| Objective1. Looking for an oral squamous cell carcinoma animal model which is more simple and has high survival rate and biological similarity in order to provide convenience for the experimental study of oral tumors.2. Study sustained release 5-FU with photodynamic therapy in the treatment of oral squamous cell carcinoma ; the combination of PDT and sustained-release 5-FU may be more effective in OSCC.MethodsNew Zealand white rabbits weighing 1.5 to 2.0 kg, maintained on a standard laboratord diet were given transplants of partially homogenized Vx-2 carcinoma in oral. One hundred rabbits were randomly divided into five groups:①control group;②intravenous group③sustained release 5-FU group;④PDT group;⑤sustained release 5-FU combined with PDT group. Continuous measurement of tumor volum for five weeks, and five weeks later killed the animals for histological observation(stained with hematoxylin and eosin, H&E) , immunohistochemistry and flow cytometry, and to evaluate tumor inhibition rates, growth state, the rate of tumor cell apoptosis and expression of p53. Our purpose is to preliminary study the efficacy of sustained release 5-FU combined with PDT. The data was analyzed by SPSS11.0 software package with P <0.05 for having a significant difference. Results1 It is successful to set up rabbit Vx-2 Oral Squamous Cell Carcinoma model, and the success rate of method that tissue mass of the tumor transplanted is obviously higher than the other methods. Tumor had the similar biological features of human oral squamous cell carcinoma so that it is an option for oral cancer animal model.2 On our continuous observation and measurement of tumor size for five weeks we found that in the first week there were no significant differences between groups in tumor size. from the second week on, the tumor of the control group, the intravenous group and the PDT group were grown faster than the sustained release 5-FU group and the joint group. Rabbits of the last group had advantages in spirit, eating, active than the other groups.3 5 weeks later, we got the inhibition rate of tumor: intravenous group is (39.9%±15.9%); sustained-release group is (73.8%±22.3%); PDT group is (50.6%±21.8%); therapeutic alliance group is (93.6%±19.5%). The results showed that the inhibition rate based on tumor measurement of therapeutic alliance group was higher than the other groups, having significant difference.4 Hematoxylin and eosin(H&E) staining of tumor tissue were observed for squamous cell carcinoma. In the therapeutic alliance group we found that the proliferation of the tumor cells was relatively suppressed, rare nuclear fission, massive cell death or apoptosis, cell vacuolar changes and karyopyknosis phenomenon.5 Immunohistochemistry was measured for p53 protein expression : the control group (60%), intravenous injection group (50%), sustained-release 5-FU group (30%), the PDT group (45%), the therapeutic alliance group (15%), the therapeutic alliance group was significantly lower than that of other groups, with significant differences (P<0.05).6 FCM rate of tumor cell apoptosis shows that the control group was (5.05±1.19)%, intravenous group was (11.81±0.89)%, sustained-release 5-FU group was (25.80±13.78)%, the PDT group was (20.32±11.24)%, the therapeutic alliance group was (32.51±15.32)%. We found that the therapeutic alliance group was significantly higher than that of other groups with a significant difference (P<0.05). The sustained-release 5-FU was higher than the intravenous group and the control group, having a significant difference between groups (P<0.05). Between the PDT group, the control group and the intravenous group also had significant difference (P<0.05), but the sustained-release group was compared with the PDT group showing no significant difference (P>0.05).ConclusionVx-2 by tumor tissue transplantation is a simple operation to made oral squamous cell carcinoma with a high survival rate. It is a better way for oral cancer research in animal models. In the treatment of oral squamous cell carcinoma the sustained-release 5-FU compared with conventional intravenous administration was more effective in anti-tumor concentration. Our study demonstrates that the combination of PDT and sustained-release 5-FU was more effective at the inhibition of tumor growth, and was able to promote apoptosis of tumor cells. Therefore, we can say that 5-FU combined with PDT may become a new clinical approach on OSCC's treatment. |
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