Man Interleukin -24 Recombinant Plasmid Subcutaneous Tumor Growth Of Cervical Cancer Siha Cells In Nude Mice

Cervical cancer is one of the biggest killers of women worldwide. Morbidity rate and mortality rate are second only to breast cancer. At present, the treatment of cervical cancer is mainly surgery, radiotherapy, chemotherapy, but these treatments have not significantly improved 5-year survival rate of patients. In recent years, gene therapy for cancer has become a hot research. Studies have shown that IL-24 was an ideal gene that could inhibit tumor growth, but have no effect on normal tissue cells. There was nearly no research about gene therapy of IL-24 in cervical cancer at home and abroad, for which we have designed this experiment.Objective:To evaluate the inhibitory activity and underlying mechanisms of IL-24 on the growth of cervical cancer subcutaneous tumor xenografts in BALB/C nude mice.Methods:1. Siha cells frozen in liquid nitrogen were revived in routine method and inoculated in MEM blended with 10% fetal cattle serum.2. 1×107 human cervical cancer Siha cells were implanted into nude mice subcutaneous to get the tumor model of Siha cell line. The transplanted tumors were observed every day.3. After established the model of human cervical cancer xenografts in nude mice, the 15 mice were randomly divided into 3 groups:IL-24 recombinant plasmid group, empty-vector plasmid group, and PBS group. The next day subcutaneous xenograft tumors in IL-24 recombinant plasmid group were injected by Pre-transfection reagent mixture PDC316-hIL-24 (10μg) every other day, at the same time, Pre-transfection reagent mixture PDC316 (10μg) and PBS 0.2ml as empty vector control and negative control,a total of five injections. The transplanted tumor diameters were measured, calculating tumor volume every three day. Tumor growth curve was used to examine changes in tumor volume.4. On the seven day after treatment, the mice were killed and tumor tissues were processed for several examination, calculating tumor inhibition rate.5. The expression change of IL-24 was detected by RT-PCR in all groups transplanted tumors.6. Cell-cycle of Siha cells were measured by Flow cytometry in all groups transplanted tumors.Result:1. After 15 nude mice were inoculated subcutaneously with cervical cancer Siha cells, every nude mouse subcutaneous tumor diameter covered 0.5cm after 8-10 days. Cervical cancer Siha cell xenograft tumor model in BALB/C Nude Mice was constructed successfully.2. Tumor growth curve showed that in vivo, treatment of subcutaneous tumor xenografts with IL-24 recombinant plasmid resulted in significant tumor growth inhibition when compared with that in control groups (P<0.05). There was no significant difference between the empty-vector plasmid group and PBS group (P>0.05).3. The tumor inhibitory rate in IL-24 recombinant plasmid group was 56.5%, significantly higher than empty-vector plasmid group,1.3%(P<0.05). Comparing to the control groups, the proliferation of Siha cells was inhibited by transfection with PDC316-hIL-24 (P<0.05).4. IL24 mRNA and GADPH were tested by RT-PCR. IL-24 recombinant plasmid group showed positive result that 620bp position could be observed a specific band, while the empty vector group and PBS control group, neither of the expected bands occured.5. In each group transplanted tumor cells by flow cytometry analysis showed that the G0/G1 phase of the transfected cells was increased, but the S phase and G2/M phase of transfected cells were reduced (P<0.05). No significant difference was shown between the empty-vector plasmid group and PBS group (P>0.05). Conclusion Growth rate of tumor in tumor carring mice was significantly inhibited by IL-24 gene therapy.Conclusion:1. Growth rate of tumor in tumor carring mice was significantly inhibited by IL-24 gene therapy.2. Cervical cancer Siha transplanted tumor cells were arrested in G0/G1 phase by IL-24 recombinant plasmid.