Efficient Intravenous Tumor Targeting Using the αvβ6 Integrin-Selective Precision Virotherapy Ad5_NULL-A20.

Area of Science:

• Oncolytic virotherapy
• Cancer gene therapy
• Adenovirus engineering

Background:

• Native adenoviruses infect broadly, limiting therapeutic use.
• Targeting aggressive epithelial cancers requires tumor-specific vectors.
• αvβ6 integrin is a marker for aggressive epithelial cancers.

Purpose of the Study:

• To evaluate the tumor-selective infection and oncolytic efficacy of Ad5_NULL-A20.
• To assess the biodistribution of Ad5_NULL-A20 in preclinical cancer models.

Main Methods:

• Developed Ad5_NULL-A20 with tropism ablating mutations and an A20 peptide for αvβ6 integrin targeting.
• Performed reporter gene and cell viability assays on pancreatic and breast cancer cell lines.
• Quantified viral genome biodistribution via qPCR in mice bearing xenografts with varying αvβ6 levels.

Main Results:

• Ad5_NULL-A20 demonstrated αvβ6-selective transduction and oncolytic cell killing.
• Intravenous administration showed reduced liver accumulation and increased tumor accumulation of Ad5_NULL-A20 compared to Ad5.
• Tumor-to-liver ratios improved with increasing αvβ6 expression.

Conclusions:

• Ad5_NULL-A20 efficiently targets αvβ6-integrin-positive tumors after intravenous administration.
• Ad5_NULL-A20 shows promise for systemic virotherapy applications.
• Enables tumor-selective overexpression of therapeutic transgenes.