ACTIVATION OF THE HUMAN HOMOLOG OF THE DROSOPHILA-SINA GENE IN APOPTOSIS AND TUMOR SUPPRESSION

Developmentally regulated genes in Drosophila, which are conserved thr ough evolution, are potential candidates for key functions in biologic al processes such as cell cycle, programmed cell death, and cancer. We report cloning and characterization of the human homologue of the Dro sophila seven in absentia gene (HUMSIAH), which codes for a 282 amino acids putative zinc finger protein, HUMSIAH is localized on human chro mosome 16q12-q13, This gene is activated during the physiological prog ram of cell death in the intestinal epithelium, Moreover, human cancer -derived cells selected for suppression of their tumorigenic phenotype exhibit constitutively elevated levels of HUMSIAH mRNA, A similar pat tern of expression is also displayed by the p21(waf1). These results s uggest that mammalian seven in absentia gene, which is a target for ac tivation by p53, may play a role in apoptosis and tumor suppression.