Ubiquitous expression of the rtTA2S-M2 inducible system in transgenic mice driven by the human hnRNPA2B1/CBX3 CpG island

Background. A sensitive, ubiquitously expressed tetracycline inducible system would be a valuable tool in mouse transgenesis. However, this has been difficult to obtain due to position effects observed at different chromosomal sites of transgene integration, which negatively affect expression in many tissues. The aim of this study was to test the utility of a mammalian methylation-free CpG island to drive ubiquitous expression of the sensitive doxycycline (Dox) inducible rtTA2S-M2 Tet-transactivator in transgenic mice. Results. An 8 kb genomic fragment from the methylation-free CpG island of the human hnRNPA2B1-CBX3 housekeeping gene locus was tested. In a number of transgenic mouse lines obtained, rtTA2S-M2 expression was detected in many tissues examined. Characterisation of the highest expressing rtTA2S-M2 transgenic mouse line demonstrated Dox-inducible GFP transgene expression in many tissues. Using this line we also show highly sensitive quantitative induction wit

The dual role of LSD1 and HDAC3 in STAT5-dependent transcription is determined by protein interactions, binding affinities, motifs and genomic positions

STAT5 interacts with other factors to control transcription, and the mechanism of regulation is of interest as constitutive active STAT5 has been reported in malignancies. Here, LSD1 and HDAC3 were identified as novel STAT5a interacting partners in pro-B cells. Characterization of STAT5a, LSD1 and HDAC3 target genes by ChIP-seq and RNA-seq revealed gene subsets regulated by independent or combined action of the factors and LSD1/HDAC3 to play dual role in their activation or repression. Genes bound by STAT5a alone or in combination with weakly associated LSD1 or HDAC3 were enriched for the canonical STAT5a GAS motif, and such binding induced activation or repression. Strong STAT5 binding was see

Persistent fetal γ-globin expression in adult transgenic mice following deletion of two silencer elements located 3′ to the human Aγ-globin gene

Natural deletions of the human γ-globin gene cluster lead to specific syndromes characterized by increased production of fetal hemoglobin in adult life and provide a useful model to delineate novel cis-acting elements involved in the developmental control of hemoglobin switching. A hypothesis accounting for these phenotypic features assumes that silencers located within the Aγ-to δ-gene region are deleted in hereditary persistence of fetal hemoglobin (HPFH) and δβ-thalassemias, leading to failure of switching. In the present study, we sought to clarify the in vivorole of two elements, termed Enh and F, located 3′ to the Aγ-globin, in silencing the fetal genes. To this end, we generated three transgenic lines using cosmid constructs containing the full length of the globin locus control region (LCR) linked to the 3.3-kb Aγ-gene lacking both the Enh and F elements. The Enh/F deletion resulted in high levels of Aγ-globin gene expression in adult mice in all single copy lines, whereas, the LCR-Aγ single copy lines which retain the Enh and F elements exhibited complete normal switching of the fetal Aγ-gene. Our study documents directly for the first time the in vivorole of these two gene-proximal negative regulatory elements in silencing the fetal globin gene in the perinatal period, and thus these data may permit their eventual exploitation in therapeutic approaches for thalassemias. © 2009 The Feinstein Institute for Medical Research

Dynamic expression of the vertebrate-specific protein Nucks during rodent embryonic development

The nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS) is a highly phosphorylated nuclear protein that is overexpressed in many types of cancer. The flexibility of NUCKS and its extensive posttranslational modifications indicate that it is multifunctional, and its expression in most cell types suggests a housekeeping function. However, spatiotemporal expression of the Nucks protein during rodent development has not been reported. Thus, we investigated the expression of both the Nucks mRNA and protein during rat and mouse development by immunohistochemistry, in situ hybridization, Western immunoblotting, and reverse-transcription PCR analysis. We also used BLAST analysis against expressed sequence tag databases to determine whether a NUCKS homologue is expressed in invertebrate organisms. We found that Nucks expression increased during the initial stages of embryonic development, and then gradually decreased until birth in all tissues except the nervous tissue and muscle fibers. Interestingly, the expression of Nucks was very strong in migrating neural crest cells at E13.5 and ectoderm-derived tissues. In most tissues analyzed, the levels of Nucks correlated with the levels of Bax and activated caspase-3, which are indicative of apoptosis. Moreover, Nucks was upregulated very early during neuronal apoptosis in vitro. Expression analysis revealed that no transcript with close homology to the Nucks gene was present in invertebrates. The expression of Nucks in both proliferating and quiescent cells and its correlation with Bax levels and apoptosis strongly suggest that Nucks plays complex roles in cell homeostasis. Furthermore, the lack of homology in invertebrate organisms indicates a specific role for Nucks in vertebrate embryogenesis. © 2013 Elsevier Ltd. All rights reserved

