Project description:In our investigations of the molecular pathways of prostate tumorigenesis in Nkx3.1; Pten mutant mice using gene expression profiling, we now find that the AP-1 transcription factors, c-Jun and c-Fos, are significantly up-regulated during cancer progression. Forced expression of c-Fos and c-Jun in prostate cancer cells results in increased tumorigenicity, activation of Erk MAP kinase, and enhanced survival in the absence of androgens, which are hallmarks of disease progression. In humans, Jun and Fos proteins are significantly up-regulated during prostate cancer progression and significantly correlated with activation of Erk MAP kinase. Most notably, expression of Jun is associated with disease recurrence independent of other currently used prognostic indicators. These analyses reveal a hitherto unappreciated role for AP-1 transcription factors in prostate cancer progression vis-à-vis Erk MAP kinase signaling, as well as the identification of a novel marker of disease recurrence, namely c-Jun. Keywords: Stages of Prostate Cancer
Project description:In our investigations of the molecular pathways of prostate tumorigenesis in Nkx3.1; Pten mutant mice using gene expression profiling, we now find that the AP-1 transcription factors, c-Jun and c-Fos, are significantly up-regulated during cancer progression. Forced expression of c-Fos and c-Jun in prostate cancer cells results in increased tumorigenicity, activation of Erk MAP kinase, and enhanced survival in the absence of androgens, which are hallmarks of disease progression. In humans, Jun and Fos proteins are significantly up-regulated during prostate cancer progression and significantly correlated with activation of Erk MAP kinase. Most notably, expression of Jun is associated with disease recurrence independent of other currently used prognostic indicators. These analyses reveal a hitherto unappreciated role for AP-1 transcription factors in prostate cancer progression vis-à -vis Erk MAP kinase signaling, as well as the identification of a novel marker of disease recurrence, namely c-Jun. Experiment Overall Design: Mouse prostate was collected from wild-type or the Nkx3.1; Pten compound mutant mice at the age of 8-16 months. One lobe of dosolateral prostate was snap-frozen in OCT and stored at -80ºC for laser capture microdissection (LCM). To obtain androgen-independent lesions, mice were castrated at 7 to 14 months of age. Mice were sacrificed for analysis at 8 to 16 months of age and one dosolateral prostatic lobe was snap-frozen in OCT and stored at -80ºC for LCM. Approximate 1000 Prostate epithelial cells were isolated from normal prostate, dysplasia, prostatic intraepithelial neoplasia (PIN) or cancer lesions using PixCell IIE LCM system (Arcturus), followed by RNA linear amplification and labeling using Small Sample Labeling Protocol VII (Affymetrix). Samples were labeled using a BioArray High Yield RNA transcript labeling kit (Enzo Life Scientific) and were hybridized to MOE430A GeneChips containing 22,690 well characterized mouse genes/ESTs (Affymetrix).
Project description:Expression and function of the oncogenic transcription factor AP-1 (mainly composed of Jun and Fos proteins) is required for neoplastic transformation of mouse and human keratinocytes in vitro and tumor promotion as well as malignant progression in vivo. Here, we describe the identification of novel Fos target genes using global gene expression profiling with samples from a tumor model of mouse skin (K5-SOS-F). We could identify 366 differentially expressed genes comparing expression profiles from tumor samples of control animals with samples derived form mice with a specific deletion of fos in keratinocytes. Keywords: Fos-deletion, Fos-floxed, K5-SOS-F mouse tumor model, skin papilloma, global gene expression, microarray, Fos target in skin carcinogenesis
Project description:FOS, a subunit of the activator protein-1 (AP-1) transcription factor, has been implicated in various cellular changes. In the human ovary, the expression of FOS and its heterodimeric binding partners JUN, JUNB, and JUND increases in periovulatory follicles. However, the specific role of the FOS/AP-1 remains elusive. The present study determined the regulatory mechanisms driving the expression of FOS and its partners and functions of the FOS/AP-1 using primary human granulosa/lutein cells (hGLC). hCG induced a biphasic increase in the expression of FOS, peaking at 1-3h and 12h. The levels of JUN proteins were also increased by hCG, with varying expression patterns. Co-immunoprecipitation analyses revealed that FOS is present as heterodimers with all JUN proteins. hCG immediately activated PKA and p42/44MAPK signaling pathways, and inhibitors for these pathways abolished hCG-induced increases in the levels of FOS, JUN, and JUNB. To identify the genes regulated by FOS, high throughput RNA sequencing was performed using hGLC treated with hCG ± T-5224 (FOS inhibitor). Sequencing data analysis revealed that FOS inhibition affects the expression of numerous genes, including a cluster of genes involved in the periovulatory process such as matrix remodeling, prostaglandin synthesis, glycolysis/gluconeogenesis, and cholesterol biosynthesis. qPCR analysis verified hCG-induced, T-5224-regulated expression of a selection of these genes. Consistently, T-5224 attenuated hCG-induced increases in metabolic activities and cholesterol levels. This study unveiled potential downstream target genes of and a role for the FOS/AP-1 in granulosa cell metabolic changes and cholesterol biosynthesis in human periovulatory follicles.
