Cluster regulation of RUNX family by "gene switch" triggers a profound tumor regression of diverse origins.
ABSTRACT: Although Runt-related transcription factor 1 (RUNX1) has been generally considered to be a tumor suppressor, a growing body of evidence strongly suggests its pro-oncogenic property in acute myeloid leukemia (AML), Here we demonstrate that anti-leukemic effect mediated by RUNX1 depletion is highly dependent on a functional p53-mediated cell death pathway. Based on our present findings, anti-tumor effect elicited by RUNX1 silencing was compensated by the other RUNX family members such as RUNX2 and RUNX3, and a simultaneous attenuation of whole RUNX family members as a cluster displayed a much stronger anti-tumor effect relative to their individual suppression. Notably, switching off RUNX cluster utilizing the novel alkylating agent-conjugated pyrrole-imidazole (PI) polyamides, which specifically bound to the consensus RUNX-binding sequences, was highly effective against leukemia as well as dismal-prognostic solid tumors arising from diverse origins in vivo without any significant adverse events. Together, this work identifies the crucial role of RUNX cluster in the maintenance and the progression of cancer cells, and the indicated gene switch technology-dependent its modulation would be a novel strategy to control malignancies. Overall design: Genome-wide gene expression change by knockdown of RUNX family genes or alkylating PIP conjugates were examined.
INSTRUMENT(S): [HuGene-2_1-st] Affymetrix Human Gene 2.1 ST Array [transcript (gene) version]
Project description:The Runx genes are important in development and cancer, where they can act either as oncogenes or tumour supressors. We compared the effects of ectopic Runx expression in established fibroblasts, where all three genes produce an indistinguishable phenotype entailing epithelioid morphology and increased cell survival under stress conditions. Gene array analysis revealed a strongly overlapping transcriptional signature, with no examples of opposing regulation of the same target gene. A common set of 50 highly regulated genes was identified after further filtering on regulation by inducible RUNX1-ER. This set revealed a strong bias toward genes with annotated roles in cancer and development, and a preponderance of targets encoding extracellular or surface proteins reflecting the marked effects of Runx on cell adhesion. Keywords: Comparative study of gene targets regulated by overexpression of the different Runx family members Overall design: 6 samples (expression of different Runx family members); 5 in duplicate, 1 single. 2 control samples (empty vector) in duplicate. Cultures of Runx expressing cells were grown to confluence, treated with ethanol +/- 4OHT tamoxifen for 24 hours and harvested for RNA extraction and hybridization on Affymetrix microarrays
Project description:The Runx genes are important in development and cancer, where they can act either as oncogenes or tumour supressors. We compared the effects of ectopic Runx expression in established fibroblasts, where all three genes produce an indistinguishable phenotype entailing epithelioid morphology and increased cell survival under stress conditions. Gene array analysis revealed a strongly overlapping transcriptional signature, with no examples of opposing regulation of the same target gene. A common set of 50 highly regulated genes was identified after further filtering on regulation by inducible RUNX1-ER. This set revealed a strong bias toward genes with annotated roles in cancer and development, and a preponderance of targets encoding extracellular or surface proteins reflecting the marked effects of Runx on cell adhesion. Experiment Overall Design: 6 samples (expression of different Runx family members); 5 in duplicate, 1 single. 2 control samples (empty vector) in duplicate. Cultures of Runx expressing cells were grown to confluence, treated with ethanol +/- 4OHT tamoxifen for 24 hours and harvested for RNA extraction and hybridization on Affymetrix microarrays
Project description:An antagonistic interplay between YAP and RUNX where RUNX proteins abrogate YAP-mediated transcription of EMT and Stemness associated genes in mammary epithelial cells in an interaction dependent manner. Overall design: YAP and RUNX1 or RUNX3 were stably expressed together or alone in MCF10A cell line. Genes that are co-regulated by both were studied in the context of breast cancer.
