INHIBITION OF GAP JUNCTIONAL INTERCELLULAR COMMUNICATION AND ENHANCEMENT OF GROWTH IN BALB C 3T3 CELLS TREATED WITH CONNEXIN43 ANTISENSE OLIGONUCLEOTIDES/

Many studies have correlated reductions in gap junctional intercellula r communication (GJIC) with altered cellular growth, tumor promotion, and neoplastic transformation. To test directly whether reduced GJIC a ffects cellular growth, GJIC was inhibited in murine BALB/c 3T3 fibrob lasts by treatment with a phosphorothioate-modified antisense oligonuc leotide targeted against the connexin43 translation start codon, and i n vitro cell growth was monitored. The eel Is were incubated with the oligonucleotide (0.1-0.5 mu M) in liposomes in serumless culture mediu m for 16 h; washed and refed with serum-containing medium; and analyze d for dye-coupling, connexin43 protein and mRNA levels, and cell growt h over the next 5 d. The antisense oligonucleotide inhibited dye-coupl ing and reduced connexin43 protein levels in a concentration-dependent manner but had no effect on connexin43 mRNA levels. Cell growth rate was not affected, but saturation density was increased approximately t hreefold by the oligonucleotide. These data support a role for GJIC in the establishment of contact inhibition of in vitro cell growth. (C) 1995 Wiley-Liss, Inc.