Expression data from MCF7 Scrambled and SIM2si cells
Ontology highlight
ABSTRACT: MCF7 breast cancer cells are a luminal-type breast cancer with moderate native levels of SIM2s. To determine effects of SIM2s on tumor progression, cells were stably transduced with SIM2si shRNA to knockdown expression, inducing an EMT effect. Microarray analysis was performed to determine genetic pathways involved in this phenotype. The coordination of cellular metabolism is a key factor in the progression of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC). Pathways regulating the balance between oxidative phosphorylation and glycolysis are unclear. We have found that transcription factor Singleminded-2s (SIM2s), commonly lost with breast cancer progression, contributes to metabolic regulation by controlling glycolytic flux and cellular senescence. Through promotion of p21 and cellular senescence, SIM2s decreases glycolytic enzyme activity and promotes oxidative phosphorylation in breast cancer. These, coupled with increased autophagy and ROS, inhibit tumor growth and metastasis. We use microarrays to detail the global gene programming changes that occur with loss of SIM2s gene expression.
Project description:MCF7 breast cancer cells are a luminal-type breast cancer with moderate native levels of SIM2s. To determine effects of SIM2s on tumor progression, cells were stably transduced with SIM2si shRNA to knockdown expression, inducing an EMT effect. Microarray analysis was performed to determine genetic pathways involved in this phenotype. The coordination of cellular metabolism is a key factor in the progression of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC). Pathways regulating the balance between oxidative phosphorylation and glycolysis are unclear. We have found that transcription factor Singleminded-2s (SIM2s), commonly lost with breast cancer progression, contributes to metabolic regulation by controlling glycolytic flux and cellular senescence. Through promotion of p21 and cellular senescence, SIM2s decreases glycolytic enzyme activity and promotes oxidative phosphorylation in breast cancer. These, coupled with increased autophagy and ROS, inhibit tumor growth and metastasis. We use microarrays to detail the global gene programming changes that occur with loss of SIM2s gene expression. Scrambled and SIM2si cells were grown in triplicate for RNA extraction and hybridization on Amersham microarrays.
Project description:This SuperSeries is composed of the following subset Series: GSE41194: Differentially Expressed Genes Regulating the Progression of Ductal Carcinoma In Situ to Invasive Breast Cancer (Group 1) GSE41196: Differentially Expressed Genes Regulating the Progression of Ductal Carcinoma In Situ to Invasive Breast Cancer (Group 2) GSE41197: Differentially Expressed Genes Regulating the Progression of Ductal Carcinoma In Situ to Invasive Breast Cancer (Group 3) GSE41198: Differentially Expressed Genes Regulating the Progression of Ductal Carcinoma In Situ to Invasive Breast Cancer (Group 4 stroma) GSE41227: Differentially Expressed Genes Regulating the Progression of Ductal Carcinoma In Situ to Invasive Breast Cancer (Group 4 Epithelial) Refer to individual Series
Project description:<p>Metabolic reprogramming is a hallmark of cancer and is crucial for cancer progression, making it an attractive therapeutic target. Understanding the role of metabolic reprogramming in cancer initiation could help identify prevention strategies. To address this, we investigated metabolism during acinar-to-ductal metaplasia (ADM), the first step of pancreatic carcinogenesis. Glycolytic markers were elevated in ADM lesions compared to normal tissue from human samples. Comprehensive metabolic assessment in three mouse models with pancreas-specific activation of KRAS, PI3K or MEK1 using Seahorse measurements, NMR metabolome analysis, mass spectrometry, isotope tracing and RNA-seq analysis revealed a switch from oxidative phosphorylation to glycolysis in ADM. Blocking the metabolic switch attenuated ADM formation. Furthermore, mitochondrial metabolism was required for de novo synthesis of serine and glutathione but not for ATP production. MYC mediated the increase in GSH intermediates in ADM, and inhibition of GSH synthesis suppressed ADM development. This study thus identifies metabolic changes and vulnerabilities in the early stages of pancreatic carcinogenesis.</p>
Project description:Metabolism is tightly coupled with the process of aging, and tumorigenesis. However, the mechanisms regulating metabolic properties in different contexts remain unclear. Cellular senescence is widely recognized as an important tumor suppressor function and accompanies metabolic remodeling characterized by increased mitochondrial oxidative phosphorylation (OXPHOS). Here we showed retinoblastoma (RB) is required for the increased OXPHOS in oncogene-induced senescent (OIS) cells. Combined metabolic and gene expression profiling revealed that RB mediated activation of the glycolytic pathway in OIS cells, causing upregulation of several glycolytic genes and concomitant increases in the levels of associated metabolites in the glycolytic pathway. Knockdown of these genes by small interfering RNAs (siRNAs) resulted in decreased mitochondrial respiration, suggesting that RB-mediated glycolytic gene activation promotes metabolic flux into the OXPHOS pathway. These results suggest that coordinate transcriptional activation of metabolic genes by RB enables OIS cells to maintain metabolically bivalent states that both glycolysis and OXPHOS are highly active. Collectively, our findings demonstrated a previously unrecognized function of RB in OIS cells. To understand the role of RB, we investigated the effect of RB1-knockdown in the transcription profile of oncogene-induced senescent (OIS) cells. IMR90 ER:Ras cells were treated with 100 nM 4-OHT for 6 days to induce senescence. RNA was isolated 6 days after OHT treatment and hybridized to Affymetrix microarrays. SiRNA transfection (control siRNA or siRB1) was performed 4 days before RNA isolation.
