Growth inhibition by adenosine 3',5-monophosphate derivatives does not require 3',5' phosphodiester linkage

Analogs of adenosine 3',5'-monophosphate (cyclic AMP) inhibit the growth of cultured cell lines. The effects of 8-bromo- and N6-butyryl-substituted analogs of cyclic and noncyclic AMP on six cell lines were examined and were equally inhibitory. Variant cell lines with altered cyclic AMP-dependent protein kinase were more resistant to both cyclic and noncyclic nucleotides. We conclude that growth inhibition by analogs of cyclic AMP (i) does not require a 3',5' phosphodiester bond and (ii) may be mediated by a pathway involving endogenous cyclic AMP.