Smyd3 is a transcriptional potentiator of multiple cancer-promoting genes and required for liver or colon cancer development
ABSTRACT: Smyd3 is a histone methyltransferase implicated in tumorigenesis. Here we show that Smyd3 expression in mice is required but not sufficient for chemically induced liver and colon cancer formation. In these organs Smyd3 is functioning in the nucleus as a direct transcriptional activator of several key genes involved in cell proliferation, epithelial-mesenchymal transition, JAK/Stat3 oncogenic pathways, as well as of the c-myc and b-catenin oncogenes. Smyd3 specifically interacts with H3K4Me3-modified histone tails and is recruited to the core promoter regions of many but not all active genes. Smyd3 binding density on target genes positively correlates with increased RNA Pol-II density and transcriptional outputs. The results suggest that Smyd3 is an essential transcriptional potentiator of a multitude of cancer-related genes. Standard Smyd3-deficient (Smyd3-KO) mice were generated using gene-trap ES cell clones (AS0527 from International Gene Trap Consortium), in which a selection cassette, containing the splice acceptor site from mouse EN2 exon 2 followed by the beta-galactosidase and neomycin resistance gene fusion gene and the SV40 polyadenylation sequence was inserted into the 5th intron of the Smyd3 gene. The resulting mice were devoid of Smyd3 mRNA and protein in all tissues, including liver and colon. For the generation of Smyd3-Tg mice the open reading frame of the mouse Smyd3 cDNA, which contained 3 Flag epitopes at the 3’ end was inserted into the StuI site of the pTTR1-ExV3 plasmid (Yan et al, 1990). The 6.8 kb HindIII fragment containing the mouse transthyretin enhancer/promoter, intron 1, Smyd3 cDNA, three Flag epitopes and SV40 poly-A site was used to microinject C57Bl/6 fertilized oocytes. Founder animals were identified by Southern blotting and crossed with F1 mice to generate lines. Specific overexpression in the liver was tested by RT-PCR analysis in different tissues.
Project description:PR-SET7-mediated histone-4 lysine-20 methylation has been implicated in mitotic condensation, DNA damage response and replication licencing. Here we show that PR-SET7 function in the liver is pivotal for maintaining genome integrity. Hepatocyte-specific deletion of PR-SET7 in mouse embryos resulted in G2 arrest followed by massive cell death and defect in liver organogenesis. Inactivation at postnatal stages caused cell duplication-dependent hepatocyte necrosis with unusual features of autophagy, termed "endonucleosis". Necrotic death was accompanied by inflammation, fibrosis and compensatory growth induction of neighboring hepatocytes and resident ductal progenitor cells. Prolonged necrotic-regenerative cycles coupled with oncogenic STAT3 activation replaced pre-existing hepatocytes with hepatocellular carcinoma derived entirely from ductal progenitor cells. Hepatocellular carcinoma in these mice displays a cancer stem cell gene signature specified by the co-expression of ductal progenitor markers and oncofetal genes. Mice carrying hepatocyte specific inactivation of PR-SET7 were generated in order to investigate the function of PR-SET7 histone methyl transferase in liver organogenesis, hepatocyte proliferation and liver regeneration. P15 WT mice were injected intra-peritoneally (ip) with 25ml per kg DEN (diethyl nitrosamine). Mice were examined for RNA expression at 8 months old.
Project description:Subtypes of innate lymphoid cells (ILC), defined by effector function and transcription factor expression, have recently been identified. In the adult, ILC derive from common lymphoid progenitors in bone marrow, although transcriptional regulation of the developmental pathways involved remains poorly defined. TOX is required for development of lymphoid tissue inducer cells, a type of ILC3 required for lymph node organogenesis, and NK cells, a type of ILC1. We show here that production of multiple ILC lineages requires TOX, as a result of TOX-dependent development of common ILC progenitors. Comparative transcriptome analysis demonstrated failure to induce various aspects of the ILC gene program in the absence of TOX, implicating this nuclear factor as a key early determinant of ILC lineage specification. TOX KO vs. wild tyype
Project description:microRNAs (miRNAs) accomplish a remarkable variety of biological functions. Their expression is tightly controlled, and the final production of a miRNA is dependent on the cooperation of multiple mechanisms and their net effect. Here we show that miR-124-1 is transcriptionally activated during erythroid differentiation by GATA-1, however its post-transcriptional processing is attenuated. We found that QKI5 binds to a distal QKI response element (QRE) embedded in the primary transcript of miR-124-1 (pri-124-1) and modulates Microprocessor function by direct association with DGCR8. Strikingly, Microprocessor recruitment to pri-124-1 is disrupted upon RNAi-mediated depletion of QKI5, consistent with the decrease in mature miR-124. Moreover, addition of QKI5 increases the conversion efficiency of pri-124-1 in cell-free extracts. For erythropoiesis, the decreased QKI5 leads to attenuated Microprocessor-mediated processing of pri-124-1, which confers the exquisite miRNA abundance necessary for development. This regulation also gives rise to a unique miRNA signature required for normal erythropoiesis. Thus, this QKI5-regulated miRNA processing may represent a common paradigm for erythroid development, and specifically, it may serve as a post-transcriptional fault security to prevent misexpression of certain miRNAs, that is essential for the establishment of particular gene expression patterns during development. Two samples are analyzed: K562 cells transduced with GFP lentivirus; and K562 cells transduced with QKI5-overexpressing lentivirus.
