Identification of the receptor tyrosine kinase AXL in triple negative breast cancer as a novel target for the human miR-34a microRNA
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Mark Mackiewicz
PROVIDER: E-GEOD-21834 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Triple negative breast cancer (TNBC) is histologically characterized by the absence of the hormone receptors estrogen and progesterone, in addition to having a negative immunostain for HER-2. The aggressiveness of this disease and lack of targeted therapeutic options for treatment is of high clinical importance. MicroRNAs are short 21- to 23 nucleotide endogenous non-coding RNAs that regulate gene expression by binding to mRNA transcripts, resulting in either decreased protein translation or mRNA degradation. Dysregulated expression of miRNAs is now a hallmark of many human cancers. In order to identify a miRNA/mRNA interaction that is biologically relevant to the triple negative breast cancer genotype/phenotype, we initially conducted a miRNA profiling experiment to detect differentially expressed miRNAs in cell line models representing the triple negative (MDA-MB-231), ER+ (MCF7), and HER-2 overexpressed (SK-BR-3) histotypes. We identified human miR-34a expression as being >3-fold down (from its median expression value across all cell lines) in MDA-MB-231 cells, and identified AXL as a putative mRNA target using multiple miRNA/target prediction algorithms. The miR-34a/AXL interaction was functionally characterized through ectopic overexpression experiments with a miR-34a mimic. In reporter assays, miR-34a binds to the putative target site within the AXL 3’UTR to affect luciferase expression. We also observed degradation of AXL mRNA and decreased AXL protein levels, as well as cell signaling effects on AKT phosphorylation and phenotypic effects on cell migration. Finally, we present an inverse correlative trend in miR-34a and AXL expression for both cell line and patient tumor samples. Comparison of the changes in gene expression as a result of transfections with miR-34a mimic molecules (representing two different vendors; Qiagen and Dharmacon) in MDA-MB-231 cells. MDA-MB-231 cells were transfected in 6-well dishes (600,000 cells) with either AllStar negative control, Qmimic, or Dmimic at 10 nM final concentration using Lipofectamine™ 2000 (Invitrogen; Carlsbad, CA). All transfections were performed in triplicate. Forty-eight hours post-transfection, total RNA was isolated from each sample using Qiagen’s miRNeasy extraction kit (Qiagen; Germantown, MD). Total RNA samples were sent to the Laboratory of Molecular Technology (National Cancer Institute at Frederick; Frederick, MD), for processing on Affymetrix GeneChip Human Genome U133 Plus 2.0 microarrays (Affymetrix; Santa Clara, CA). Expression values were normalized using Robust Multichip Averaging (RMA). Only gene probes (AllStar vs. Mimic) that passed a log2 1.5-fold change, p < 0.05 threshold using an Empirical Bayes moderated t statistics with a Benjamini-Hochberg correction for the false discovery rate were reported. All analyses were performed with Bioconductor packages AFFYGUI and LIMMA on a R environment.
