Project description:Mutations in KRAS occur in a variety of tumors of epithelial origin, driving the oncogenic phenotype.The NF-kB transcription factor pathway is important for oncogenic RAS to transform cells and to drive tumorigenesis in animal models. Recently TAK1, an upstream regulator of IKK which controls canonical NF-kB, was shown to be important for chemoresistance in pancreatic cancer and for regulating KRAS+ colorectal cancer cell growth and survival. Here we show that GSK-3alpha is upregulated by KRAS leading to interaction with TAK1 to stabilize the TAK1/TAB complex to promote IKK activity. Additionally, GSK-3alpha is required for promoting critical non-canonical NF-kB signaling in pancreatic cancer cells. Pharmacologic inhibition of GSK-3 suppresses growth of human pancreatic tumor explants, consistent with loss of expression of genes such as c-myc and TERT. These data identify GSK-3alpha as a key downstream effector of oncogenic RAS via its ability to coordinately regulate distinct NF-kB signaling pathways GSK-3 inhibition at 2 and 8 hours
Project description:Mouse muscle stem cells, defined as Pax7+ satellite cells, can initiate rhabdomyosarcoma when transformed by oncogenic Kras and concomitant loss of p53. Mouse Pax7+ satellite cells were transformed in vitro and in vivo utilizing the Cre-ER/loxp system. We wanted to address two major questions: do the in vitro and in vivo tumors cluster together compared to another mouse to another mouse derived soft-tissue sarcoma AND which human soft-tissue sarcoma do the in vivo derived tumors resemble transcriptionally? Therefore, tumors from cells transformed in vitro and tumors from mice that restrict the oncogenic lesions to Pax7+ satellite cells in vivo were compared to answer these two questions.
Project description:Long noncoding RNAs play important roles in the spatial and temporal regulation of muscle development and regeneration. Nevertheless, the determination of their biological functions and mechanisms underlying muscle satellite cell differentiation remains challenging. Here, we identified a novel lncRNA named lncMREF as a specific positive regulator of muscle regeneration in mice, pigs and humans. Functional studies demonstrated that lncMREF is significantly upregulated in activated skeletal muscle satellite cells and promotes myogenic differentiation and muscle regeneration. Mechanistically, lncMREF interacts with Smarca5 to promote chromatin remodeling and accessibility when muscle satellite cells are activated, thereby facilitating genomic binding of p300/H3K27 to upregulate the expression of myogenic regulators, such as MyoD and cell differentiation. Our results unravel a new temporal-specific epigenetic regulation during muscle regeneration and reveal that lncMREF/Smarca5-mediated epigenetic programming is responsible for muscle satellite cell differentiation, which provides new insights into the regulatory mechanism of muscle regeneration in adult animals.
Project description:Long noncoding RNAs play important roles in the spatial and temporal regulation of muscle development and regeneration. Nevertheless, the determination of their biological functions and mechanisms underlying muscle satellite cell differentiation remains challenging. Here, we identified a novel lncRNA named lncMREF as a specific positive regulator of muscle regeneration in mice, pigs and humans. Functional studies demonstrated that lncMREF is significantly upregulated in activated skeletal muscle satellite cells and promotes myogenic differentiation and muscle regeneration. Mechanistically, lncMREF interacts with Smarca5 to promote chromatin remodeling and accessibility when muscle satellite cells are activated, thereby facilitating genomic binding of p300/H3K27 to upregulate the expression of myogenic regulators, such as MyoD and cell differentiation. Our results unravel a new temporal-specific epigenetic regulation during muscle regeneration and reveal that lncMREF/Smarca5-mediated epigenetic programming is responsible for muscle satellite cell differentiation, which provides new insights into the regulatory mechanism of muscle regeneration in adult animals.
