0000000000310232

AUTHOR

Viviana Bartella

showing 3 related works from this author

Insulin-dependent leptin expression in breast cancer cells.

2008

Abstract Pathologic conditions associated with hyperinsulinemia, such as obesity, metabolic syndrome, and diabetes, seem to increase the risk of breast cancer. Here, we studied molecular mechanisms by which insulin activates the expression of leptin, an obesity hormone that has been shown to promote breast cancer progression in an autocrine or paracrine way. Using MDA-MB-231 breast cancer cells, we found that (a) insulin stimulated leptin mRNA and protein expression, which was associated with increased activation of the leptin gene promoter; (b) insulin increased nuclear accumulation of transcription factors hypoxia inducible factor (HIF)-1α and Sp1 and their loading on the leptin promoter;…

LeptinTranscriptional ActivationCancer Researchmedicine.medical_specialtySmall interfering RNAChromatin ImmunoprecipitationSp1 Transcription FactorBlotting WesternFluorescent Antibody TechniqueBreast NeoplasmsEnzyme-Linked Immunosorbent AssayBiologyParacrine signallingPhosphatidylinositol 3-Kinasesbreast cancerInternal medicinemedicineHyperinsulinemiaTumor Cells CulturedHumansHypoglycemic AgentsInsulinRNA MessengerRNA Small InterferingAutocrine signallingLuciferasesPromoter Regions GeneticTranscription factorCell NucleusMitogen-Activated Protein Kinase 1Gene knockdownLeptin receptorMitogen-Activated Protein Kinase 3Reverse Transcriptase Polymerase Chain ReactionLeptinmedicine.diseaseHypoxia-Inducible Factor 1 alpha SubunitCell HypoxiaEndocrinologyOncologyCancer researchFemalehormones hormone substitutes and hormone antagonistsCancer research
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Mechanism of leptin expression in breast cancer cells: role of hypoxia-inducible factor-1α

2007

We reported previously that the obesity hormone leptin is overexpressed in breast cancer biopsies. Here, we investigated molecular mechanisms involved in this process, focusing on conditions that are associated with obesity, that is, hyperinsulinemia and induction of hypoxia. By using quantitative real-time PCR, immunofluorescent detection of proteins and enzyme-linked immunosorbent assays, we found that treatment of MCF-7 breast cancer cells with high doses of insulin or the hypoxia-mimetic agent CoCl2, or culturing the cells under hypoxic conditions significantly increased the expression of leptin mRNA and protein. Notably, the greatest leptin mRNA and protein expression were observed und…

Transcriptional ActivationCancer Researchmedicine.medical_specialtyActive Transport Cell NucleusBreast NeoplasmsBiologymedicine.disease_causeleptinbreast cancerInternal medicineCoactivatorGene expressionTumor Cells CulturedGeneticsmedicineHumansInsulinHIFp300-CBP Transcription FactorsPromoter Regions GeneticMolecular BiologyCell NucleusRegulation of gene expressionBinding SitesLeptin receptorLeptinPromoterCobaltHypoxia-Inducible Factor 1 alpha SubunitCell HypoxiaGene Expression Regulation NeoplasticEndocrinologyhyperinsulinemiaCarcinogenesisChromatin immunoprecipitationhormones hormone substitutes and hormone antagonistsProtein BindingOncogene
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Insulin-like growth factor 1 differentially regulates estrogen receptor-dependent transcription at estrogen response element and AP-1 sites in breast…

2007

Cross-talk between insulin-like growth factor 1 (IGF-1) and estrogen receptor alpha (ER) regulates gene expression in breast cancer cells, but the underlying mechanisms remain unclear. Here, we studied how 17-beta-estradiol (E2) and IGF-1 affect ER transcriptional machinery in MCF-7 cells. E2 treatment stimulated ER loading on the estrogen response element (ERE) in the pS2 promoter and on the AP-1 motif in the cyclin D1 promoter. On ERE, similar amounts of liganded ER were found at 1-24-h time points, whereas on AP-1, ER binding fluctuated over time. At 1 h, liganded ER was recruited to ERE together with histone acetyltransferases SRC-1 and p300, ubiquitin ligase E6-AP, histone methyltransf…

Transcription GeneticActive Transport Cell NucleusEstrogen receptorBreast NeoplasmsLigandsResponse ElementsBiochemistryCyclin D1Cell Line TumorHumansCyclin D1RNA MessengerInsulin-Like Growth Factor IHistone H3 acetylationMolecular BiologyHormone response elementbiologyEstradiolTumor Suppressor ProteinsEstrogen Receptor alphaCell BiologyUbiquitin ligaseCell biologyUp-RegulationTranscription Factor AP-1Histone methyltransferasebiology.proteinCancer researchMdm2Trefoil Factor-1Estrogen receptor alphahormones hormone substitutes and hormone antagonistsThe Journal of biological chemistry
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