Transcriptional regulation of urokinase receptor in high- (95D) and low-metastatic (95C) human lung cancer cells.

To study the transcriptional regulation of urokinase receptor (uPAR) in high- (95D) and low-metastatic (95C) human lung cancer cells, we performed PCR to amplify 2238 bp uPAR promoter from 95C and 95D cells. According to the results of sequencing, five different bases are found in uPAR promoter between 95C and 95D cells. The results of luciferase activity assay showed that these differences have no significant effect on the uPAR promoter activity. Based on a normal uPAR promoter, progressive truncated mutants were constructed. The transient transfection/reporter assay showed that the promoter region from -136 to +9 may interact with relevant nuclear factors, which result in different levels of uPAR expression between 95C and 95D cells.