Gene Summary

Gene:RRM1; ribonucleotide reductase M1
Aliases: R1, RR1, RIR1
Summary:This gene encodes one of two non-identical subunits that constitute ribonucleoside-diphosphate reductase, an enzyme essential for the production of deoxyribonucleotides prior to DNA synthesis in S phase of dividing cells. It is one of several genes located in the imprinted gene domain of 11p15.5, an important tumor-suppressor gene region. Alterations in this region have been associated with the Beckwith-Wiedemann syndrome, Wilms tumor, rhabdomyosarcoma, adrenocrotical carcinoma, and lung, ovarian, and breast cancer. This gene may play a role in malignancies and disease that involve this region. [provided by RefSeq, Jul 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:ribonucleoside-diphosphate reductase large subunit
Source:NCBIAccessed: 27 February, 2015


What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 27 February 2015 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 27 February, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (6)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: RRM1 (cancer-related)

Zhang Q, Zhu X, Zhang L, et al.
A prospective study of biomarker-guided chemotherapy in patients with non-small cell lung cancer.
Cancer Chemother Pharmacol. 2014; 74(4):839-46 [PubMed] Free Access to Full Article Related Publications
PURPOSE: To assess the therapeutic value of biomarker-guided chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).
METHODS: Eighty-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.
RESULTS: The 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.
CONCLUSIONS: Biomarker-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.

Marino N, Collins JW, Shen C, et al.
Identification and validation of genes with expression patterns inverse to multiple metastasis suppressor genes in breast cancer cell lines.
Clin Exp Metastasis. 2014; 31(7):771-86 [PubMed] Related Publications
Metastasis suppressor genes (MSGs) have contributed to an understanding of regulatory pathways unique to the lethal metastatic process. When re-expressed in experimental models, MSGs block cancer spread to, and colonization of distant sites without affecting primary tumor formation. Genes have been identified with expression patterns inverse to a single MSG, and found to encode functional, druggable signaling pathways. We now hypothesize that common signaling pathways mediate the effects of multiple MSGs. By gene expression profiling of human MCF7 breast carcinoma cells expressing a scrambled siRNA, or siRNAs to each of 19 validated MSGs (NME1, BRMS1, CD82, CDH1, CDH2, CDH11, CASP8, MAP2K4, MAP2K6, MAP2K7, MAPK14, GSN, ARHGDIB, AKAP12, DRG1, CD44, PEBP1, RRM1, KISS1), we identified genes whose expression was significantly opposite to at least five MSGs. Five genes were selected for further analysis: PDE5A, UGT1A, IL11RA, DNM3 and OAS1. After stable downregulation of each candidate gene in the aggressive human breast cancer cell line MDA-MB-231T, in vitro motility was significantly inhibited. Two stable clones downregulating PDE5A (phosphodiesterase 5A), an enzyme involved in the regulation of cGMP-specific signaling, exhibited no difference in cell proliferation, but reduced motility by 47 and 66 % compared to the empty vector-expressing cells (p = 0.01 and p = 0.005). In an experimental metastasis assay, two shPDE5A-MDA-MB-231T clones produced 47-62 % fewer lung metastases than shRNA-scramble expressing cells (p = 0.045 and p = 0.009 respectively). This study demonstrates that previously unrecognized genes are inversely related to the expression of multiple MSGs, contribute to aspects of metastasis, and may stand as novel therapeutic targets.

Ormanns S, Assmann G, Reu S, et al.
ALK expression is absent in pancreatic ductal adenocarcinoma.
J Cancer Res Clin Oncol. 2014; 140(9):1625-8 [PubMed] Related Publications
PURPOSE: It has not yet been clearly defined whether anaplastic lymphoma kinase (ALK) expression can be detected in pancreatic ductal adenocarcinoma (PDAC).
METHODS: Within a retrospective study, archival PDAC surgical specimens were screened for ALK expression in tumor and normal tissue by immunohistochemistry (IHC) with the use of a specific ALK detection kit on a tissue microarray (TMA).
RESULTS: PDAC tumor tissue was available from 99 resected cases: fifty-eight out of 99 patients (59 %) had nodal-positive disease, and 80 patients (81 %) had pT3 tumors. Forty-nine patients underwent R0 resection, and in 48 cases, resection status was classified R1. Regarding ALK expression, five cases showed faint immunoreactivity on TMA, which was negative on whole mount sections. All other 94 cases showed no ALK expression.
CONCLUSION: In 99 PDAC cases, no ALK expression was detected by IHC; ALK thus may not serve as a relevant drug target in PDAC.

Okimoto T, Tsubata Y, Sutani A, et al.
Immunohistochemical comparison of biomarker expression in biopsy and surgical specimens of non-small cell lung cancer.
Anticancer Res. 2014; 34(6):2755-61 [PubMed] Related Publications
BACKGROUND: Single tumors may show heterogeneity, and it is unclear whether biomarker expression in surgical and diagnostic biopsy samples correlates.
MATERIALS AND METHODS: We retrospectively identified lung cancer patients who were diagnosed by biopsy and underwent surgery between January 2007 and October 2010 at the Shimane University Hospital, Shimane, Japan. Thirty-two patients were identified. The expression of four predictive biomarkers was assessed, namely excision repair cross-complementing gene 1 (ERCC1), ribonucleotide diphosphate reductase M1 (RRM1), thymidylate synthase (TS), and class III beta-tubulin (BT). We also compared immunohistochemical staining in diagnostic biopsy and corresponding resected surgical samples.
RESULTS: Moderate correlation was seen between the expression of ERCC1, RRM1, TS, and BT in the biopsy and surgical specimens, with r values of 0.512 (p=0.003), 0.411 (p=0.020), 0.475 (p=0.006), and 0.404 (p=0.027), respectively.
CONCLUSION: Assessment of biopsy samples with immunohistochemical staining is a feasible and reliable method for use in clinical decision making.

Wang TB, Zhang NL, Wang SH, et al.
Expression of ERCC1 and BRCA1 predict the clinical outcome of non-small cell lung cancer in patients receiving platinum-based chemotherapy.
Genet Mol Res. 2014; 13(2):3704-10 [PubMed] Related Publications
We examined mRNA expression levels of ERCC1, BRCA1, RRM1, and human β-tubulin-III (TUBB3) in non-small-cell lung carcinoma (NSCLC) patients and investigated the association between expression of these genes and the clinical outcome of NSCLC treatment. A total of 366 patients who underwent surgery for NSCLC were included in this study. All patients received third-generation platinum-based chemotherapy as first-line treatment. The relative cDNA quantification for ERCC1, RRM1, BRCA1, and TUBB3 was determined using a fluorescence-based, real-time detection method. We found that low expression of ERCC1 and BRCA1 was associated with a good response to platinum-based chemotherapy, with an odds ratio [95% confidence interval (CI)] of 2.09 (1.33-3.27) and 2.92 (1.85-4.62), respectively. Multivariate Cox regression analysis indicated that patients with low expression of ERCC1 and BRCA1 attained a longer overall survival time than those with high expression, with a hazard ratio (95%CI) of 0.42 (0.23-0.77) and 0.39 (0.21-0.71), respectively. However, RMM1 and TUBB2 expressions were not correlated with clinical outcome of NSCLC. In conclusion, we found that low expression of ERCC1 and BRCA1 can be useful for selecting NSCLC patients who would benefit from chemotherapy and warrants further investigation in prospective studies.

