A CONNEXIN-43 ANTISENSE VECTOR REDUCES THE ABILITY OF NORMAL-CELLS TOINHIBIT THE FOCI FORMATION OF TRANSFORMED-CELLS

Antisense gene constructs have been very useful in the functional anal ysis of genes and their products. In this report we used a connexin 43 (Cx43) antisense gene construct to study the role that heterologous g ap-junctional intracellular communication (GJIC) plays in the ability of untransformed fibroblasts to suppress the foci-forming ability of s rc oncogene-transformed cells. Untransformed Rat-1 fibroblasts transfe cted with the Cx43 antisense DNA construct showed marked decreases in Cx43 RNA and protein, which were accompanied by a corresponding decrea se in GJIC. These Cx43 antisense-transfected cells maintained normal c ell morphology, growth rates, and saturation densities and did not gro w in soft-agar suspension. However, in coculture experiments, the Cx43 antisense cells were less effective than vector-alone-transfected, se nse-transfected, and untransfected cells at inhibiting foci formation of pp60(v-src)-transformed cells. These effects of junctionally compet ent, normal cells were associated with the existence of heterologous G JIC with the transformed cells and did not appear to result from the e laboration of a stable, diffusible inhibitory factor. Thus, gap-juncti on-mediated transfer of putative regulatory molecules may play a role in the ability of untransformed cells to suppress the expression of ce rtain properties of transformed cells. (C) 1994 Wiley-Liss, Inc.