Subsequent cell viability assay and animal experiments showed that selleck chemical Ad-TRAIL-MRE-1-133-218 greatly suppressed the growth of bladder cancer. More importantly, survival of normal bladder epithelial cells was almost not affected by Ad-TRAIL-MRE-1-133-218, suggesting biosafety of this MREs-regulated TRAIL-expressing adenoviral vector. To further improve the biosafety of the adenoviral vector expressing TRAIL, other MREs should also be applied to suppress the undesirable exogenous gene expression in normal tissue, such as liver. miR-122 has been extensively reported

to be highly expressed in normal hepatic cells and downregulated in hepatocellular carcinoma, and thus, its MRE can be utilized to prevent cytotoxicity from liver cells [50]. TRAIL has been demonstrated as a potent anti-tumor cytokine in our study. Other therapeutic cytokines also PI3K inhibitor act as candidates for cancer gene therapy, especially the natural inhibitors against signaling pathway that is critical for cancer progression. For example, DKK1 has been shown to suppress the gastric cancer progression by inhibiting WNT/β-catenin pathway [51]. Our

novel MRE-regulated adenoviral vector is believed to be a suitable expression vehicle for these inhibitors with high bladder cancer specificity. Conclusions We generated a bladder cancer-specific adenoviral vector that expressed TRAIL based on MREs GDC-0449 of miRNAs whose levels were reduced in bladder cancer. The anti-tumor capacity and biosafety of this new adenoviral vector was proved by a series of experimental approaches. We proposed that the MREs-targeted adenovirus is a promising tool for gene therapy against bladder cancer. Electronic supplementary material Additional file 1: Figure S1: Etoptic miRNA expression profile of T24 and RT-4 cells. Expression of miR-1, miR-99a,

miR-101, miR-133a, miR-218, miR-490-5p, miR-493 and miR-517a were detected in T24 and RT-4 cells. miRNA Ribose-5-phosphate isomerase level in noncancerous bladder tissue was regarded as standard and U6 was selected as endogenous reference. Means ± SEM of three independent experiments were shown. (DOC 39 kb) (PPT 116 KB) Additional file 2: Figure S2: Differential expression levels of miR-1, miR-133a and miR-218 between normal cells and bladder cancer Expression of miR-1, miR-133a and miR-218 were detected in HUV-EC-C and L-02 cells. miRNA level in HUV-EC-C cells was regarded as standard and U6 was selected as endogenous reference. Means ± SEM of three independent experiments were shown. (PPT 115 kb) (PPT 234 KB) References 1. Jacobs BL, Lee CT, Montie JE: Bladder cancer in 2010: how far have we come? CA Cancer J Clin 2010,60(4):244–272.PubMedCrossRef 2. Voutsinas GE, Stravopodis DJ: Molecular targeting and gene delivery in bladder cancer therapy. J Buon 2009,14(Suppl 1):S69-S78.PubMed 3.