PPAR is a member of the nuclear receptor family for which agonist ligands have anti-growth effects. However, clinical studies using PPAR ligands as a monotherapy failed to show a beneficial effect. Here we have studied the effects of PPAR activation with chemotherapeutic agents in current use for specific cancers. We observed a striking synergy between rosiglitazone and platinum-based drugs in several different cancers both in vitro and using transplantable and chemically induced spontaneous tumor models. The effect appears to be due in part to PPAR-mediated downregulation of metallothioneins, proteins that have been shown to be involved in resistance to platinum-based therapy. These data strongly suggest combining PPAR agonists and platinum-based drugs for the treatment of certain human cancers
Synergy between PPARgamma ligands and platinum-based drugs in cancer.
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View SamplesPGC1a is a transcriptional coactivator that regulates energy metabolism. PGC1a is highly expressed in a subset of melanoma tumors and cell lines. We generated gene-expression profile of control and PGC1alpha depleted A375P melanoma cells, a melanoma cell line that expresses very high levels of PGC1a to investigate the role of this gene in melanoma.
PGC1α expression defines a subset of human melanoma tumors with increased mitochondrial capacity and resistance to oxidative stress.
Specimen part
View SamplesTo elucidate the mechanisms by which Nrf2 regulates cell growth, we performed global gene expression profiling of A549 lung cancer cells with knockdown of Nrf2. Gene networks associated with carbohydrate metabolism and drug metabolism were significantly downregulated in Nrf2-depleted A549 cells. Gene Set Enrichment Analysis revealed significant enrichment of genes associated with carbohydrate catabolic processes, positive regulation of metabolic processes, PPP, and arachidonic acid metabolism. In summary, this analysis revealed that Nrf2 positively regulates transcription of genes that play key roles in central carbon metabolism.
Transcription factor NRF2 regulates miR-1 and miR-206 to drive tumorigenesis.
Specimen part, Cell line
View SamplesWe examine the potential of Kras as a metabolic target in lung cancer using the KrasLSL-G12D lung cancer model. We demonstrate that mutant Kras drives a lipogenic gene expression program, and that fatty acid synthesis is important in Kras-induced tumorigenesis.
De novo lipogenesis represents a therapeutic target in mutant Kras non-small cell lung cancer.
Specimen part
View SamplesDevelopmental morphogenesis, tissue injury, and oncogenic transformation can cause the detachment of epithelial cells. These cells are eliminated by a specialized form of apoptosis (anoikis). While the processes that contribute to this form of cell death have been studied, the underlying mechanisms remain unclear. Here we tested the role of the cJUN NH2-terminal kinase (JNK) signaling pathway using murine models with compound JNK-deficiency in mammary and kidney epithelial cells. These studies demonstrated that JNK is required for efficient anoikis in vitro and in vivo. Moreover, JNK-promoted anoikis required pro-apoptotic members of the BCL2 family of proteins. We show that JNK acts through a BAK/BAX-dependent apoptotic pathway by increasing BIM expression and phosphorylating BMF leading to death of detached epithelial cells. Overall design: In order to understand the role of the JNK pathway in anoikis, Rosa-CreER (Control) and Jnk1flox/flox Jnk2-/- Rosa-CreER (Jnk1-/-Jnk2-/-) cells were grown as attached monoloayers or suspended for 4 hours. RNA was isolated from these cells and subjected to RNASeq to measure differential gene expression. Three separate samples from each condition were analyzed.
JNK Promotes Epithelial Cell Anoikis by Transcriptional and Post-translational Regulation of BH3-Only Proteins.
Cell line, Subject
View SamplesInvolution returns the lactating mammary gland to a quiescent state after weaning. The mechanism of involution involves collapse of the mammary epithelial cell compartment. To test whether the cJUN NH2-terminal kinase (JNK) signal transduction pathway contributes to involution, we established mice with JNK deficiency in the mammary epithelium. We found that JNK is required for efficient involution. JNK deficiency did not alter the STAT3/5 or SMAD2/3 signaling pathways that have been previously implicated in this process. Nevertheless, JNK promotes the expression of genes that drive involution, including matrix metalloproteases, cathepsins, and BH3-only proteins. These data demonstrate that JNK has a key role in mammary gland involution post lactation. Overall design: WAP-Cre and Jnk1f/f Jnk2f/f WAP-Cre mice were bred for a single pregnancy and litters were normalized to 6-8 pups. The pups were allowed to nurse for 9 days before forced weaning. At that point, some mice were euthanized and their mammary glands were harvested to isolate RNA (0 days). Other mice were kept for 3 days before euthanasia and mammary gland harvest (3d). In this way, gene expression differences could be determined between JNK-null and JNK-wildtype mammary glands before and during involution.
