Resveratrol induces downregulation of DNA repair genes in MCF7 human breast cancer cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Uribe Laura
PROVIDER: S-ECPF-GEOD-25412 | biostudies-other |
REPOSITORIES: biostudies-other
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Project description:Breast cancer is a worlwide health problem. One of the factors involved in carcinogenesis is diet. Several studies indicate that resveratrol, a polyphenol present in diet, has several antitumor properties. The purpose of the study is gain an insight of resveratrol effect in cancer by determining the gene expression profile of breast cancer cell lines treated with the compound. MCF7 cell lines were treated for a 48 hour period with two concentrations (150 and 250 uM) of resveratrol. 9 plates were used for each condition. The RNA obtained from 3 plates of the same condition was pooled, processed and hybridized to the Affymetrix Human Gene 1.0 ST array. The arrays were analyzed using Partek Genomics suite software-.
2011-07-31 | E-GEOD-25412 | biostudies-arrayexpress
Project description:Breast cancer is a worlwide health problem. One of the factors involved in carcinogenesis is diet. Several studies indicate that resveratrol, a polyphenol present in diet, has several antitumor properties. The purpose of the study is gain an insight of resveratrol effect in cancer by determining the gene expression profile of breast cancer cell lines treated with the compound.
2011-08-01 | GSE25412 | GEO
Project description:Aim:The aim of the study was to determine the relationship between single nucleotide polymorphisms (SNPs) of DNA repair genes and modulation of the risk of breast cancer. The following SNPs were analysed: XRCC1-Arg399Gln (rs25487), hMSH2-Gly322Asp (rs4987188), XRCC2-Arg188His (rs3218536), XPD- Lys751Gln (rs13181), RAD51--4719A/T (rs2619679) and RAD51--4601A/G (rs5030789). Material and Methods:The study included n = 600 patients: 300 with breast cancer and 300 healthy controls. The HRM (High-Resolution Melter) technique was applied for polymorphism analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each genotype and allele. Results:Statistically significant correlations were identified between four single nucleotide polymorphisms and the breast cancer risk: XRCC1-Arg399Gln, hMSH2-Gly322Asp, XPD- Lys751Gln and RAD51--4719A/T. Allele XRCC1-Gln (OR 6.37; 95% CI 4.86-8.35, p < .0001), hMSH2-Asp (OR 4.41; 95% CI 3.43-5.67, p < .0001), XPD -Gln (OR 2.56; 95% CI 2.02-3.25, p < .0001) and RAD51-T genes (OR 1.44; 95% CI 1.15-1.80, p = 0.002) strongly correlated with breast carcinoma. No relationship was observed between the studied polymorphisms and the cancer progression grade according to Scarf-Bloom-Richardson classification. Conclusions:The results implies that polymorphisms of DNA repair genes may be associated with breast cancer occurrence.
| S-EPMC6355183 | biostudies-literature
Project description:Transforming growth factor beta (TGF?) proteins are multitasking cytokines, in which high levels at tumor sites generally correlate with poor prognosis in human patients with cancer. Previously, it was reported that TGF? downregulates the expression of ataxia telangiectasia-mutated (ATM) and mutS homolog 2 (MSH2) in breast cancer cells through an miRNA-mediated mechanism. In this study, expression of a panel of DNA-repair genes was examined, identifying breast cancer 1, early onset (BRCA1) as a target downregulated by TGF? through the miR181 family. Correlations between the expression levels of TGF?1 and the miR181/BRCA1 axis were observed in primary breast tumor specimens. By downregulating BRCA1, ATM, and MSH2, TGF? orchestrates DNA damage response in certain breast cancer cells to induce a "BRCAness" phenotype, including impaired DNA-repair efficiency and synthetic lethality to the inhibition of poly (ADP-ribose) polymerase (PARP). Xenograft tumors with active TGF? signaling exhibited resistance to the DNA-damaging agent doxorubicin but increased sensitivity to the PARP inhibitor ABT-888. Combination of doxorubicin with ABT-888 significantly improved the treatment efficacy in TGF?-active tumors. Thus, TGF? can induce "BRCAness" in certain breast cancers carrying wild-type BRCA genes and enhance the responsiveness to PARP inhibition, and the molecular mechanism behind this is characterized.These findings enable better selection of patients with sporadic breast cancer for PARP interventions, which have exhibited beneficial effects in patients carrying BRCA mutations.