Project description:The zebrafish is a powerful model for the study of hematopoietic stem and progenitor cells (HSPC). We have developed a novel HSPC-specific transgenic line (Runx1+23:GFP). We have used this line in time-lapse live imaging studies to track the migration of HSPC during development. We have also performed a chemical genetic screen to find small molecules that modulate HSPC numbers during development. Treating embryos from 2-3 days post fertilization (2-3 dpf) then fixing for in situ staining with HSPC probes cmyb and runx1, we found the compound lycorine increased HSPC numbers. Applying this compound during time-lapse live imaging showed increased accumulation of Runx+ HSPC in the caudal hematopoietic tissue (CHT). Treatment from 2-3 dpf, then washing off the compound, had a sustained effect on the size of the HSPC with Runx+ numbers higher at 5 and 7 dpf. We have performed microarray analysis to elucidate the molecular changes within HSPC and endothelial cells after Lycorine treatment. We treated Runx1+23:GFP;kdrl:DsRed2 embryos from 2-3 dpf with 75 uM lycorine in 1% DMSO. We then dissociated the embryos and sorted the Runx+ GFP cells, the kdrl+ DsRed2 cells, and the non-fluorescent negative cells from the total embryo as a comparator population. Total RNA was amplified and biotin labled for hybridization on Affymetrix microarrays. 18 samples were collected and analyzed. There are 3 biological replicates. There are 3 cell type populations: 1) Runx+ HSPC; 2) kdrl+ endothelial cells; 3) non-fluorescent negative cells. There are cell populations from dissociated Lycorine-treated embryo pools, and control DMSO-treated embryo pools.
Project description:In B cells infected by the cancer-associated Epstein-Barr virus (EBV), RUNX3 and RUNX1 transcription is manipulated to control cell growth. The EBV-encoded EBNA2 transcription factor (TF) activates RUNX3 transcription leading to RUNX3-mediated repression of the RUNX1 promoter and the relief of RUNX1-directed growth repression. We show that EBNA2 activates RUNX3 through a specific element within a -97 kb super-enhancer in a manner dependent on the expression of the Notch DNA-binding partner RBP-J. We also reveal that the EBV TFs EBNA3B and EBNA3C contribute to RUNX3 activation in EBV-infected cells by targeting the same element. Uncovering a counter-regulatory feed-forward step, we demonstrate EBNA2 activation of a RUNX1 super-enhancer (-139 to -250 kb) that results in low-level RUNX1 expression in cells refractory to RUNX1-mediated growth inhibition. EBNA2 activation of the RUNX1 super-enhancer is also dependent on RBP-J. Consistent with the context-dependent roles of EBNA3B and EBNA3C as activators or repressors, we find that these proteins negatively regulate the RUNX1 super-enhancer, curbing EBNA2 activation. Taken together our results reveal cell-type specific exploitation of RUNX gene super-enhancers by multiple EBV TFs via the Notch pathway to fine tune RUNX3 and RUNX1 expression and manipulate B-cell growth. Overall design: Examination of EBNA2 protein binding using a monoclonal antibody (PE2) in single ChIP-seq experiments carried out in the human GM12878 EBV transformed lymphoblastoid cell line.
Project description:The primary function of RUNX1 in leukemogenesis has been controversial since classical understanding of RUNX1 as an oncosuppressor was challenged by our recent discovery of novel oncogenic features of RUNX1. Here we provide insight into the dual function of RUNX1 through determining the significance of total RUNX expressions in AML cells. Our data indicate that moderately attenuated RUNX1 expression induces increased total RUNX expressions, which subsequently enhances proliferation of AML cells via GSTA2-mediated intracellular ROS removal. Indeed, inhibiting GSTA2 function in vivo prolonged the overall survival period of mice xeno-transplanted with human AML cells. These findings suggest that modulation of RUNX-GST-ROS axis could potentially be a novel therapeutic target in the poorest-prognostic AML patients with intermediate RUNX1 expression levels. Overall design: MV4-11 cells were transduced with series of shRNAs targeting RUNX1 at various efficacies (Moderate knockdown; MV4-11_sh_Rx1_moderate, Profound knockdown; MV4-11_sh_Rx1_profound_#1 and #2). Control shRNA targets luciferase sequence (sh_Luc.).
