Novel method for selective killing of transformed rodent cells through intercellular communication, with possible therapeutic applications.

A novel method for killing transformed cells selectively, without affecting surrounding nontransformed cells, has been developed. The method is based on our finding that transformed cells form their own gap-junctional communication compartment which is independent of that of adjacent nontransformed cells; transformed cells and adjacent normal cells transfer molecules through gap junctions among their homologous cells, but there is no heterologous transfer. Thus, when Lucifer Yellow CH is microinjected into transformed cells, it spreads only among the transformed cells and not to surrounding nontransformed cells. Subsequent irradiation of cells with blue light (around 430 nm) kills only those cells containing Lucifer Yellow CH (i.e., transformed cells), and surrounding normal cells continue to grow after treatment. We succeeded in killing BALB/c 3T3 transformed foci induced in situ by a chemical carcinogen or by an activated oncogene, and in killing tumorigenic rat liver epithelial cells cocultured with nontumorigenic counterparts. Potential development of this phenomenon for cancer therapy is suggested.