| S-EPMC4233161 | biostudies-literature
Project description:Homologous recombination (HR) DNA repair-deficient (HRD) breast cancers have been shown to be sensitive to DNA repair targeted therapies. Burgeoning evidence suggests that sporadic breast cancers, lacking germline BRCA1/BRCA2 mutations, may also be HRD. We developed a functional ex vivo RAD51-based test to identify HRD primary breast cancers. An integrated approach examining methylation, gene expression, and whole-exome sequencing was employed to ascertain the aetiology of HRD. Functional HRD breast cancers displayed genomic features of lack of competent HR, including large-scale state transitions and specific mutational signatures. Somatic and/or germline genetic alterations resulting in bi-allelic loss-of-function of HR genes underpinned functional HRD in 89% of cases, and were observed in only one of the 15 HR-proficient samples tested. These findings indicate the importance of a comprehensive genetic assessment of bi-allelic alterations in the HR pathway to deliver a precision medicine-based approach to select patients for therapies targeting tumour-specific DNA repair defects. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
| S-EPMC5516531 | biostudies-literature
Project description:Estrogen overproduction is closely associated with the development of estrogen receptor-positive breast cancer. Aromatase, encoded by the cytochrome P450 19 (CYP19) gene, regulates estrogen biosynthesis. This study aimed to identify active flavones that inhibit CYP19 expression and to explore the underlying mechanisms. CYP19 expression was evaluated using reverse transcription PCR, quantitative real-time PCR, and immunoblot analysis. The role of transcription factor early growth response gene 1 (EGR-1) in CYP19 expression was assessed using the short-hairpin RNA (shRNA)-mediated knockdown of EGR-1 expression in estrogen receptor-positive MCF-7 breast cancer cells. We screened 39 flavonoids containing 26 flavones and 13 flavanones using the EGR1 promoter reporter activity assay and observed that chrysoeriol exerted the highest inhibitory activity on tumor necrosis factor alpha (TNF?)-induced EGR-1 expression. We further characterized and demonstrated that chrysoeriol inhibits TNF?-induced CYP19 expression through inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2)-mediated EGR-1 expression. Chrysoeriol may be beneficial as a dietary supplement for the prevention of estrogen receptor-positive breast cancer, or as a chemotherapeutic adjuvant in the treatment of this condition.
| S-EPMC7588959 | biostudies-literature
Project description:Background:Oxidized human DNA or plasmid DNAs containing human ribosomal genes can easily penetrate into the breast cancer cells MCF7 and stimulate the adaptive response induction. Plasmid DNA containing a CMV promoter, gene EGFP, and the insertion of the human ribosomal genes can be expressed. A hypothesis is proposed: these features of the ribosomal DNA are due to the presence of dGn motifs that are prone to oxidize. Methods:Cells of MCF7 line were cultured with plasmids which contained a CMV promoter and gene of fluorescent protein EGFP. Genetic construction pEGFP-Gn contains pEGFP vector and a small insertion with dG11 and dG13 motifs that are inclined to oxidation. The accumulation of pEGFP and pEGFP-Gn in MCF7 (qPCR), the levels of ROS in the cells, the content of 8-oxodG in plasmids and cellular DNA (flow cytometry, immunoassay, and fluorescent microscopy), the expression of NOX4 and EGFP, the localization of NOX4 and EGFP in MCF7 (qPCR, flow cytometry, and fluorescent microscopy), and the levels of the cell DNA damage (comet assay) were analyzed. Results:(dG)n insertions in the plasmid pEGFP increase the levels of ROS, the cell DNA oxidation and DNA damage, and the level of transfection of plasmid into the MCF7 cells. NOX4 participates in the oxidation of pEGFP-Gn and pEGFP. The expression of EGFP gene in MCF7 is significantly increased in case of pEGFP-Gn. Stimulation of ROS synthesis (H2O2 40 ?M or 10?cGy IR) increases the level of expression of EGFP. Conclusions:GC-rich DNA fragments containing dGn motifs that are inclined to oxidation penetrate into MCF7 cancer cells, stimulate the adaptive response, and can be expressed. This property of GC-rich cell-free DNA should be considered and/or could potentially be used in therapy of tumors.
