Anti-angiogenic effects of interleukin-12 delivered by a novel hyperthermia induced gene construct.
OBJECTIVE
Interleukin-12 (IL-12) is a pro-inflammatory cytokine possessing anti-cancer and anti-angiogenic properties. This study quantitatively assessed the anti-angiogenic effect of IL-12 delivered using an adenoviral vector with murine IL-12 placed under control of a heat shock promoter. This approach limits systemic toxicity by restricting IL-12 delivery locally to the tumour. The kinetics of the downstream cytokines interferon-gamma (IFN-gamma) and interferon inducible protein-10 (IP-10) and other molecules affecting angiogenesis, vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) were also studied.


METHODS
4T1 tumours were grown in Balb/C mice and the AdhspmIL-12 construct was injected intra-tumourally. The tumours were heated after 24 h using a water bath. At various time points post-heating the tumours were collected and quantitatively assessed for cytokine production and vascularity.


RESULTS
A significant reduction was seen in the tumour vasculature of the treated group vs. the control group mice. Systemic effects of IL-12 were limited to generalized immunostimulation. No hepatoxicity was noted.


CONCLUSIONS
This study suggests that IL-12 can be effectively delivered using a gene-based approach with a heat shock promoter. This results in quantitatively measurable anti-angiogenesis and general immunostimulation. The complex inter-play of other pro- and anti-angiogenic factors (IFN-gamma, IP-10, VEGF and PAI-1) was also studied.
Siddiqui
Farzan
F
Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA. fsiddiq1@hfhs.org
Ehrhart
E J
EJ
Charles
Brad
B
Chubb
Laura
L
Li
Chuan-Yuan
CY
Zhang
Xiuwu
X
Larue
Susan M
SM
Avery
Paul R
PR
Dewhirst
Mark W
MW
Ullrich
Robert L
RL
D000256:Adenoviridae; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D000818:Animals; D054357:Chemokine CXCL10; D019743:Chemokines, CXC / Q000096:biosynthesis / Q000627:therapeutic use; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006979:Hyperthermia, Induced; D007371:Interferon-gamma / Q000096:biosynthesis / Q000627:therapeutic use; D018664:Interleukin-12 / Q000008:administration & dosage* / Q000096:biosynthesis; D008175:Lung Neoplasms / Q000556:secondary; D015674:Mammary Neoplasms, Animal / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009362:Neoplasm Metastasis / Q000517:prevention & control; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis / Q000627:therapeutic use; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000627:therapeutic use
D020533:Angiogenesis Inhibitors; D054357:Chemokine CXCL10; D019743:Chemokines, CXC; D017395:Plasminogen Activator Inhibitor 1; D042461:Vascular Endothelial Growth Factor A; D018664:Interleukin-12; D007371:Interferon-gamma