Project description:MiR-544 was inhibited by either a miR-544 antagomir or compound 1 under hypoxic conditions in MDA-MB-231 cells MiRNA microarray was utilized to examine the specificity of 1 for miR-544. 3 MDA-MB-231 samples treated with a miR-544 antagomir or compound 1 were subjected to hypoxia for a period of 5 days. After 5 days, samples were pooled and subjected to miRNA microarray analysis.
Project description:MiR-544 was inhibited by either a miR-544 antagomir or compound 1 under hypoxic conditions in MDA-MB-231 cells U133 Plus 2.0 microarray was utilized to examine the specificity of 1 for miR-544. 3 MDA-MB-231 samples treated with a miR-544 antagomir or compound 1 were subjected to hypoxia for a period of 5 days. After 5 days, samples were pooled and subjected to gene level microarray analysis.
Project description:Acquired drug resistance represents a major challenge in chemo-therapy treatment for various types of cancers. We have found that the retinoid X receptorâselective agonist bexarotene (LGD1069, Targretin) was efficacious in treating chemo-resistant cancer cells. The goal of this microarray study was to understand the mechanism of bexaroteneâs role in overcoming acquired drug resistance using human breast cancer cells MDA-MB-231 as a model system and paclitaxel as model compound. After MDA-MB-231 cells were repeatedly treated with paclitaxel for 8 cycles with each cycle including a 3-day treatment with 30 nM paclitaxel and followed by a 7-day exposure to control medium, MDA cells resistant to paclitaxel were developed and their growth was no longer inhibited by paclitaxel treatment. Those MDA cells with acquired drug resistance, when treated with paclitaxel and bexarotene in combination, could regain their sensitivity and their growth were again inhibited. Therefore, RNA samples from parental MDA-MB-231 cells, paclitaxel-resistant MDA cells treated with vehicle, paclitaxel alone or in combination with bexarotene, were used for perform global gene expression profiling with Affymetrix HG-U133A gene chips. Keywords: Drug Treatment MDA-MB-231 cells were exposed to regimens on a 10-day cycle: a 3-day treatment with 30 nM paclitaxel and followed by a 7-day exposure to control medium. Paclitaxel resistant MDA-MB-231 cells (MDA-PR) were established within 8 cycles of such treatment (80 days). These MDA-PR cells were then treated with vehicle control, paclitaxel along, or the combination of 30 nM paclitaxel ( 3 days on and 7 days off) and 1 µM Targretin (10 days on) in a new 10-day cycle for 3 months. Thus, there are four treatment groups, parent MDA cells, MDA-PR, MDA-PR treated with paclitaxel, MDA-PR treated with paclitaxel and bexarotene, and each group had four biological replicates.
Project description:We recently showed that inactivation of the WASF3/WAVE3 gene in breast cancer cells results in loss of cell motility and invasion in vitro and metastasis in vivo. To obtain a better understanding of molecular mechanisms of action of WASF3, we have established the stable WASF3 knockdown MDA-MB-231 cells using shRNA strategy. We used microarrays to detail the global programme of gene expression after silencing WASF3 and identified distinct classes of up or down-regulated genes associated with breast cancer cell migration and motility The three stable WASF3 knockdown single clones and three control clones were selected for RNA extraction and hybridization on Affymetrix microarrays. To identify altered gene expression patterns in the knockdown cells, we compared gene expression levels between three different knockdown and three different control clones.
Project description:We used microarray gene expression analyses to search for epithelial-mesenchymal transition (EMT)-related genes that exhibited the greatest differences in expression in the MZF-1 fragment vector-transfected cells relative to the empty vector-transfected cells. Of the 22,203 genes analyzed in both cell lines, 1209 genes had a two-fold increase and 1557 genes had a two-fold decrease in Hs578T-M(S3) cells (P<0.05), and 1272 genes increased and 1494 genes decreased by a similar amount in MDA-MB-231-M(V4) cells. Combined, 821 of the same genes from both cell lines were up-regulated, and 931 of the same genes from both cell lines were down-regulated. The biological functions of these affected genes were diverse and included 11 EMT-related genes (ITGA5, SERPINE1 GNGI1, SEAP1, TIMP1, FN1, TMEFF1, SNAI2, VIM, CALD1 and MSN) which were down-regulated, and 5 MET-related genes (CDH1, TSPAN13, OCLN, KRT19 and DSP) which were up-regulated. To understand functions of MZF-1/Elk-1 heterodimers, we transfected the binding site-derived peptide to the cells to interrupt heterodimer formation, their DNA binding activity, PKCα expression, cell migration and tumorigenicity were decreased, and the mesenchymal-epithelial transition (MET) was present.