2010-12-31 | E-GEOD-21832 | biostudies-arrayexpress
Project description:Triple negative breast cancer (TNBC) is histologically characterized by the absence of the hormone receptors estrogen and progesterone, in addition to having a negative immunostain for HER-2. The aggressiveness of this disease and lack of targeted therapeutic options for treatment is of high clinical importance. MicroRNAs are short 21- to 23 nucleotide endogenous non-coding RNAs that regulate gene expression by binding to mRNA transcripts, resulting in either decreased protein translation or mRNA degradation. Dysregulated expression of miRNAs is now a hallmark of many human cancers. In order to identify a miRNA/mRNA interaction that is biologically relevant to the triple negative breast cancer genotype/phenotype, we initially conducted a miRNA profiling experiment to detect differentially expressed miRNAs in cell line models representing the triple negative (MDA-MB-231), ER+ (MCF7), and HER-2 overexpressed (SK-BR-3) histotypes. We identified human miR-34a expression as being >3-fold down (from its median expression value across all cell lines) in MDA-MB-231 cells, and identified AXL as a putative mRNA target using multiple miRNA/target prediction algorithms. The miR-34a/AXL interaction was functionally characterized through ectopic overexpression experiments with a miR-34a mimic. In reporter assays, miR-34a binds to the putative target site within the AXL 3’UTR to affect luciferase expression. We also observed degradation of AXL mRNA and decreased AXL protein levels, as well as cell signaling effects on AKT phosphorylation and phenotypic effects on cell migration. Finally, we present an inverse correlative trend in miR-34a and AXL expression for both cell line and patient tumor samples. The small RNA (sRNA) fraction from four separate passages (biological replicates) of MCF7, SK-BR-3, MDA-MB-231, and MCF10A cells were extracted using Qiagen’s miRNeasy kit following the manufacturer’s instructions (Qiagen; Germantown, MD). Five micrograms of sRNA was labeled with either Cy3 (MCF10A) or Cy5 (breast cancer cell) fluorescent label (GE Healthcare; Piscataway, NJ) using the mirVana miRNA labeling kit (Ambion; Austin, TX). The labeled products were hybridized to miRVana miRNA Bioarrays V2 (Ambion, Austin, TX) and washed following the manufacturer’s protocol. Each array was comprised of 328 human miRNA probes in addition to 114 mouse and 46 rat miRNAs. The comparative hybridization for each breast cancer cell line to the reference MCF10A cell line control was conducted in quadruplicate (n=12 total arrays). Processed arrays were scanned for dual channel hybridization using a GenePix 4000B scanner (Molecular Devices; Sunnyvale, CA). Analyses were performed using BRB-Array Tools Version 3.8.1 (http://linus.nci.nih.gov/BRB-ArrayTools.html). Replicate spots for each miRNA were averaged within the array, background adjusted, and log2 normalized. Normalization was performed using a per chip median normalization method. Only those miRNAs with at least a 3-fold change in expression from its median value across all arrays, in at least 33% of all arrays tested, were retained. Samples and genes were hierarchical clustered with average linkage under the Euclidian distance similarity metric using the Cluster 3.0 (http://rana.stanford.edu/software) and Java TreeView 1.1.4r3 applications. MiRNA probes of mouse, rat, and manufacturer’s (Ambion) origins that passed the gene filter were excluded from future analyses.
2010-12-31 | E-GEOD-21719 | biostudies-arrayexpress
Project description:Overexpression and amplification of AXL receptor tyrosine kinase (RTK) has been found in several hematologic and solid malignancies. Activation of AXL by its ligand GAS6 can enhance tumor-promoting processes such as proliferation, migration, invasion, and survival. Despite the important role of AXL in cancer development, a deep and quantitative mapping of its signaling transduction has not been performed. Here, we used a mass spectrometry-based quantitative proteomic approach to characterize the temporal dynamics of the phosphotyrosine proteome of MDA-MB-231 cells stimulated with GAS6
2021-08-24 | PXD025457 | Pride
Project description:Triple negative breast cancer (TNBC) is histologically characterized by the absence of the hormone receptors estrogen and progesterone, in addition to having a negative immunostain for HER-2. The aggressiveness of this disease and lack of targeted therapeutic options for treatment is of high clinical importance. MicroRNAs are short 21- to 23 nucleotide endogenous non-coding RNAs that regulate gene expression by binding to mRNA transcripts, resulting in either decreased protein translation or mRNA degradation. Dysregulated expression of miRNAs is now a hallmark of many human cancers. In order to identify a miRNA/mRNA interaction that is biologically relevant to the triple negative breast cancer genotype/phenotype, we initially conducted a miRNA profiling experiment to detect differentially expressed miRNAs in cell line models representing the triple negative (MDA-MB-231), ER+ (MCF7), and HER-2 overexpressed (SK-BR-3) histotypes. We identified human miR-34a expression as being >3-fold down (from its median expression value across all cell lines) in MDA-MB-231 cells, and identified AXL as a putative mRNA target using multiple miRNA/target prediction algorithms. The miR-34a/AXL interaction was functionally characterized through ectopic overexpression experiments with a miR-34a mimic. In reporter assays, miR-34a binds to the putative target site within the AXL 3’UTR to affect luciferase expression. We also observed degradation of AXL mRNA and decreased AXL protein levels, as well as cell signaling effects on AKT phosphorylation and phenotypic effects on cell migration. Finally, we present an inverse correlative trend in miR-34a and AXL expression for both cell line and patient tumor samples. Comparison of the changes in gene expression as a result of transfections with miR-34a mimic molecules (representing two different vendors; Qiagen and Dharmacon) in MDA-MB-231 cells.
