Abstract: The present invention relates to: pharmaceutical compositions for inducing apoptosis in cells, the pharmaceutical compositions comprising a prostacyclin synthase gene as an active ingredient; pharmaceutical compositions for gene therapy of cancer, the pharmaceutical compositions comprising the above pharmaceutical compositions for inducing apoptosis as an active ingredient; and a screening method for an agent that induces apoptosis in a cell, the method comprising determining the activation of peroxisome proliferator-activated receptor (PPAR)-? in the presence of a test substance. The pharmaceutical composition of the present invention for inducing apoptosis enables treatment of diseases on which induction of apoptosis has a therapeutic effect. In addition, the pharmaceutical composition of the present invention for gene therapy can lead cancer cells to cell death. Furthermore, the screening method of the present invention can be used conveniently to screen for agents capable of inducing apoptosis.

Abstract: According to the present invention, the gene for IL-13, an anti-inflammatory cytokine, was shown to be a target of prostacyclin (PGI2)-activated Peroxisome proliferator-activated receptor (PPAR) ?. Furthermore, the PGI2-PPAR? signaling pathway was revealed to regulate the expression of IL-13 gene in human vascular endothelial cells, and controls inflammatory responses induced by proinflammatory cytokines through the production of IL-13 in an autocrine or paracrine manner. Thus, the present invention provides a method for treating or preventing inflammatory disorders, which comprises administering a therapeutically effective amount of PPAR? agonist into a subject. Furthermore, the present invention provides a method for treating or preventing inflammatory disorders, which comprises administering a prostacyclin synthase gene or a protein encoded by the gene into a subject.