(812) An AAV9-Based Strategy for the Treatment of Cervical Dysplasia

Introduction/Rationale: Cervical cancer is the fourth most commonly diagnosed cancer in women worldwide and in some countries is the most lethal cancer in women. Ninety-nine percent of cervical cancers are attributable to HPV infection, which has decreased dramatically with the introduction of HPV vaccines. However, the incidence of cervical cancer remains high in generations of women for whom the vaccine was not available as well as in unvaccinated women, as up to 40% of eligible individuals did not receive an HPV vaccination. There is a critical unmet need for noninvasive treatment options among these groups.

Methods: A hallmark of HPV-mediated oncogenesis is dysregulated E2F transcription factor activity. Leveraging this, we developed a rationally designed series of synthetic AAV transgene promoters for specific activity in HPV-positive cervical cancer cells, which can then be used to deliver therapeutic payloads to tumor tissue. Our panel of candidate promoter sequences was assessed for activity in HPV+ cervical cancer cell lines as well as normal epithelial cells for expression of a luciferase reporter, as determined by comparative expression in a dual-luciferase system.

Results: Testing our candidate promoters in a dual luciferase reporter assay we identified a construct with activity in multiple cell lines. This candidate achieved an 18.31-fold and a 4.45-fold increase in reporter expression in HPV16+ CaSki and SiHa cancer lines compared to normal controls, respectively. Further, it produced a 15.18-fold increase in the HPV18+ C4I line compared to normal controls. By modulating the levels of activating E2F family members in normal cells, we have shown a positive relationship between E2F levels and reporter expression.

Conclusion: Based upon our results in vitro we have developed a candidate AAV transgene construct for specific delivery of a therapeutic payload to cervical cancer cells in vivo.