Antisense oligodeoxynucleotides targeted against different regions of cyclin D1 mRNA may exert different inhibitory effects on cell growth and gene expression.

The alteration of cyclin D1 gene expression is a common feature of malignancies of diverse histogenesis. Our recent results showed that over expression of cyclin D1 protein is frequently found in human ovarian cancer. In this study, we investigated the effect of cyclin D1 antisense oligodeoxynucleotides on cell growth and gene expression in PA-1 ovarian cancer cells. Our results demonstrated that cyclin D1 antisense oligodeoxynucleotides indeed functioned as an antiproliferative agent. More strikingly, we found that different cyclin D1 antisense oligodeoxynucleotides exert different efficacy on the inhibition of cell growth and gene expression. We suggest that selection and characterization of high affinity oligodeoxynucleotides is strictly required before the application of antisense technology.