MOUSE EMBRYONIC TRANSFORMING GROWTH-FACTORS RELATED TO THOSE ISOLATED FROM TUMOR-CELLS

Abstract

Growth factors with the 2 characteristic properties of sarcoma growth factor, the ability to stimulate anchorage-independent growth of normal mouse or rat fibroblasts and the ability to compete with 125I-labeled epidermal growth factor for receptor binding, can be isolated from 12-13-day-old normal mouse embryos of various strains. Two size classes of the transforming factor from embryo cells can be isolated with apparent MW of 20,000 and 10,000. The lower MW factor was purified several hundred-fold and has the same properties as the peptide with a MW of 10,000 produced by mouse sarcoma virus-transformed 3T3 cells. Whole-mouse sarcoma virus-transformed 3T3 cells. Whole-mouse embryos contain .apprx. 10% as much sarcoma growth factor per gram of tissue as do the murine sarcoma virus-transformed cells; how it is distributed among the embryonic tissues remains to be determined.