Inhibition of Proliferation By C-myb Antisense Rna and Oligodeoxynucleotides in Transformed Neuroectodermal Cell-lines

Transfection of a neuroblastoma cell line with expression vector scontaining two different segments of human c-mybcomplementary DNAin antisense orientation yielded far fewer transfectant clones than didthe transaction with the identical segments in sense orientation. In cellclones expressing c-myb antisense RNA, levels of the c-myb proteinwere down-regulated and the proliferation rate was slower than that of cells transfected with sense constructs or the untransfected parental cellline. Treatment of neuroblastoma and neuroepithelioma cell lines with ac-myb antisense oligodeoxynucleotide strongly inhibited cell growth. These data indicate a definite involvement of c-myh in the proliferationof neuroectodermal tumor cells extending the role of this protooncogenebeyond the hematopoietic system. The availability of cell clones thattranscribe c-myh antisense RNA provides a useful tool to study theinvolvement of other genes in the proliferation and differentiation ofneuroblastoma cells.