Project description:RNA sequencing of HepG2 was performed to explore the molecular basis of microprotein APPLE encoded by LncRNA ASH1L-AS1 in hepatocellular carcinoma (HCC). In order to overexpress microprotein APPLE in HepG2, we constructed the overexpression plasmid containing open reading frame (ORF) of LncRNA ASH1L-AS1.
Project description:Ash1l encodes a histone methyltransferase, a member of the trithorax group proteins, which regulates developmental essential gene expression by catalyzing H3K36 methylation and counteracting polycomb silencing. Accumulating reports suggest the loss-of-function mutants in Ash1l gene are associated with intellectual disability (ID), attention-deficit/hyperactivity (ADHD), autism spectrum disorder (ASD), Tourette syndrome (TS) and multiple congenital anomalies (MCA). We performed transcriptional profiling of dorsal striatum in 1-year-old Ash1l mutant brain via RNA sequencing (RNA-seq). Ash1l haploinsufficiency induces transcription alternation of genes involved in synaptic function and cortical development, implicating the deficits in synapse pruning and behavior in adult mice.
Project description:The histone methyltransferases MLL and ASH1L are trithorax-group proteins that interact genetically through undefined molecular mechanisms to regulate developmental and hematopoietic gene expression. Here we show that the lysine 36-dimethyl mark of histone H3 (H3K36me2) written by ASH1L is preferentially bound in vivo by LEDGF, an MLL-associated protein that co-localizes with MLL, ASH1L and H3K36me2 on chromatin genome wide. Furthermore, ASH1L facilitates recruitment of LEDGF and wild type MLL proteins to chromatin at key leukemia target genes, and is a crucial regulator of MLL-dependent transcription and leukemic transformation. Conversely KDM2A, an H3K36me2 demethylase and Polycomb-group silencing protein, antagonizes MLL-associated leukemogenesis. Our studies illuminate the molecular mechanisms underlying epigenetic interactions wherein placement, interpretation and removal of H3K36me2 contribute to the regulation of gene expression and MLL leukemia, and suggest ASH1L as a target for therapeutic intervention. Investigation of multiple transcription factors and histone modification marks in MV4-11 human leukemia cells.
Project description:Ash1l encodes a histone methyltransferase, a member of the trithorax group proteins, which regulates developmental essential gene expression by catalyzing H3K36 methylation and counteracting polycomb silencing. Accumulating reports suggest the loss-of-function mutants in Ash1l gene are associated with intellectual disability (ID), attention-deficit/hyperactivity (ADHD), autism spectrum disorder (ASD), Tourette syndrome (TS) and multiple congenital anomalies (MCA). We performed transcriptome analysis of auditory cortex in 1-month-old and 1-year-old Ash1l Ash1l heterozygous mice with their age-matched WT littermates via RNA sequencing (RNA-seq). Ash1l haploinsufficiency induces transcription alternation of genes involved in synaptic function and cortical development, implicating the deficits in synapse pruning and behavior in adult mice.
Project description:ASH1L is frequently amplified and mutated in various human cancers, including lung adenocarcinoma, liver, uterine and balder cancers. We used two shRNAs to knockdown endogenous ASH1L proteins in A549 cells, and carried out RNA-seq analysis to identified the genes regulated by ASH1L. We found that compared with the control cells, 541 genes were upregulated in both ASH1L knockdown cells, whereas 398 genes were upregulated. Ingenuity Pathway Analysis (IPA) revealed that the downregulated genes are enriched in fundamental cellular activities, including cell cycle, replication, cell death and survival, and cell growth, and are important for caner and some other diseases . Gene Ontology (GO) analysis also revealed similar cellular pathways that the downregulated genes are involved, whereas the upregulated genes are not enriched in any specific pathways that are statistically significant. Taken together, these data suggest that ASH1L has an oncogenic role in lung adenocarcinoma promoting cancer cell growth, therefore may serve as a potential therapeutic target for the treatment of lung adenocarcinoma patients that have ASH1L amplifications.
Project description:ASH1L and MLL1 are two histone methyltransferases that facilitate transcriptional activation during normal development. However, the roles of ASH1L and its enzymatic activity in the development of MLL-rearranged leukemias are not fully elucidated in Ash1L gene knockout animal models. In this study, we used an Ash1L conditional knockout mouse model to show that loss of ASH1L in hematopoietic progenitor cells impaired the initiation of MLL-AF9-induced leukemic transformation in vitro. Furthermore, genetic deletion of ASH1L in the MLL-AF9-transformed cells impaired the maintenance of leukemic cells in vitro and largely blocked the leukemia progression in vivo. Importantly, the loss of ASH1L function in the Ash1L-deleted cells could be rescued by wild-type but not the catalytic-dead mutant ASH1L, suggesting the enzymatic activity of ASH1L was required for its function in promoting MLL-AF9-induced leukemic transformation. At the molecular level, ASH1L enhanced the MLL-AF9 target gene expression by directly binding to the gene promoters and modifying the local histone H3K36me2 levels. Thus, our study revealed the critical functions of ASH1L in promoting the MLL-AF9-induced leukemogenesis, which provides a molecular basis for targeting ASH1L and its enzymatic activity to treat MLL-arranged leukemias.