Project description:The HIV-1 accessory protein Vif hijacks a cellular Cullin-RING ubiquitin ligase, CRL5, to promote degradation of the APOBEC3 (A3) family of restriction factors. Recently, the cellular transcription cofactor CBFb was shown to form a complex with CRL5-Vif and to be essential for A3 degradation and viral infectivity. We now demonstrate that CBFb is required for assembling a well-ordered CRL5-Vif complex by inhibiting Vif oligomerization and by activating CRL5-Vif via direct interaction. The CRL5-Vif-CBFb holoenzyme forms a welldeﬁned heterohexamer, indicating that Vif simultaneously hijacks CRL5 and CBFb. Heterodimers of CBFb and RUNX transcription factors contribute toward the regulation of genes, including those with immune system functions. We show that binding of Vif to CBFb is mutually exclusive with RUNX heterodimerization and impacts the expression of genes whose regulatory domains are associated with RUNX1. Our results provide a mechanism by which a pathogen with limited coding capacity uses one factor to hijack multiple host pathways. Identification of RUNX1 binding sites in the Jurkat cell line
Project description:The RUNX genes encode for transcription factors involved in development and human disease. RUNX1 and RUNX3 are frequently associated with leukemias, yet the basis for their involvement in leukemogenesis is not fully understood. Here we show that Runx1;Runx3 double knockout (DKO) mice exhibited lethal phenotypes due to bone marrow failure and myeloproliferative disorder. These contradictory clinical manifestations are reminiscent of human inherited bone marrow failure syndromes like Fanconi anemia (FA), caused by defective DNA repair. Indeed, Runx1;Runx3 DKO cells showed mitomycin C hypersensitivity, due to impairment of monoubiquitinated-FANCD2 recruitment to DNA damage foci, although FANCD2 monoubiquitination in the FA pathway was unaffected. RUNX1 and RUNX3 interact with FANCD2 independent of CBFβ, suggesting non-transcriptional role for RUNX in DNA repair. These findings suggest that RUNX dysfunction causes DNA repair defect, besides transcriptional misregulation, and promotes development of leukemias and other cancers. 6 mice were analyzed in this study. 3 Runx1;Runx3 double knockout cKit+Sca1+Lin- hematopoietic stem/progenitor cells were compared with their wild type littermate controls. RNA was isolated from 3 independent Runx1;Runx3 WT KSL samples, each pooled from 3 Runx1;Runx3 WT mice, and 3 independent Runx1;Runx3 DKO KSL samples, using the RNeasy Micro Kit (QIAgen). RNA integrity and quantity was assessed using the Agilent 2000 Bioanalyzer system. 3 μg to 5 μg RNA was processed using WT-Ovation Pico RNA Amplification System (NuGEN) paired with the WT-Ovation Exon Module and FL-Ovation cDNA Biotin Module (NuGEN). A detailed protocol in the user’s guide kit was used without modification. cDNA were prepared for hybridization on GeneChip Mouse Gene 1.0 ST Arrays (Affymetrix) according to the instructions in GeneChip Hybridization Wash and Stain Kit for ST arrays (Affymetrix). Microarray hybridization, scanning and preliminary MAS 5.0 normalizations were completed at the A*STAR Biopolis Shared Facilities (BSF).
Project description:RSPO is a WNT pathway activator and functions as a potent regulator of stem cell growth in colon. RSPO family members were produced by several human tumors representing multiple tumor types including ovarian, pancreatic, colon, breast and lung cancer. Specific monoclonal antibody antagonists of RSPO family members were developed. In human patient-derived tumor xenograft models, anti-RSPO treatment markedly inhibited tumor growth either as single agents or in combination with chemotherapy. Furthermore, blockade of RSPO signaling reduced the tumorigenicity of cancer cells based on serial transplantation studies. In order to assess the impact of RSPO3 inhibition and gain insight in the anti-RSPO3 treatment mechanism of action, the global gene expression profiles of 4 human colorectal cancer patient derived models (PDX) were performed using Affymetrix microarray for the xenografts treated by the anti-RSPO3 antibody. Overall design: 4 CRC PDX models were treated by control anbodies, anti-RSPO3 antibodies, or anti-RSPO3 antibodies combined with standard-of-care. 4 weeks after the treatment, tumors were harvesed for the microarray analysis