The cJUN NH<sub>2</sub>-terminal kinase (JNK) pathway contributes to mouse mammary gland remodeling during involution.
Specimen part, Cell line, Subject
View SamplesMembers of the JNK pathway have been found to be mutated in human breast cancer. Mouse studies examining JNK loss in different tissues have demonstrated that the JNK pathway can play a role in cancer. Using and autochthonous mouse model, we found that JNK deficiency on a p53-null background resulted in more rapid tumor onset. To learn more about these tumors we generated cells lines and performed various in vitro assays, as well as RNAseq in hope of finding differentially expressed genes that may explain the differences we observed in vivo. Overall design: Tumors were harvested from mice and cells lines were established from them. RNA was isolated from established tumor cell lines.
The cJUN NH<sub>2</sub>-terminal kinase (JNK) signaling pathway promotes genome stability and prevents tumor initiation.
Cell line, Subject
View SamplesRNA-seq was used to evaluate transcriptional changes in alloreactive TCR-Tg CD8 T cells during activation and tolerance induction. CBA mice were exposed to a low dose whole body irradiation and then injected with bone marrow from TCR-Tg KB5 mice to generate synchimeric mice. The KB5 TCR recognizes alloantigens from H2b MHC molecules, specifically Kb, that are expressed by C57BL/6 mice. The injection of bone marrow from KB5 mice into CBA mice enables the development of small and traceable population of TCR-Tg KB5 CD8 T cells. A clonotypic antibody specific for the KB5 TCR allows these cells to be monitored and sorted from the periphery of synchimeric mice by flow cytometry. KB5 CD8 T cells were purified by sorting cells from synchimeric mice under the following conditions: 1) not exposed to alloantigens and in a naïve state, 2) exposed to H2b antigens from C57BL/6 mice to activate the KB5 CD8 T cells, 3) exposed to H2b antigens in the presence of anti-CD154 that blocks costimulatory signals and induces transplantation tolerance, or 4) treated with alloantigens, anti-CD154 and LPS, that induces an inflammatory response and abrogates the induction of tolerance. KB5 CD8 T cells were FACS purified to a level of greater than 95%, RNA was recovered from the purified cells and RNA-seq was performed on triplicate samples from 3 independent experiments. Overall, the analyses revealed expression changes for a number of genes that regulate immune responses and inflammation, cell proliferation and immune cell homing. Overall design: Determine the changes in gene expression profiles that are induced during constimulation blockade.
Cutting Edge: Early Attrition of Memory T Cells during Inflammation and Costimulation Blockade Is Regulated Concurrently by Proapoptotic Proteins Fas and Bim.
Specimen part, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Estrogen Receptor α Promotes Breast Cancer by Reprogramming Choline Metabolism.
Specimen part, Cell line
View SamplesEstrogen receptor (ER) is a key regulator of breast growth and breast cancer development. However, the role of ER in metabolic reprogramming, a hallmark of cancer, is not well documented. In this study, using an integrated approach combining genome-wide mapping of chromatin bound ER with estrogen induced transcript and metabolic profiling, we demonstrate that ER reprograms metabolism upon estrogen stimulation, including changes in aerobic glycolysis, nucleotide and amino acid synthesis, and choline metabolism. We show, for the first time, that the ER target gene choline phosphotransferase 1 (CHPT1) plays an essential role in estrogen induced increases in phosphatidylcholine (PtdCho) levels and that CHPT1 promotes tumorigenesis and proliferation. Furthermore, we show that CHPT1 is overexpressed in tumors compared to normal breast. We also demonstrate that ER promotes aerobic glycolysis through increased expression of glycolytic genes. In conclusion, this study highlights the importance of ER for metabolic alterations in breast cancer cells. Furthermore, overexpression of the ER target CHPT1 in breast cancer supports its potential as a therapeutic target.
Estrogen Receptor α Promotes Breast Cancer by Reprogramming Choline Metabolism.
Specimen part, Cell line
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