Project description:To recognize DNA damage, nucleotide excision repair (NER) deploys a multipart mechanism by which the XPC sensor detects helical distortions followed by engagement of TFIIH for lesion verification. Accessory players ensure that this factor handover takes place on chromatin where DNA is wrapped around histones. We show that the histone methyltransferase ASH1L, once activated by MRG15, accelerates global-genome NER activity. Upon UV irradiation, ASH1L deposits H3K4me3 marks all over the genome (except in gene promoters), thus priming chromatin for relocations of XPC from native to damaged DNA. ASH1L further recruits the histone chaperone FACT to UV lesions. In the absence of ASH1L, MRG15 or FACT, XPC persists on damaged DNA without being able to deliver lesions to the TFIIH verifier. We conclude that ASH1L implements repair hotspots whose H3K4me3 and FACT occupancy confers an active promoter-like code and organization of histones that make DNA damage verifiable by the NER machinery.
Project description:The histone methyltransferase ASH1L, first discovered for its role in transcription, has been shown to accelerate the removal of ultraviolet (UV) light-induced cyclobutane pyrimidine dimers (CPDs) by nucleotide excision repair. Previous reports demonstrated that CPD excision is most efficient at transcriptional regulatory elements, including enhancers, relative to other genomic sites. Therefore, we analyzed DNA damage maps in ASH1L-proficient and ASH1L-deficient cells to understand how ASH1L controls enhancer stability. This comparison showed that ASH1L protects enhancer sequences against the induction of CPDs besides stimulating repair activity. ASH1L reduces CPD formation at C-containing but not at TT dinucleotides, and no protection occurs against pyrimidine-(6,4)-pyrimidone photoproducts or cisplatin crosslinks. The diminished CPD induction extends to gene promoters but excludes retrotransposons. This guardian role against CPDs in regulatory elements is associated with the presence of H3K4me3 and H3K27ac histone marks, which are known to interact with the PHD and BRD motifs of ASH1L, respectively. Molecular dynamics simulations identified a DNA-binding AT hook of ASH1L that alters the distance and dihedral angle between neighboring C nucleotides to disfavor dimerization. The loss of this protection results in a higher frequency of C–>T transitions at enhancers of skin cancers carrying ASH1L mutations compared to ASH1L-intact counterparts.
Project description:The histone methyltransferase ASH1L, first discovered for its role in transcription, has been shown to accelerate the removal of ultraviolet (UV) light-induced cyclobutane pyrimidine dimers (CPDs) by nucleotide excision repair. Previous reports demonstrated that CPD excision is most efficient at transcriptional regulatory elements, including enhancers, relative to other genomic sites. Therefore, we analyzed DNA damage maps in ASH1L-proficient and ASH1L-deficient cells to understand how ASH1L controls enhancer stability. This comparison showed that ASH1L protects enhancer sequences against the induction of CPDs besides stimulating repair activity. ASH1L reduces CPD formation at C-containing but not at TT dinucleotides, and no protection occurs against pyrimidine-(6,4)-pyrimidone photoproducts or cisplatin crosslinks. The diminished CPD induction extends to gene promoters but excludes retrotransposons. This guardian role against CPDs in regulatory elements is associated with the presence of H3K4me3 and H3K27ac histone marks, which are known to interact with the PHD and BRD motifs of ASH1L, respectively. Molecular dynamics simulations identified a DNA-binding AT hook of ASH1L that alters the distance and dihedral angle between neighboring C nucleotides to disfavor dimerization. The loss of this protection results in a higher frequency of C–>T transitions at enhancers of skin cancers carrying ASH1L mutations compared to ASH1L-intact counterparts.
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified a novel androgen-regulated long non-coding (lnc) RNA, SOCS2-AS1. In order to investigate the SOCS2-AS1 function in prostate cancer cells, we performed gene expression in AR-positive prostate cancer cell lines (LNCaP and LTAD) after siSOCS2-AS1 or siSOCS2 treatment. We also treated cells with vehicle or androgen to analyzed the effects of siSOCS2-AS1 on AR function. Observation of androgen dependent gene expression changes after treatmet with siSOCS2-AS1 with microarray.