EXTENSION OF BRANCHING-PROCESSES FROM HYBRIDS OF BRAIN AND CHINESE-HAMSTER OVARY CELLS

Stable hybrids formed by fusion of auxotrophic mutants of the transformed CHO-Kl cells with cells isolated from biopsies of Chinese hamster and human brains respectively have been established and characterized. All hybrids exhibited an altered response to cyclic AMP derivatives as compared to the previously described Reverse Transformation reaction exhibited by the parental CHO-Kl cell. Most of such cloned hybrids exhibited little response to cAMP derivatives. Occasional clones extended thin branched processes forming a network-like arrangement. Testololactone synergizes the extension of these processes, Colcemid inhibits it, and cycloheximide does not affect the reaction, in parallel with their respective effects on Reverse Transformation. However, cytochalasin B which inhibits Reverse Transformation and butyrate which affects it in a complex fashion have little or no effect on this process extension. Human chromosomal constitutions of positively and negatively reacting hybrids with human brain cells have been partially characterized. © 1979.