Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; Humans ; Leukemia, B-Cell ; genetics

RUNX1, also called AML1, is a member of RUNX transcriptional factor family, and also is the most frequent target for chromosomal translocations in leukemia. RUNX1 is a very important transcription factor, can enhance or repress the expressions of many hematopoiesis related genes. RUNX1 may receive a series of post-translational modifications, and the activity of RUNX1 can be affected by these post-translational modifications, thus RUNX1 regulates the differentiation, apoptosis and self-renewal of hematopoietic cells. This article reviews the role of RUNX1 in the pathogenesis of leukemia mainly including its target genes, transcriptional mechanism and post-translational modifications.
Core Binding Factor Alpha 2 Subunit ; genetics ; Epigenesis, Genetic ; Humans ; Leukemia ; genetics ; metabolism ; Protein Processing, Post-Translational

Runt-related transcription factor 1 (RUNX1) is an essential regulator of normal hematopoiesis. Its dysfunction, caused by either fusions or mutations, is frequently reported in acute myeloid leukemia (AML). However, RUNX1 mutations have been largely under-explored compared with RUNX1 fusions mainly due to their elusive genetic characteristics. Here, based on 1741 patients with AML, we report a unique expression pattern associated with RUNX1 mutations in AML. This expression pattern was coordinated by target repression and promoter hypermethylation. We first reanalyzed a joint AML cohort that consisted of three public cohorts and found that RUNX1 mutations were mainly distributed in the Runt domain and almost mutually exclusive with NPM1 mutations. Then, based on RNA-seq data from The Cancer Genome Atlas AML cohort, we developed a 300-gene signature that significantly distinguished the patients with RUNX1 mutations from those with other AML subtypes. Furthermore, we explored the mechanisms underlying this signature from the transcriptional and epigenetic levels. Using chromatin immunoprecipitation sequencing data, we found that RUNX1 target genes tended to be repressed in patients with RUNX1 mutations. Through the integration of DNA methylation array data, we illustrated that hypermethylation on the promoter regions of RUNX1-regulated genes also contributed to dysregulation in RUNX1-mutated AML. This study revealed the distinct gene expression pattern of RUNX1 mutations and the underlying mechanisms in AML development.
Core Binding Factor Alpha 2 Subunit/metabolism* ; DNA Methylation ; Gene Expression ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Promoter Regions, Genetic

This study was aimed to establish the protein expression profile of tel/aml-1+ childhood acute lymphoblastic leukemia (ALL) with different prognoses by two-dimensional polyacrylamide gel electrophoresis and explore the nosogenesis of tel/aml-1+ ALL childhood. On the basis of leukocyte count at new diagnosis, early reaction to therapy and clinical prognosis, the patients with tel/aml-1+ ALL were divided into 3 groups: early relapse group, high leukocyte count group and standard risk group. The bone marrow was taken from newly diagnosed patients for isolating protein, then the protein in leukemia cells was isolated by two-dimensional polyacrylamide gel electrophoresis, the image analysis of differential protein among 3 groups was carried out by using the PDQuest 7.3.0 image analysis software. The results showed that there were significant difference of protein expression profile among 3 groups. As compared with high leukocyte count and standard risk groups, 71 protein spots disappeared, 93 new protein spots appeared, the expression of 37 protein spots was up-regulated and the expression of 23 protein spots was down-regulated in early relapse group. As compared with high leukocyte count group, 6 protein spots disappeared, 56 new protein spots appeared, the expression of 7 protein spots was up-regulated, and expression of 19 protein spots was down-regulated in standard risk group. It is concluded that the protein expression profile in early relapse group is significantly different from other groups. Some proteins may play an important role in pathogenesis of childhood tel/aml-1+ ALL, and probably become new molecular indicators and targets for individualized treatment.
Child ; Child, Preschool ; Core Binding Factor Alpha 2 Subunit ; metabolism ; Electrophoresis, Gel, Two-Dimensional ; Female ; Humans ; Male ; Oncogene Proteins, Fusion ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; metabolism ; pathology

OBJECTIVETo set up a method of analyzing gene expression profile from mouse whole embryos.

METHODSMouse whole mount RNA in situ hybridization(WM-ISH) of E10.5-E14 embryos was carried out by using digoxigenin-labeled Runx1 and Runx3 RNA probes and their expression profile was observed by detecting the existence and status of corresponding mRNAs in the embryonic tissues.

RESULTSClear hybridization signals were observed in different tissues and organs hybridized by Runx1 or Runx3 RNA probe. Different probes and ages of embryos had need of their own optimal proteinase K treatment conditions.

