[Anticancer efficacy of combining cytosine deaminase/5-fluorocytosine gene therapy and radiotherapy on cervical carcinoma].
OBJECTIVE
To observe the effect of combining cytosine deaminase (CD)/5-fluorocytosine (5-FC) gene therapy with radiotherapy on cervical carcinoma in nude mice, and to explore if there is a synergistic effect between the two therapies.


METHODS
HeLa cells were injected into the 24 female nude mice who were 6-8 weeks old. When the tumors grew to 4.0-7.0 mm in diameter, the mice were divided into 4 groups randomly: control group, CD/5-FC gene therapy group, CD/5-FC gene therapy plus radiotherapy group, radiotherapy group. The volumes and inhibiting rates of the tumors were calculated.


RESULTS
(1) The tumor volumes in CD/5-FC gene therapy group (728 +/- 201) mm(3), CD/5-FC gene therapy plus radiotherapy group (357 +/- 113) mm(3), radiotherapy group (739 +/- 419) mm(3), were smaller compared with that in the control group (1168 +/- 380) mm(3), the difference was significant (P < 0.05); tumor volumes in CD/5-FC gene therapy plus radiotherapy group was significantly smaller compared with that in the CD/5-FC gene therapy group and radiotherapy group (P < 0.05). (2) The tumor-inhibiting rate of the radiotherapy group was 36.74%, of the CD/5-FC gene therapy group was 37.66%, and of the CD/5-FC gene therapy plus radiotherapy group was 69.45%, the latter being significantly higher than that of the former two groups (P < 0.05). (3) There was a synergistic effect between CD/5-FC gene therapy and radiotherapy.


CONCLUSIONS
There is a synergistic effect between CD/5-FC gene therapy and radiotherapy. CD/5-FC gene therapy combined with radiotherapy may be a good supplementary method for cancer synthetic treatment.
Gao
Xiao-lin
XL
Department of Obstetrics and Gynecology, West China Second University Hospital, Chengdu 610041, China.
Li
Qing-li
QL
Peng
Zhi-lan
ZL
Wang
He
H
D000818:Animals; D003131:Combined Modality Therapy; D043525:Cytosine Deaminase / Q000008:administration & dosage; D005260:Female; D005437:Flucytosine / Q000008:administration & dosage; D015316:Genetic Therapy; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011897:Random Allocation; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy / Q000628:therapy*
D005437:Flucytosine; D043525:Cytosine Deaminase