2010-12-31 | GSE21832 | GEO
Project description:MicroRNAs (miRNAs or miRs) are small, noncoding RNAs that are implicated in the regulation of nearly all biological processes. Global miRNA biogenesis is altered in many cancers and RNA-binding proteins (RBPs) have been shown to play a role in this process, presenting a promising avenue for targeting miRNA dysregulation in disease. miR-34a exhibits tumor-suppressive functions by targeting cell cycle regulators CDK4/6 and anti-apoptotic factor Bcl-2, among other regulatory pathways such as Wnt, TGF-, and Notch signaling. Many cancers show downregulation or loss of miR-34a, and synthetic miR-34a supplementation has been shown to inhibit tumor growth in vivo; however, the post-transcriptional mechanisms by which miR-34a is lost in cancer are not entirely understood. Here, we have used a proteomics-mediated approach to identify Squamous cell carcinoma antigen recognized by T-cells 3 (SART3) as a putative pre-miR-34a-binding protein. SART3 is a spliceosome recycling factor and nuclear RBP with no previously reported role in miRNA regulation. We demonstrate that SART3 binds pre-miR-34a with specificity over pre-let-7d and begin to elucidate a new functional role for this protein in non-small lung cancer cells. Overexpression of SART3 led to increased miR-34a levels, downregulation of the miR-34a target genes CDK4 and CDK6, and cell cycle arrest in the G1 phase. In vitro binding studies showed that the RNA-recognition motifs within the SART3 sequence are responsible for selective pre-miR-34a binding. Collectively, our results present evidence for an influential role of SART3 in miR-34a biogenesis and cell cycle progression.
2019-10-14 | PXD015278 | Pride
Project description:Triple negative breast cancer (TNBC) is histologically characterized by the absence of the hormone receptors estrogen and progesterone, in addition to having a negative immunostain for HER-2. The aggressiveness of this disease and lack of targeted therapeutic options for treatment is of high clinical importance. MicroRNAs are short 21- to 23 nucleotide endogenous non-coding RNAs that regulate gene expression by binding to mRNA transcripts, resulting in either decreased protein translation or mRNA degradation. Dysregulated expression of miRNAs is now a hallmark of many human cancers. In order to identify a miRNA/mRNA interaction that is biologically relevant to the triple negative breast cancer genotype/phenotype, we initially conducted a miRNA profiling experiment to detect differentially expressed miRNAs in cell line models representing the triple negative (MDA-MB-231), ER+ (MCF7), and HER-2 overexpressed (SK-BR-3) histotypes. We identified human miR-34a expression as being >3-fold down (from its median expression value across all cell lines) in MDA-MB-231 cells, and identified AXL as a putative mRNA target using multiple miRNA/target prediction algorithms. The miR-34a/AXL interaction was functionally characterized through ectopic overexpression experiments with a miR-34a mimic. In reporter assays, miR-34a binds to the putative target site within the AXL 3’UTR to affect luciferase expression. We also observed degradation of AXL mRNA and decreased AXL protein levels, as well as cell signaling effects on AKT phosphorylation and phenotypic effects on cell migration. Finally, we present an inverse correlative trend in miR-34a and AXL expression for both cell line and patient tumor samples.
