Angiogenesis inhibition by an oncolytic herpes virus expressing interleukin 12.
OBJECTIVE
Oncolytic herpes simplex viruses (HSVs) may have significant antitumor effects resulting from the direct lysis of cancer cells. HSVs may also be used to express inserted transgenes to exploit additional therapeutic strategies. The ability of an interleukin (IL)-12-expressing HSV to treat squamous cell carcinoma (SCC) by inhibition of tumor angiogenesis is investigated in this study.


METHODS
A replication-competent, attenuated, oncolytic HSV carrying the murine IL-12 gene (NV1042), its non-cytokine-carrying analog (NV1023), or saline was used to treat established murine SCC flank tumors by intratumoral injection. The expression of secondary antiangiogenic mediators was measured. Angiogenesis inhibition was assessed by in vivo Matrigel plug assays, flank tumor subdermal vascularity, and in vitro endothelial cell tubule formation assay.


RESULTS
Intratumoral injections of NV1042 (2 x 10(7) plaque-forming units) into murine SCC VII flank tumors resulted in smaller tumor volumes as compared with NV1023 or saline. IL-12 and IFN-gamma expression in tumors was 440 and 2.2 pg/mg, respectively, at 24 h after NV1042 injection, but both IL-12 and IFN-gamma were undetectable (<0.2 pg/mg) after NV1023 or saline injections. Expression of two antiangiogenesis mediators, monokine induced by IFN-gamma and IFN-inducible protein 10, was elevated after NV1042 treatment. Matrigel plug assays of NV1042-transfected SCC VII tumor cells demonstrated significantly decreased hemoglobin content and microvessel density as compared with NV1023 and PBS. Excised murine flank tumors treated with NV1042 had decreased subdermal vascularity as compared with NV1023 and PBS. Both splenocytes and IL-12 expression by NV1042 were required for in vitro inhibition of endothelial tubule formation.


CONCLUSIONS
IL-12 expression by an oncolytic herpes virus enhances therapy of SCC through antiangiogenic mechanisms. Strategies combining HSV oncolysis with angiogenesis inhibition merit further investigation for potential clinical application.
Wong
Richard J
RJ
Head and Neck Service, Memorial Sloan-Kettering Cancer Center, New York, New York, USA. wongr@mskcc.org
Chan
Mei-Ki
MK
Yu
Zhenkun
Z
Ghossein
Ronald A
RA
Ngai
Ivan
I
Adusumilli
Prasad S
PS
Stiles
Brendon M
BM
Shah
Jatin P
JP
Singh
Bhuvanesh
B
Fong
Yuman
Y
D000818:Animals; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D045744:Cell Line, Tumor; D054357:Chemokine CXCL10; D019743:Chemokines, CXC / Q000378:metabolism; D018920:Coculture Techniques; D003094:Collagen / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D004338:Drug Combinations; D042783:Endothelial Cells / Q000166:cytology; D004730:Endothelium, Vascular / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006564:Herpesviridae / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism*; D007797:Laminin / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008809:Mice, Inbred C3H; D009389:Neovascularization, Pathologic; D011509:Proteoglycans / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection; D019076:Transgenes
D054357:Chemokine CXCL10; D019743:Chemokines, CXC; D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D018664:Interleukin-12; D007371:Interferon-gamma; D003094:Collagen