) and decreased OS (9.1 months vs 18.4 months; P < .0001). High ERCC1 expression was associated with reduced RFS (6.1 months vs 15 months; P = .04) and decreased OS (8.9 months vs 18.1 months; P = .03). After accounting for known adverse tumor factors, high expression of RRM2 and ERCC1 persisted as negative prognostic factors for RFS and OS. A subset analysis of patients who received adjuvant therapy (n = 74) revealed the same negative effect of high RRM2 and ERCC1 expression on RFS and OS. CONCLUSIONS High tumor expression of RRM2 and ERCC1 are associated with reduced RFS and OS after resection of pancreas cancer. These biomarkers may help to personalize adjuvant therapy.

The effect of Bcl-2 gene silencing on the sensitivity of cell line A549 to chemotherapeutic drugs

To investigate the effects of miRNA-mediated down-regulation of the Bcl-2 gene on the chemotherapeutic sensitivities and mRNA transcriptions of sensitivity associated genes in human lung adenocarcinoma cell line A549 cells, and therefore to provide experimental data for improving the chemotherapeutic effects on non-small cell lung cancer (NSCLC). The miRNA recombinant plasmid targeting to human Bcl-2 gene was designed, synthesized and stably transferred into A549 cells by lipofectin technique as the experiment group. The transcription of Bcl-2 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) by agarose gel electrophoresis, real-time PCR, and the protein level of Bcl-2 was measured by Western blot to confirm the function of miRNA plasmid. The cell proliferation was examined by methyl thiazolyl tetrazolium (MTT) assay. Cell cycle was measured by flow cytometry. Drug sensitivities of A549 cells to etoposide, 5-fluorouracil, cisplatin, adriamycin, vincristine, paclitaxel and navelbine were analyzed by MTT assay. The mRNA expressions of excision repair cross-complementing gene 1 (ERCC1), thymidylate synthase (TYMS), Class III β-tubulin, topoisomerase 2 alpha (TOP2α) genes were detected by RT-PCR and real-time PCR. The recombinant miRNA plasmid was successfully synthesized and stably transferred into A549 cells. The transcription of Bcl-2 mRNA dramatically decreased by 98.1% in the experiment group (RQ = 0.002 ± 0.001) compared to that in the negative control group (RQ = 0.104 ± 0.003) by real-time PCR (t = 98.70, P < 0.05); and the protein level of Bcl-2 in the experiment group decreased by 57.6% by Western blot (t = 7.66, P < 0.05). The cell cycle profile showed that the low expression of Bcl-2 gene led to A549 cell cycle arrest at G1-phase. The results of MTT showed that the growth of A549 cells in the experiment group was markedly inhibited. The sensitivities of A549 cells to etoposide, cisplatin, paclitaxel, and navelbine were significantly enhanced [IC₅₀ values in the experiment group were (107.3 ± 0.1) mg/L, (7.7 ± 0.6) mg/L, (11.5 ± 1.9) mg/L and (10.8 ± 1.6) mg/L; IC₅₀ values in the negative control group were (145.8 ± 0.1) mg/L, (60.7 ± 1.4) mg/L, (80.6 ± 1.7) mg/L and (20.6 ± 1.7) mg/L], the respective t values being 655.33, 108.04, 82.16 and 12.48, all P < 0.05. The mRNA level of ERCC1, TYMS, and TOP2α genes in the experiment group decreased by 99.6%, 92.9% and 96.1% respectively, but Class III β-tubulin mRNA increased by 122% compared to the negative control group (1.154 ± 0.008, 0.520 ± 0.009), the respective t values being 689.79, 689.37, 768.04 and 160.07, all P < 0.05. Targeting to inhibit antiapoptotic mitochondrial gene Bcl-2 expression in A549 cells specifically decreased the mRNA of ERCC1, TYMS, and TOP2α genes, and significantly increased the sensitivities of A549 cells to chemotherapeutic agents such as etoposide, cisplatin, paclitaxel and navelbine.

Differential expression and prognostic value of ERCC1 and thymidylate synthase in resected gastric adenocarcinoma.

