Gabriel Ghiaur

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Connexin-43 (Cx43), a gap junction protein involved in control of cell proliferation, differentiation and migration, has been suggested to have a role in hematopoiesis. Cx43 is highly expressed in osteoblasts and osteogenic progenitors (OB/P). To elucidate the biologic function of Cx43 in the hematopoietic microenvironment (HM) and its influence in(More)
Despite antiretroviral therapy (ART), human immunodeficiency virus (HIV)-1 persists in a stable latent reservoir, primarily in resting memory CD4(+) T cells. This reservoir presents a major barrier to the cure of HIV-1 infection. To purge the reservoir, pharmacological reactivation of latent HIV-1 has been proposed and tested both in vitro and in vivo. A(More)
UNLABELLED MicroRNAs (miRs) recently emerged as prominent regulators of cancer processes. In the current study we aimed at elucidating regulatory pathways and mechanisms through which miR-494, one of the miR species found to be down-regulated in cholangiocarcinoma (CCA), participates in cancer homeostasis. miR-494 was identified as down-regulated in CCA(More)
Identifying cellular reservoirs of human immunodeficiency virus type 1 (HIV-1) in patients on antiretroviral therapy (ART) is critical to finding a cure for HIV-1. In addition to resting CD4(+) T cells, CD34(+) hematopoietic progenitor cells have been proposed as another reservoir. We obtained bone marrow aspirates from 11 patients on ART who had(More)
Ras-related Rho GTPases regulate actin cytoskeletal organization, adhesion, gene transcription, and cell-cycle progression. The Rac subfamily of Rho GTPases and Cdc42 has been shown to play essential roles in hematopoietic stem cell (HSC) engraftment and mobilization. Here, we study the role of RhoA, a related Rho GTPase, in HSC functions. Using(More)
Hematopoietic stem cell (HSC) aging has become a concern in chemotherapy of older patients. Humoral and paracrine signals from the bone marrow (BM) hematopoietic microenvironment (HM) control HSC activity during regenerative hematopoiesis. Connexin-43 (Cx43), a connexin constituent of gap junctions (GJs) is expressed in HSCs, down-regulated during(More)
Evidence gathered over the past two decades confirms earlier reports that suggested that hematologic malignancies exhibit a hierarchical differentiation structure similar to normal hematopoiesis. There is growing evidence that some solid tumors may also exhibit a differentiation program similar to the normal tissue of origin. Many excellent reviews on the(More)
FMS-like tyrosine kinase 3 (FLT3)-mutant acute myeloid leukemia (AML) portends a poor prognosis, and ineffective targeting of the leukemic stem cell (LSC) population remains one of several obstacles in treating this disease. All-trans retinoic acid (ATRA) has been used in several clinical trials for the treatment of nonpromyelocytic AML with limited(More)
The high expression of aldehyde dehydrogenase 1, also known as retinaldehyde dehydrogenase, by hematopoietic stem cells (HSCs) suggests an important role for retinoic acid (RA) signaling in determining the fate of these cells. We found that primitive human bone marrow-derived CD34(+)CD38(-) cells not only highly express aldehyde dehydrogenase 1, but also(More)
C/EBPα is required for the formation of granulocyte-monocyte progenitors; however, its role in subsequent myeloid lineage specification remains uncertain. Transduction of murine marrow with either of two Cebpa shRNAs markedly increases monocyte and reduces granulocyte colonies in methylcellulose or the monocyte to neutrophil ratio in liquid culture. Similar(More)