Study Of The Effect Of Endostar Injected Into Tumor On Mice Lewis Lung Cancer

ObjectiveTo observe the effect of recombinant human endostain(Endostar)injected into tumour or combined with cisplatin(DDP)on the mouse model of Lewis lung cancer.Methods1.The models of LLC were established via subeutaneous injection of LLC cells in the site of the right upper extremity of C57BL/6 mice.2. Experiment groupsThe mice were randomly divided into 5 groups by their weights until tumor's volume reached about 400mm3. One group of mice(NS group)(n=10)was treated with Sodium Chloride. The second group of mice(DDP group)(n=10)was injected intraperitoneally cisplatin(2mg·kg-1·d-1 for 1 to 7 days). The third group [Endo(it) group](n=10)was injected endostar(5 mg·kg-1·d-1,for 1 to 10 days)into tumour.The fourth group[DDP+Endo(ip)group] (n=10)was injected cisplatin(2mgkg-1d-1,for 1 to 7 days)and endostar(5 mg·kg-1·d-1,for 1 to 10days)intraperitoneally.And the fifth group[DDP+Endo(it)group](n=10)was injected cispl-atin(2mg·kg-1·d-1,for 1 to 7 days)intraperitoneally and endostar(5 mg·kg-1·d-1,for 1 to 10 days)into tumour.3.Observe the general state of health of LLC models daily.4.Measure the tumour volume every two days.And on the 11th day of the experiment draw growth curve of the tumour volume.5.Weight the tumours and calculate the tumour weight inhibition rate.6. Observe the ultrastructure of the tumours and detect the expression of vascular endothelial growth factor(VEGF)and microvessel density(MVD)in tumor tissue of the mice by immunohistochemistry.7. Serum VEGF was determined by ELISA.Results1.5 days after implantation,the mice were all observed tumor appearancing.2.Effects on the the general state of health of LLC models With the gradual growth of the transplanted tumor,their consumption of food,water and movement got slowly in NS group of mice.The activity and foodintake of LLC models in the three DDP groups reduced but the weight did not get lost obviously,which maintained to the end of the study.The weight of Endo(it) group had been on the increase until the end of the study.3.Effect on the tumour volume and tumour weightTumor volume(mm3):The tumor volume increased gradually in all groups and tumor volume of NS group increased fast,but the volume of other groups increased slowly. When the experiment was over,the volume of NS group,DDP group,Endo(it) group,DDP+Endo (ip)group,DDP+Endo(it)group was 2481.00±392.36,1124.98±278.25,1796.79±256.51,734. 97±279.77,708.345±189.77,respectively. Compared with other four groups,there were significant differences(P<0.05)in NS group,DDP group,Endo(it)group respectively on tumour volume.But there was no significantly difference of tumour volume between the DDP+Endo(ip) group and DDP+ Endo(it) group(P>0.05).Tumor weight(g):tumour weight of the NS group,DDP group,Endo(it)group, DDP+ Endo (ip)group,DDP+Endo(it)group was 3.86±0.40,1.49±0.30,2.80±0.17,1.16±0.30, 1.00±0.23,respectively.And the toumor inhibition rate (TIR) of all treated groups were calculated.On the 11th day the TIR were 61.77%,24.94%,70.30%,74.32% respectively. Compared with control group,there were significant decreases(P<0.05) in treated groups on tumour weight.And the tumour weight loss of the fifth group was the most obvious, inhibition rate of tumor weight of it reached 74.32%.4. Effect on microvessel density in tumor tissueCD34 was employed as the marker of vascular endothelial cell and its cytoplasm was dyed yellow-brown.The mean values of MVD on NS group,DDP group, Endo (it) group, DDP+Endo (ip)group,DDP+Endo(it)group were 11.8±2.4,4.4±1.7,4.2±1.3,1.8±0.8,13.8±1.9,respectively.Compared with NS group,the mean values of MVD reduced in other four groups,but there were significant decreases(P<0.05) only in the three endostar groups. There were significant decreases between the DDP group and the three endostar groups;Between the two combined-drug groups, the differences were significant (P<0.05) and the mean values of MVD of DDP+Endo(it) group were both remarkably lower than DDP+Endo(ip) group.5. Effect on the expression of vascular endothelial growth factor in tumor tissueThe VEGF expressed in the cytoplasm of cancerous cells and its cytoplasm was also dyed yellow-brown. The mean values of the expression of VEGF on NS group,DDP group, Endo(it) group,DDP+Endo(ip) group,DDP+Endo(it) group were 6.4±0.9,6.2±0.8,4.4±0.5, 4.6±0.5,3.4±1.1,respectively.Compared with NS group,the mean values of VEGF reduced in other four groups,but there were significant decreases (P<0.05)only in the three endostar groups. There were significant decreases between the DDP group and the three endostar groups;Between the two combined-drug groups,the differences were significant (P<0.05) and the mean values of VEGF of DDP+Endo(it) group were both remarkably lower than DDP+Endo(ip) group.6.Effect on the serum VEGFSerum VEGF (pg·ml-1):Serum VEGF of the NS group,DDP group,Endo(it) group, DDP+Endo(ip) group and DDP+Endo(it) group was 115.58±19.92,58.97±14.27, 51.90±11.02,31.10±7.56,12.63±3.94,respectively. Compared with NS group, there were lower dose of the serum VEGF in other groups, and the differences were significant (P<0.05);The level of serum VEGF in DDP group was higher than Endo(it) group, but there was no obvious difference (P>0.05); Between the two combined-drug groups,and between the Endo(it)group and the two combined-drug groups the differences were significant (P<0.05).Conclusions1.Recombinant human endostain(Endostar) injected into tumour can inhibit the growth and metastasis of implanted LLC in mice,and compared with systemic administration of Endostar,it dose not increase the side effect of Endostar but can increase the effect of inhibiting the growth and metastasis of tumour.2.Recombinant human endostain injected into tumour can decrease the level of serum VEGF by reducing expression of VEGF protein,preventing proliferation and migration of ascular endothelial cell,inhibiting angiogenesis of tumor and decreasing migration of tumour.3.Recombinant human endostain injected into tumour in combination with cisplatin has synergistic effect on inhibitory activity against the growing and metastasis of lung cancer. The combination don't increase the side effect of chemotherapeutical drug.