CONCLUSIONMouse whole mount RNA in situ hybridization is an effective method of analyzing gene expression. It is useful for revealing whole gene expression profile and has a great potentiality in the era of functional genomics. It provides an alternative method of studies on gene expression which is at least as good as LacZ staining and immunohistochemistry. The key factor of the success to mouse whole mount RNA in situ hybridization is whether the proteinase K treatment conditions are optimal or not.

Animals ; Core Binding Factor Alpha 2 Subunit ; Core Binding Factor Alpha 3 Subunit ; DNA-Binding Proteins ; genetics ; Embryo, Mammalian ; metabolism ; Gene Expression Profiling ; methods ; Gene Expression Regulation, Developmental ; In Situ Hybridization ; methods ; Mice ; Proto-Oncogene Proteins ; genetics ; RNA ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Sensitivity and Specificity ; Transcription Factors ; genetics

This study was aimed to investigate the effect of AML1-ETO fusion protein on the anti-apoptotic gene BCL-2 in leukemic cells and to explore its role in leukemogenesis. The apoptotic levels of U937-WT, U937-Mock and U937-A/E1-4 cells were examined by flow cytometry. And cleaved caspase-3 protein expression was detected by Western blot. BCL-2 gene expression both in AML1-ETO-expressing cells or U937 nonexpressing cells and in leukemia cells of AML patients with or without t(8;21) was assessed by quantitative PCR. The chromatin immunoprecipitation (ChIP)-based PCR was used to investigate the direct interaction between the AML1-ETO and BCL-2 promoter in AML1-ETO positive leukemia cell line. The results indicated that in U937-A/E cells but not in U937-WT or U937-Mock cells, apoptotic cells statistically significantly increased, and AML1-ETO expression also significantly enhanced activation of caspase-3. AML1-ETO-expressing cell subclones displayed significantly low levels of BCL-2 mRNA in comparison with the non-transfected U937. In primary bone marrow cells of acute myeloid leukemia containing AML1-ETO, levels of BCL-2 mRNA were markedly lower as compared with other acute myeloid leukemias lacking this translocation. The enriched regions in transfected cells were located within BCL-2 promoter. It is concluded that BCL-2 is the direct target gene of AML1-ETO. AML1-ETO can down-regulate the expression of BCL-2.
Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RUNX1 Translocation Partner 1 Protein ; U937 Cells

As a dioxygenase, Ten-Eleven Translocation 2 (TET2) catalyzes subsequent steps of 5-methylcytosine (5mC) oxidation. TET2 plays a critical role in the self-renewal, proliferation, and differentiation of hematopoietic stem cells, but its impact on mature hematopoietic cells is not well-characterized. Here we show that Tet2 plays an essential role in osteoclastogenesis. Deletion of Tet2 impairs the differentiation of osteoclast precursor cells (macrophages) and their maturation into bone-resorbing osteoclasts in vitro. Furthermore, Tet2 mice exhibit mild osteopetrosis, accompanied by decreased number of osteoclasts in vivo. Tet2 loss in macrophages results in the altered expression of a set of genes implicated in osteoclast differentiation, such as Cebpa, Mafb, and Nfkbiz. Tet2 deletion also leads to a genome-wide alteration in the level of 5-hydroxymethylcytosine (5hmC) and altered expression of a specific subset of macrophage genes associated with osteoclast differentiation. Furthermore, Tet2 interacts with Runx1 and negatively modulates its transcriptional activity. Our studies demonstrate a novel molecular mechanism controlling osteoclast differentiation and function by Tet2, that is, through interactions with Runx1 and the maintenance of genomic 5hmC. Targeting Tet2 and its pathway could be a potential therapeutic strategy for the prevention and treatment of abnormal bone mass caused by the deregulation of osteoclast activities.
5-Methylcytosine ; analogs & derivatives ; chemistry ; metabolism ; Animals ; Cell Differentiation ; Cells, Cultured ; Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; DNA-Binding Proteins ; physiology ; Genome ; Genomics ; Mice ; Mice, Knockout ; Osteoclasts ; cytology ; metabolism ; Proto-Oncogene Proteins ; physiology

OBJECTIVETo investigate the effect of osthole on bone metabolism in rat femoral tissues in vitro.

