PRAME induces apoptosis and inhibits proliferation of leukemic cells in vitro and in vivo.

PRAME is a germinal tissue-specific gene that is expressed at high levels in haematological malignancies, but the physiological functions of PRAME in leukemia cells are unknown. It has reported that PRAME was found to be predominantly expressed in acute leukemias and high PRAME expression is correlated with a favorable prognosis in childhood acute leukemias, which suggested that PRAME could be involved in the regulation of cell death or apoptosis. In the present study, we tested a hypothesis that the PRAME gene plays a role in the regulation of apoptosis and proliferation of leukemia cells. We observed that KG-1 cells transient overexpressing the PRAME gene (when transfected with pcDNA3.1-PRAME plasmid) significantly induces apoptosis and decreases proliferation in vitro, and repression of PRAME expression by a short interfering RNA exhibited a increased proliferation in K562 cells in vitro and increases tumorigenicity of K562 leukemic cells in nude mice. Our results suggest that the leukemias expressing high levels of PRAME has favorable prognosis. PRAME may be as an attractive target for potential immunotherapy for acute leukemic.