Bepler G, Zinner RG, Moon J, et al.
A phase 2 cooperative group adjuvant trial using a biomarker-based decision algorithm in patients with stage I non-small cell lung cancer (SWOG-0720, NCT00792701).
Cancer. 2014; 120(15):2343-51 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: This cooperative group adjuvant phase 2 trial in patients with completely resected stage I non-small cell lung cancer with tumor diameters measuring ≥ 2 cm was designed to assess the feasibility and preliminary efficacy of assigning patients to therapy or observation using a molecularly based decision algorithm.
METHODS: At least a lobectomy and sampling of recommended mediastinal lymph node stations, good Zubrod performance status, adequate organ function, and a formalin-fixed and paraffin-embedded tumor specimen were required. Excision repair cross-complementing group 1 (ERCC1) and ribonucleotide reductase M1 (RRM1) were analyzed using immunofluorescence-based in situ automated quantitative image analysis and categorized as high or low using prespecified cutoff values. Patients with high ERCC1 and RRM1 were assigned to observation and all others to 4 cycles of cisplatin and gemcitabine. Feasibility was defined as treatment assignment within 84 days from surgery in > 85% of patients. Secondary objectives were to estimate the 2-year survival.
RESULTS: Treatment assignment met the feasibility criteria in 88% of eligible patients (71 of 81 patients). The collective 2-year disease-free and overall survival rates were 80% and 96%, respectively. Protein levels for RRM1 fell within the previously established range, ERCC1 levels were slightly lower than expected, and they were significantly correlated (correlation coefficient, 0.4). The rates of assignment of patients to observation (22%) and chemotherapy (78%) were as expected.
CONCLUSIONS: Gene expression analysis for treatment assignment is feasible. Survival results are encouraging and require future validation. Real-time performance of quantitative in situ ERCC1 and RRM1 analysis requires further development.

Garimella SV, Gehlhaus K, Dine JL, et al.
Identification of novel molecular regulators of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in breast cancer cells by RNAi screening.
Breast Cancer Res. 2014; 16(2):R41 [PubMed] Free Access to Full Article Related Publications
INTRODUCTION: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) binds to its receptors, TRAIL-receptor 1 (TRAIL-R1) and TRAIL-receptor 2 (TRAIL-R2), leading to apoptosis by activation of caspase-8 and the downstream executioner caspases, caspase-3 and caspase-7 (caspase-3/7). Triple-negative breast cancer (TNBC) cell lines with a mesenchymal phenotype are sensitive to TRAIL, whereas other breast cancer cell lines are resistant. The underlying mechanisms that control TRAIL sensitivity in breast cancer cells are not well understood. Here, we performed small interfering RNA (siRNA) screens to identify molecular regulators of the TRAIL pathway in breast cancer cells.
METHODS: We conducted siRNA screens of the human kinome (691 genes), phosphatome (320 genes), and about 300 additional genes in the mesenchymal TNBC cell line MB231. Forty-eight hours after transfection of siRNA, parallel screens measuring caspase-8 activity, caspase-3/7 activity, or cell viability were conducted in the absence or presence of TRAIL for each siRNA, relative to a negative control siRNA (siNeg). A subset of genes was screened in cell lines representing epithelial TNBC (MB468), HER2-amplified breast cancer (SKBR3), and estrogen receptor-positive breast cancer (T47D). Selected putative negative regulators of the TRAIL pathway were studied by using small-molecule inhibitors.
RESULTS: The primary screens in MB231 identified 150 genes, including 83 kinases, 4 phosphatases, and 63 nonkinases, as potential negative regulators of TRAIL. The identified genes are involved in many critical cell processes, including apoptosis, growth factor-receptor signaling, cell-cycle regulation, transcriptional regulation, and DNA repair. Gene-network analysis identified four genes (PDPK1, IKBKB, SRC, and BCL2L1) that formed key nodes within the interaction network of negative regulators. A secondary screen of a subset of the genes identified in additional cell lines representing different breast cancer subtypes and sensitivities to TRAIL validated and extended these findings. Further, we confirmed that small-molecule inhibition of SRC or BCL2L1, in combination with TRAIL, sensitizes breast cancer cells to TRAIL-induced apoptosis, including cell lines resistant to TRAIL-induced cytotoxicity.
CONCLUSIONS: These data identify novel molecular regulators of TRAIL-induced apoptosis in breast cancer cells and suggest strategies for the enhanced application of TRAIL as a therapy for breast cancer.

Koch KR, Refaian N, Hos D, et al.
Autocrine impact of VEGF-A on uveal melanoma cells.
Invest Ophthalmol Vis Sci. 2014; 55(4):2697-704 [PubMed] Related Publications
PURPOSE: Tumor-derived VEGF-A, apart from expediting sufficient vascularization, subsequent tumor growth, and metastatic spread, can act on malignant cells themselves provided that VEGF receptors 1 or 2 (VEGF-R1, -R2) are co-expressed. The study goal was to investigate whether such autocrine VEGF-A signaling exists in uveal melanoma (UM).
METHODS: Primary (MEL-270, OM-431) and metastatic (OMM-2.3, OMM-2.5) UM cell lines were analyzed for VEGF-A, VEGF-R1, and VEGF-R2 expression by RT-PCR, ELISA (VEGF-A protein), and immunocytochemistry (VEGF receptors). Proliferation of UM cells incubated with neutralizing anti-VEGF-A antibody bevacizumab (≤ 2.5 mg/mL), or VEGF-A (≤ 100 ng/mL) was assessed by bromodeoxyuridine (BrdU) ELISA. It was measured by real-time PCR, whether VEGF-A (100 ng/mL) modulated the expression ratio of VEGF-A itself and its antiangiogenic antagonist pigment epithelium-derived factor (PEDF).
RESULTS: All UM cells expressed VEGF-A, VEGF-R1, VEGF-R2 mRNA, and protein. In each cell line, the proliferation was stimulated by VEGF-A or inhibited by blocking VEGF-A, or both: bevacizumab significantly decreased the proliferation in MEL-270 (P = 0.005), OMM-2.3 (P = 0.001), and OMM-2.5 (P = 0.011). Increased VEGF-A signaling significantly raised the proliferation in MEL-270, OM-431 (P < 0.001, respectively), and OMM-2.3 (P = 0.043) in a dose-dependent manner but did not significantly change the VEGF-A/PEDF mRNA expression ratio.
CONCLUSIONS: Autocrine VEGF-A signaling seems to be present in UM, sustaining the proliferation of both primary and metastatic UM cells. Apparently, VEGF-A signaling in UM cells neither acts retroactively on VEGF-A expression, in the sense of a feedback loop, nor contributes to a pro-angiogenic shift of the VEGF-A/PEDF ratio.