38 Background: Excision repair cross complementing gene-1 (ERCC1) and thymidylate synthase (TS) are key regulatory enzymes whose expression patterns are variably associated with overall survival (OS) in several malignancies. For example, in lung cancer, high ERCC1 expression is inversely associated with OS depending on whether or not patients receive perioperative chemotherapy with surgery. The expression pattern and prognostic value of ERCC1 and TS in resected gastric adenocarcinoma (GAC) are not known. Methods: 109 patients who underwent resection of GAC between 1/00-6/11 had tissue available for analysis. Primary objective was to assess for differential expression of ERCC1 and TS using immunohistochemistry. Secondary objective was to assess for association of ERCC1 and TS expression with OS. Results: Median age was 64yrs. Median FU was 21.2mos and median OS was 28.8mos. Resected GAC exhibited differential expression of ERCC1 (23% high, n=25) and TS (43% high, n=47). ERCC1 and TS expression were not associated with OS. In a planned subset analysis, however, of patients who received chemotherapy (n=73), high ERCC1 expression was associated with decreased OS (16.7 vs. 53.8mos; p=0.03). After controlling for tumor size, margin, grade, T-stage, lymph node involvement, and presence of lymphovascular or perineural invasion, the negative prognostic value of high ERCC1 expression persisted on multivariate Cox regression analysis (HR 2.5; 95%CI: 1.03-6.0; p=0.04). By contrast, in patients who underwent resection only (n=35), high ERCC1 expression was associated with improved OS (40.4 vs. 12.7mos; p=0.10). This finding persisted on multivariate analysis (HR 0.20; 95%CI: 0.04-.86; p=0.03). Conclusions: Resected gastric adenocarcinoma exhibits differential expression of TS and ERCC1. TS expression is not associated with OS. However, similar to what is reported in lung cancer, high ERCC1 tumor expression is associated with decreased OS in patients receiving chemotherapy, but is associated with increased OS in those treated with surgery alone. ERCC1 expression has prognostic value in resected gastric cancer and further investigation is warranted.

Gene polymorphisms of prognostic factors in non-small cell lung cancer

Many studies show that excision repair cross-complementing gene 1 (ERCC1),ribonucleotide reductase subunit M1 (RRM1),p53,epidermal growth factor receptor (EGFR),and vascular endothelial growth factor (VEGF) are closely related to the curative effect and prognosis of non-small cell lung cancer (NSCLC).In recent years,many studies have investigated the association between polymorphisms of these factors and the curative effect and prognosis in patients with NSCLC.The polymorphisms of these factors may be potential biomarkers to predict the clinical outcome in patients with NSCLC. Key words: Carcinoma, non-small cell lung; Prognosis; Polymorphism, genetic

Emodin regulating excision repair cross-complementation group 1 through fibroblast growth factor receptor 2 signaling

To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC₅₀) and reversal index (IC₅₀ in experimental group/IC₅₀ 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. Compared with the IC₅₀ of 120.78 μmol/L in HepG2/OXA cells, the IC₅₀ 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. 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.

『臨床現場からの情報発信』 オキサリプラチンによる末梢神経障害の遺伝的背景

がん薬物療法における有害事象として，末梢神経障害を引き起こす薬剤が注目されている．大腸がんのキードラッグであるオキサリプラチン（L-OHP）による末梢神経障害は，蓄積性で用量規定因子である．重篤な場合，治療の遂行が不可能となり，治療効果の障害となる．L-OHPによる末梢神経障害の発現のメカニズムは十分には解明されていない．そこで，シュウ酸（オキサレート）の代謝に関係する2つの酵素であるアラニングリオキシル酸アミノ転移酵素（alanine glyoxylate aminotransferase：AGXT），グリオキシル酸還元酵素-ヒドロキシピルビン酸塩還元酵素（glyoxylate reductase-hydroxypyruvate reductase：GRHPR）の他，解毒酵素であるグルタチオンS-転移酵素（gluthathione S-transferase π1：GSTP 1），および損傷を受けたDNAを修復する除去修復交差相補群1（excision repair cross-complementing gene 1：ERCC 1）の遺伝子多型について，mFOLFOX療法が施行された進行大腸がん患者を対象として末梢神経障害との関連を検討した．その結果，ERCC 1とGSTP 1の遺伝子多型は，L-OHPによる末梢神経障害の発現までの期間と強い関連がみられた．これらの遺伝子多型は末梢神経障害の予測因子であるとともに，その発症機序に関わっている可能性がある．遺伝子多型の頻度やその臨床的意義には人種差が存在する可能性があるため，海外からの研究結果を検証する必要がある．末梢神経障害の精度の高い予測因子が同定されれば，末梢神経障害をきたすL-OHPを避けて治療を行う，あるいは慎重にモニタリングを行うなど，個別化医療の進展に寄与するものと考えられる．

