Efficacy of an Improved Cancer Stroma- Targeted Oncolytic Adenovirus on Human Derived Gynecologic Tumor Samples

ALEJANDRO NICOLA CANDIA; ANA L ALFANO; CRISTIAN M MALNERO; ISMAEL R BERMÚDEZ; NICASIO A CUNEO; MARIELA A GANGEMI; ALEJANDRO SODERINI; OSVALDO L PODHAJCER; VERONICA M LOPEZ

Nueva Orleans

Congreso; ASGCT 18th Annual Meeting; 2015

Gynecologic cancers originated in the female reproductive organs, including the cervix, ovaries, uterus, fallopian tubes, vagina and vulva. In 2013, it was estimated that 91,730 women would be diagnosed with a gynecologic cancer. Cervical cancer accounted for approximately 13%, ovarian cancer 24% and uterine cancer 54% of cases of cancer (American Cancer Society, Inc). We have recently developed a stroma-targeted CRAd also responsive to the tumor microenvironment, AdF512v4, that contain a chimeric promoter that combines a 0.5 Kb of the SPARC promoter, a Hypoxia-Response Element (HRE) and a NFkB-response element (NFkB). The chimeric promoter drives the expression of delta-RB E1A and the CRAd was pseudotyped with a chimeric fiber 5/3. We also constructed the non-replicative version of AdF512v4 (AdF512v4-luc). We have previously demonstrated the activity of the new promoter in ovarian cancer cell lines. First, we assessed the promoter activity following transduction of cervix cancer cell lines (HeLa, CaSki and SiHa) with the non-replicative adenovirus. We observed 10-35 fold induction of luciferase activity under hypoxic condition (0.1% O2) or/and TNF treatment (5 ng/ml). Next, we measured the efficacy of the CRAd in the 3 cervical cancer cell lines under normal oxygen levels (21% O2), hypoxic condition or TNF treatment. By using the MTS assay we observed that the larger lytic capacity was obtained in the presence of TNF treatment. In order to establish the potential clinical utility of AdF512v4 we assayed its replication capacity in a most rigorous preclinical setting by using slices obtained from fresh tissue explants of human tumors. AdF512v4 replicated in three out of six human cervix cancers, one tumor from uterus and three of four human ovarian carcinomas with no lytic effect on the paired normal tissues. It is of note that Ad-wt 5/3 could replicate in both malignant and normal ovarian samples. In conclusion, AdF512v4 demonstrated a strong killing effect on cervix and ovarian cancer cells in vitro, as well as a replication capacity in fresh human ovary, uterus and cervix cancer explants. AdF512v4 appears safe since no replication was observed in normal human ovary raising its potential use in the clinics.