Project description:HERV-K protein Rec functions as RNA transport protein shuttling unspliced viral genomic RNA from the nucleus to the cytoplasm. Rec was found to be expressed in several tumors and transformed cell lines and contributes to cell transformation by inhibiting the transcription factor Promyelocytic Leukemia Zinc Finger Protein
Project description:Sensitivity to Interferon (IFN) is determined by a complex coordination of genetic and environmental factors. A previous experiment using two renal cancer cell lines differing markedly in their response to IFN were analyzed for their ISG profiles in order to determine gene expression changes associated with IFN sensitivity (Holko M, Williams BR. Functional annotation of IFN-alpha-stimulated gene expression profiles from sensitive and resistant renal cell carcinoma cell lines. J Interferon Cytokine Res 2006 Aug;26(8):534-47). Higher and more persistent expression of a subset of ISGs was noted in the IFN-sensitive RCC1 cells when compared with the relatively IFN-insensitive ACHN cells. A subset of Interferon stimulated genes (ISGs) whose sustained expression correlates with heightened IFN sensitivity were analyzed for functional and sequence similarities. This subset predominately contains genes involved in transcription, and most were found to contain in their promoters binding sites for promyleocytic zinc finger factor (PLZF), a transcriptional repressor identified by virtue of its role in the etiology of Acute Promyelocytic Leukemia (APL). Analysis of gene expression in a lymphoid cell line with inducible PLZF expression reveals that increased expression of immune system related genes including ISGs, depends on PLZF expression. Chromatin Immunoprecipitation assays show direct association between PLZF and in silico identified PLZF binding sites in ISG promoters. This study reveals a novel interaction between PLZF and IFN signaling. A time course of IFNa treatment (0, 6, 16, 24 hrs) was performed in tetetracycline induced PLZF overexpressing and control U937T:PLZF45 cells. For the 0 hr time point, PLZF overexpression (Cy5) was compared with control cells (Cy3). For the 6, 16, and 24 hr IFN treated time points, treated RNA was labelled with Cy5 and non-IFN treated RNA with Cy3. Each IFN treatment time point was performed on control and PLZF-overexpressing cells respectively.
Project description:Sensitivity to Interferon (IFN) is determined by a complex coordination of genetic and environmental factors. A previous experiment using two renal cancer cell lines differing markedly in their response to IFN were analyzed for their ISG profiles in order to determine gene expression changes associated with IFN sensitivity (Holko M, Williams BR. Functional annotation of IFN-alpha-stimulated gene expression profiles from sensitive and resistant renal cell carcinoma cell lines. J Interferon Cytokine Res 2006 Aug;26(8):534-47). Higher and more persistent expression of a subset of ISGs was noted in the IFN-sensitive RCC1 cells when compared with the relatively IFN-insensitive ACHN cells. A subset of Interferon stimulated genes (ISGs) whose sustained expression correlates with heightened IFN sensitivity were analyzed for functional and sequence similarities. This subset predominately contains genes involved in transcription, and most were found to contain in their promoters binding sites for promyleocytic zinc finger factor (PLZF), a transcriptional repressor identified by virtue of its role in the etiology of Acute Promyelocytic Leukemia (APL). Analysis of gene expression in a lymphoid cell line with inducible PLZF expression reveals that increased expression of immune system related genes including ISGs, depends on PLZF expression. Chromatin Immunoprecipitation assays show direct association between PLZF and in silico identified PLZF binding sites in ISG promoters. This study reveals a novel interaction between PLZF and IFN signaling.
Project description:Interferon (IFN)-γ is a central regulator of cell-mediated immunity in human health and disease, but reduced expression of the target receptors impairs signaling activity and leads to immunotherapy resistance. Although intracellular expression of IFN-γ restores signaling and downstream functions, we lack tools to activate the IFNG gene instead of cell surface receptors. This work describes the design and characterization of an artificial transcription factor (ATF) protein that recognizes the IFNG gene with six zinc finger domains, which are dovetailed to a VP64 signaling domain that promotes gene transcription and translation. Biological studies with human Jurkat T cells reveal that the ATF treatment induces potent IFN-γ expression and amplifies the gene transcriptome profile for multiple class I HLA alleles and interferon-stimulated genes (ISGs). Biophysical characterization showed the recombinant ATF protein recognizes the human IFNG gene with nanomolar affinity (KD = 5.27 ± 0.3 nM), adopts a protein secondary structure associated with the ββα-fold of zinc finger domains, and is resistant to thermal denaturation. These studies demonstrate that transcriptional targeting of cytokine genes, rather than surface receptors, can activate cytokine expression and show potential for directing immune function.
Project description:Zinc finger protein 32 (ZNF32), is regarded as a transcription factor that regulates gene transcription. But the function of ZNF32 in breast cancer metastasis remains unknown. Here, the MCF-7 was transfected with the pENTER-ZNF32 or empty vector to search the target genes with ChIP-seq.
Project description:Lineage plasticity is a prominent feature of pancreatic ductal adenocarcinoma (PDA) cells, which can occur via deregulation of lineage-specifying transcription factors. Here, we show that the zinc finger protein ZBED2 is aberrantly expressed in PDA and regulates tumor cell identity in this disease. Unexpectedly, our epigenomic experiments reveal that ZBED2 is a sequence-specific transcriptional repressor of interferon-stimulated genes, which occurs through antagonism of Interferon Regulatory Factor 1 (IRF1)-mediated transcriptional activation at co-occupied promoter elements. Consequently, ZBED2 attenuates the transcriptional output and growth arrest phenotypes downstream of interferon signaling in multiple PDA cell line models. We also found that ZBED2 is preferentially expressed in the squamous molecular subtype of human PDA, in association with inferior patient survival outcomes. Consistent with this observation, we show that ZBED2 can repress the pancreatic progenitor transcriptional program, enhance motility, and promote invasion in PDA cells. Collectively, our findings suggest that high ZBED2 expression is acquired during PDA progression to suppress the interferon response pathway and to promote lineage plasticity in this disease.
Project description:Lineage plasticity is a prominent feature of pancreatic ductal adenocarcinoma (PDA) cells, which can occur via deregulation of lineage-specifying transcription factors. Here, we show that the zinc finger protein ZBED2 is aberrantly expressed in PDA and regulates tumor cell identity in this disease. Unexpectedly, our epigenomic experiments reveal that ZBED2 is a sequence-specific transcriptional repressor of interferon-stimulated genes, which occurs through antagonism of Interferon Regulatory Factor 1 (IRF1)-mediated transcriptional activation at co-occupied promoter elements. Consequently, ZBED2 attenuates the transcriptional output and growth arrest phenotypes downstream of interferon signaling in multiple PDA cell line models. We also found that ZBED2 is preferentially expressed in the squamous molecular subtype of human PDA, in association with inferior patient survival outcomes. Consistent with this observation, we show that ZBED2 can repress the pancreatic progenitor transcriptional program, enhance motility, and promote invasion in PDA cells. Collectively, our findings suggest that high ZBED2 expression is acquired during PDA progression to suppress the interferon response pathway and to promote lineage plasticity in this disease.