Pharmacokinetics of combined gene therapy expressing constitutive human GM-CSF and hyperthermia-regulated human IL-12.
BACKGROUND
An adenovirus that expresses both interleukin (IL)-12 and granulocyte-macrophage colony-stimulating-factor (GM-CSF) has been proven to be very effective in treating several tumors, but causes serious normal tissue toxicities.


METHODS
In this study, a novel adenoviral vector was constructed by placing the human GM-CSF gene under the control of the CMV-IE promoter and human IL-12 gene under the control of heat shock protein 70B gene promoter. Both hGM-CSF and hIL-12 expressions in virus-infected tumor cells were analyzed in vitro and in vivo when underlying single or multiple rounds of hyperthermia.


RESULTS
We observed constitutive high expression of human GM-CSF and heat-induced expression of human IL-12 after a single round of hyperthermia post viral infection. The heat-induced hIL-12 expression exhibited a pulse-like pattern with a peak at 24 hrs followed by a decline 48 hrs post heat stress. Repeated heat treatment was more effective in inducing hIL-12 expression than a one-time heat treatment. Interestedly, we also observed that constitutive expression of hGM-CSF could be stimulated by heat stress in tested tumor cells.


CONCLUSIONS
Our study provided a novel strategy for combined gene therapy that allows constitutive expression of a non-toxic gene such as GM-CSF and heat-induced expression of a toxic gene such as IL-12. In addition, our study also showed that hyperthermia can be used to trigger gene expression in temporal and special manner.
Experimental Research Center, First People's Hospital, School of Medicine, Shanghai Jiaotong University, 85 Wujin Road, Shanghai, 200080, China. chuan.li@duke.edu
Fang
F
Wei
Huiping
H
Wang
Jufeng
J
Zhang
Xiafang
X
Chen
Chuanyuan
C
Li
Qian
Q
Huang
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism / Q000628:therapy / Q000821:virology; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D015316:Genetic Therapy / Q000379:methods*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics* / Q000493:pharmacokinetics; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D018664:Interleukin-12 / Q000096:biosynthesis / Q000235:genetics* / Q000493:pharmacokinetics; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000628:therapy / Q000821:virology; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000628:therapy / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D023041:Xenograft Model Antitumor Assays
D018664:Interleukin-12; D016178:Granulocyte-Macrophage Colony-Stimulating Factor