lal-1:: a differentially expressed novel gene during proliferation in liver regeneration and in hepatoma cells

Background: During liver regeneration, 95% of the resting hepatocytes enter in G1/S phase of the cell cycle. A number of hormones, growth factors and cytokines were identified that activate signal transduction pathways playing a primary role in hepatocyte proliferation. A wide and representative cDNA library containing 1.5 x 10(6) independent clones was constructed from regenerating liver in order to identify and characterize gene the products which play a crucial role in the first hours of the proliferative process of liver regeneration. Results: A novel gene expressed in liver regeneration was cloned by subtractive hybridization. The putative protein displays in the N'-terminal a annexin-like domain and an aminopeptidase domain. We named the novel gene Liver Annexin Like1 (lal-1 ). The lal-1 gene is modulated during liver regeneration, in hepatoma cells following physiological stimulation and after cAMP induction. Conclusion: The results indicate that lal-1 is involved in liver regeneration and that its expression is finely regulated during proliferative process. The isolation of lal-1 paves the way for a further characterization helping to assess lal-1 involvement in cell function and proliferation.