Cotargeting Prostate Cancer and Supporting Bone Stroma Using Dual Controlled Oncolytic Adenovirus

• Main Authors: I-Hui Wu, 吳怡蕙
• Other Authors: Chia-Ling Hsieh
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/95613304539966060268

碩士 === 中國醫藥大學 === 癌症生物學研究所碩士班 === 99 === Our laboratory previously developed a conditional replicating adenoviral vector (CRAd), Ad-hOC-E1 to co-target bone metastatic prostate cancer cells (PCa) and bone stroma. Owing to the importance of tumor microenvironment in supporting cancer growth and metastasis, Ad-hOC-E1 is superior to currently clinically used signal-targeting CRAds for the treatment of bone metastasis PCa. It has been known that microRNAs inhibit gene expression at post-transcriptional level and many of them are dyregulated during cancer progression. We hypothesized that incorporating microRNA regulation into Ad-hOC-E1 could restrict toxicity of microRNAs to cancer-associated stroma but not normal tissues. To select the appropriate microRNAs, we performed microRNA microarray using normal and PCa-associated bone stromal cell lines. By RT-qPCR, we confirmed that miR-195 and miR-199a were down-regulated in both PCa and cancer-associated stroma but over-expressed in normal stroma. To test whether the miR-195 target sequence (miR-195T) or miR-199a target sequence (mir-199aT) is able to suppress the expression of transgene in normal stroma, we constructed microRNA-regulated luciferase reporter by insertion of synthetic miR-195T, miR-199aT and miR-scrambleT into the 3’-UTR of pMIR. Our results demonstrated that miR-199aT significantly suppressed luciferase expression in normal stroma but not in Pca and Pca-associated stroma in comparison to mir-scrambleT. Similarly, incorporating miR-199aT into luciferase expression cassette driven by tumor-specific hOC-promoter also decreased luciferase expression in normal cells. Further, inserting miR-199aT into oncolytic adenovirus driven by bidirectional hOC-promoter could also de-target virus replication in normal cells. These results suggested that miR-199aT-regulated oncolytic adenovirus dual control by tumor-specific promoter and microRNA regulation could provide a safe tumor-targeting approach.