Role of Integrin-Linked Kinase in Multi-drug Resistance of Human Gastric Carcinoma SGC7901/DDP Cells

Gastric carcinoma is a leading cause of cancer death in the world and multi-drug resistance (MDR) is an essential aspect of gastric carcinoma chemotherapy failure. Recent studies have shown that integrin-linked kinase (ILK) is involved in metastasis of human tumors, expression silencing of ILK inhibiting the metastasis of several types of cultured human cancer cells. However, the role and potential mechanism of ILK to reverse the multi- drug resistance in human gastric carcinoma is not fully clear. In this report, we focused on roles of expression silencing of ILK in multi-drug resistance reversal of human gastric carcinoma SGC7901/DDP cells, including increased drug sensitivity to cisplatin, cell apoptosis rates, and intracellular accumulation of Rhodamine-123, and decreased mRNA and protein expression of multi-drug resistance gene (MDR1), multi-drug resistance- associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), glutathione S-transferase -π (GST-π) and RhoE, and transcriptional activation of AP-1 and NF-κB in ILK silenced SGC7901/DDP cells. We also found that there was a decreased level of p-Akt and p-ERK. The results indicated that ILK might be used as a potential therapeutic strategy to combat multi-drug resistance through blocking PI3K-Akt and MAPK-ERK pathways in human gastric carcinoma.

TFPI‐2 Downregulates Multidrug Resistance Protein in 5‐FU‐Resistant Human Hepatocellular Carcinoma BEL‐7402/5‐FU Cells

Tissue factor pathway inhibitor-2 (TFPI-2) is known to induce apoptosis and to suppress tumor metastasis in several types of cancer cells. However, there is little known about its reversal effect on chemoresistant tumor cells. This study investigated the effect of TFPI-2 in 5-fluorouracil (5-FU)-resistant human hepatocellular cancer BEL-7402/5-FU cells in vitro. We constructed TFPI-2 overexpression BEL-7402/5-FU cell lines and explored resistance index (RI) of 5-FU, function of the P-glycoprotein (P-gp) efflux pump, and the mRNA and protein expression of drug resistance gene, including multidrug resistance gene (MDR1), lung-resistance protein (LRP), multidrug resistance-associated protein (MRP1), glutathione-S-transferase-π (GST-π), excision repair cross-complementing gene 1 (ERCC1), and p38 phosphorylation. We found that TFPI-2 improved the RI of 5-FU and inhibited P-gp function. Western blotting and real-time PCR revealed that TFPI-2 also decreased mRNA and protein expression of MDR1, LRP, MRP1, GST-π, and ERCC1, whereas p38 phosphorylation was increased. We considered that TFPI-2 reduces 5-FU resistance in BEL-7402/5-FU cells, and the mechanism appears to involve p38-mediated downregulation of drug resistance gene expression such as MDR1, LRP, MRP1, GST-π, and ERCC1.

Differential expression of ERCC-1 in the primary tumors and metastatic lymph nodes of patients with non-small cell lung cancer adenocarcinoma

About 80 % of lung cancers are carcinomas that are classified histologically as non-small-cell lung carcinoma (NSCLC) and targeted chemotherapy of this cancer is currently based on sensitivity of the primary tumor to specific drugs. The purpose of this study was to compare the levels of four serum markers of cancer and the levels of six molecular markers which are possibly associated with drug selection in the primary tumors and metastatic lymph nodes of 39 consecutive NSCLC patients who were admitted to a single institution in China. Serum markers of cancer (neuron-specific enolase, carcinoembryonic antigen (CEA), cancer antigen 125, cytokeratin fragment 21-1) were measured by an automated electrochemiluminescence system and molecular markers (multidrug resistance protein 1, LDL receptor-related protein, ribonucleotide reductase M1, epidermal growth factor receptor, excision repair cross-complementing gene 1, and breast cancer 1) were measured by immunohistochemistry of the primary tumors and metastatic lymph nodes. The results indicate that the serum level of CEA was higher in NSCLC patients with adenocarcinoma relative to those with squamous cell carcinoma, but no significant differences in the other serum markers. Expression of excision repair cross-complementing gene 1 was significantly different in the primary tumors and metastatic sites of NSCLC patients with adenocarcinoma, but there were no other significant differences. This study provides an initial step toward the development of individualized chemotherapy of NSCLC based on measurement of molecular markers in the primary tumors and metastatic lymph nodes.