Khatri N, Baradia D, Vhora I, et al.
cRGD grafted liposomes containing inorganic nano-precipitate complexed siRNA for intracellular delivery in cancer cells.
J Control Release. 2014; 182:45-57 [PubMed] Related Publications
Development of effective vector for intracellular delivery of siRNA has always been a challenge due to its hydrophilicity, net negative surface charge and sensitivity against nucleases in biological milieu. The present investigation was aimed to develop a novel non-viral liposomal carrier for siRNA delivery. Nano-precipitate of calcium phosphate was entrapped in liposomes composed of a neutral lipid (DPPC), a fusogenic lipid (DOPE), a PEGylated lipid (DSPE-mPEG2000) and cholesterol. siRNA was made permeable through liposomal bilayer and complexed to calcium phosphate precipitates inside the liposomes. siRNA entrapped liposomes were further grafted with cRGD to achieve targeting potential against cancer cells. More than 80% of siRNA was entrapped inside the liposomes having average particle size below 150nm. Cryo-transmission electron microscopy revealed the intra-liposomal calcium phosphate precipitation and unilamellar morphology of prepared liposomes. The viability of A549 lung cancer cells was significantly higher after treatment with siRNA entrapped liposomes as compared to Lipofectamine2000 complexed siRNA. Fluorescent intensity in lung carcinoma cells was significantly higher after exposure to fluorescent siRNA entrapped liposomes than with Lipofectamine2000, which were confirmed by both confocal microscopy and flow cytometry. Live imaging by confocal microscopy ascertained the targeting efficacy of cRGD grafted liposomes compared to naked siRNA and non-grafted liposomes. Developed liposomal formulation showed effective protection of siRNA against serum nucleases along with less haemolytic potential and excellent stability against electrolyte induced flocculation. At 5nM concentration gene expression of target protein was reduced up to 24.1±3.4% while Lipofectamine2000 reduced expression level up to 26.35±1.55%. In vivo toxicity in mice suggested admirable safety profile for developed lipid based delivery vector. These results advocate that prepared liposomal system would be of high value for intracellular delivery of siRNA.

Li Y, Wang LR, Chen J, et al.
First-line gemcitabine plus cisplatin in nonsmall cell lung cancer patients.
Dis Markers. 2014; 2014:960458 [PubMed] Free Access to Full Article Related Publications
AIM: To evaluate the predictive value of RRM1, ERCCl, and BRCA1 expression in Chinese NSCLC patients treated with gemcitabine and cisplatin.
METHODS: Real-time fluorescent quantitative PCR was used to determine the RRM1, ERCC1, and BRCA1 mRNA expression levels of peripheral blood in late-stage NSCLC patients. The relationship between peripheral blood and mRNA expression in tumor tissues was analyzed further.
RESULTS: In terms of the tumor susceptibility to chemotherapy, the response rate in the low-RRM1-expression group was significantly greater than in the high-expression group (52.9% versus 5.9%, χ(2) test, P = 0.007). Subjects with low peripheral blood RRM1 expression survived longer than those with high RRM1 expression (15.5 versus 12.0 months, logrank 3.980, P = 0.046). Linear correlations were observed between peripheral blood and tumor tissue expression levels for RRM1 (R (2) = 0.045, P = 0.048) and BRCA1 (R(2) = 0.021, P = 0.001).
CONCLUSION: Our study demonstrates increased survival and superior efficacy of gemcitabine and cisplatin combination chemotherapy in the treatment of NSCLC patients with low peripheral blood RRM1 expression. The linear correlations of the relative expression of mRNA were observed between peripheral blood and tumor tissue expression levels for RRM1 and BRCA1. RRM1 gene expression may contribute to chemotherapy sensitivity and may be an indicator of survival. It was significant to individual chemotherapy of patients with advanced NSCLC who do not have sufficient tumor tissue.

Happold C, Roth P, Silginer M, et al.
Interferon-β induces loss of spherogenicity and overcomes therapy resistance of glioblastoma stem cells.
Mol Cancer Ther. 2014; 13(4):948-61 [PubMed] Related Publications
Glioblastoma is the most common malignant brain tumor in adults and characterized by a poor prognosis. Glioma cells expressing O(6)-methylguanine DNA methyltransferase (MGMT) exhibit a higher level of resistance toward alkylating agents, including the standard of care chemotherapeutic agent temozolomide. Here, we demonstrate that long-term glioma cell lines (LTL) as well as glioma-initiating cell lines (GIC) express receptors for the immune modulatory cytokine IFN-β and respond to IFN-β with induction of STAT-3 phosphorylation. Exposure to IFN-β induces a minor loss of viability, but strongly interferes with sphere formation in GIC cultures. Furthermore, IFN-β sensitizes LTL and GIC to temozolomide and irradiation. RNA interference confirmed that both IFN-β receptors, R1 and R2, are required for IFN-β-mediated sensitization, but that sensitization is independent of MGMT or TP53. Most GIC lines are highly temozolomide-resistant, mediated by MGMT expression, but nevertheless susceptible to IFN-β sensitization. Gene expression profiling following IFN-β treatment revealed strong upregulation of IFN-β-associated genes, including a proapoptotic gene cluster, but did not alter stemness-associated expression signatures. Caspase activity and inhibition studies revealed the proapoptotic genes to mediate glioma cell sensitization to exogenous death ligands by IFN-β, but not to temozolomide or irradiation, indicating distinct pathways of death sensitization mediated by IFN-β. Thus, IFN-β is a potential adjunct to glioblastoma treatment that may target the GIC population. IFN-β operates independently of MGMT-mediated resistance, classical apoptosis-regulatory networks, and stemness-associated gene clusters.

Tian Y, Liu Y, He P, et al.
Arsenic sulfide promotes apoptosis in retinoid acid resistant human acute promyelocytic leukemic NB4-R1 cells through downregulation of SET protein.
PLoS One. 2014; 9(1):e83184 [PubMed] Free Access to Full Article Related Publications
Tetra-arsenic tetra-sulfide (As4S4) is an arsenic compound with anti-tumor activity, especially in acute promyelocytic leukemia (APL) that are resistant to retinoic acid (RA). Although recent studies revealed that the therapeutic action of As4S4 is closely associated with the induction of cellular apoptosis, the exact molecular mechanism of action of As4S4 in RA-resistant APL remains to be clarified. In this study, we found that As4S4-induced apoptosis was accompanied by reduced mRNA and protein expression of SET gene in RA-resistant NB4-R1 cells. Moreover, RNAi knockdown of SET gene further promoted As4S4-induced apoptosis, while SET over-expression inhibited it, suggesting that As4S4 induces apoptosis through the reduction of SET protein in NB4-R1 cells. We also demonstrated that the knockdown of SET gene resulted in the upregulation of protein phosphatase 2 (PP2A) expression and the downregulation of promyelocytic leukemia and retinoic acid receptor α fusion gene (PML-RARα) expression, which were enhanced by As4S4 treatments. By contrast, over-expression of SET gene resulted in PP2A downregulation and PML-RARα upregulation, which were abolished by As4S4 pretreatment. Since PP2A is a pro-apoptotic factor and PMLRARα is an anti-apoptotic factor, our results suggest that As4S4-induced apoptosis in NB4-R1 cells is through the downregulation of SET protein expression, which in turn increases PP2A and reduces PML-RARα expressions to lead to cell apoptosis.

