Oncolytic adenovirus expressing interferon alpha in a syngeneic Syrian hamster model for the treatment of pancreatic cancer.
BACKGROUND
The addition of interferon (IFN) alpha to adjuvant chemoradiotherapy regimens resulted in remarkable improvements in survival for pancreatic cancer patients. However, systemic toxicities and insufficient levels of IFN at the tumor sites have limited its widespread adoption in treatment schemes. We have previously developed an IFN-expressing conditionally replicative oncolytic adenovirus and demonstrated its therapeutic effects both in vitro and in vivo. Here, the same vectors were tested in a syngeneic and immunocompetent Syrian hamster model to better understand the roles of adenoviral replication and of the pleiotropic effects of IFN on pancreatic tumor growth suppression.


METHODS
Oncolytic adenoviruses expressing human or hamster IFN were designed and generated. Viral vectors were tested in vitro to determine qualitative and quantitative cell viability, cyclooxygenase 2 (Cox2) promoter activity, and IFN production. For the in vivo studies, subcutaneous hamster pancreatic cancer tumors were treated with 1 intratumoral dose of virus. Similarly, 1 intraperitoneal dose of virus was used to prolong survival in a carcinomatosis model.


RESULTS
All cell lines tested demonstrated Cox2 promoter activity. The oncolytic potential of a replication competent adenovirus expressing the IFN cytokine was clearly demonstrated. These viruses resulted in significant tumor growth suppression and survival increases compared with controls in a hamster model.


CONCLUSIONS
The profound therapeutic potential of an IFN-expressing oncolytic adenovirus for the treatment of pancreatic cancer was demonstrated in a syngeneic Syrian hamster model. These results strongly suggest the potential application of our viruses as part of combination regimens with other therapeutics.
Department of Surgery, University of Minnesota, Minneapolis, MN.
Christopher J
CJ
LaRocca
Department of Surgery, University of Minnesota, Minneapolis, MN.
Joohee
J
Han
Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL.
Tatyana
T
Gavrikova
Department of Surgery, University of Minnesota, Minneapolis, MN; Department of Surgery, Cambridge Medical Center, Cambridge, MN.
Leonard
L
Armstrong
Department of Surgery, University of Minnesota, Minneapolis, MN.
Amanda R
AR
Oliveira
Department of Biostatistics, University of Minnesota, Minneapolis, MN.
Ryan
R
Shanley
Department of Surgery, University of Alabama at Birmingham, Birmingham, AL.
Selwyn M
SM
Vickers
Department of Surgery, University of Minnesota, Minneapolis, MN; Masonic Cancer Center, University of Minnesota, Minneapolis, MN; Institute of Molecular Virology, University of Minnesota, Minneapolis, MN.
Masato
M
Yamamoto
Department of Surgery, University of Minnesota, Minneapolis, MN; Masonic Cancer Center, University of Minnesota, Minneapolis, MN. Electronic address: davyd003@umn.edu.
Julia
J
Davydova
D000256:Adenoviridae / Q000378:metabolism; D000818:Animals; D002277:Carcinoma / Q000628:therapy*; D045744:Cell Line, Tumor; D006224:Cricetinae; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage* / Q000378:metabolism; D016898:Interferon-alpha / Q000008:administration & dosage* / Q000378:metabolism; D008647:Mesocricetus; D009374:Neoplasms, Experimental; D050130:Oncolytic Virotherapy / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000628:therapy*
D007155:Immunologic Factors; D016898:Interferon-alpha