Project description:We report the gene expression profiles by NGFR knockdown in H460 and H1299 cell lines and reveal that NGFR ablation activates p53 target gene expression. We examined gene expression in two different non-small-cell lung cancer cell lines, one with wild-type p53 and the other without p53.
Project description:To date, most proteomic analyses towards cancer biomarker discovery have been based on protein quantification. However, proteins function in association with other proteins to form modules that are localized in specific subcellular compartments. Cellular mislocalization of proteins has in fact been detected as a key feature in a variety of cancer cells1,2. Here, we describe a strategy for biomarker detection based on a mitochrondrial enrichment score (mtES), which is sensitive to protein abundance as well as protein translocation between mitochondria and cytosol. The mtES score integrates protein expression data from total cellular lysates and enriched mitochondrial fractions and provides important information for the classification of cancer samples, which is not apparent from conventional quantitative protein measurements. We apply the new strategy to a panel of wild-type and mutant mice that are either healthy or present liver cancer. We show that proteome changes based on mtES scores outperform protein abundance measurements in discriminating liver cancer from healthy liver tissue and that they are uniquely robust against strong genetic perturbation. Overall, our method provides a more sensitive approach to cancer biomarker discovery that takes into account contextual information of tested proteins.
Project description:To-date, most proteomic studies aimed at discovering tissue-based cancer biomarkers have compared the quantity of selected proteins between case and control groups. However, proteins generally function in association with other proteins to form modules localized in particular subcellular compartments in specialized cell types and tissues. Sub-cellular mislocalization of proteins has in fact been detected as a key feature in a variety of cancer cells. Here, we describe a strategy for tissue-biomarker detection based on a mitochondrial fold enrichment (mtFE) score, which is sensitive to protein abundance changes as well as changes in subcellular distribution between mitochondria and cytosol. The mtFE score integrates protein abundance data from total cellular lysates and mitochondria-enriched fractions, and provides novel information for the classification of cancer samples that is not necessarily apparent from conventional abundance measurements alone. We apply this new strategy to a panel of wild-type and mutant mice with a liver-specific gene deletion of Liver receptor homolog 1 (Lrh-1hep-/-), with both lines containing control individuals as well as individuals with liver cancer induced by diethylnitrosamine (DEN). Lrh-1 gene deletion attenuates cancer cell metabolism in hepatocytes through mitochondrial glutamine processing. We show that proteome changes based on mtFE scores outperform protein abundance measurements in discriminating DEN-induced liver cancer from healthy liver tissue, and are uniquely robust against genetic perturbation. We validate the capacity of selected proteins with informative mtFE scores to indicate hepatic malignant changes in two independent mouse models of hepatocellular carcinoma (HCC), thus demonstrating the robustness of this new approach to biomarker research.
Project description:We identified RNA binding motif protein 47 (RBM47) as a target gene of transforming growth factor (TGF)-beta in mammary gland epithelial cells (NMuMG cells) that have undergone the epithelial-to-mesenchymal transition (EMT). TGF-beta repressed RBM47 expression in NMuMG cells and lung cancer cell lines. Expression of RBM47 correlated with good prognosis in patients with lung, breast, and gastric cancer. RBM47 suppressed the expression of cell metabolism-related genes, which were the direct targets of nuclear factor erythroid 2-related factor 2 (Nrf2; also known as NFE2L2). RBM47 bound to KEAP1 and Cullin3 mRNAs, and knockdown of RBM47 inhibited their protein expression, which led to enhanced binding of Nrf2 to target genomic regions. Knockdown of RBM47 also enhanced the expression of some Nrf2 activators, p21/CDKN1A and MafK induced by TGF-beta. Both mitochondrial respiration rates and the side population cells in lung cancer cells increased in the absence of RBM47. Our findings, together with the enhanced tumor formation and metastasis of xenografted mice by knockdown of the RBM47 expression, suggested tumor suppressive roles for RBM47 through the inhibition of Nrf2 activity. Effect of shRNA for RBM47 and TGF-beta on gene expression was evaluated by RNA-seq and RBM47-bound RNAs were identified by RIP-seq in A549 cells.
Project description:TTF-1/NKX2-1 was expressed by adenoviral vector and changes in gene expression were determined by RNA-sequencing. A549 cells were infected with Ad-TTF-1 or Ad-LacZ vectors and stimulated with TGF-beta for 24 hours or left untreated. Expression of polyA RNA was determined.
Project description:Tumor-specific alternative splicing is implicated in the progression of cancer, including clear cell renal cell carcinoma (ccRCC). Using ccRCC RNA-sequencing data from The Cancer Genome Atlas, we found that epithelial splicing regulatory protein 2 (ESRP2), one of the key regulators of alternative splicing in epithelial cells, is expressed in ccRCC. ESRP2 mRNA expression did not correlate with the overall survival rate of ccRCC patients, but the expression of some ESRP-target exons correlated with the good prognosis and with the expression of Arkadia (also known as RNF111) in ccRCC. Arkadia physically interacted with ESRP2, induced polyubiquitination, and modulated its splicing function. Arkadia and ESRP2 suppressed ccRCC tumor growth in a coordinated manner. Lower expression of Arkadia correlated with advanced tumor stages and poor outcomes in ccRCC patients. This study thus reveals a novel tumor-suppressive role of the Arkadia-ESRP2 axis in ccRCC. Expression of mRNA in a ccRCC cell line OS-RC-2 under the knockdown of Arkadia or ESRP2. Knock-down of ESRP2 was confirmed by RT-PCR because of low expression of ESRP2 which resulted in non-quantitative FPKM value.