PCTAIRE3: a putative mediator of growth arrest and death induced by CTS-1, a dominant-positive p53-derived synthetic tumor suppressor, in human malignant glioma cells

Chimeric tumor suppressor-1 (CTS-1) is based on the sequence of p53 and was designed as a therapeutic tool resisting various mechanisms of p53 inactivation. We previously reported that an adenovirus expressing CTS-1 (Ad-CTS-1) has superior cell deathinducing activity in glioma cells compared with wild-type p53. Here, we used cDNA microarrays to detect changes in gene expression preferentially induced by Ad-CTS-1. The putative serin threonine kinase, PCTAIRE3, and the quinone oxireductase, PIG3, were strongly induced by Ad-CTS-1 compared with wild-type p53. An adenoviral vector encoding PCTAIRE3 (Ad-PCTAIRE3) induced growth arrest and killed a minor proportion of the glioma cells. Ad-PIG3 alone affected neither growth nor viability. However, coinfection with Ad-PCTAIRE3 and Ad-PIG3 resulted in enhanced growth inhibition compared with Ad-PCTAIRE3 infection alone. Ad-CTS1, Ad-PCTAIRE3 or Ad-PIG3 induced the formation of free reactive oxygen species (ROS). However, the prevention of ROS formation induced by Ad-PCTAIRE3 and Ad-CTS-1 did not block growth arrest and cell death, suggesting that ROS formation is not essential for these effects. Altogether, these data identify PCTAIRE3 as one novel growth-inhibitory and deathinducing p53 response gene and suggest that changes in the expression of specific target genes contribute to the superior antiglioma activity of CTS-1. Cancer Gene Therapy (2006) 13, 469–478. doi:10.1038/sj.cgt.7700917; published online 4 November 2005