[Proliferative activity of normal, transformed and tumor cells in in vitro contact with Syrian hamster neutrophils]

The effect of casein-induced peritoneal neutrophils (Nph) of Syrian hamsters on the proliferative activity of normal, embryonal, transformed, and tumour cells was determined by their ability to inhibit or to stimulate 3H-thymidine incorporation in the replicating target cells. The enhanced proliferation of normal embryonal cells (HE) of hamsters was observed after their in vitro contact with Nph, in contrast to the cells of SFHE (spontaneously transformed in vitro HE cells of low tumourigenicity) which were highly susceptible to cytostatic activity of Nph. The high-tumourigenic cells of Syrian hamster tumour strains in vivo or in vitro transformed by Rous sarcoma virus (RSV) were highly resistant to cytostatic activity of Nph.