Non-reciprocal interactions in normal-neoplastic human cells. A quantitative, kinetic approach to cell interactions in vitro.

The mechanism of altered neoplastic growth has been investigated using a co-culture system for a kinetic study of normal-neoplastic human cell interactions in vitro. It was concluded that the cancer cells produced a growth factor for normal cells whereas normal cells produced both labile inhibitory and stable growth factors for cancer cells. Inhibition of the cancer cells was found to be proportional to normal cell growth rate. These heterologous growth interactions were potentiated through diffusable factors.