Identification of a STAT5 Target Gene, Dpf3, Provides Novel Insights in Chronic Lymphocytic Leukemia

STAT5 controls essential cellular functions and is encoded by two genes, Stat5a and Stat5b. To provide insight to the mechanisms linking hematologic malignancy to STAT5 activation/regulation of target genes, we identified STAT5 target genes and focused on Dpf3 gene, which encodes for an epigenetic factor. Dpf3 expression was induced upon IL-3 stimulation in Ba/F3 cells, while strong binding of both STAT5a and STAT5b was detected in its promoter. Reduced expression of Dpf3 was detected in Ba/F3 cells with Stat5a and Stat5b knock-down, suggesting that this gene is positively regulated by STAT5, upon IL-3 stimulation. Furthermore, this gene was significantly up-regulated in CLL patients, where DPF3 gene/protein up-regulation and strong STAT5 binding to the DPF3 promoter, correlated with increased STAT5 activation, mainly in non-malignant myeloid cells (granulocytes). Our findings provide insights in the STAT5 dependent transcriptional regulation of Dpf3, and demonstrate for the first time increased STAT5 activation in granulocytes of CLL patients. Novel routes of investigation are opened to facilitate the understanding of the role of STAT5 activation in the communication between non-malignant myeloid and malignant B-cells, and the functions of STAT5 target genes networks in CLL biology. © 2013 Theodorou et al

miR-183 as a molecular and protective biomarker for cancer in schizophrenic subjects

Previous studies have suggested that schizophrenia is associ ated with a reduced risk of cancer. Genes that are involved in cell cycle regulation seem to have additional functions in post-mitotic neurons involved in neuronal migration and synaptic plasticity. MicroRNAs (miRNAs) play a dominant role in the regulation of gene expression in the central nervous system (CNS). Due to their involvement in a large number of CNS pathways, miRNAs pose as appealing molecules for further investigation, with potential diagnostic, prognostic and therapeutic value. In the present study, we investigated the potential association between cancer and schizophrenia in 2 patient sample groups. We analyzed a large number of miRNAs in a control group of 6 schizophrenic patients and a study group of 8 schizophrenic patients with a solid tumor. A comparison between the control and study groups showed that only miR-183 was differentially expressed. Specifically, a significant downregulation of miR-183 in the samples of the study group was observed. Although a larger sample size is required to validate this result for the general patient population, our findings provide a first indication that miR-183 may play a role in regulating the expression of other genes with onco-suppressor activity. Our results are in agreement with the theory that patients with schizophrenia may have a tumor suppressor gene or enhanced neuronal apoptotic activities. Further studies are required in order to shed light on the role of miRNAs and particularly, on the suppressive role of miR-183 in the neurobiological pathways involved in schizophrenia

MiRNAs and their role in the correlation between schizophrenia and cancer (Review)

Schizophrenia (SZ) and cancer (Ca) have a broad spectrum of clinical phenotypes and a complex biological background, implicating a large number of genetic and epigenetic factors. SZ is a chronic neurodevelopmental disorder signified by an increase in the expression of apoptotic molecular signals, whereas Ca is conversely characterized by an increase in appropriate molecular signaling that stimulates uncontrolled cell proliferation. The rather low risk of developing Ca in patients suffering from SZ is a hypothesis that is still under debate. Recent evidence has indicated that microRNAs (miRNAs or miRs), a large group of small non-coding oligonoucleotides, may play a significant role in the development of Ca and major psychiatric disorders, such as SZ, bipolar disorder, autism spectrum disorders, suicidality and depression, through their interference with the expression of multiple genes. For instance, the possible role of let-7, miR-98 and miR-183 as biomarkers for Ca and SZ was investigated in our previous research studies. Therefore, further investigations on the expression profiles of these regulatory, small RNA molecules and the molecular pathways through which they exert their control may provide a plausible explanation as to whether there is a correlation between psychiatric disorders and low risk of developing C.a

Signs of striatal dopamine transporter density increase in association with improvement of tardive dyskinesia in a patient with schizophrenia, as demonstrated by a DAT scan

The imaging of the dopamine transporter could demonstrate the implication of dopaminergic pathway in the appearance of tardive dyskinesia. We report a case with psychotic and tardive dyskinesia symptoms. A DAT scan showed decreased dopamine transporter uptake in the area of brain's basal gaglia. A trial with quetiapine improved both psychotic and TD symptoms while a second DAT scan showed improvement status. We conclude that increased dopamine transporter uptake seemed to associate with the improvement of TD. © 2009 Elsevier B.V. All rights reserved