To determine whether the erythropoietin receptor (Epo-R) plays a role in the course of malignant erythropoietic disorders, this gene was studied in murine and human erythroleukemia cells. An altered Epo-R gene was found in a murine Friend erythroleukemia cell line, FCL1, due to a spleen focus-forming virus (SFFV) long terminal repeat insertion within the noncoding region of the first exon, lead...

To study oncogenesis in the erythroid lineage, we have generated transgenic mice carrying the human c-MYC proto-oncogene under the control of mouse GATA-1 regulatory sequences. Six transgenic lines expressed the transgene and displayed a clear oncogenic phenotype. Of these, five developed an early onset, rapidly progressive erythroleukemia that resulted in death of the founder animals 30-50 d a...

Members of the mitogen-activated protein kinase (MAPK) family, including Jun amino-terminal kinase (JNK) and extracellular signal-related kinase (ERK), play an important role in the proliferation of erythroid cells in response to erythropoietin (Epo). Erythroid cells infected with the Friend spleen focus-forming virus (SFFV) proliferate in the absence of Epo and show constitutive activation of ...

Well-coupled mitochondria of hematopoietic tumors were iso lated from mouse erythroleukemia and rat chloroma tumors grown in male DBA/2J mice and Long-Evans rats, respectively. We used erythroleukemia and chloroma mitochondria to deter mine their ability to utilize glutamine as an energy source for adenosine triphosphate formation. Oxypolarographic tests showed the following, (a) Presence of a ...

DNA from mammalian cells has been shown to contain significant amounts of 5-methyl cytosine resulting from enzymatic transfer of methyl groups from s-adenosylmethionine to cytosine residues in the DNA polymer. The function of this modification is not known. We have found that DNA synthesized during chemically induced differentiation of friend erythroleukemia cells is hypomethylated, as measured...

Well-coupled mitochondria of hematopoietic tumors were isolated from mouse erythroleukemia and rat chloroma tumors grown in male DBA/2J mice and Long-Evans rats, respectively. We used erythroleukemia and chloroma mitochondria to determine their ability to utilize glutamine as an energy source for adenosine triphosphate formation. Oxypolarographic tests showed the following. (a) Presence of a pr...

HEMATOLOGICAL MALIGNANCIES IN HUMANS TYPICALLY INVOLVE TWO TYPES OF GENETIC CHANGES: those that promote hematopoietic cell proliferation and survival (often the result of activation of tyrosine kinases) and those that impair hematopoietic cell differentiation (often the result of changes in transcription factors). The multi-stage erythroleukemia induced in mice by Friend spleen focus-forming vi...

It’s a depressingly familiar sight when an oil well blows or a tanker runs aground: thousands of stranded, helpless animals wallowing in cloying crude oil. ‘Birds are often used as the poster children for the deadly effects of oil’, says Ivan Maggini from Western University, Canada, recalling the shocking images of struggling animals that accompanied the catastrophic Deepwater Horizon oil spill...

Defining how the stromal requirements of hematopoietic progenitors change during leukemia progression is an important topic that is not well understood at present. The murine ELM erythroleukemia is an interesting model because the erythroid progenitors retain dependence on bone marrow-derived stromal cells for long-term growth in vitro, and they also undergo erythroid differentiation in the pre...