Cytosolic
5'-nucleotidase II (cN-II) has been reported to be involved in cell survival,
nucleotide metabolism and in the cellular response to anticancer drugs. With the aim to further evaluate the role of this
enzyme in cell biology, we stably modulated its expression the human
glioblastoma cell ADF in which the transient inhibition of cN-II has been shown to induce cell death. Stable cell lines were obtained both with inhibition, obtained with plasmids coding cN-II-targeting
short hairpin RNA, and stimulation, obtained with plasmids coding Green Fluorescence
Protein (GFP)-fused wild type cN-II or a GFP-fused hyperactive mutant (GFP-cN-II-R367Q), of cN-II expression. Silenced cells displayed a decreased proliferation rate while the over expressing cell lines displayed an increased proliferation rate as evidenced by impedance measurement using the xCELLigence device. The expression of
nucleotide metabolism relevant genes was only slightly different between cell lines, suggesting a compensatory mechanism in transfected cells. Cells with decreased cN-II expression were resistant to the
nucleoside analog fludarabine confirming the involvement of cN-II in the metabolism of this drug. Finally, we observed sensitivity to
cisplatin in cN-II silenced cells and resistance to this same drug in cN-II over-expressing cells indicating an involvement of cN-II in the mechanism of action of
platinum derivatives, and most probably in DNA repair. In summary, our findings confirm some previous data on the role of cN-II in the sensitivity of
cancer cells to
cancer drugs, and suggest its involvement in other cellular phenomenon such as cell proliferation.