Serotype chimeric and fiber-mutated adenovirus Ad5/19p-HIT for targeting renal cancer and untargeting the liver

Despite some advances, patients with advanced renal cell carcinoma (RCC) cannot usually be cured. Alteration of the natural tropism of adenoviruses may permit more specific gene transfer to target tissues. The aim of this study was to use novel targeting moieties for adenoviral gene therapy of RCC. Previous work in rats suggested that use of Ad5/19p (Ad5 capsid with Ad19p fiber) with kidney vascular targeting moieties HTTHREP (HTT), HITSLLS (HIT), and APASLYN (APA) placed into the fiber knob might be useful for targeting kidney vasculature. Therefore, we sought to investigate the utility of Ad5/19p variants for gene delivery to human RCC cell lines, clinical samples, and orthotopic murine models of metastatic RCC. Six different human RCC cell lines were infected but only Ad5/19p-HIT showed increased transduction, and only in one cell line. Thus, we analyzed human normal and cancerous kidney specimens fresh from patients, which might better mimic the three-dimensional architecture of clinical tumors and found that Ad5/19p-HIT showed transduction levels similar to Ad5. In mice, we found that intraperitoneal and intravenous Ad5/19p-HIT transduced tumors at levels comparable to Ad5, and that intratumoral Ad5/19p-HIT was superior to Ad5. Liver tropism was significantly reduced in comparison with Ad5. Improvements in tumor-to-liver transduction ratios suggested that Ad5/19p-HIT may be promising for systemic gene delivery to kidney tumors

Human Telomerase Reverse Transcriptase Promoter-Driven Oncolytic Adenovirus with E1B-19 kDa and E1B-55 kDa Gene Deletions

We constructed an oncolytic adenovirus, Adeno-hTERT-E1A, with deletions of the viral E1B, E3A, and E3B regions and insertion of a human telomerase reverse transcriptase (hTERT) promoter-driven early viral 1A (E1A) cassette that confers high transcriptional activity in multiple human tumor cell lines. The oncolytic potential of Adeno-hTERT-E1A was characterized in comparison with that of the E1B-55kDa- and E3B-region-deleted oncolytic adenovirus ONYX-015. Tumor cells infected with Adeno-hTERT-E1A expressed dramatically higher levels of E1A oncoprotein, underwent enhanced lysis, and displayed an earlier and higher apoptotic index than cells infected with ONYX-015. Despite the increase in virus-induced apoptotic death, Adeno-hTERT-E1A replicated and produced functional progeny leading to viral spread, but with reduced efficiency compared with ONYX-015, in particular in A549 cells. Virus-induced E1A expression, host cell apoptosis, viral hexon protein production, and DNA synthesis were markedly reduced in primary human hepatocytes after infection with Adeno-hTERT-E1A as compared with ONYX-015. The strong oncolytic activity of Adeno-hTERT-E1A in tumor cell culture translated into superior antitumor activity in vivo in an MDA-MB-231 solid tumor xenograft model. Adeno-hTERT-E1A thus has strong therapeutic potential and an improved safety profile compared with ONYX-015, which may lead to reduced toxicity in the clinic

Development of targeted viral vectors for cardiovascular gene therapy

No abstract available