Tetra-O-methyl nordihydroguaiaretic acid induces growth arrest and cellular apoptosis by inhibiting Cdc2 and survivin expression

We previously reported that Sp1-dependent Cdc2 gene expression is inhibited by tetra-O-methyl nordihydroguaiaretic acid (M4N) and that M4N is likely responsible for causing growth arrest in M4N-treated transformed C3 cells. Here, we show that after M4N treatment and cell-cycle arrest, expression of the Sp1-dependent survivin gene, a member of the inhibitor of apoptosis family, is also suppressed, and the mitochondrial apoptotic pathway is activated. To confirm that inhibition of Cdc2 and survivin gene expression is necessary for M4N-induced growth arrest and apoptosis, we tested the effect of adding Cdc2 and survivin back to M4N-treated cells. Cell division was transiently restored in the presence Of M4N after transfection of an exogenous Cdc2 gene copy under the control of the Sp1-independent cytomegalovirus promoter. Caspase-3 activation was also reduced by 50% and 75% in transiently and stably survivin-transfected C3 cells, respectively. The results suggest that M4N induces growth arrest and apoptosis by suppressing Cdc2 and survivin expression, which constitutes the cellular basis of its antitumoric action.