The inhibition of Endostar on the angiogenesis and growth of gastrointestinal stromal tumor xenograft.

To investigate whether Endostar can inhibit the angiogenesis and growth of gastrointestinal stromal tumor (GIST) xenografts in nude mice and the feasibility of antiangiogenesis as a treatment modality for GIST. Twenty Balb/c-nu/nu mice burdened with GIST were randomly divided into two groups. Endostar (2 mg/kg) was injected around the tumor once per day for 10 days in the experimental group and with normal saline (NS) (0.1 ml) in the control group. The tumor bulk was measured every 5 days until 5 days after the end of the injections. The inhibition tumor rate (ITR) was calculated. Tumor bulk, microvascular density (MVD), rate of bcl-2-positive expression, and AI were assessed in the two groups. Tumor volumes were compared before and after treatment in the experimental group. The difference in tumor bulk between the two groups was not statistically significant before treatment (P = 0.628), but at the end of test, the difference was significant (P < 0.0001), and in the test group, the tumor bulk was also decreased significantly after treatment (P < 0.0001). The ITR was 86.5%. All xenografts showed CD117-positive staining. MVD and bcl-2-positive rate were lower in the experimental group than in the control group (P = 0.020 and P = 0.023, respectively). AI increased significantly in the experimental group compared with the control group (P = 0.020). Endostar can reduce angiogenesis,promote cell apoptosis, and inhibit the growth of a GIST xenograft. It is possible that Endostar will be used as an effective drug for GIST in the future.