METHODSThe rat femoral tissues were isolated in vitro. The optimal concentrations of ostehole (1×10(-5) mol/L) and estradiol (1×10(-8) mol/L) (the positive control) were selected by alkaline phosphatase activity (ALP). The ALP and calcium levels were detected by commmerical regents, and the expressions of osteoprotegerin, receptor activator of nuclear factor-κB ligand, runx-related gene 2, and bone morphogenetic protein-2 mRNA were determined by real-time reverse transcription-polymerase chain reaction.

RESULTThe osthole (1×10(-5) mol/L) significantly increased the activity of ALP, calcium level as well as the expressions of osteoprotegerin, receptor activator of nuclear factor-κB ligand, runx-related gene-2 and bone morphogenetic protein-2 mRNA in rat femoral tissues in vitro.

CONCLUSIONOsthole can improve calcium level and ALP activity and regulate the bone metabolism-related genes in rat femoral tissues.

Alkaline Phosphatase ; metabolism ; Animals ; Bone Morphogenetic Protein 2 ; metabolism ; Calcium ; metabolism ; Core Binding Factor Alpha 1 Subunit ; metabolism ; Coumarins ; pharmacology ; Femur ; drug effects ; metabolism ; In Vitro Techniques ; Male ; Osteoprotegerin ; metabolism ; RANK Ligand ; metabolism ; Rats ; Rats, Sprague-Dawley

BACKGROUNDBone morphogenetic protein 9 (BMP9) and Wnt/β-catenin signaling pathways are able to induce osteogenic differentiation of mesenchymal stem cells (MSCs), but the role of Wnt/β-catenin signaling pathway in BMP9-induced osteogenic differentiation is not well understood. Thus, our experiment was undertaken to investigate the interaction between BMP9 and Wnt/β-catenin pathway in inducing osteogenic differentiation of MSCs.

METHODSC3H10T1/2 cells were infected with recombinant adenovirus expressing BMP9, Wnt3a, and BMP9+Wnt3a. ALP, the early osteogenic marker, was detected by quantitative and staining assay. Later osteogenic marker, mineral calcium deposition, was determined by Alizarin Red S staining. The expression of osteopotin (OPN), osteocalcin (OC), and Runx2 was analyzed by Real time PCR and Western blotting. In vivo animal experiment was carried out to further confirm the role of Wnt3a in ectopic bone formation induced by BMP9.

RESULTSThe results showed that Wnt3a enhanced the ALP activity induced by BMP9 and increased the expressions of OC and OPN, with increase of mineral calcium deposition in vitro and ectopic bone formation in vivo. Furthermore, we also found that Wnt3a increased the level of Runx2, an important nuclear transcription factor of BMP9.

CONCLUSIONCanonical Wnt/β-catenin signal pathway may play an important role in BMP9-induced osteogenic differentiation of MSCs, and Runx2 may be a linkage between the two signal pathways.

Blotting, Western ; Cell Differentiation ; genetics ; physiology ; Core Binding Factor Alpha 1 Subunit ; genetics ; metabolism ; Growth Differentiation Factor 2 ; genetics ; metabolism ; Humans ; Osteocalcin ; genetics ; metabolism ; Osteogenesis ; genetics ; physiology ; Wnt3A Protein ; genetics ; metabolism

OBJECTIVETo establish a real-time quantitative reverse transcriptase polymerase chain reaction (RQ-RT-PCR) for quantitative detection of the common molecular markers that have affirmative clinical significance in the acute and chronic leukemia patients, and evaluate its significance in diagnosing leukemias and monitoring minimal residual disease (MRD).

METHODSPrimers and TaqMan probes were designed for detecting various fusion transcripts and normal abl gene was used as the internal control. The expression level of fusion transcripts in 202 newly diagnosed leukemias were determined.

RESULTSIn absolute quantity, expression level of the fusion transcripts in various leukemias was b3a2 (b2a2) 47614.63, e1a2 98847.53, AML1-ETO 300029.51, PML-RAR alpha 25506.28, respectively, while in relative quantity to abl, the levels were 1.05, 0.91, 5.33 and 0.55, respectively.

CONCLUSIONThe relative quantification of gene expression level by using RQ-RT-PCR to abl control gene is more accurate and direct viewing. Different levels of transcription of corresponding fusion genes are found in various subtypes of leukemias at diagnosis, among which the level of AML1-ETO was higher and PML-RAR alpha lower.

Biomarkers, Tumor ; genetics ; metabolism ; Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; Fusion Proteins, bcr-abl ; genetics ; metabolism ; Humans ; Leukemia ; diagnosis ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; RUNX1 Translocation Partner 1 Protein ; Reverse Transcriptase Polymerase Chain Reaction ; Transcription, Genetic