Filters
Technology
Platform
SRP075643
Homo sapiens
4 Downloadable Samples
Illumina Genome Analyzer IIx
Description
Retinoic acid (RA), the main active vitamin A metabolite, controls multiple biological processes such as cell proliferation and differentiation through genomic programs and kinase cascades activation. Several breast cancer cells respond to the antiproliferative effects of RA, but others are RA-resistant. In several cases resistance has been correlated to the amplification of the erb-b2 receptor tyrosine kinase 2 (ERBB2) gene, but the overall signaling and transcriptional pathways that are altered in such cells have not been elucidated. Here we compared two human breast cancer cell lines, the MCF7 cell line, which responds to the antiproliferative action of RA and the BT474 cell line, which is RA-resistant subsequent to ERBB2 amplification in a large-scale analysis of the phosphoproteins and in a genome-wide analysis of the RA-regulated genes. Using high-resolution nano-LC-LTQ-Orbitrap mass spectrometry associated to phosphopeptide enrichment, we found that several proteins involved in signaling and in transcription, are differentially phosphorylated after RA addition. The paradigm of these proteins is the RA receptor a (RARa), which was phosphorylated in MCF7 cells but not in BT474 cells. The panel of the RA-regulated genes was also different. Overall our results indicate that ERBB2 amplification interferes with the ability of RA to activate kinases with consequences on the phosphorylation of several proteins involved in transcription and thus on gene expression. Overall design: Two human breast cancer cell lines were compared for their repertoire of genes regulated by retinoic acid (RA): the RA sensitive MCF7 cell line and the RA resistant B7474 cell line
Publication Title
Phosphoproteome and Transcriptome of RA-Responsive and RA-Resistant Breast Cancer Cell Lines.
Sample Metadata Fields
Specimen part, Cell line, Treatment, Subject
View Samples- Mus musculus
- 12 Downloadable Samples
Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Mitochondrial calcium is an important second-messenger controlling fight-or-flight responses in the heart. The molecular identity of MCU (Mitochondrial Calcium Uniporter) was recently discovered allowing us to test this hypothesis in vivo by expressiing a myocardial delimited dominant negative form of MCU.
Publication Title
Inhibition of MCU forces extramitochondrial adaptations governing physiological and pathological stress responses in heart.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Caenorhabditis elegans
- 6 Downloadable Samples
- Affymetrix C. elegans Genome Array (celegans)
Description
We used Au nanoparticles (Au-NPs) as a model for studying particle specific effects of manufactured nanomaterials (MNMs) by examining the toxicogenomic responses in a model soil organism, free living nematode Caenorhabditis elegans. Global genome expression for nematodes exposed to 4-nm citrate-coated Au-NPs at the LC10 (5.9 mg L-1) revealed significant differential expression of 797 genes. The levels of expression for five genes (apl-1, dyn-1, act-5, abu-11, and hsp-4) were confirmed independently with qRT-PCR. Seven common biological pathways associated with 38 of these genes were identified. Activation of 26 pqn/abu genes from noncanonical Unfolded Protein Response (UPR) pathway and up-regulation of molecular chaperones (hsp-16.1, hsp-70, hsp-3 and hsp-4) were observed and are likely indicative of endoplasmic reticulum stress. Inhibition of abu-11 with RNAi showed increase in mortality in Au-NP exposed nematodes suggesting possible involvement of abu-11 (a gene associated with specific to C. elegans UPR) in a protective mechanism against Au-NPs. Exposure to Au-NPs also caused activation of genes involved in apoptosis and necrosis and resulted ultimately in 10% mortality. These results demonstrate that Au-NPs are bioavailable and cause adverse effects to a model ecoreceptor which activate both general and specific biological pathways.
Publication Title
Toxicogenomic responses of the model organism Caenorhabditis elegans to gold nanoparticles.
Sample Metadata Fields
Treatment
View Samples