Liu Y, He P, Liu F, et al.
Tetra-arsenic tetra-sulfide (As4S 4) promotes apoptosis in retinoid acid -resistant human acute promyelocytic leukemic NB4-R1 cells through downregulation of SET protein.
Tumour Biol. 2014; 35(4):3421-30 [PubMed] Related Publications
Tetra-arsenic tetra-sulfide (As4S4) is an arsenic compound with antitumor activity, especially in acute promyelocytic leukemia (APL) that are resistant to retinoic acid (RA). Although recent studies have revealed that the therapeutic action of As4S4 is closely associated with the induction of cellular apoptosis, the exact molecular mechanism underlying this action in RA-resistant APL remains to be clarified. In this study, we found that As4S4-induced apoptosis was accompanied by reduced mRNA and protein expression of SET gene in RA-resistant NB4-R1 cells. Moreover, RNAi knockdown of SET gene further promoted As4S4-induced apoptosis, while SET overexpression recovered the cell viability, suggesting that As4S4 induces apoptosis through the reduction of SET protein in NB4-R1 cells. We also observed that the knockdown of SET gene resulted in the upregulation of protein phosphatase 2 (PP2A) expression and the downregulation of promyelocytic leukemia and retinoic acid receptor α fusion gene (PML-RARα) expression, which were enhanced by As4S4 treatments. By contrast, overexpression of SET gene resulted in PP2A downregulation and PML-RARα upregulation, which were abolished by As4S4 pretreatment. Since PP2A is a proapoptotic factor and PML-RARα is an antiapoptotic factor, our results suggest that As4S4-induced apoptosis in RA-resistant NB4-R1 cells is through the downregulation of SET protein expression, which, in turn, increases PP2A and reduces PML-RARα expressions to lead to cell apoptosis.

Wu JG, Yu JW, Wu HB, et al.
Expressions and clinical significances of c-MET, p-MET and E2f-1 in human gastric carcinoma.
BMC Res Notes. 2014; 7:6 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: To investigate on the expressions and the clinical significances of hepatocyte growth factor receptor (c-MET), phosphorylated c-MET (p-MET) and e2f-1 transcription factor in primary lesion of gastric adenocarcinoma (GC).
METHOD: Tissue samples from the primary lesion of GC in patients who accepted D2/D3 radical gastrectomy with R0/R1 resection were stained by immunohistochemistry of c-MET, p-MET, e2f-1 and Ki-67. The univariate and the multivariate analyses involving in clinicopathological parameters and prognostic factors were evaluated.
RESULTS: The positivity rates for c-MET (66.12%, 80 cases/121 cases), p-MET (59.50%, 72 cases/121 cases), e2f-1 (38.84%, 47 cases/121 cases) and Ki-67 (72.73%, 88 cases/121 cases) in primary lesion of GC was significantly higher than that in non-cancerous tissue at 5 cm places far from the margin of primary lesion (P < 0.05, respectively). The deeper tumor invasion, the severer lymph node metastasis, the later stage of TNM and the higher expression of Ki-67 was respectively an independent risk factor for the higher expression of c-MET or p-MET, but the younger age and the shorter survival time was an independent risk factor for the higher expression of e2f-1 respectively. Survival analysis showed that the worse prognosis could be observed in the patients with the combination of both c-MET-positive and e2f-1-negative (P = 0.038) or both p-MET-positive and e2f-1-negative (P = 0.042). Cox analysis demonstrated that the severer lymphatic node metastasis and the higher positivity rate of c-MET, p-MET or e2f-1 were an independent prognosis factor respectively. The higher expression of e2f-1 was identified in patients with Stage I-II, which correlated with a shorter survival time. Survival analysis also revealed that the prognosis of patients with positive expression of e2f-1 at Stage I-II was significantly worse than that in patients with negative expression of e2f-1 (χ2 = 13.437, P = 0.001). However, in the cases with Stage III-IV, no significant difference could be identified in the prognostic comparison between positive and negative expressions of e2f-1.
CONCLUSIONS: The expression of c-MET or p-MET is an independent prognosis factor. It has been observed that the higher expression of e2f-1 occurred in the early stages while the lower expression of it in the later stages in GC.

Lee SY, Im SA, Park YH, et al.
Genetic polymorphisms of SLC28A3, SLC29A1 and RRM1 predict clinical outcome in patients with metastatic breast cancer receiving gemcitabine plus paclitaxel chemotherapy.
Eur J Cancer. 2014; 50(4):698-705 [PubMed] Related Publications
BACKGROUND: Paclitaxel and gemcitabine (PG) combination chemotherapy is effective as a maintenance chemotherapeutic regimen in metastatic breast cancer (MBC) patients because it increases progression-free survival (PFS), which increases overall survival (OS). The primary purpose of our study was to investigate the association between genetic polymorphisms in the genes involved in PG pathways and clinical outcomes in MBC patients treated with PG chemotherapy.
METHODS: A total of 324 MBC patients were enrolled in this prospective multicenter trial of PG as the first-line chemotherapy. Eighty-five of the 324 patients from two institutes were available for analysis of single nucleotide polymorphisms (SNPs). Germline DNA was extracted from peripheral blood mononuclear cells. Thirty-eight SNPs in 15 candidate genes selected from pathways that may influence the metabolism and transport of, or sensitivity, to PG were analysed.
RESULTS: The median PFS and OS of all 324 patients were 8.7 months (95% confidence interval [CI]: 7.5-9.6 months) and 26.9 months (95% CI: 23.6-30.1 months), respectively. An SNP in SLC28A3 (rs7867504, C/T) was associated with OS (CC or CT versus TT: 37 versus 21 months, p = 0.027, hazard ratio [HR] 2.6, 95% CI: 1.1-6.3). SLC29A1 GA haplotype had a significantly shorter OS (p = 0.030, HR 3.391, 95% CI: 1.13-10.19). RRM1 (ribonucleotide reductase large subunit M1) SNP (rs9937), and haplotypes ATAA and ATGA were significantly associated with neurotoxicity.
CONCLUSION: Genetic polymorphisms in SLC28A3, SLC29A1 and RRM1 can influence the clinical outcome of MBC patients treated with PG chemotherapy. Further studies on the functional mechanisms relating to these germline polymorphisms in these genes are warranted.

