Combination of oncolytic adenovirus and luteolin exerts synergistic antitumor effects in colorectal cancer cells and a mouse model

In recent years, oncolytic viruses have attracted increasing interest due to their potent antitumor effects. Luteolin, a natural product, has additionally been observed to exhibit various pharmacological antitumor activities. Previously, a novel dual-targeting oncolytic adenovirus, complement decay-accelerating factor (CD55)-tumor necrosis factor ligand superfamily member 10 (TRAIL), was constructed, which exhibited significant growth inhibitory effects in various types of tumor cell. The present study investigated whether the combination of luteolin and CD55-TRAIL was able to exert a synergistic antitumor effect in colorectal carcinoma (CRC) cells. The cytotoxicity and tumor cell apoptosis mediated by combination treatment in CRC cells were detected via an MTT assay, Hoechst staining and western blotting, respectively. Tumor growth in vivo was examined in a CRC mouse xenograft model following various treatments. The results demonstrated that the addition of luteolin enhanced oncolytic adenovirus-mediated enhanced green fluorescent protein, early region 1A and TRAIL expression. The combination of CD55-TRAIL with luteolin synergistically inhibited tumor growth and promoted CRC cellular apoptosis in vitro and in vivo. Additionally, the combination of CD55-TRAIL with luteolin significantly decreased cytotoxicity in lung/bronchial normal epithelial cells, compared with single treatment. Therefore, the combination of CD55-TRAIL with luteolin may be a novel efficient therapeutic strategy for CRC in the future.