The ETS oncogene family member PU.1 is a transcriptional activator that is dysregulated by Friend erythroleukemia virus insertion. Northern analysis found that PU.1 is highly expressed in cells of myeloid and B-lymphoid origin, but not expressed at all in a number of nonhematopoietic tissues. Interferon-gamma and retinoic acid downregulated PU.1 expression in marrow macrophages. In situ immunoh...

The rotational diffusion of concanavalin A receptors of viable Friend erythroleukemia cells and the band 3 anion transport system of human erythrocytes has been measured via the time-dependent phosphorescence emission intensity and anisotropy of triplet probes excited by a 5-ns laser pulse. High-quality phosphorescence decay curves with a 10-microseconds time resolution were obtained at concent...

In vitro differentiation of murine erythroleuekemia cells recapitulates many aspects of the erythroid terminal differentiation program, including hemoglobin synthesis and proliferation arrest. It also provides an opportunity to study the changes occurring during reprogramming of tumor cells into their normal differentiation program. This review is focused on the recent progress made in understa...

Friend spleen focus-forming virus (F-SFFV) is a replicationdefective retrovirus that induces a multistage erythroleukemia in mice. In the first stage, expression of the SFFV envelope glycoprotein results in erythroid hyperplasia. Subsequently, the F-SFFV integrates near the Spi-1 gene and activates its expression, resulting in immortalized cells that represent a second stage in the disease proc...

Bishydroxamic acids are effective inducers of differentiation in murine erythroleukemia cells. Flexible analogs of suberic acid bisdimethylamide are approximately 100 times as active as the parent compound or hexamethylenebisacetamide. They also induce differentiation of human promyelocytic leukemia cells (HL-60) and a subclone of human colon carcinoma cells (HT-29-U4). Some rigid bishydroxamic...

During normal hematopoietic differentiation, lineage-specific cell surface antigens have been identified in both avian (1) and mammalian (2) species. These differentiation antigens can be found in most cellular compartments of the hematopoietic system and have added a new dimension to the classical morphologic identification of individual cell types during normal differentiation and leukemia. I...

Disruption of the transforming growth factor(TGF) pathway is observed in the majority of cancers. To further understand TGFpathway inactivation in cancer, we stably expressed the v-ErbA oncoprotein in TGFresponsive cells. v-ErbA participates in erythroleukemic transformation of cells induced by the avian erythroblastosis virus (AEV). Here we demonstrate that expression of v-ErbA was sufficient ...

A spectrin-based membrane skeleton is important for the stability and organization of the erythrocyte. To study the role of spectrin in cells that possess complex cytoskeletons, we have generated alpha-spectrin-deficient erythroleukemia cell lines from sph/sph mice. These cells contain beta-spectrin, but lack alpha-spectrin as determined by immunoblot and Northern blot analyses. The effects of ...

Janus kinase 2 (JAK2) is a non-receptor tyrosine kinase that regulates the signal transducer and activator of transcription (STAT) signaling pathway. Deregulation of JAK2 signaling has previously been observed in hematologic malignancies, including erythroleukemia. In the present study, an aminopyridine derivative compound, KRC-180, exhibited direct inhibition of the JAK2 protein at the catalyt...