Project description:Many cancers rely on glycolytic metabolism to fuel rapid proliferation. This has spurred interest in designing drugs that target tumor glycolysis such as AZD3965, a small molecule inhibitor of Monocarboxylate Transporter 1 (MCT1) currently undergoing Phase I evaluation for cancer treatment. Since MCT1 mediates proton-linked transport of monocarboxylates such as lactate and pyruvate across the plasma membrane (Halestrap and Meredith, 2004), AZD3965 is thought to block tumor growth through disruption of lactate transport and glycolysis. Here we show that MCT1 inhibition impairs proliferation of glycolytic breast cancer cells that express MCT4 via disruption of pyruvate rather than lactate export. We found that MCT1 expression is elevated in glycolytic breast tumors and cell lines as well as in malignant breast and lung tissues. High MCT1 expression predicts poor prognosis in breast and lung cancer patients. Stable knockdown and AZD3965-mediated inhibition of MCT1 promote oxidative metabolism. Acute inhibition of MCT1 reduces pyruvate export rate but does not consistently alter lactate transport or glycolytic flux in breast cancer cells that also express MCT4. Despite the lack of glycolysis impairment, MCT1 loss-of-function decreases breast cancer cell proliferation and blocks growth of mammary fat pad xenograft tumors. Our data suggest that MCT1 expression is elevated in glycolytic cancers to promote pyruvate export, which when inhibited enhances oxidative metabolism and reduces proliferation. This study presents an alternative molecular consequence of MCT1 inhibitors that further supports their use as anti-cancer therapeutics. Since MCT1 levels are elevated in glycolytic and malignant breast tumors, we hypothesized that MCT1 may contribute to the Warburg effect metabolic phenotype. To test this hypothesis, we generated whole genome microarray data from breast cancer cell lines either a) expressing a short hairpin (sh)RNA-mediated stable knockdown of MCT1; or b) treated for 24 hours with an MCT1 inhibitor (AZD3965). Scramble shRNA or DMSO were used as controls, and all conditions were analzed in triplicate. The cell lines used â HS578T, SUM149PT, and SUM159PT â are among the most glycolytic in a panel of 31 breast cancer cell lines.
Project description:Overcoming cellular growth restriction, including the evasion of cellular senescence, is a hallmark of cancer. We report that PAK4 is overexpressed in all human breast cancer subtypes and associated with poor patient outcome. In mice, MMTV-PAK4 overexpression promotes spontaneous mammary cancer, while PAK4 gene depletion delays MMTV-PyMT driven tumors. Importantly, PAK4 prevents senescence-like growth arrest in breast cancer cells in vitro, in vivo and ex vivo, but is not needed in non-immortalized cells, while PAK4 overexpression in untransformed human mammary epithelial cells abrogates H-Ras-V12-induced senescence. Mechanistically, a PAK4 – RELB - C/EBPa axis controls the senescence-like growth arrest and a PAK4 phosphorylation residue (RELB-Se151) is critical for RELB-DNA interaction, transcriptional activity and expression of the senescence regulator C/EBPa. These findings establish PAK4 as a promoter of breast cancer that can overcome oncogene-induced senescence and reveal a selective vulnerability of cancer to PAK4 inhibition.
Project description:Metabolic reprogramming is a hallmark of cancer. Herein we discover that the key glycolytic enzyme pyruvate kinase M2 isoform (PKM2), but not the related isoform PKM1, is methylated by co-activator-associated arginine methyltransferase 1 (CARM1). PKM2 methylation reversibly shifts the balance of metabolism from oxidative phosphorylation to aerobic glycolysis in breast cancer cells. Oxidative phosphorylation depends on mitochondrial calcium concentration, which becomes critical for cancer cell survival when PKM2 methylation is blocked. By interacting with and suppressing the expression of inositol-1,4,5-trisphosphate receptors (InsP3Rs), methylated PKM2 inhibits the influx of calcium from the endoplasmic reticulum to mitochondria. Inhibiting PKM2 methylation with a competitive peptide delivered by nanoparticles perturbs the metabolic energy balance in cancer cells, leading to a decrease in cell proliferation, migration and metastasis. Collectively, the CARM1-PKM2 axis serves as a metabolic reprogramming mechanism in tumorigenesis, and inhibiting PKM2 methylation generates metabolic vulnerability to InsP3R-dependent mitochondrial functions.
Project description:The progression of noninvasive ductal carcinoma in situ to invasive ductal carcinoma for patients with breast cancer results in a significantly poorer prognosis and is the precursor to metastatic disease. In this work, we have identified insulin-like growth factor–binding protein 2 (IGFBP2) as a potent adipocrine factor secreted by healthy breast adipocytes that acts as a barrier against invasive progression. In line with this role, adipocytes differentiated from patient-derived stromal cells were found to secrete IGFBP2, which significantly inhibited breast cancer invasion. This occurred through binding and sequestration of cancer-derived IGF-II. Moreover, depletion of IGF-II in invading cancer cells using small interfering RNAs or an IGF-II–neutralizing antibody ablated breast cancer invasion, highlighting the importance of IGF-II autocrine signaling for breast cancer invasive progression. Given the abundance of adipocytes in the healthy breast, this work exposes the important role they play in suppressing cancer progression and may help expound upon the link between increased mammary density and poorer prognosis.
Project description:Compared transccriptome of breast cancer in young women to those arising in two mature groups to characterize the underlying biological mechanisms of the breast cancer in Middle Eastern young women. Also, compared the gene expression profile characteristic of the sequential disease stages (ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC)) of breast cancer to elucidate the molecular mechanisms of breast cancer progression in young women. Analyzed the whole-genome mRNA expression profile from tumor (n=73) and adjacent disease free tissues (n=36) using Affymetrix GeneChip Human Genome U133 Plus 2.0 Arrays.