Lin HP, Lin CY, Hsiao PH, et al.
Difference in protein expression profile and chemotherapy drugs response of different progression stages of LNCaP sublines and other human prostate cancer cells.
PLoS One. 2013; 8(12):e82625 [PubMed] Free Access to Full Article Related Publications
Androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, 80-90% of the patients who receive androgen ablation therapy ultimately develop recurrent tumors in 12-33 months after treatment with a median overall survival time of 1-2 years after relapse. LNCaP is a commonly used cell line established from a human lymph node metastatic lesion of prostatic adenocarcinoma. We previously established two relapsed androgen receptor (AR)-rich androgen-independent LNCaP sublines 104-R1 (androgen depleted for 12 months) and 104-R2 cells (androgen depleted for 24 months) from AR-positive androgen-dependent LNCaP 104-S cells. LNCaP 104-R1 and 104-R2 mimics the AR-positive hormone-refractory relapsed tumors in patients receiving androgen ablation therapy. Androgen treatment stimulates proliferation of 104-S cells, but causes growth inhibition and G1 cell cycle arrest in 104-R1 and 104-R2 cells. We investigated the protein expression profile difference between LNCaP 104-S vs. LNCaP 104-R1, 104-R2, PC-3, and DU-145 cells as well as examined the sensitivity of these prostate cancer cells to different chemotherapy drugs and small molecule inhibitors. Compared to 104-S cells, 104-R1 and 104-R2 cells express higher protein levels of AR, PSA, c-Myc, Skp2, BCL-2, P53, p-MDM2 S166, Rb, and p-Rb S807/811. The 104-R1 and 104-R2 cells express higher ratio of p-Akt S473/Akt, p-EGFR/EGFR, and p-Src/Src, but lower ratio of p-ERK/ERK than 104-S cells. PC-3 and DU-145 cells express higher c-Myc, Skp2, Akt, Akt1, and phospho-EGFR but less phospho-Akt and phospho-ERK. Overexpression of Skp2 increased resistance of LNCaP cells to chemotherapy drugs. Paclitaxel, androgen, and inhibitors for PI3K/Akt, EGFR, Src, or Bcl-2 seem to be potential choices for treatment of advanced prostate cancers. Our study provides rationale for targeting Akt, EGFR, Src, Bcl-2, and AR signaling as a treatment for AR-positive relapsed prostate tumors after hormone therapy.

Zhu H, Huang M, Ren D, et al.
The synergistic effects of low dose fluorouracil and TRAIL on TRAIL-resistant human gastric adenocarcinoma AGS cells.
Biomed Res Int. 2013; 2013:293874 [PubMed] Free Access to Full Article Related Publications
The TNF-related apoptosis-inducing ligand (TRAIL) is a TNF family member which has been under intense focus because of its remarkable ability to induce apoptosis in malignant human cells while leaving normal cells unscathed. However, many cancer cells remain resistant to TRAIL. In this study, we had investigated the synergistic effects of low dose fluorouracil (5-Fu) and TRAIL on TRAIL-resistant human gastric adenocarcinoma AGS cells and explored the potential mechanisms. Cell viability was analyzed by sulforhodamine B (SRB) assay and the synergistic effects were evaluated by Jin's formula and confirmed by both morphological changes under inverted microscope and flow cytometry. The expression of TRAIL-R1 (death receptor 4, DR4), TRAIL-R2 (DR5), TRAIL-R3 (decoy receptor, DcR1), TRAIL-R4 (DcR2), procaspase-3, procaspase-8, and procaspase-9 was detected by western blotting. Our results showed that there were significant synergistic effects of low dose 5-Fu and TRAIL on TRAIL-resistant AGS cells, and this effect was supposed to be mediated by decreasing DcR2 expression and increasing DR5 expression. The extrinsic and intrinsic apoptosis pathways were both activated. The data suggest that combined treatment of low dose 5-Fu and TRAIL can be an effective therapeutic approach for gastric adenocarcinoma.

Bergot E, Levallet G, Campbell K, et al.
Predictive biomarkers in patients with resected non-small cell lung cancer treated with perioperative chemotherapy.
Eur Respir Rev. 2013; 22(130):565-76 [PubMed] Related Publications
The aim of this article is to summarise the published data on prognostic and predictive biomarkers for early-stage non-small cell lung cancer (NSCLC), and discuss how to integrate them into clinical trials. Large phase III trials have been published in resected NSCLC with biomarkers identifying subsets of patients benefitting from perioperative chemotherapy. Initial findings of predictive implications for the DNA repair protein, ERCC1, were not confirmed in a larger series of patients due to the versatility of the commercially available monoclonal ERCC1 antibody. Prediction of survival by RRM1 tumour expression was not confirmed in a prospective phase III trial in 275 patients with stage IV disease, precluding its use in early-stage NSCLC. BRCA1 mRNA tumour content also failed to predict platinum resistance in 287 stage IV NSCLC patients included in a phase II trial, and the results of a similar trial in early-stage patients are still pending. Of the several cDNA gene expression studies in early-stage NSCLC with non-overlapping prognostic signatures, few have been replicated in independent cohorts for prognostic value, and none received external validation for predictive value. Therefore, use of biomarkers predicting chemotherapy efficacy still needs additional validation before becoming routine practice in oncogene-driven pan-negative NSCLC patients.

Wang LH, Ni CW, Lin YZ, et al.
Targeted induction of apoptosis in glioblastoma multiforme cells by an MRP3-specific TRAIL fusion protein in vitro.
Tumour Biol. 2014; 35(2):1157-68 [PubMed] Related Publications
Single-chain Fv fragments (scFvs) consist of the variable heavy-chain (VH) and variable light-chain (VL) domains, which are the smallest immunoglobulin fragments containing the whole antigen-binding site. Human soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) proves to acquire a potent pro-apoptotic activity only after selective binding to a predefined tumor cell surface antigen and has no off-target effects towards normal cells. Glioblastoma multiforme (GBM) is the most frequent and aggressive type of brain tumor and overexpresses human multidrug resistance protein 3 (MRP3). In this study, we designed a novel fusion protein, termed scFvM58-sTRAIL, in which the MRP3-specific scFv antibody M58 was genetically fused to the N-terminus of human soluble TRAIL (sTRAIL). The recombinant scFvM58-sTRAIL fusion protein, expressed in Escherichia coli, was purified by chromatography and tested for cytotoxicity. scFvM58-sTRAIL showed a significant apoptosis-inducing activity towards MRP3-positive GBM cells in vitro. The pro-apoptotic activity of scFvM58-sTRAIL towards GBM cells was strongly inhibited in the presence of the parental scFvM58 antibody, suggesting that cytotoxic activity is MRP3-restricted. In a control experiment with MRP3-negative Jurkat cells, scFvM58-sTRAIL did not induce apparent apoptosis. In addition, through target antigen-restricted binding, scFvM58-sTRAIL was capable of activating not only TRAIL-R1 but also TRAIL-R2. In conclusion, our results suggest that fusion protein scFvM58-sTRAIL with specificity for MRP3 is a highly selective therapeutic agent and may provide an alternative therapy for human GBM.

