EFFECT OF CLOSTRIDIUM-PERFRINGENS DERIVED WOUND-HEALING SUBSTANCE AS COMPARED WITH EPIDERMAL GROWTH-FACTOR ON THE GROWTH AND MORPHOLOGICAL TRANSFORMATION OF BALB 3T3 A31-1-1 CELLS/

Clostridium perfringens-derived wound-healing substance (WHS), having growth-stimulating activity, was examined to determine its effect on t he growth and morphological transformation of BALB/3T3 A31-1-1 cells. WHS accelerated the cell growth at the exponential growth phase, short ening the doubling time by 8-18%. The maximum cell density of the trea ted cultures was slightly higher than that of the control culture, and the cell number decreased in the same way as the control cells did. O n the other hand, the cells treated with epidermal growth factor (EGF) or insulin showed growth rates similar to that of the control cells d uring the exponential growth phase, and after the control cells attain ed the maximum cell number, the number of the treated cells continued to increase gradually for more than 4 days and then decreased. Under t he experimental conditions of the two-stage transformation assay, appl ication of WHS at the tumor-initiation or promotion stage did not acce lerate the formation of transformed foci. Although treatment with EGF at the initiation stage induced no enhancement, marked enhancement of morphological transformation was observed in the treatment at the prom otion stage. These results indicate that the mode of action between WH S and EGF or insulin is different on the growth-stimulating activity a nd morphological transformation of BALB/3T3 A31-1-1 cells.