Previous reports have shown low vitamin D serum levels and polymorphisms in the vitamin D receptor (VDR) to be associated with increased risk for TB. Given that 1,25-dihydroxyvitamin D3 has a role in lipid metabolism control, we tested whether the link between 1,25-dihydroxyvitamin D3 and tuberculosis involves macrophage lipid metabolism. Since formation of lipid droplets (LD) is a hallmark of lipid dysregulation in M. tuberculosis-infected macrophages, we measured LD content as a readout of altered lipid metabolism in infected THP-1 cells. Induction of LD, which peaked by 24 hours post-infection was prevented by addition of 1,25-dihydroxyvitamin D3 at the time of infection. To investigate the mechanism of 1,25-dihydroxyvitamin D3 modulation of LD formation, we analyzed the transcriptome of M. tuberculosis-infected THP-1 cells with and without 1,25-dihydroxyvitamin D3 treatment.
Cutting edge: Vitamin D regulates lipid metabolism in Mycobacterium tuberculosis infection.
Cell line, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Loss of <i>FAM46C</i> Promotes Cell Survival in Myeloma.
Specimen part, Cell line
View SamplesFAM46C is one of the most recurrently mutated genes in multiple myeloma (MM), however its role in disease pathogenesis is not determined. Here we demonstrate that wild type (WT) FAM46C overexpression induces substantial cytotoxicity in MM cells. In contrast, FAM46C mutations found in MM patients abrogate this cytotoxicity indicating a MM survival advantage conferred by the FAM46C mutant phenotype. WT FAM46C overexpression downregulated IRF4, CEBPB, MYC and upregulated immunoglobulin (Ig) light chain and HSPA5/BIP. Furthermore, pathway analysis suggests that enforced FAM46C expression activates the unfolded protein response (UPR) pathway and induces mitochondrial dysfunction. In contrast, endogenous CRISPR FAM46C depletion enhanced MM cell growth and notably decreasing Ig light chain and BIP expression, activating of ERK and anti-apoptotic signaling and conferring relative resistance to dexamethasone and lenalidomide treatment. The genes altered in FAM46C depleted cells are enriched for signaling pathways regulating estrogen, glucocorticoid, B cell receptor signaling and ATM signaling. Together these results implicate FAM46C in myeloma cell growth and survival. FAM46C mutation contributes to myeloma pathogenesis and disease progression by perturbation in plasma cell differentiation and endoplasmic reticulum homeostasis.
Loss of <i>FAM46C</i> Promotes Cell Survival in Myeloma.
Specimen part, Cell line
View SamplesAutophagy genes play an important role in the T cell activation and proliferation. We examined the role of ATG7 during the process of CD8 T cell memory formation. In the absence of ATG7, antigen-specific CD8 T cells failed to survive past the contraction phase and failed to give rise to memory cells.
Autophagy is essential for effector CD8(+) T cell survival and memory formation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cereblon expression is required for the antimyeloma activity of lenalidomide and pomalidomide.
Cell line
View SamplesThe precise molecular mechanism of action and targets through which thalidomide and related immunomodulatory drugs (IMiDs) exert their anti-tumor effects remains unclear. We investigated the role of cereblon (CRBN), a primary teratogenic target of thalidomide, in the anti-myeloma activity of IMiDs. CRBN depletion is initially cytotoxic to human myeloma cells but surviving cells with stable CRBN depletion become highly resistant to both lenalidomide and pomalidomide, but not to the unrelated drugs bortezomib, dexamethasone and melphalan. Acquired deletion of CRBN was found to be the primary genetic event differentiating isogenic MM1.S cell lines cultured to be sensitive or resistant to lenalidomide and pomalidomide. Gene expression changes induced by lenalidomide were dramatically suppressed in the presence of CRBN depletion further demonstrating that CRBN is required for lenalidomide activity. Downstream targets of CRBN include interferon regulatory factor 4 (IRF4) previously reported to also be a target of lenalidomide. Patients exposed to and putatively resistant to lenalidomide had lower CRBN levels in paired samples before and after therapy. In summary, CRBN is an essential requirement for IMiD activity, and a possible biomarker for the clinical assessment of anti-myeloma efficacy.
Cereblon expression is required for the antimyeloma activity of lenalidomide and pomalidomide.
Cell line
View SamplesType-I (/) and -II () interferons (IFN), through an incompletely understood combination of redundant and unique mechanisms, are essential for host resistance to viral infection. We report a requirement for the Atg5-Atg12/Atg16L1 autophagosome elongation complex in IFN-mediated control of murine norovirus in macrophages. We use microarrays to compare transcriptional changes induced in control and Atg5 deficient macrophages by IFN treatment.