Kanakkanthara A, Eras J, Northcote PT, et al.
Resistance to peloruside A and laulimalide: functional significance of acquired βI-tubulin mutations at sites important for drug-tubulin binding.
Curr Cancer Drug Targets. 2014; 14(1):79-90 [PubMed] Related Publications
Cancer cell lines selected for resistance to microtubule targeting agents (MTA) often have acquired mutations in the β-tubulin binding sites for these agents. Despite strong correlational evidence, the functional and quantitative significance of such mutations in the resistance to MTA remains unknown. We recently showed that peloruside A (PLA) and laulimalide (LAU)-resistant cancer cell lines, 1A9-R1 (R1) and 1A9-L4 (L4), generated through multi-step selection of human 1A9 ovarian cancer cells with high concentrations of either PLA (for R1) or LAU (for L4) have single distinct mutations in their βI-tubulin gene. The R1 cells have a mutation at amino acid position 296 (A296T), and the L4 cells have a mutation at position 306 (R306H/C), both of which lie at the putative binding sites of PLA and LAU. To gain insights on the functional role of these mutations in the resistance phenotype, R1 and L4 cells were transfected with wild type βI-tubulin. MTT cell proliferation assays revealed that restoration of wild type βI-tubulin expression partially sensitized the R1 and L4 cells to PLA and LAU. Cell cycle analysis and intracellular tubulin polymerization assays demonstrated that the increased sensitivity was correlated with an increased ability of PLA and LAU to induce G2-M arrest and tubulin polymerization in the cells. Unlike paclitaxel-selected clones of 1A9 cells, both R1 and L4 cells exhibited a functional p53 gene, and the abundance of the mismatch repair gene hMSH2 (human mutS homolog 2) was comparable to the parental 1A9 cells. This study provides the first direct evidence that A296 and R306 of βI-tubulin are important determinants of the PLA and LAU response in cancer cells.

Jørgensen CL, Ejlertsen B, Bjerre KD, et al.
Gene aberrations of RRM1 and RRM2B and outcome of advanced breast cancer after treatment with docetaxel with or without gemcitabine.
BMC Cancer. 2013; 13:541 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The purpose of the present study was to retrospectively evaluate whether copy number changes of the genes encoding the ribonucleotide reductase subunit M1 (RRM1) and/or subunit M2B (RRM2B) predict sensitivity to gemcitabine administered in combination with docetaxel compared to single agent docetaxel in advanced breast cancer patients.
METHODS: Primary tumor samples from patients randomly assigned to gemcitabine plus docetaxel or docetaxel alone were analyzed for RRM1 and RRM2B copy number changes using Fluorescence In Situ Hybridization (FISH) technology with probes covering respectively RRM1 at 11p15.5 and a reference probe covering the centromere of chromosome 11 (CEN-11), and RRM2B at 8q22.3 and a reference probe covering the centromere of chromosome 8 (CEN-8). The assays were validated in a material of 60 normal breast samples. Time to progression (TTP) was the primary endpoint. Overall survival (OS) and response rate (RR) were secondary endpoints. Associations between RRM1/CEN-11 and/or RRM2B/CEN-8 ratios and time-to-event endpoints were analyzed by unadjusted and adjusted Cox proportional hazards regression models. Heterogeneity of treatment effects on TTP and OS according to gene status were investigated by subgroup analyses, and the Wald test was applied. All statistical tests were two-sided.
RESULTS: FISH analysis for both RRM1 and RRM2B was successful in 251 patients. RRM1 and RRM2B aberrations (deletions and amplifications) were observed in 15.9% and 13.6% of patients, respectively. RRM1 aberrations were associated with a decreased OS in the time interval 1.5-7.4 years (hazard ratio = 1.72, 95% confidence interval = 1.05-2.79, P = 0.03). RRM2B aberrations alone or in combination with RRM1 aberrations had no prognostic impact in terms of TTP or OS. RR was not different by gene status. No significant differences were detected in TTP or OS within subgroups according to gene status and chemotherapy regimen.
CONCLUSIONS: This study demonstrated the presence of RRM1 and RRM2B copy number changes in primary breast tumor specimens. Nevertheless, we found no support of the hypothesis that aberrations of RRM1 or RRM2B, neither individually nor in combination, are associated with an altered clinical outcome following chemotherapy with gemcitabine in combination with docetaxel compared to docetaxel alone in advanced breast cancer patients.

Chen G, Jundong GU, Chen J, et al.
Association between clinical pathology and multiple genes mRNA expression in Chinese patients with NSCLC.
J Cancer Res Ther. 2013; 9 Suppl 2:S98-100 [PubMed] Related Publications
OBJECTIVE: The aim of this study was to evaluate whether there was an association between pathology type and ERCC1, BRCA1, RRM1, TUBB3, STMN1, TOP2A and epidermal growth factor receptor (EGFR) messenger ribonucleic acid (mRNA) expression level in Chinese patients with non-small cell lung carcinoma (NSCLC).
MATERIALS AND METHODS: mRNA expression level of these genes was analyzed in 181 cancer tissues by using xTAG-step liquid-chip array. The mRNA expression level of the seven genes was evaluated in association with the clinical pathology type.
RESULTS: The average mRNA expression level of the seven genes were ERCC1 (1.02 ± 0.03), BRCA1 (0.15 ± 0.04), RRM1 (0.19 ± 0.05), TUBB3 (0.31 ± 0.06), STMN1 (2.78 ± 0.42), TOP2A (3.04 ± 0.42) and EGFR (0.58 ± 0.09), respectively in Chinese patients with NSCLC. The mRNA expression level of ERCC1, STMN1 and TOP2A genes were statistical different with different pathology type (p(a) < 0.05); STMN1 and TOP2A genes mRNA expression were much higher in squamous cell lung carcinoma than that in non-squamous cell lung carcinoma (p(a) < 0.05). And ERCC1 gene expression was much lower in squamous cell carcinoma than that in non-squamous cell carcinoma (p(a) < 0.05).
CONCLUSION: mRNA expression level of STMN1, TOP2A and ERCC1 were correlated with the clinical pathology type.

Wang L, Meng L, Wang XW, et al.
Expression of RRM1 and RRM2 as a novel prognostic marker in advanced non-small cell lung cancer receiving chemotherapy.
Tumour Biol. 2014; 35(3):1899-906 [PubMed] Related Publications
The aim of this study was to examine the prognostic value of BRCA1, RRM1, and RRM2 in patients with non-small cell lung cancer (NSCLC) who received adjuvant chemotherapy. A total of 418 patients who underwent curative pulmonary resection were obtained between January 2007 and November 2009. The relative cDNA quantification for BRCA1, RRM1, and RRM2 was conducted using a fluorescence-based, real-time detection method, and β-actin was used as a reference gene. The low expression of RRM1 and RRM2 significantly increased the platinum-based chemotherapy response (For RRM1: odds ratio (OR) = 2.09, 95% confidence interval (CI) = 1.38-3.18; For RRM2: OR = 1.64, 95% CI = 1.09-2.48). The univariate analysis indicated that low expression of RRM1 attained a longer time to progression and overall survival time, with HR (95% CI) of 0.50 (0.33-0.77) and 0.60 (0.39-0.92), respectively. Similarly, low expression of RRM2 had a longer time to progression and overall survival, with HR (95% CI) of 0.57 (0.38-0.86) and 0.47 (0.31-0.71), respectively. In conclusion, low expression of RRM1 and RRM2 could be used to predict the treatment response to platinum-based chemotherapy and survival in NSCLC. The RRM1 and RRM2 could substantially contribute to the future design of individualized cancer treatment in NSCLC patients.

