BTB/POZ Domain Containing Protein 7 (BTBD7)

By cDNA/EST microarray analysis, Pan et al. (2001) identified BTBD7, which they called FUP1, as a gene expressed preferentially in hepatocellular carcinoma compared to normal liver. The deduced protein contains a predicted nucleus-targeting motif. Transient transfection of FLAG-tagged FUP1 in NIH3T3 cells confirmed the nuclear localization. Northern blot analysis detected highest expression of FUP1 in heart, with low expression in all other tissues tested.

FUP1-transfected NIH3T3 cells displayed increased cellular proliferation, whereas antisense FUP1-transfected hepatoma cells displayed decreased proliferation. In addition, injection of FUP1-transfected NIH3T3 cells into nude mice induced tumor formation. Pan et al. (2001) concluded that FUP1 stimulates cell proliferation and tumor formation.