2010-12-31 | GSE21719 | GEO
Project description:Bone metastases is a common severe complication for breast cancer. We previously showed that conditioned medium (CM) from osteocytes stimulated with oscillatory fluid flow, mimicking bone mechanical loading during routine physical activities, reduced breast cancer cell extravasation across endothelial monolayers. Endothelial cells are situated at an ideal location to mediate signals between osteocytes in the bone matrix and metastasizing cancer cells in the blood vessels. Therefore, we used RNA sequencing to show that CM from endothelial cells conditioned in CM from flow-stimulated osteocytes significantly altered gene expression in bone-metastatic breast cancer cells. This This provides insights into the capability of bone-loading activity in preventing bone metastases.
2018-11-13 | E-MTAB-7176 | biostudies-arrayexpress
Project description:Axl expression is deregulated in several cancer types, predicts poor overall patient survival and is linked to increase in resistance to drug therapy. Here, we have evaluated a library of natural compounds for inhibitors of Axl. We identified dihydroartemisin (DHA), the active principle of the anti-malarial drug artemisinin, as a specific Axl inhibitor in prostate cancer (PCa). DHA blocks Axl expression leading to apoptosis induction, decrease in cell proliferation, migration and tumor development of PCa cells. Furthermore, DHA treatment synergizes with docetaxel, a standard of care in metastatic PCa, and increases the overall survival of mice with human PCa xenografts. We demonstrated that DHA-mediated control of miR-34a and miR-7 expression leads to inhibition of Axl expression. This process is dependent on regulation of the chromatin via methylation of histone H3 lysine 27 residues (H3K27) by Jumonji, AT-rich interaction domain containing 2 (JARID2) and the enhancer of zeste homolog 2 (EZH2), components of the Polycomb Complex Repressor 2 (PCR2). Our discovery of a previously unidentified miR-34a/miR-7/JARID2 pathway that controls DHA-mediated effects on Axl expression and inhibition of cancer cell proliferation, migration, invasion and tumor formation provides new molecular and mechanistic insights into DHA’s anti-cancer effect on PCa with potential therapeutic implications.
2018-11-17 | GSE122625 | GEO
Project description:Elevated expression and activity of the epidermal growth factor receptor (EGFR) is associated with development and progression of head and neck cancer (HNC) and a poor prognosis. Clinical trials with EGFR tyrosine kinase inhibitors (TKIs; eg. erlotinib) have been disappointing in HNC. To investigate the mechanisms mediating resistance to these agents, we developed a HNC cell line (HN5-ER) with acquired erlotinib resistance. In contrast to parental HN5 HNC cells, HN5-ER cells exhibited an epithelial-mesenchymal (EMT) phenotype with increased migratory potential, reduced E-cadherin and epithelial-associated miRNAs, and elevated vimentin expression. Phosphorylated RTK profiling identified Axl activation in HN5-ER cells. Growth and migration of HN5-ER cells was blocked with a specific Axl inhibitor, R428, and R428 re-sensitized HN5-ER cells to erlotinib. Microarray analysis of HN5-ER cells confirmed the EMT phenotype associated with acquired erlotinib resistance, and identified activation of gene expression associated with cell migration and inflammation pathways. Moreover, increased expression and secretion of interleukin (IL)-6 and IL-8 in HN5-ER cells suggested a role for inflammatory cytokine signaling in EMT and erlotinib resistance. Expression of the tumor suppressor miR-34a was reduced in HN5-ER cells and increasing its expression abrogated Axl expression and reversed erlotinib resistance. Finally, analysis of 302 HNC patients revealed that high tumor Axl mRNA expression was associated with poorer survival (HR 1.66, p=0.007). In summary, our results identify Axl as a key mediator of acquired erlotinib resistance in HNC and suggest that therapeutic inhibition of Axl by small molecule drugs or specific miRNAs might overcome anti-EGFR therapy resistance. Differential gene expression between parental and acquired erlotinib resistant head and neck cancer cell lines of HN5.
2013-08-10 | E-GEOD-49135 | biostudies-arrayexpress
Project description: Not available
2011-03-31 | E-TABM-941 | biostudies-arrayexpress