[Anti-tumor and bystander effects of cationic liposome-mediated CD/5-FC suicide gene system combined with interferon-gamma in vivo].
OBJECTIVE
To study the antitumor and distant bystander effects of cationic liposome-mediated cytosine deaminase (CD)/5-fluorocytosine (5-FC) suicide gene system combined with interferon-gamma (IFN-gamma) in vivo.


METHODS
Murine hepatoma 22 (H22) cells transfected by CD gene were inoculated subcutaneous in Kunming mice in the left axillary region, and the H22 cells without CD gene transfection were inoculated in the right axillary region. The mice were randomly divided into 4 groups and treated with normal saline , 5-FC, IFN-gamma, and 5-FC+ IFN-gamma on a daily basis. The tumor inhibition and distant bystander effects were observed in the mice.


RESULTS
Exposure of CD gene-transfected tumor to 5-Fc resulted in obvious tumor growth inhibition with an inhibition rate of 78.38%, which was significantly increased to 93.21% (P<0.01) with 5-Fc +IFN-gamma treatment. A notable distant bystander effect in the CD/5-FC suicide gene system was observed in vivo, with a tumor inhibition rate of was 54.42%; when combined with IFN-gamma, the inhibition rate increased significantly to 87.57% (P<0.05).


CONCLUSIONS
When combined with IFN-gamma, CD/5-FC suicide system has stronger anti-tumor and distant bystander effects. CD/5-FC suicide gene system combined with IFN-gamma may provide a potential therapy for malignant tumors.
Luo
Qi
Q
Department of General Surgery, Zhongshan Hospital, Xiamen University, Xiamen, China. luoqi@medmail.com.cn
Lu
Yi-zhuo
YZ
Liu
Guo-yan
GY
Zhang
Son-en
SE
D000818:Animals; D024201:Bystander Effect; D002412:Cations / Q000737:chemistry; D043525:Cytosine Deaminase / Q000235:genetics*; D005437:Flucytosine / Q000494:pharmacology*; D041722:Genes, Transgenic, Suicide / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods; D007371:Interferon-gamma / Q000627:therapeutic use*; D008081:Liposomes; D008114:Liver Neoplasms, Experimental / Q000628:therapy*; D008297:Male; D051379:Mice; D011897:Random Allocation
D002412:Cations; D008081:Liposomes; D007371:Interferon-gamma; D005437:Flucytosine; D043525:Cytosine Deaminase