Tumor-Selective Replication of an Oncolytic Adenovirus Carrying Oct-3/4 Response Elements in Murine Metastatic Bladder Cancer Models

Abstract

Purpose: Oncolytic adenoviruses are attractive therapeutics for cancer because they selectively replicate in tumors. However, targeting tumor metastasis remains a major challenge for current virotherapy for cancer. Oct-3/4 is specifically expressed in embryonic stem cells and tumor cells. Oct-3/4 highly expressed in cancer cells may be a potential target for cancer therapy. We developed an E1B-55 kDa–deleted adenovirus, designated Ad.9OC, driven by nine copies of Oct-3/4 response element for treating Oct-3/4–expressing metastatic bladder cancer. Experimental Design: We examined the expression of Oct-3/4 in human bladder tumor tissues and bladder cancer cell lines. We also evaluated the cytolytic and antitumor effects of Ad.9OC on bladder cancer cells in vitro and in vivo. Results: Oct-3/4 expression was detected in bladder cancer cell lines, as well as in human bladder tumor tissues. Notably, Oct-3/4 expression was higher in metastatic compared with nonmetastatic bladder cancer cells. Ad.9OC induced higher cytolytic activity in metastatic bladder cancer cells than in their nonmetastatic counterparts, whereas it did not cause cytotoxicity in normal cells. Pharmacologic and short hairpin RNA–mediated Oct-3/4 inhibition rendered bladder cancer cells more resistant to Ad.9OC-induced cytolysis. Replication of Ad.9OC was detected in murine bladder cancer cells and bladder tumor tissues. We also showed the effectiveness of Ad.9OC for treating bladder cancer in subcutaneous, as well as metastatic, bladder tumor models. Conclusions: Ad.9OC may have therapeutic potential for treating Oct-3/4–expressing tumors. Especially, metastatic bladder tumors are good target for Ad.9OC treatment. Because Oct-3/4 is expressed in a broad spectrum of cancers, Ad.9OC may be broadly applicable.

High Expression of SOX2 and OCT4 Indicates Radiation Resistance and an Independent Negative Prognosis in Cervical Squamous Cell Carcinoma

“…For example, SOX2 silencing in glioblastoma tumor-initiating cells can stop proliferation and loss of tumorigenicity (Gangemi et al 2009). Also, oncolytic adenovirus carrying OCT4 response elements in murine metastatic bladder cancer models can induce cytolysis (Wu et al 2008).…”

Oct-3/4 Expression Reflects Tumor Progression and Regulates Motility of Bladder Cancer Cells

“…Details of their clinicopathologic characteristics can be found in Supplementary Material. Human and murine bladder cancer cell lines (TCCSUP, J82, T24, TSGH-8301, and MBT-2), immortalized normal human urothelial cell line (SV-HUC-1), normal murine mammary gland epithelial cell line (NMuMG), murine ES cell line (HM-1), murine fibroblasts (NIH3T3 and primary fibroblasts), and C3H/HeN mice used in this study have been previously described (11,12).…”

“…Semiquantitative reverse transcription-PCR (RT-PCR) was done as described previously (11). Expression levels of Oct-3/4, fibroblast growth factor-4 (FGF-4), and matrix metalloproteinase-13 (MMP-13) mRNA in cell lines were determined by real-time quantitative RT-PCR using LightCycler FastStart DNA Master SYBR Green I kit (Roche) and LightCycler 1.5 Real-Time PCR System (Roche).…”

“…Tissue sections of the mouse lungs were prepared and stained with H&E as previously described (11). Detections of Oct-3/4 and adenovirus hexon and fiber proteins in frozen tissues or cell lines were done by immunohistochemical staining or immunoblotting (11).…”

Conditionally replicating E1B-deleted adenovirus driven by the squamous cell carcinoma antigen 2 promoter for uterine cervical cancer therapy

“…26,27 The fragment encompassing the SCCA2 promoter was excised from pSTBlue-1-SCCA2 and subcloned into pAd5YS. 28 The fragment encompassing sequences of SCCA2 promoter, E1A, E1B 19 kDa and E1B 55 kDa that carried two point mutations at bases 2253 (C-T) and 2262 (G-T) of the nucleotide sequence of human adenovirus type 5 (GenBank accession no. AC 000008) to generate premature translation stop codons 25,29 was excised from pAd5YS by BsrGI and MunI digestions and cloned into pShuttle to generate pShuttle-YS/SCCA2.…”