Project description:The DKAT cell line is a novel model of triple-negative breast cancer that was isolated from the pleural effusion of a 35 year-old caucasian woman with triple-negative breast cancer. We used microarrays to look at gene expression in the DKAT cell line compared to several other commonly-used breast cancer cell lines as well as a previously published data set in order to determine the molecular subtype of the DKAT cell line. DKAT, HMEC, and MDA-MB-231 cells were cultured in Mammary Epithelial Growth Media (MEGM, Lonza). RNA was isolated using Qiagen RNeasy kit and hybridization on Affymetrix microarrays was performed. Three separate cDNA reactions were performed and these were run as replicates.
Project description:Small-molecule Smac mimetics target inhibitor of apoptosis (IAP) proteins to induce TNFα-dependent apoptosis in cancer cells and several Smac mimetics have been advanced into clinical development as a new class of anticancer drugs. However, preclinical studies have shown that only a small subset of cancer cell lines are sensitive to Smac mimetics used as single agents and these cell lines are at risk of developing drug resistance to Smac mimetics. Thus, it is important to understand the molecular mechanisms underlying intrinsic and acquired resistance of cancer cells to Smac mimetics in order to develop effective therapeutic strategies to overcome or prevent Smac mimetic resistance. We established Smac mimetic resistant sublines derived from MDA-MB-231 breast cancer cells, which exhibit exquisite sensitivity to the Smac mimetic SM-164, and used microarrays to detail the global programme of gene expression underlying SM-164 resistance in MDA-MB-231 cells and identified differentially expressed genes in SM-164-resistant and -sensitive MDA-MB-231 cells. SCID mice with MDA-MB-231 xenograft tumors were treated with 5 mg/kg of SM-164 intravenously for 5 days/week for 2 weeks. SM-164-regressed MDA-MB-231 tumors regrew after treatment ended. Tumor cells from these regrown MDA-MB-231 tumors were isolated and total RNAs were prepared for microarray analysis.
Project description:The transcription factor GATA3 is essential for luminal cell differentiation during mammary gland development and critical for formation of the luminal subtypes of breast cancer. Ectopic expression of GATA3 promoted global alterations of the transcriptome of basal triple-negative breast cancer cells resulting in molecular and cellular changes associated with a more differentiated, luminal tumor subtype and a concomitant reduction in primary tumor growth, lung metastasis, and macrophage recruitment at the metastatic site. Importantly, we demonstrate that the inhibition of metastases by GATA3 results from the suppression of lysyl oxidase (LOX) expression, a metastasis promoting matrix protein that affects cell proliferation, cross-linking of extracellular collagen types, and establishment of the metastatic niche. There are 2 samples sent in triplicates.
Project description:The Sin3/HDAC multi-protein complex consists of at least 17 subunits and is known to have roles in diverse biological and cellular processes including transcription, chromatin structure, and the cell cycle. ING2 is a non-catalytic component of this complex. To obtain a better mechanistic understanding of the Sin3/HDAC complex in cancer, we extended its protein-protein interaction network and identified a mutually exclusive pair within the complex. Suberoylanilide hydroxamic acid (SAHA) is an FDA approved HDAC inhibitor used for the treatment of cutaneous T-cell lymphoma. We assessed the effects of SAHA on the disruption of the complex network through six homologous baits. SAHA perturbs multiple protein interactions and therefore compromises the composition of large parts of the Sin3/HDAC network. A comparison of the effect of SAHA treatment on gene expression in breast cancer cells to a knockdown of the ING2 subunit indicated that a portion of the anticancer effects of SAHA may be attributed to the disruption of ING2âs association with the complex. ING2 siRNA knockdowns in human breast cancer cell line MDA-MB-231 were compared to a non-targeting control in triplicate, for a total of 6 samples.
Project description:This SuperSeries is composed of the following subset Series: GSE33145: Expression data from DKAT and other breast cancer cell lines under baseline growth conditions GSE33146: Expression data from DKAT breast cancer cell line pre- and post-EMT Refer to individual Series