Expression of two dead box gene (DDX1 amd DDX6) is independent of that of MYCN in human neuroblastoma cell lines

Abstract

Summary. To examine whether two DEAD box genes, DDX1 and DDX6, would have some roles in the progression of tumors, we investigated the correlation of the expression of these genes with that of MYCN in neuroblastomas either with or without MYCN amplification. The mRNA of MYCN was observed only in the cell lines with amplification of MYCN. The mRNAs of DDX1 and DDX6 were found in all the cell lines examined, but the correlation between the mRNA levels of DDX1 or DDX6 and MYCN was poor. These findings suggest that the expression of neither DEAD box gene is correlated with the gene expression of MYCN.

The E1∧E4 Protein of Human Papillomavirus Type 16 Associates with a Putative RNA Helicase through Sequences in Its C Terminus

“…Like SrmB, DeaD, and RhlB, the human Ddx1 protein also shared homology with E4-DBP in its Nterminal extension. Ddx1 and MrDb are frequently upregulated along with myc in human cancers and are thought to confer a proliferative advantage to cells (1,26,37). Only one protein showed homology with E4-DBP throughout its length (Caenorhabditis elegans protein; GenBank accession number Z29115) (Fig.…”

“…With the exception of eIF4A, which is involved in unwinding mRNAs at their 5Ј ends (64), the roles of most DEAD box proteins are poorly defined. Several have been found to affect cell proliferation (1,10,26,27,37,60,72), although in most cases, the direct effect on RNA processing which gives rise to this phenotype is not known. Among proteins with known functions, E4-DBP shares the greatest homology with Rrp3 (55) in its central domain and with the E. coli DEAD box protein SrmB (43) in its N-terminal extension.…”