Project description:Proto-oncogene c-Fos is a leucine-zipper containing transcription factor which has a DNA binding domain and a transactivation domain. Fos dimerizes with another transcription factor Jun to form AP1 transcription factor. The AP-1 complex has been implicated in transformation and progression of cancer. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Map binding sites of transcription factor Fos in the genome of K562 cells. The K562 input data has been deposited in GEO as GSM325934.
Project description:Proto-oncogene c-jun is a leucine-zipper containing transcription factor which has a DNA binding domain and a transactivation domain. Jun dimerizes with another transcription factor Fos to form AP1 transcription factor. The AP-1 complex has been implicated in transformation and progression of cancer. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Map binding sites of transcription factor Jun in the genome of K562 cells. The K562 input data has been deposited in GEO as GSM325934.
Project description:Systemic hypertension increases cardiac workload and subsequently induces signaling networks in heart that underlie myocyte growth (hypertrophic response) through expansion of sarcomeres with the aim to increase contractility. However, conditions of increased workload can induce both adaptive and maladaptive growth of heart muscle. Previous studies implicate two members of the AP-1 transcription factor family, junD and fra-1, in regulation of heart growth during hypertrophic response. In this study, we investigate the function of the AP-1 transcription factors, c-jun and c-fos, in heart growth. Using pressure overload-induced cardiac hypertrophy in mice and targeted deletion of Jun or Fos in cardiomyocytes, we show that c-jun is required for adaptive cardiac hyphertrophy, while c-fos is dispensable in this context. c-jun promotes expression of sarcomere proteins and suppresses expression of extracellular matrix proteins. Capacity of cardiac muscle to contract depends on organization of principal thick and thin filaments, myosin and actin, within the sarcomere. In line with decreased expression of sarcomere-associated proteins, Jun-deficient cardiomyocytes present disarrangement of filaments in sarcomeres and actin cytoskeleton disorganization. Moreover, Jun-deficient hearts subjected to pressure overload display pronounced fibrosis and increased myocyte apoptosis finally resulting in dilated cardiomyopathy. In conclusion, c-jun but not c-fos is required to induce a transcriptional program aimed at adapting heart growth upon increased workload. Microarrays were used to identify specific genes that might be globally affected in the absence of c-jun in cardiomyocytes. Total RNA was extracted from the hearts of 10 weeks old Junf/f (n=2) and Jun delta mu (n=2) mice using TRIzol Reagent.
