Lorna Pearn

Learn More
Although hyperactivation of Ras is a common feature of myeloid malignancy, its role in subverting hematopoiesis is unclear. We have examined the influence of Ras on normal human uncommitted myeloid subsets and show that expression of this oncogene strongly favors monocyte lineage selection in bipotential granulocyte/macrophage progenitors while inhibiting(More)
Excessive production of reactive oxygen species (ROS) is a feature of human malignancy and is often triggered by activation of oncogenes such as activated Ras. ROS act as second messengers and can influence a variety of cellular process including growth factor responses and cell survival. We have examined the contribution of ROS production to the effects of(More)
The t(8;21) translocation, which encodes the AML1-ETO fusion protein (now known as RUNX1-CBF2T1), is one of the most frequent translocations in acute myeloid leukemia, although its role in leukemogenesis is unclear. Here, we report that exogenous expression of AML1-ETO in human CD34(+) cells severely disrupts normal erythropoiesis, resulting in virtual(More)
RAS mutations are one of the most frequent molecular abnormalities associated with myeloid leukemia and preleukemia, yet there is a poor understanding of how they contribute to the pathogenesis of these conditions. Here, we describe the consequences of ectopic mutant N-Ras (N-Ras*) expression on normal human erythropoiesis. We show that during early(More)
Excessive production of reactive oxygen species (ROS) is frequently observed in cancer and is known to strongly influence hematopoietic cell function. Here we report that extracellular ROS production is strongly elevated (mean >10-fold) in >60% of acute myeloid leukemia (AML) patients and that this increase is attributable to constitutive activation of(More)
PDK1 is a master kinase that activates at least six protein kinase groups including AKT, PKC and S6K and is a potential target in the treatment of a range of malignancies. Here we show overexpression of PDK1 in over 40% of myelomonocytic acute leukemia patients. Overexpression of PDK1 occurred uniformly throughout the leukemic population, including putative(More)
Though both low-speed centrifugation and the use of fibronectin (Retronectin) fragments increase gene transduction efficiency, they still do not overcome the adverse effects of the presence of virus-containing medium (VCM). In this study, we improved transduction efficiency of primitive human hematopoietic cells by optimizing the conditions for preadsorbing(More)
Hyperactivation of Ras is one of the most common abnormalities in acute myeloid leukemia. In experimental models, Ras inhibits myeloid differentiation, which is characteristic of leukemia; however, the mechanism through which it disrupts hematopoiesis is poorly understood. In multipotent FDCP-mix cells, Ras inhibits terminal neutrophil differentiation,(More)
(1930 articles) Signal Transduction (4217 articles) Neoplasia Articles on similar topics can be found in the following Blood collections Information about subscriptions and ASH membership may be found online at: digital object identifier (DOIs) and date of initial publication. the indexed by PubMed from initial publication. Citations to Advance online(More)
  • 1