Analysis of candidate promoters for transcriptional targeting of adenovirus-mediated gene expression and correlation to the mRNA copy number of the corresponding genes in primary breast cancer cells. (a) Evaluation of candidate promoters for transcriptional targeting of primary breast cancer cells derived from patients. Primary breast cancer cells were isolated from eight patients and purified and infected with AdCXCR4Luc, AdSurvivinLuc, AdCox2MLuc, AdSLPILuc, AdEGP-2Luc or AdCMVLuc, at a multiplicity of infection of 100. Gene expression was measured 24 h after infection and is presented for the candidate promoters as percentage of cytomegalovirus promoter activity in relative light units (RLU). Each bar presents the mean of three experiments ± standard deviation. (b) Gene expression of candidate tumor-specific genes in breast cancer patient samples. Messenger RNA was extracted from human primary breast cancer samples from eight patients and reverse-transcribed into cDNA. Real-time PCR was performed to evaluate the expression of the genes encoding cyclooxygenase (Cox)-2, epithelial glycoprotein (EGP)-2, secretory leukoprotease inhibitor (SLPI), survivin and the α-chemokine SDF-1 receptor (CXCR4). The mRNA copy numbers are normalized by the glyceraldehyde-3-phosphate dehydrogenase copy number. Each bar presents the mean of three experiments ± standard deviation.