Project description:MLL-fusions represent a large group of leukemia drivers, whose diversity originates from the vast molecular heterogeneity of C-terminal fusion partners of MLL. While studies of selected MLL-fusions have revealed critical molecular pathways, unifying mechanisms across all MLL-fusions remain poorly understood. We present the first comprehensive survey of protein-protein interactions of seven distantly related MLL-fusion proteins. Functional investigation of 128 conserved MLL-fusion-interactors identified a specific role for the lysine methyltransferase SETD2 in MLL-leukemia. SETD2 loss caused growth arrest and differentiation of AML cells, and led to increased DNA damage. In addition to its role in H3K36 tri-methylation, SETD2 was required to maintain high H3K79 di-methylation and MLL-AF9 binding to critical target genes, such as Hoxa9. SETD2 loss synergized with pharmacologic inhibition of the H3K79 methyltransferase DOT1L to induce DNA damage, growth arrest, differentiation and apoptosis. These results uncover a dependency for SETD2 during MLL-leukemogenesis, revealing a novel actionable vulnerability in this disease.
Project description:Patients with polycystic kidney disease (PKD) encounter a high risk of clear cell renal cell carcinoma (ccRCC), a malignant tumor with dysregulated lipid metabolism. SET domain–containing 2 (SETD2) has been identified as an important tumor suppressor gene in ccRCC. However, the role of SETD2 in tumorigenesis during the transition from PKD to ccRCC remains largely unexplored. Herein, we performed metabolomics, lipidomics, transcriptomics and proteomics with SETD2 loss induced PKD-ccRCC transition mouse model. To characterize biological responses triggered by SETD2 deletion during PKD-ccRCC transition at the protein level, we conducted global proteomics studies.
Project description:SETD2/HYPB has been known as a histone H3K36 specific methyltransferase. However, its roles in physiology such as development and cellular function remain unclear. In this study, using mESCs as cellular model, we show that Setd2 mainly regulates differentiation of murine embryonic stem cells (mESCs) towards primitive endoderm. This study aimed at exploring how did Setd2 regulate primitive endoderm. differentiation. We used microarrays to detail the global programme of gene expression controled by setd2, which is required for endoderm differentiation. Wild type and Setd2 knockout mESCs were selected for RNA extraction and hybridization on Affymetrix GeneChip® mouse genome 430 2.0 arrays. We sought to obtain some deregulated genes, which were required for primitive endoderm differentiation. For comparison, three biological repeats of each were performed.
Project description:Inflammatory bowel disease (IBD) is a complex and relapsing inflammatory disease, and patients with IBD exhibit a higher risk of developing colorectal cancer (CRC). Epithelial barrier disruption is one of the major causes of inflammatory bowel disease (IBD) in which epigenetic modulations are pivotal elements. However, the epigenetic mechanisms underlying the epithelial barrier integrity regulation remain largely unexplored. Here, we investigated how SETD2, a histone H3K36 trimethyltransferase, maintains intestinal epithelial homeostasis under inflammatory conditions. GEO public database and IBD tissues were used to investigate the clinical relevance of SetD2 in IBD. To define the role of SetD2 in the colitis, we generated mice with epithelial-specific deletion of Setd2 (Setd2Vil-KO mice). Acute colitis was induced by 2% dextran sodium sulfate (DSS), and colitis-associated CRC was induced by injecting azoxymethane (AOM), followed by three cycles of 2% DSS treatments. Colon tissues were collected from mice and analyzed by histology, immunohistochemistry and immunoblots. Organoids were generated from Setd2Vil-KO and control mice, and were stained with 7-AAD to detect apoptosis. We isolated intestinal epithelial cells (IECs), performed RNA-seq and H3K36me3 ChIP-seq analysis to uncover the mechanism. Results were validated in functional rescue experiments by N-acetyl-l-cysteine (NAC) treatment and transgenes expression in IECs. SETD2 expression was decreased in IBD patients and DSS-treated colitis mice. Setd2Vil-KO mice had abnormal loss of mucosa-producing goblet cells and antimicrobial peptide (AMP)-producing Paneth cells, and promoted early intestinal inflammation development. Consistent with the reduced SETD2 expression in IBD patients, Setd2Vil-KO mice exhibited increased susceptibility to DSS-induced colitis, accompanied by more severe epithelial barrier disruption. Intestinal permeability was markedly increased in Setd2Vil-KO mice. Setd2 ablation drived inflammation-associated CRC. Deletion of Setd2 resulted in excess reactive oxygen species (ROS), which led to cellular apoptosis and the defects in barrier integrity. N-acetyl-l-cysteine (NAC) treatment in Setd2Vil-KO mice rescued epithelial barrier injury and apoptosis. Moreover, overexpression of antioxidase PRDX6 in Setd2Vil-KO IECs largely alleviated the overproductions of ROS and improved the cellular survival. Deficiency of Setd2 specifically in the intestine aggravates epithelial barrier disruption and inflammatory response in colitis via a mechanism dependent on oxidative stress. More importantly, we show that Setd2 depletion results in excess ROS by directly down-regulating PRDX6, an antioxidant protein that inhibit excess ROS. Thus, our results highlight an epigenetic mechanism by which Setd2 mediates oxidative stress to modulate intestinal epithelial homeostasis.
