Oct4 and Hypoxia Dual-Regulated Oncolytic Adenovirus Armed with shRNA-Targeting Dendritic Cell Immunoreceptor Exerts Potent Antitumor Activity against Bladder Cancer

Che-Yuan Hu; Chi-Feng Hung; Pi-Che Chen; Jia-Yu Hsu; Chung-Teng Wang; Ming-Derg Lai; Yuh-Shyan Tsai; Ai-Li Shiau; Gia-Shing Shieh; Chao-Liang Wu

doi:10.3390/biomedicines11102598

Oct4 and Hypoxia Dual-Regulated Oncolytic Adenovirus Armed with shRNA-Targeting Dendritic Cell Immunoreceptor Exerts Potent Antitumor Activity against Bladder Cancer

Biomedicines. 2023 Sep 22;11(10):2598. doi: 10.3390/biomedicines11102598.

Authors

Che-Yuan Hu¹, Chi-Feng Hung², Pi-Che Chen², Jia-Yu Hsu³, Chung-Teng Wang⁴, Ming-Derg Lai³, Yuh-Shyan Tsai¹, Ai-Li Shiau^{4

5}, Gia-Shing Shieh^{1

6}, Chao-Liang Wu^{3

5}

Affiliations

¹ Department of Urology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
² Department of Urology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan.
³ Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
⁴ Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
⁵ Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 60002, Taiwan.
⁶ Department of Urology, Tainan Hospital, Ministry of Health and Welfare, Executive Yuan, Tainan 70043, Taiwan.

Abstract

Immunotherapy has emerged as a promising modality for cancer treatment. Dendritic cell immunoreceptor (DCIR), a C-type lectin receptor, is expressed mainly by dendritic cells (DCs) and mediates inhibitory intracellular signaling. Inhibition of DCIR activation may enhance antitumor activity. DCIR is encoded by CLEC4A in humans and by Clec4a2 in mice. Gene gun-mediated delivery of short hairpin RNA (shRNA) targeting Clec4a2 into mice bearing bladder tumors reduces DCIR expression in DCs, inhibiting tumor growth and inducing CD8⁺ T cell immune responses. Various oncolytic adenoviruses have been developed in clinical trials. Previously, we have developed Ad.LCY, an oncolytic adenovirus regulated by Oct4 and hypoxia, and demonstrated its antitumor efficacy. Here, we generated a Clec4a2 shRNA-expressing oncolytic adenovirus derived from Ad.LCY, designated Ad.shDCIR, aimed at inducing more robust antitumor immune responses. Our results show that treatment with Ad.shDCIR reduced Clec4a expression in DCs in cell culture. Furthermore, Ad.shDCIR exerted cytolytic effects solely on MBT-2 bladder cancer cells but not on normal NIH 3T3 mouse fibroblasts, confirming the tumor selectivity of Ad.shDCIR. Compared to Ad.LCY, Ad.shDCIR induced higher cytotoxic T lymphocyte (CTL) activity in MBT-2 tumor-bearing immunocompetent mice. In addition, Ad.shDCIR and Ad.LCY exhibited similar antitumor effects on inhibiting tumor growth. Notably, Ad.shDCIR was superior to Ad.LCY in prolonging the survival of tumor-bearing mice. In conclusion, Ad.shDCIR may be further explored as a combination therapy of virotherapy and immunotherapy for bladder cancer and likely other types of cancer.

Keywords: Oct4; bladder cancer; dendritic cell; dendritic cell immunoreceptor; hypoxia; immunotherapy; oncolytic adenovirus.

Grants and funding

This work was supported in part by research grants from Ditmanson Medical Foundation Chia-Yi Christian Hospital (NCKUCYC-P-11101) and the Ministry of Science and Technology, Taiwan (108-2320-B-006-026).