Murine c-myc retroviruses alter the growth requirements of myeloid cell lines.

Recombinant retroviruses encoding a murine c-myc gene were utilised to explore the consequences of constitutive c-myc expression for interleukin 3-dependent murine myeloid cell lines. The c-myc virus-infected cells exhibited a diminished requirement for growth factor and serum when grown in soft agar, but no factor-independent cells could be isolated and the cells were not tumorigenic. Thus deregulated expression of a c-myc gene at physiological levels apparently renders myeloid cells more responsive to growth factors but cannot abrogate this requirement or render the cells malignant.