Lentivirus-mediated p21/Waf-1 short hairpin RNA enhances the cytotoxic effects and replicative potential of a bladder cancer-specific oncolytic adenovirus in vitro.
Our previous work confirmed that the bladder cancer-specific oncolytic adenovirus Ad/PSCAE/UPII/E1A could selectively replicate in bladder cancer cells, thus causing specific tumor cell lysis. The replicative potential is a crucial factor in determining the therapeutic efficacy of oncolytic adenoviruses. However, viral replication is attenuated by the low-activity promoter that we used, thus compromising viral cytotoxicity. In this study, we investigated the effect of the cell cycle-dependent kinase inhibitor p21/Waf-1 on an adenovirus. We used lentivirus-mediated short hairpin RNA to knock down p21/Waf-1 in two bladder cancer cell lines EJ and 5637. The p21/Waf-1 knockdown not only induced stronger cytopathic effects but also augmented apoptosis, which was closely associated with the enhancement of Fas and the subsequent significant activation of caspase-3. A replicative assay showed that p21/Waf-1 knockdown increased the viral particle production. Western blot analysis confirmed that p21/Waf-1 knockdown upregulated the expression of androgen receptor (AR) and two adenovirus replication indicators E1A and hexon. A luciferase activity assay indicated higher transcriptional activity of the uroplakin II (UPII) promoter in the p21/Waf-1 knockdown cells, and one possible mechanism could be that the increased expression of AR induced the UPII promoter through the AR-binding sites of the prostate stem cell antigen enhancer. These findings indicating that p21/Waf-1 knockdown could enhance cell killing and viral replication have significant implications for the development of bladder cancer-specific oncolytic adenovirus therapies.
aInstitute of Cell Biology, School of Life Sciences bDepartment of Pharmacology, School of Basic Medical Sciences, Lanzhou University cKey Laboratory of Urological Diseases in Gansu Province, Department of Urology, Institute of Urology, The Second Hospital of Lanzhou University, Lanzhou, China dDepartment of Urology, University of Texas Health Science Center, San Antonio, Texas, USA.
Jie
J
Shi
Shengjun
S
Fu
Li
L
Wang
Yan
Y
Tao
Ronald
R
Rodriguez
Zhiping
Z
Wang
D002295:Carcinoma, Transitional Cell / Q000628:therapy* / Q000821:virology; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics*; D055785:Gene Knockdown Techniques; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D016086:Lentivirus / Q000235:genetics / Q000502:physiology*; D050130:Oncolytic Virotherapy / Q000379:methods*; D034741:RNA, Small Interfering / Q000235:genetics*; D011944:Receptors, Androgen / Q000096:biosynthesis; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000628:therapy* / Q000821:virology
C410798:AR protein, human; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D034741:RNA, Small Interfering; D011944:Receptors, Androgen