Project description:Long noncoding RNAs play important roles in the spatial and temporal regulation of muscle development and regeneration. Nevertheless, the determination of their biological functions and mechanisms underlying muscle satellite cell differentiation remains challenging. Here, we identified a novel lncRNA named lncMREF as a specific positive regulator of muscle regeneration in mice, pigs and humans. Functional studies demonstrated that lncMREF is significantly upregulated in activated skeletal muscle satellite cells and promotes myogenic differentiation and muscle regeneration. Mechanistically, lncMREF interacts with Smarca5 to promote chromatin remodeling and accessibility when muscle satellite cells are activated, thereby facilitating genomic binding of p300/H3K27 to upregulate the expression of myogenic regulators, such as MyoD and cell differentiation. Our results unravel a new temporal-specific epigenetic regulation during muscle regeneration and reveal that lncMREF/Smarca5-mediated epigenetic programming is responsible for muscle satellite cell differentiation, which provides new insights into the regulatory mechanism of muscle regeneration in adult animals.
Project description:The canonical NF-κB pathway is active in 70% of all pancreatic cancer cases and NF-κB Essential Modulator (NEMO) is essential for the activation of this pathway. In our study, we used KC mice, which express the oncogenic KRAS and develop precancerous lesions termed Pancreatic Intraepithelial Neoplasias (PanINs), and KNeC mice, which express the oncogenic KRAS and have NEMO deleted in their pancreatic cells. These mice were injected with cerulein to promote the development of pancreatitis (cerulein dosage= 50μg/kg). Cerulein was injected at 8 hourly intervals for 2 days in total. The first injection day was when mice reached their sixth week of age and the second injection day was 3 days after the first injection day. Both KC and KNeC mice developed PanINs. At the age of 10 months, pancreata of KC and KNeC mice were analyzed. Using laser capture microdissection, PanINs from both groups were excised and their transcriptome was analyzed though RNA-seq.
Project description:Transcriptional deregulation of oncogenic pathways is a hallmark of cancer, and can be due to epigenetic alterations. 5-hydroxymethylcytosine is a recently discovered epigenetic modification that has not been studied in pancreatic cancer. Genome-wide analysis of 5-hmC enriched loci was conducted in low-passage pancreatic cancer cell lines and primary patient-derived xenografts and revealed strikingly altered patterns in neoplastic tissues. Differentially hydroxymethylated regions preferentially affected regulatory regions of the genome, specifically overlapping with H3K4me1 enhancers. Gain of 5-hmC was correlated with upregulation of the cognate transcripts, including many oncogenic pathways implicated in pancreatic neoplasia. Specifically, BRD4 was overexpressed and acquired 5hmC at enhancer regions in majority of neoplastic samples. Functionally, acquisition of 5hmC at BRD4 promoter regulated increase in transcript expression. Furthermore, blockade of BRD4 inhibited pancreatic cancer growth in vivo. In summary, redistribution of 5-hmC and preferential enrichment at oncogenic enhancers is a novel regulatory mechanism in human cancer. Genome-wide analysis of 5-hmC enriched loci was conducted in low-passage pancreatic cancer cell lines and primary patient-derived xenografts
Project description:Herein, we describe the landscape of m6A on super enhancer RNAs (seRNAs) in pancreatic ductal adenocarcinoma (PDAC) and demonstrate a regulatory axis involving m6A-seRNAs, H3K4me3 modification, chromatin accessibility and oncogenic transcription. our study has revealed the CFL1-YTHDC2-MLL1 epigenetic regulatory axis plays critical roles of dynamic m6A deposition in seRNAs and local chromatin state, which may be a novel oncogenic mechanism in PDAC and shed light on the crosstalk between epitranscriptome and epigenome.
Project description:Herein, we describe the landscape of m6A on super enhancer RNAs (seRNAs) in pancreatic ductal adenocarcinoma (PDAC) and demonstrate a regulatory axis involving m6A-seRNAs, H3K4me3 modification, chromatin accessibility and oncogenic transcription. our study has revealed the CFL1-YTHDC2-MLL1 epigenetic regulatory axis plays critical roles of dynamic m6A deposition in seRNAs and local chromatin state, which may be a novel oncogenic mechanism in PDAC and shed light on the crosstalk between epitranscriptome and epigenome.