AEV-transformed chicken erythroid cells secrete autocrine factors which promote soft agar growth and block erythroleukemia cell differentiation.

LSCC HD3 chicken erythroleukemia cells, transformed by a temperature-sensitive avian erythroblastosis virus (tsAEV), secreted into the medium several transforming factors which after separation by Bio-Cel P-60 chromatography, stimulated quiescent (G0) chicken embryo fibroblasts and NIH 3T3 mouse cells to replicate DNA in serum-free medium and to form colonies in soft agar. Most of these factors were also mitogenic for the LSCC HD3 cells themselves when they were rendered phenotypically untransformed by incubation at 42 degrees C to inactivate the ts AEV. The transformed LSCC HD3 cells also secreted a non-mitogenic 40 kDa factor which blocked the erythropoietin-induced differentiation of untransformed LSCC HD3 (at 42 degrees C) and the DMSO-induced differentiation of Friend murine erythroleukemia cells into hemoglobin-synthetizing erythroid cells.