ERK signaling regulates opposing functions of JUN family transcription factors in prostate cancer cell migration
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ABSTRACT: Knockdowns of c-JUN and JUND had opposite effects on PC3 prostate cell migration. We predicted that c-JUN and JUND control the same set of cell migration genes, but in opposite directions. To test this hypothesis, mRNA with expression changes in c-JUN and JUND knockdown PC3 cell lines were compared to mRNA levels in control (luciferase knockdown) PC3 cells by RNA-seq.
Project description:Knockdowns of c-JUN and JUND had opposite effects on PC3 prostate cell migration. We predicted that c-JUN and JUND control the same set of cell migration genes, but in opposite directions. To test this hypothesis, mRNA with expression changes in c-JUN and JUND knockdown PC3 cell lines were compared to mRNA levels in control (luciferase knockdown) PC3 cells by RNA-seq. mRNA profiles of luciferase knockdown (WT), c-Jun knockdown, and Jun-D knockdown in PC3 cells were generated using deep sequencing, in triplicate, using Illumina HiSeq. Knockdowns were stable shRNA expression from a lentiviral construct selected with puromycin.
Project description:The transcription factor c-JUN and its upstream kinase JNK1 have been implicated in BCR-ABL induced leukemogenesis. JNK1 has been shown to regulate BCL2 expression thereby altering leukemogenesis, but the impact of c-JUN remained unclear. In this study we show that JNK1 and c-JUN promote leukemogenesis via separate pathways, since lack of c-JUN impairs proliferation of p185BCR-ABL transformed cells without affecting viability. The decreased proliferation of c-JunD/D cells is associated with the loss of cyclin dependent kinase 6 (CDK6) expression. In c-JunD/D cells CDK6 expression becomes down-regulated upon BCR-ABL induced transformation which correlates with CpG island methylation within the 5´ region of Cdk6. We verified the impact of Cdk6 deficiency by using Cdk6-/- mice that developed BCR-ABL induced B-lymphoid leukemia with significantly increased latency and an attenuated disease phenotype. In addition we show that re-expression of CDK6 in BCR-ABL transformed c-JunD/D cells reconstitutes proliferation and tumor formation in Nu/Nu mice. In summary, our study reveals a novel function for the AP-1 transcription factor c-JUN in leukemogenesis by antagonizing promoter methylation. Moreover, we identify CDK6 as relevant and critical target of AP-1 regulated DNA methylation upon BCR-ABL induced transformation, thereby accelerating leukemogenesis. Overall, 8 samples consisting of 4 wild type and 4 c-jun knock out samples were hybridized to MoGene-1_0-st-v1 microarrays.
Project description:The transcription factor c-JUN and its upstream kinase JNK1 have been implicated in BCR-ABL induced leukemogenesis. JNK1 has been shown to regulate BCL2 expression thereby altering leukemogenesis, but the impact of c-JUN remained unclear. In this study we show that JNK1 and c-JUN promote leukemogenesis via separate pathways, since lack of c-JUN impairs proliferation of p185BCR-ABL transformed cells without affecting viability. The decreased proliferation of c-JunD/D cells is associated with the loss of cyclin dependent kinase 6 (CDK6) expression. In c-JunD/D cells CDK6 expression becomes down-regulated upon BCR-ABL induced transformation which correlates with CpG island methylation within the 5´ region of Cdk6. We verified the impact of Cdk6 deficiency by using Cdk6-/- mice that developed BCR-ABL induced B-lymphoid leukemia with significantly increased latency and an attenuated disease phenotype. In addition we show that re-expression of CDK6 in BCR-ABL transformed c-JunD/D cells reconstitutes proliferation and tumor formation in Nu/Nu mice. In summary, our study reveals a novel function for the AP-1 transcription factor c-JUN in leukemogenesis by antagonizing promoter methylation. Moreover, we identify CDK6 as relevant and critical target of AP-1 regulated DNA methylation upon BCR-ABL induced transformation, thereby accelerating leukemogenesis.
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:To further dissect whether and how activated JUN reconfigures the chromatin landscape, we performed Chromatin Immunoprecipitation (ChIP)-seq analyses for H3K4me1 and H3K27ac. Based on the significant increase of H3K27ac levels at H3K4me1+ sites, we identified 3,017 JUN-activated enhancers in JUN WT cells. In contrast, JUN AA fails to significantly induce H3K27ac accumulation at these regions. Their enrichment levels at JUN-activated enhancers were significantly decreased after JNKi treatment. Besides, these enhancers are directly driven by JUN, especially phosphorylated JUN.
Project description:Although the c-Jun NH(2)-terminal kinase (JNK) pathway has been implicated in mediating cell growth and transformation, its downstream effectors remain to be identified. Using JNK2 antisense oligonucleotides (JNK2AS), we uncovered previously a role for JNK2 in regulating cell cycle progression and survival of human PC3 prostate carcinoma cells. Here, to identify genes involved in implementing JNK2-mediated effects, we have analyzed global gene expression changes in JNK2-deprived PC3 cells using Serial Analysis of Gene Expression. More than 40,000 tags each were generated from control and PC3-JNK2AS libraries, corresponding to 15,999 and 20,698 unique transcripts, respectively. Transcripts corresponding to transcription factors, stress-induced genes, and apoptosis-related genes were up-regulated in the PC3-JNK2AS library, revealing a significant stress response after the inhibition of JNK2 expression. Genes involved in DNA repair, mRNA turnover, and drug resistance were found to be down-regulated by inhibition of JNK2 expression, further highlighting the importance of JNK2 signaling in regulating cell homeostasis and tumor cell growth. Keywords: other
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.
Project description:To examine the effects of phosphorylated JUN-mediated enhancers activation on gene expression, we conducted RNA-seq analysis in JUN wildtype (WT) or JUN inactive mutant (JUN AA) overexpressed MRC5 cells. The expression levels of genes associated with JUN-activated enhancers are significantly upregulated in JUN WT cells rather than in JUN AA cells. To quantify the effects of JUN inactivation on gene expression, we also performed RNA-seq analysis in JNKi-treated induced CAFs (iCAFs). We observed that JNKi significantly reduced expression levels of JUN-activated enhancers-associated genes.