Nondegradative role of Atg5-Atg12/ Atg16L1 autophagy protein complex in antiviral activity of interferon gamma.
Treatment
View SamplesCD70TG mice are a model for sterile chronic immune activation and develop Anemia of Inflammation, which is dependent on the production of Ifng by effector CD4 and CD8 T cells.
Chronic IFN-γ production in mice induces anemia by reducing erythrocyte life span and inhibiting erythropoiesis through an IRF-1/PU.1 axis.
Specimen part
View SamplesThe overarching goal of this study was to explore the antitumor activity of Z-endoxifen, a tamoxifen metabolite, with first-line endocrine therapies tamoxifen and letrozole in the letrozole-sensitive MCF7 aromatase expressing model (MCF7AC1), and with second-line endocrine therapies including tamoxifen, fulvestrant, exemestane, and exemestane plus everolimus, in letrozole-resistant MCF7 model (MCF7LR) in vivo.
Antitumor activity of Z-endoxifen in aromatase inhibitor-sensitive and aromatase inhibitor-resistant estrogen receptor-positive breast cancer.
Cell line, Treatment
View SamplesAberrant biliary hyperproliferation resulting from lack of differentiating signals favoring the maintenance of an immature and proliferative phenotype by biliary epithelial cells are ultimately responsible for ducto/cystogenesis and intrahepatic cholangiocarcinoma (CCA) formation. Mitogen-activated protein kinase (MAPK) signaling is pivotal for CCA-related tumorigenesis. In particular, targeted inhibition of JNK signaling has shown therapeutic potential. However, the cell-type specific role and mechanisms triggered by JNK in liver parenchymal cells during CCA remains largely unknown. Here, we aimed to investigate the relevance of JNK function in hepatocytes in experimental carcinogenesis. JNK signaling in hepatocytes was inhibited by crossing AlbCre-JNK1LoxP/LoxP mice with JNK2-deficient mice to generate Jnk1LoxP/LoxP/Jnk2−/− (JNKΔhepa) mice. JNKΔhepa mice were further interbred with hepatocyte-specific Nemo-knockout mice (NEMOΔhepa), a model of chronic liver inflammation and spontaneous hepatocarcinogenesis, to generate NEMO/JNKΔhepa mice. The impact of JNK deletion on liver damage, cell death, compensatory proliferation, fibrogenesis, and tumor development in NEMOΔhepa mice was determined. Moreover, regulation of essential genes was assessed by RT-PCR, immunoblottings and immunostains. Additionally, JNK2 inhibition, specifically in hepatocytes of NEMOΔhepa/JNK1Δhepa mice, was performed using siRNA (siJnk2) nanodelivery. Finally, active signaling pathways were blocked using specific inhibitors. Compound deletion of JNK1 and JNK2 in hepatocytes diminished hepatocarcinogenesis in both the DEN model of hepatocarcinogenesis and in NEMOΔhepa mice, but, in contrast, caused massive proliferation of the biliary ducts. Indeed, JNK deficiency in hepatocytes of NEMOΔhepa (NEMOΔhepa/JNKΔhepa) animals caused elevated fibrosis, increased apoptosis, increased compensatory proliferation, and elevated inflammatory cytokines expression, but reduced hepatocarcinogenesis. Furthermore, siJnk2 treatment in NEMOΔhepa/JNK1Δhepa mice recapitulated the phenotype of NEMOΔhepa/JNKΔhepa mice. Next, we sought to investigate the impact of molecular pathways in response to compound JNK deficiency in NEMOΔhepa mice. We found that NEMOΔhepa/JNKΔhepa livers exhibited overexpression of the IL-6/Stat3 pathway in addition to EGFR-Raf-MEK-ERK cascade. The functional relevance was tested by administering lapatinib - a dual tyrosine kinase inhibitor (TKI) of ErbB2 and EGFR signaling - to NEMOΔhepa/JNKΔhepa mice. Lapatinib effectively inhibited cystogenesis, improved transaminases and effectively blocked EGFR-Raf-MEK-ERK signaling. Our study defines a novel function of JNK in cell fate as well as hepatocarcinogenesis and opens new therapeutic avenues devised to inhibit pathways of cholangiocarcinogenesis.
Loss of c-Jun N-terminal Kinase 1 and 2 Function in Liver Epithelial Cells Triggers Biliary Hyperproliferation Resembling Cholangiocarcinoma.
Age, Specimen part, Treatment
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