AN ANTISENSE OLIGODEOXYRIBONUCLEOTIDE TO M-CALPAIN MESSENGER-RNA INHIBITS MYOBLAST FUSION

Previous studies have led to the hypothesis of a possible role for m-c alpain (EC 3.4.22.17) in myoblast fusion in culture in vitro. To suppo rt this hypothesis, an antisense strategy has been used with cultured primary rat myoblasts. Using an appropriate antisense oligodeoxyribonu cleotide to m-calpain mRNA, an inhibition of myoblast fusion has been observed, the maximum being obtained when the cell culture was treated with 30 mu M of oligomer. Synthesis of m-calpain was decreased by 48% while high concentrations of antisense oligonucleotide do not signifi cantly affect myoblast proliferation. The specificity of m-calpain int ervention during fusion has also been confirmed using antisense oligon ucleotides to mu-calpain and p94 mRNAs, respectively.