Wei CH, Gorgan TR, Elashoff DA, et al.
A meta-analysis of gemcitabine biomarkers in patients with pancreaticobiliary cancers.
Pancreas. 2013; 42(8):1303-10 [PubMed] Free Access to Full Article Related Publications
OBJECTIVES: The objective of this study was to summarize all clinical studies evaluating the prognostic role of gemcitabine (GEM) metabolic genes in pancreaticobiliary (PB) cancer patients receiving GEM therapy in the neoadjuvant, adjuvant, or palliative settings.
METHODS: Meta-analyses were performed to calculate the pooled hazard ratios for each gene by each clinical outcome (overall survival [OS], disease-free survival [DFS], and progression-free survival) using a random-effects approach.
RESULTS: The search strategy identified 16 eligible studies, composed of 632 PB patients total, with moderate quality. Compared with low expression, pooled hazard ratios for OS of hENT1, dCK, RRM1, RRM2, and DPD were 0.37 (95% confidence interval [CI], 0.28-0.47), 0.40 (95% CI, 0.20-0.80), 2.21 (95% CI, 1.12-4.36), 2.13 (95% CI, 1.00-4.52), and 1.91 (95% CI, 1.16-3.17), respectively. A similar trend was observed for each of these biomarkers in DFS and progression-free survival prognostication. Subgroup analyses for hENT1 showed a comparable survival correlation in the adjuvant and palliative settings.
CONCLUSIONS: High expression of hENT1 in PB cancer patients receiving GEM-based adjuvant therapy is associated with improved OS and DFS and may be the best examined prognostic marker to date. Evidence for other biomarkers is limited by a small number of publications investigating these markers.

Sung YY, Cheung E
Androgen receptor co-regulatory networks in castration-resistant prostate cancer.
Endocr Relat Cancer. 2014; 21(1):R1-R11 [PubMed] Related Publications
Androgen and the androgen receptor (AR) are critical effectors of prostate cancer. Consequently, androgen deprivation therapy is typically employed as a first-line treatment for prostate cancer patients. While initial responses are generally positive, prostate tumors frequently recur and progress to a lethal form known as castration-resistant prostate cancer (CRPC). Recently, considerable effort has been directed toward elucidating the molecular mechanisms of CRPC. Results from both preclinical and clinical studies suggest that AR-mediated signaling persists and remains functionally important in CRPC despite the elimination of androgens. Understanding the role of this pathway in the development of resistance will therefore be critical to identify alternative diagnostic markers as well as more effective therapies for the treatment of CRPC. Using next-generation sequencing and other high-throughput approaches, numerous groups are beginning to identify the key differences in the transcriptional regulatory and gene expression programs between androgen-dependent and CRPC. A number of mechanisms have been proposed for the differences and these mostly involve alterations to components of the AR co-regulatory network. In this review, we summarize current knowledge on co-regulators of the AR and discuss their potential roles in CRPC. It is anticipated that a deeper understanding of these factors will undercover new targets that can assist in the diagnosis and treatment of CRPC.

Haselmann V, Kurz A, Bertsch U, et al.
Nuclear death receptor TRAIL-R2 inhibits maturation of let-7 and promotes proliferation of pancreatic and other tumor cells.
Gastroenterology. 2014; 146(1):278-90 [PubMed] Related Publications
BACKGROUND & AIMS: Tumor necrosis factor-related apoptosis inducing ligand (TRAIL-R1) (TNFRSF10A) and TRAIL-R2 (TNFRSF10B) on the plasma membrane bind ligands that activate apoptotic and other signaling pathways. Cancer cells also might have TRAIL-R2 in the cytoplasm or nucleus, although little is known about its activities in these locations. We investigated the functions of nuclear TRAIL-R2 in cancer cell lines.
METHODS: Proteins that interact with TRAIL-R2 initially were identified in pancreatic cancer cells by immunoprecipitation, mass spectrometry, and immunofluorescence analyses. Findings were validated in colon, renal, lung, and breast cancer cells. Functions of TRAIL-R2 were determined from small interfering RNA knockdown, real-time polymerase chain reaction, Drosha-activity, microRNA array, proliferation, differentiation, and immunoblot experiments. We assessed the effects of TRAIL-R2 overexpression or knockdown in human pancreatic ductal adenocarcinoma (PDAC) cells and their ability to form tumors in mice. We also analyzed levels of TRAIL-R2 in sections of PDACs and non-neoplastic peritumoral ducts from patients.
RESULTS: TRAIL-R2 was found to interact with the core microprocessor components Drosha and DGCR8 and the associated regulatory proteins p68, hnRNPA1, NF45, and NF90 in nuclei of PDAC and other tumor cells. Knockdown of TRAIL-R2 increased Drosha-mediated processing of the let-7 microRNA precursor primary let-7 (resulting in increased levels of mature let-7), reduced levels of the let-7 targets (LIN28B and HMGA2), and inhibited cell proliferation. PDAC tissues from patients had higher levels of nuclear TRAIL-R2 than non-neoplastic pancreatic tissue, which correlated with increased nuclear levels of HMGA2 and poor outcomes. Knockdown of TRAIL-R2 in PDAC cells slowed their growth as orthotopic tumors in mice. Reduced nuclear levels of TRAIL-R2 in cultured pancreatic epithelial cells promoted their differentiation.
CONCLUSIONS: Nuclear TRAIL-R2 inhibits maturation of the microRNA let-7 in pancreatic cancer cell lines and increases their proliferation. Pancreatic tumor samples have increased levels of nuclear TRAIL-R2, which correlate with poor outcome of patients. These findings indicate that in the nucleus, death receptors can function as tumor promoters and might be therapeutic targets.

