A Cancer-specific Promoter for Gene Therapy of Lung Cancer, Protein Regulator of Cytokinesis 1 (PRC1)

2 Division of Radiation Cancer, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul 139-706, Korea - We have recently re- ported the PRC1 promoter as a promoter candidate to control expression of transcriptionally targeted genes for breast cancer gene therapy. We tested whether the PRC 1 promoter could be also applied for the lung cancer gene therapy. In the transient transfection assay with naked plasmids containing the luciferase fused to the PRC1 promoter, the promoter showed little activity in the normal lung cell line, MRC5. However, in the lung cancer A549 cells, PRC1 showed approximately 30-fold activa- tion which was similar to the survivin promoter, the gene whose promoter has been already re- ported as a candidate for the gene therapy of lung cancer. In viral systems, the PRC1 promoter showed approximately 75% and 66% of transcriptional activity compared to the CMV promoter in the adeno-associated virus (AAV) and the adenovirus (AV) systems, respectively. However, the PRC1 promoter in either AAV or AV showed approximately 20% activity compared to the CMV promoter in the normal lung cells. In addition, human lung tumor xenograft mice showed that the PRC1 promoter activity was as strong as the CMV activity in vivo. Taken together, these results sug- gested that PRC1 might be a potential promoter candidate for transcriptionally targeted lung cancer gene therapy.