| S-EPMC6874983 | biostudies-literature
Project description:A summary of the work associated to these microarrays is the following: The need for an integrated view of all data obtained from high-throughput technologies gave rise to network analyses. These are especially useful to rationalize phenomena in terms of how external perturbations propagate through the expression of genes. To address this issue in the case of drug resistance, we constructed Biological Association Networks of genes differentially expressed in cell lines resistant to methotrexate (MTX). Seven cell lines representative of different types of cancer including colon cancer (HT29 and Caco2), breast cancer (MCF7 and MDA-MB-468), pancreatic cancer (MIA PaCa-2), erythroblastic leukemia (K562) and osteosarcoma (Saos-2), were used. The differential expression pattern between sensitive and MTX-resistant cells was determined by microarrays covering the whole human genome and analyzed with the GeneSpring GX software package, v.7.3.1. Genes deregulated in common in the two colon cancer cell lines studied, were subject of Biological Association Networks construction. Dikkopf homolog-1 (DKK1) was a clear node of this network, and functional validations of this target using a siRNA showed a chemosensitization toward MTX. Members of the UDP-glucuronosyltransferase 1A (UGT1A) family formed a network of differentially expressed genes in the two breast cancer cell lines studied. siRNA treatment against UGT1A showed also an increase in MTX sensitivity. Eukaryotic translation elongation factor 1 alpha 1 (EEF1A1) was a gene overexpressed in common among the pancreatic cancer, leukemia and osteosarcoma cell lines, and siRNA treatment against EEF1A1 produced a chemosensitization toward MTX. Biological Association Networks identified DKK1, UGT1As and EEF1A1 as important gene nodes in MTX-resistance. Treatments using iRNA technology against these three genes show chemosensitization toward MTX. Two cell lines are compared, which are MCF7 breast cancer cells sensitive to methotrexate and MCF7 cells resistant to 10e-6M methotrexate. Six samples are provided which correspond to tripicates of each cell line. The samples provided were analyzed using the specific software GeneSpring GX.
| S-ECPF-GEOD-16070 | biostudies-other
Project description:The mechanisms driving the inverse association between recreational physical activity (RPA) and breast cancer risk are complex. While exercise is associated with increased reactive oxygen species production it may also improve damage repair systems, particularly those that operate on single-strand breaks including base excision repair (BER), nucleotide excision repair (NER) and mismatch repair (MMR). Of these repair pathways, the role of MMR in breast carcinogenesis is least investigated. Polymorphisms in MMR or other DNA repair gene variants may modify the association between RPA and breast cancer incidence. We investigated the individual and joint effects of variants in three MMR pathway genes (MSH3, MLH1 and MSH2) on breast cancer occurrence using resources from the Long Island Breast Cancer Study Project. We additionally characterized interactions between RPA and genetic polymorphisms in MMR, BER and NER pathways. We found statistically significant multiplicative interactions (p < 0.05) between MSH2 and MLH1, as well as between postmenopausal RPA and four variants in DNA repair (XPC-Ala499Val, XPF-Arg415Gln, XPG-Asp1104His and MLH1-lle219Val). Significant risk reductions were observed among highly active women with the common genotype for XPC (OR = 0.54; 95% CI, 0.36-0.81) and XPF (OR = 0.62; 95% CI, 0.44-0.87), as well as among active women who carried at least one variant allele in XPG (OR = 0.46; 95% CI, 0.29-0.77) and MLH1 (OR = 0.46; 95% CI, 0.30-0.71). Our data show that women with minor alleles in both MSH2 and MLH1 could be at increased breast cancer risk. RPA may be modified by genes in the DNA repair pathway, and merit further investigation.
| S-EPMC3830595 | biostudies-literature
Project description:We comprehensively evaluated genetic variants in DNA repair genes with premenopausal breast cancer risk.In this nested case-control study of 239 prospectively ascertained premenopausal breast cancer cases and 477 matched controls within the Nurses' Health Study II, we evaluated 1,463 genetic variants in 60 candidate genes across five DNA repair pathways, along with DNA polymerases, Fanconi Anemia complementation groups, and other related genes.Four variants were associated with breast cancer risk with a significance level of <0.01; two in the XPF gene and two in the XRCC3 gene. An increased risk was found in those harboring a greater number of missense putative risk alleles (a priori defined in an independent study) in the non-homologous end-joining (NHEJ) repair pathway of double-strand breaks (odds ratio (OR) per risk allele, 1.37 (95% confidence interval (CI), 1.03-1.82), P trend, 0.03).This study implicates variants of genes in the double-strand break repair pathway in the etiology of premenopausal breast cancer.
| S-EPMC2693208 | biostudies-literature