Olfactomedin 4 is a novel target gene of retinoic acids and 5-aza-2 '-deoxycytidine involved in human myeloid leukemia cell growth, differentiation, and apoptosis

Molecular and Clinical Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Blood (Impact Factor: 10.45). 12/2010; 116(23):4938-47. DOI: 10.1182/blood-2009-10-246439
Source: PubMed


Clinical application of retinoic acids (RAs) and demethylation agents has proven to be effective in treating certain myeloid leukemia patients. However, the target genes that mediate these antileukemia activities are still poorly understood. In this study, we identified olfactomedin 4 (OLFM4), a myeloid-lineage-specific gene from the olfactomedin family, as a novel target gene for RAs and the demethylation agent, 5-aza-2'-deoxycytidine. We demonstrated that the retinoic acid receptor alpha/retinoic X receptor alpha heterodimer binds to a retinoic acid response-element (DR5) site in the OLFM4 promoter and mediates all-trans-retinoic acid (ATRA)-induced transactivation of the OLFM4 gene. OLFM4 overexpression in HL-60 cells led to growth inhibition, differentiation, and apoptosis, and potentiated ATRA induction of these effects. Conversely, down-regulation of endogenous OLFM4 in acute myeloid leukemia-193 cells compromised ATRA-induced growth inhibition, differentiation, and apoptosis. Overexpression of OLFM4 in HL-60 cells inhibited constitutive and ATRA-induced phosphorylation of the eukaryote initiation factor 4E-binding protein 1 (4E-BP1), whereas down-regulation of OLFM4 protein in acute myeloid leukemia-193 cells increased 4E-BP1 phosphorylation, suggesting that OLFM4 is a potent upstream inhibitor of 4E-BP1 phosphorylation/deactivation. Thus, our study demonstrates that OLFM4 plays an important role in myeloid leukemia cellular functions and induction of OLFM4-mediated effects may contribute to the therapeutic value of ATRA.

Full-text preview

Available from:
  • Source
    • "The H3K27ac mark is present at this enhancer in LGR5 + stem cells but lost after differentiation. Previously, DNA methylation had also been correlated with OLFM4 expression in human cancer, and the proximal DMR we identified in the mouse Olfm4 gene contains six of the eight corresponding CpGs of the human promoter that are important for cancer-induced expression through retinoic acid signaling (Liu et al. 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The mammalian intestinal epithelium has a unique organization in which crypts harboring stem cells produce progenitors and finally clonal populations of differentiated cells. Remarkably, the epithelium is replaced every 3-5 d throughout adult life. Disrupted maintenance of the intricate balance of proliferation and differentiation leads to loss of epithelial integrity or barrier function or to cancer. There is a tight correlation between the epigenetic status of genes and expression changes during differentiation; however, the mechanism of how changes in DNA methylation direct gene expression and the progression from stem cells to their differentiated descendants is unclear. Using conditional gene ablation of the maintenance methyltransferase Dnmt1, we demonstrate that reducing DNA methylation causes intestinal crypt expansion in vivo. Determination of the base-resolution DNA methylome in intestinal stem cells and their differentiated descendants shows that DNA methylation is dynamic at enhancers, which are often associated with genes important for both stem cell maintenance and differentiation. We establish that the loss of DNA methylation at intestinal stem cell gene enhancers causes inappropriate gene expression and delayed differentiation.
    Full-text · Article · Mar 2014 · Genes & development
  • Source
    • "Olfactomedin 4 (OLFM4) is a member of the olfactomedin-related glycoprotein family, which is specifically expressed in neutrophils and the gastrointestinal tract [29], [30]. It plays an important role in myeloid leukemia cellular functions [31] and may be a novel target gene for retinoic acids and the demethylation agent, 5-aza-2′-deoxycytidine [31]. Most recently, by analyzing the expression of OLFM4 mRNA in myeloid cells from normal human bone marrow, it has been demonstrated that OLFM4 mRNA is a genuine constituent of neutrophil specific granules [32]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Identifying a distinct gene signature for myelofibrosis may yield novel information of the genes, which are responsible for progression of essential thrombocythemia and polycythemia vera towards myelofibrosis. We aimed at identifying a simple gene signature - composed of a few genes - which were selectively and highly deregulated in myelofibrosis patients. Gene expression microarray studies have been performed on whole blood from 69 patients with myeloproliferative neoplasms. Amongst the top-20 of the most upregulated genes in PMF compared to controls, we identified 5 genes (DEFA4, ELA2, OLFM4, CTSG, and AZU1), which were highly significantly deregulated in PMF only. None of these genes were significantly regulated in ET and PV patients. However, hierarchical cluster analysis showed that these genes were also highly expressed in a subset of patients with ET (n = 1) and PV (n = 4) transforming towards myelofibrosis and/or being featured by an aggressive phenotype. We have identified a simple 5-gene signature, which is uniquely and highly significantly deregulated in patients in transitional stages of ET and PV towards myelofibrosis and in patients with PMF only. Some of these genes are considered to be responsible for the derangement of bone marrow stroma in myelofibrosis. Accordingly, this gene-signature may reflect key processes in the pathogenesis and pathophysiology of myelofibrosis development.
    Full-text · Article · Jan 2014 · PLoS ONE
  • Source
    • "The current clinical trials for leukemia include the pharmaceutical medications, debilitating radiation, and a bone marrow transplant therapy but these strategies have not proven to be satisfied. Hence, new targets for treating leukemia are necessary and the best functions for agents are carried out through promoting differentiation or trigging apoptotic death in leukemia cells [7], [8]. Apoptosis, a process of programmed cell death type I, is a major method of anticancer properties to eliminate cancer cells [9]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The present study was to explore the biological responses of the newly compound, MJ-29 in murine myelomonocytic leukemia WEHI-3 cells in vitro and in vivo fates. We focused on the in vitro effects of MJ-29 on ER stress and mitochondria-dependent apoptotic death in WEHI-3 cells, and to hypothesize that MJ-29 might fully impair the orthotopic leukemic mice. Our results indicated that a concentration-dependent decrease of cell viability was shown in MJ-29-treated cells. DNA content was examined utilizing flow cytometry, whereas apoptotic populations were determined using annexin V/PI, DAPI staining and TUNEL assay. Increasing vital factors of mitochondrial dysfunction by MJ-29 were further investigated. Thus, MJ-29-provaked apoptosis of WEHI-3 cells is mediated through the intrinsic pathway. Importantly, intracellular Ca(2+) release and ER stress-associated signaling also contributed to MJ-29-triggered cell apoptosis. We found that MJ-29 stimulated the protein levels of calpain 1, CHOP and p-eIF2α pathways in WEHI-3 cells. In in vivo experiments, intraperitoneal administration of MJ-29 significantly improved the total survival rate, enhanced body weight and attenuated enlarged spleen and liver tissues in leukemic mice. The infiltration of immature myeloblastic cells into splenic red pulp was reduced in MJ-29-treated leukemic mice. Moreover, MJ-29 increased the differentiations of T and B cells but decreased that of macrophages and monocytes. Additionally, MJ-29-stimulated immune responses might be involved in anti-leukemic activity in vivo. Based on these observations, MJ-29 suppresses WEHI-3 cells in vitro and in vivo, and it is proposed that this potent and selective agent could be a new chemotherapeutic candidate for anti-leukemia in the future.
    Preview · Article · May 2012 · PLoS ONE
Show more