A murine recombinant retrovirus containing the src oncogene transforms erythroid precursor cells in vitro

Area of Science:

• Molecular Biology
• Hematology
• Virology

Background:

• Murine retrovirus (MRSV) induces erythroproliferative disease in mice.
• The virus contains the src gene from Rous sarcoma virus.

Purpose of the Study:

• To investigate the in vitro transformation of erythroid progenitor cells by MRSV.
• To determine the effects of pp60src expression on erythroid cell differentiation and erythropoietin sensitivity.

Main Methods:

• Infection of fetal liver cells and adult mouse bone marrow/spleen cells with MRSV.
• Culture of infected cells in methylcellulose to assess colony formation.
• Immune complex protein kinase assay to detect pp60src activity.

Main Results:

• MRSV transformed erythroid progenitor cells (6- to 8-day burst-forming units) in vitro.
• Transformed cells expressed active pp60src and exhibited increased growth.
• Differentiation and hemoglobinization were not blocked; erythropoietin sensitivity was enhanced.
• MRSV transformation was independent of the Fv-2 locus.

Conclusions:

• MRSV directly affects erythroid progenitors, causing in vivo erythroproliferation.
• Transformed erythroid precursors gain a growth advantage but retain differentiation capacity and responsiveness to erythropoietin.