Gene expression profiling of Nm23-H2 overexpressing CAL 27 cells using DNA microarray.

Nm23-H1/NDPKA and Nm23-H2/NDPKB belong to a large family of NDP kinases, group of structurally and functionally closely related enzymes. The Nm23/NDPs are known to catalyse the transfer of terminal phosphates from ATP to other NTPs and dNTPs. Besides their role in the maintenance of the cells NTP pool the nm23 genes/proteins are known to have additional different biological functions, the most important being its metastasis suppressor activity. The complete picture of roles, actions and targets of nm23 genes/proteins is yet to be discovered. Our goal was to identify the downstream targets of Nm23-H2 by subjecting Nm23-H2 overexpressing CAL 27 cells (oral squamous cell carcinoma of the tongue) to microarray analysis. Using this powerful technology we identified genes, groups of genes and signalling pathways that could be clustered into several groups: apoptosis related genes, cell cycle and DNA damage, TGFbeta (transforming growth factor beta) signalling pathway and related molecules, WNT signalling pathway, differentiation and epithelial structural and related molecules, cell adhesion, metalloproteinases and their inhibitors, vesicular transport related molecules, proteasome associated, ubiquitin mediated proteolysis and several metabolic pathways. Based on these results we suggest that nm23-H2 might have an important role in oral squamous cell carcinoma which is to be confirmed by future studies.