Involvement of Prolonged Ras Activation in Thrombopoietin-Induced Megakaryocytic Differentiation of a Human Factor-Dependent Hematopoietic Cell Line

• DOI: 10.1128/mcb.18.7.4282
• Publication Date: 2015-10-10T00:32:32Z
• Authors: Itaru Matsumura; Koichi Nakajima; Hiroshi Wakao; Seisuke Hattori; Koji Hashimoto; Hiroyuki Sugahara; Takashi Kato; Hiroshi Miyazaki; Toshio Hirano; Yuzuru Kanakura
• Keywords: Thrombopoiesis; Megakaryocytopoiesis

Thrombopoietin (TPO) is a hematopoietic growth factor that plays fundamental roles both megakaryopoiesis and thrombopoiesis through binding to its receptor, c-mpl. Although TPO has been shown activate various types of intracellular signaling molecules, such as the Janus family protein tyrosine kinases, signal transducers activators transcription (STATs), ras, precise mechanisms underlying TPO-induced proliferation differentiation remain unknown. In an effort clarify differentiation, c-mpl was introduced into F-36P, human interleukin-3 (IL-3)-dependent erythroleukemia cell line, effects on c-mpl-transfected F-36P (F-36P-mpl) cells were investigated. F-36P-mpl found proliferate differentiate at high rate mature megakaryocytes in response TPO. Dominant-negative (dn) forms STAT1, STAT3, STAT5, ras inducibly expressed cells, their megakaryocytic analyzed. Among these dn STAT5 reduced TPO- or IL-3-induced by ∼30%, only could inhibit differentiation. accord with this result, overexpression activated (H-rasG12V) for 5 days led cells. time course analysis H-rasG12V-induced activation pathway 24 28 h required sufficient induce Consistent treatment able prolonged more than h, whereas IL-3 had transient effect. These results suggest may be involved