Project description:Inflammatory bowel disease (IBD) is a complex and relapsing inflammatory disease, and patients with IBD exhibit a higher risk of developing colorectal cancer (CRC). Epithelial barrier disruption is one of the major causes of inflammatory bowel disease (IBD) in which epigenetic modulations are pivotal elements. However, the epigenetic mechanisms underlying the epithelial barrier integrity regulation remain largely unexplored. Here, we investigated how SETD2, a histone H3K36 trimethyltransferase, maintains intestinal epithelial homeostasis under inflammatory conditions. GEO public database and IBD tissues were used to investigate the clinical relevance of SetD2 in IBD. To define the role of SetD2 in the colitis, we generated mice with epithelial-specific deletion of Setd2 (Setd2Vil-KO mice). Acute colitis was induced by 2% dextran sodium sulfate (DSS), and colitis-associated CRC was induced by injecting azoxymethane (AOM), followed by three cycles of 2% DSS treatments. Colon tissues were collected from mice and analyzed by histology, immunohistochemistry and immunoblots. Organoids were generated from Setd2Vil-KO and control mice, and were stained with 7-AAD to detect apoptosis. We isolated intestinal epithelial cells (IECs), performed RNA-seq and H3K36me3 ChIP-seq analysis to uncover the mechanism. Results were validated in functional rescue experiments by N-acetyl-l-cysteine (NAC) treatment and transgenes expression in IECs. SETD2 expression was decreased in IBD patients and DSS-treated colitis mice. Setd2Vil-KO mice had abnormal loss of mucosa-producing goblet cells and antimicrobial peptide (AMP)-producing Paneth cells, and promoted early intestinal inflammation development. Consistent with the reduced SETD2 expression in IBD patients, Setd2Vil-KO mice exhibited increased susceptibility to DSS-induced colitis, accompanied by more severe epithelial barrier disruption. Intestinal permeability was markedly increased in Setd2Vil-KO mice. Setd2 ablation drived inflammation-associated CRC. Deletion of Setd2 resulted in excess reactive oxygen species (ROS), which led to cellular apoptosis and the defects in barrier integrity. N-acetyl-l-cysteine (NAC) treatment in Setd2Vil-KO mice rescued epithelial barrier injury and apoptosis. Moreover, overexpression of antioxidase PRDX6 in Setd2Vil-KO IECs largely alleviated the overproductions of ROS and improved the cellular survival. Deficiency of Setd2 specifically in the intestine aggravates epithelial barrier disruption and inflammatory response in colitis via a mechanism dependent on oxidative stress. More importantly, we show that Setd2 depletion results in excess ROS by directly down-regulating PRDX6, an antioxidant protein that inhibit excess ROS. Thus, our results highlight an epigenetic mechanism by which Setd2 mediates oxidative stress to modulate intestinal epithelial homeostasis.
Project description:Purpose: This study aimed at exploring the deregulated genes in setd2 knockout mESCs compared with wt, more particularly to find the mechanism controlled by setd2,which was required for endoderm differentiation. Methods: Setd2 wt and ko mESCs were generated by deep sequencing, using Illumina GAIIx. Using Avadis NGS (version:1.3) software to analyze the sequence reads that passed quality filter to acquire the expression level of all genes. qRT–PCR validation was performed usingSYBR Green assays. Results: Using an optimized data analysis workflow, we mapped about 80 million sequence reads per sample to the mouse genome (build mm9) and identified 17,827 transcripts in the sted2 wt and ko mESCs. About 2,516 genes were deregulated in setd2 ko mESCs, more than 10 genes were validated using qRT-PCR. Conclusions: Through RNA-seq,we noticed that a subset of genes that related to MAPK signaling pathways were down-regulated in ko mESCs. This provided a bridge to connect setd2 and mESCs endoderm differentiation. One wt and one ko mESCs were generated by deep sequencing, using Illumina GAIIx.