An antisense oligodeoxyribonucleotide to m-calpain mRNA inhibits myoblast fusion.

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