Project description:Ikaros family transcription factors regulate lymphocyte biology and are targets of the immunomodulatory imide drugs (IMiDs) for hematological malignancies. Ikaros (Ikzf1/IKZF1) is the most broadly expressed family member in lymphocytes, yet its role in innate lymphopoiesis is unknown. Here we used gene inactivation to reveal that NK cell-expression of Ikaros is essential for normal NK lymphopoiesis. Mechanistically, IKZF1 directly repressed Cish and Socs2, known negative regulators of IL-15R resulting in impaired IL-15 signaling in Ikzf1-null NK cells. Bcl2l11/BIM levels and apoptosis were increased in Ikzf1-null NK cells which in part accounted for the NK lymphopenia since both apoptosis and NK cell frequency were restored to normal levels when Ikzf1 and Bcl2l11 were co-deleted. Ikzf1-null NK cells presented extensive transcriptional alterations with a striking reduction in expression of genes encoding AP-1 transcriptional complexes (Fos/Jun members) and a compensatory increase in Ikzf2 and Ikzf3. Both IKZF1 and IKZF3 directly bound AP-1 family members and deletion of both Ikzf1 and Ikzf3 in NK cells resulted in a further reduction in Jun/Fos expression and a complete loss of peripheral NK cells in mice. Consistently, IKZF1 bound Jun/Fos genes at the same locations in activated B cells identifying a novel and conserved role for IKZF1 in Jun/Fos regulation. Collectively we show the Ikaros-family are novel regulators of apoptosis, cytokine responsiveness and AP-1 transcriptional activity required for NK cell development and function.
Project description:Ikaros family transcription factors regulate lymphocyte biology and are targets of the immunomodulatory imide drugs (IMiDs) for hematological malignancies. Ikaros (Ikzf1/IKZF1) is the most broadly expressed family member in lymphocytes, yet its role in innate lymphopoiesis is unknown. Here we used gene inactivation to reveal that NK cell-expression of Ikaros is essential for normal NK lymphopoiesis. Mechanistically, IKZF1 directly repressed Cish and Socs2, known negative regulators of IL-15R resulting in impaired IL-15 signaling in Ikzf1-null NK cells. Bcl2l11/BIM levels and apoptosis were increased in Ikzf1-null NK cells which in part accounted for the NK lymphopenia since both apoptosis and NK cell frequency were restored to normal levels when Ikzf1 and Bcl2l11 were co-deleted. Ikzf1-null NK cells presented extensive transcriptional alterations with a striking reduction in expression of genes encoding AP-1 transcriptional complexes (Fos/Jun members) and a compensatory increase in Ikzf2 and Ikzf3. Both IKZF1 and IKZF3 directly bound AP-1 family members and deletion of both Ikzf1 and Ikzf3 in NK cells resulted in a further reduction in Jun/Fos expression and a complete loss of peripheral NK cells in mice. Consistently, IKZF1 bound Jun/Fos genes at the same locations in activated B cells identifying a novel and conserved role for IKZF1 in Jun/Fos regulation. Collectively we show the Ikaros-family are novel regulators of apoptosis, cytokine responsiveness and AP-1 transcriptional activity required for NK cell development and function.
Project description:Ikaros family transcription factors regulate lymphocyte biology and are targets of the immunomodulatory imide drugs (IMiDs) for hematological malignancies. Ikaros (Ikzf1/IKZF1) is the most broadly expressed family member in lymphocytes, yet its role in innate lymphopoiesis is unknown. Here we used gene inactivation to reveal that NK cell-expression of Ikaros is essential for normal NK lymphopoiesis. Mechanistically, IKZF1 directly repressed Cish and Socs2, known negative regulators of IL-15R resulting in impaired IL-15 signaling in Ikzf1-null NK cells. Bcl2l11/BIM levels and apoptosis were increased in Ikzf1-null NK cells which in part accounted for the NK lymphopenia since both apoptosis and NK cell frequency were restored to normal levels when Ikzf1 and Bcl2l11 were co-deleted. Ikzf1-null NK cells presented extensive transcriptional alterations with a striking reduction in expression of genes encoding AP-1 transcriptional complexes (Fos/Jun members) and a compensatory increase in Ikzf2 and Ikzf3. Both IKZF1 and IKZF3 directly bound AP-1 family members and deletion of both Ikzf1 and Ikzf3 in NK cells resulted in a further reduction in Jun/Fos expression and a complete loss of peripheral NK cells in mice. Consistently, IKZF1 bound Jun/Fos genes at the same locations in activated B cells identifying a novel and conserved role for IKZF1 in Jun/Fos regulation. Collectively we show the Ikaros-family are novel regulators of apoptosis, cytokine responsiveness and AP-1 transcriptional activity required for NK cell development and function.