Mazzoni F, Cecere FL, Meoni G, et al.
Phase II trial of customized first line chemotherapy according to ERCC1 and RRM1 SNPs in patients with advanced non-small-cell lung cancer.
Lung Cancer. 2013; 82(2):288-93 [PubMed] Related Publications
OBJECTIVES: Customized chemotherapy has several advantages: patients are more likely to be treated with the most effective agents and can be spared the toxicity of ineffective drugs. Based on the literature, excision repair cross complementation group 1 (ERCC1) and ribonucleotide reductase M1 (RRM1) genes represent predictive biomarkers of response to platinum compound and gemcitabine, in NSCLC.
MATERIALS AND METHODS: We had planned a phase II trial (Simon design) to evaluate combination chemotherapy according to single nucleotide polymorphisms (SNPs) of ERCC1 (118T/C and 8092C/A) and RRM1 (-37C/A and -524T/C) in naïve patients affected by advanced NSCLC. ERCC1 and RRM1 SNPs assessment was performed in peripheral blood lymphocytes (PBLs). Combination chemotherapy was selected based on ERCC1 and RRM1 SNPs: we assume that patients with one or two C alleles at position 118 and with one or two A alleles at position 8092 in ERCC1 gene would correspond to Cisplatin non-responder and than with two A alleles at -37 and two C alleles at -524 in RRM1 gene to gemcitabine non-responder. Four schedules were provided: cisplatin+gemcitabine, cisplatin+docetaxel, gemcitabine+docetaxel; docetaxel+vinorelbine. Primary endpoint was overall response (ORR) in the intention-to-treat population.
RESULTS: 42 patients were enrolled from January 2010 to November 2011; 40 patients received at least 1 cycle of chemotherapy; median age was 66 years (range: 47-72); 36(90%) had stage IV, 4(10%) IIIB; 23(58%) had adenocarcinoma, 14(35%) squamous carcinoma. Twenty-five (62%) patients received treatment A, 3(8%) treatment B, 11(28%) treatment C, 1(23%) treatment D. ORR was 55%, analysis in squamous patients subgroups showed 71.4% ORR. The median follow-up was 19.7 months, PFS was 23 weeks (95% CI = 15-26) and OS was 40.4 weeks (95% CI = 32-55). Treatment was well tolerated.
CONCLUSION: We observed an increase of ORR in NSCLC patients when they were treated with chemotherapy according to ERCC1 and RRM1 SNPs status.

Cao X, Mitra AK, Pounds S, et al.
RRM1 and RRM2 pharmacogenetics: association with phenotypes in HapMap cell lines and acute myeloid leukemia patients.
Pharmacogenomics. 2013; 14(12):1449-66 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Ribonucleotide reductase catalyzes an essential step in the cellular production of deoxyribonucleotide triphosphates and has been associated with clinical outcome in cancer patients receiving nucleoside analog-based chemotherapy.
MATERIALS & METHODS: In the current study, we sequenced the genes RRM1 and RRM2 in genomic DNA from HapMap cell lines with European (Utah residents with northern and western European ancestry [CEU]; n = 90) or African (Yoruba people in Ibadan, Nigeria [YRI]; n = 90) ancestry.
RESULTS: We identified 44 genetic variants including eight coding SNPs in RRM1 and 15 SNPs including one coding SNP in RRM2. RRM1 and RRM2 mRNA expression levels were significantly correlated with each other in both CEU and YRI lymphoblast cell lines, and in leukemic blasts from acute myeloid leukemia (AML) patients (AML97, n = 89; AML02, n = 187). Additionally, RRM1 expression was higher among patient features indicative of a high relapse hazard. We evaluated SNPs within the RRM1 and RRM2 genes in the HapMap lymphoblast cell lines from CEU and YRI panels for association with expression and cytarabine chemosensitivity. SNPs of potential significance were further evaluated in AML patients. RRM1 SNPs rs1042919 (which occurs in linkage disequilbrium with multiple other SNPs) and promoter SNP rs1561876 were associated with intracellular 1-β-D-arabinofuranosyl-CTP levels, response after remission induction therapy, risk of relapse and overall survival in AML patients receiving cytarabine and cladribine.
CONCLUSION: These results suggest that SNPs within ribonucleotide reductase might be helpful predictive markers of response to nucleoside analogs and should be further validated in larger cohorts.

Germano A, Rapa I, Volante M, et al.
Cytotoxic activity of gemcitabine, alone or in combination with mitotane, in adrenocortical carcinoma cell lines.
Mol Cell Endocrinol. 2014; 382(1):1-7 [PubMed] Related Publications
We aimed at investigating in vitro the cytotoxic activity (determined using WST-1, apoptosis and cell cycle assays) of gemcitabine, alone or in combination with mitotane, in mitotane-sensitive H295R and mitotane-insensitive SW-13 cells. Results of these experiments were compared with drug-induced modulation of RRM1 gene, the specific target of gemcitabine. In H295R cells, mitotane and gemcitabine combinations showed antagonistic effects and interfered with the gemcitabine-mediated inhibition of the S phase of the cell cycle. By contrast, in SW-13 cells, except when mitotane was sequentially administered prior to gemcitabine, the combination of the two drugs was synergistic. Such opposite effects were associated with opposite expression profiles of the target gene, with significant up-modulation in H295R but not in SW-13 under gemcitabine and mitotane combination treatment.

Mlak R, Krawczyk P, Ramlau R, et al.
Predictive value of ERCC1 and RRM1 gene single-nucleotide polymorphisms for first-line platinum- and gemcitabine-based chemotherapy in non-small cell lung cancer patients.
Oncol Rep. 2013; 30(5):2385-98 [PubMed] Related Publications
Platinum-based chemotherapy with third generation drugs (such as gemcitabine) is an efficacious regimen of first-line treatment of patients with advanced, unresectable non-small cell lung cancer (NSCLC), without activating EGFR mutations. Mechanism of action of cytostatics are distortions in the DNA. ERCC1 and RRM1 are key proteins involved in the repair of DNA, thus, they may be responsible for the ineffectiveness of therapy. We investigated whether ERCC1 (19007C>T) and RRM1 (-37C>A) polymorphisms impact response to chemotherapy and survival in 62 patients with NSCLC treated with platinum and gemcitabine. Single nucleotide polymorphisms (SNPs) were assessed using a PCR-RFLP method in DNA isolated from PBLs. There were no statistically significant relationships between ERCC1 genotypes and response to therapy (p=0.581, χ2=1.09) as well as patient overall survival (OS). Carriers of the RRM1 AC genotype showed disease progression significantly more frequently (p=0.019, χ2=5.473) compared to carriers of the AA or CC genotypes. Carriers of the ERCC1/RRM1TT/CC genotype combination showed disease control significantly more frequently (p=0.047, χ2=3.95) compared to carriers of other genotype combinations. Patients with AA or CC genotypes of RRM1 showed significantly higher progression-free survival probability (p=0.0001, HR=0.39, 95% CI, 0.22-0.70) and OS probability (p=0.0104, HR=0.39, 95% CI, 0.18-0.82) compared to those with the AC genotype. In Cox regression model, poor performance status (p=0.0016, HR=4.78, 95% CI, 1.82-12.56), AC genotype of RRM1 gene (p=0.0414, HR=2.47, 95% CI, 1.04-5.87), lack of prior surgical treatment (p=0.0425, HR=4.71, 95% CI, 1.06-20.92) and lack of subsequent lines of treatment (p=0.0127, HR=3.23, 95% CI, 1.29-8.11) were significantly associated with shortening of patient survival. The analysis of RRM1 (-37C>A) more than ERCC1 (19007C>T) polymorphism may be a promising tool in the qualification of NSCLC patients for chemotherapy containing platinum compounds and gemcitabine.

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