[Antitumor efficacy of CD/5-FC suicide gene therapy system mediated by Bifidobacterium infantis against melanoma].
OBJECTIVE
To observe the antitumor efficacy of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system mediated by Bifidobacterium infantis against melanoma in vitro and in vivo.


METHODS
Bifidobacterium infantis transfected by CD gene was incubated with 5-FC in anaerobic condition. The supernatant of bacteria was collected and added to the melanoma B16-F10 cells for assessment of the killing effect of this suicide gene system. Mice were incubated with melanoma B16-F10 cells to establish animal models. Then the mice bearing melanoma were treated by a combination of Bifidobacterium infantis transfected by CD gene and 5-FC. Bifidobacterium infantis transfected by CD gene was injected into the tail vein of mice and 5-FC was given introperitoneally.


RESULTS
(1) In vitro, the tumor cells in test groups appeared damaged with remarkable changes in morphology, and the cell growth was significantly inhibited as compared against those in the control group. (2) In animal experiment, after the mice melanoma model being treated with the recombined bacteria and 5-FC for 21 days, the tumor growth span was remarkably prolonged and the tumor volume was significantly inhibited when compared with control. The differences became more obvious with the passage of observation time.


CONCLUSIONS
CD/5-FC suicide gene therapy system mediated by Bifidobacterium infantis was noted to have good antitumor effect on melanoma.
Yi
Cheng
C
Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China.
Guo
Zhi-ying
ZY
Huang
Ying
Y
Wang
Hao-yi
HY
Wang
Shu-ren
SR
D000818:Animals; D001644:Bifidobacterium / Q000235:genetics* / Q000502:physiology; D043525:Cytosine Deaminase / Q000235:genetics*; D005260:Female; D005437:Flucytosine / Q000494:pharmacology*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D008546:Melanoma, Experimental / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D014407:Tumor Cells, Cultured
D005437:Flucytosine; D043525:Cytosine Deaminase