Objective: To clone human endostatin gene, detect its biological activities of endostatin protein and use it to cure human SHG44 gliomas of nude mice in vivo.
Methods: The mRNA from the human liver tissue was extracted. And the functional fragment of endostatin gene was amplified by RT-PCR. It was cloned into pUC19 and sequenced according to Dye primer sequencing kit. The non-fusion expression vector pDH-endo was constructed. The recombinant human endostatin gene was expressed in DH5alphaat the condition of temperature induction. The protein activities were tested by Chicken Chorio-Allantoic Membrane (CAM) assay and endothelial cell proliferation inhibitory assay. Endostatin protein was applied to the nude mice through hypodermic injection in order to cure the SHG44 glioma.
Results: The acquired endostatin gene is 551 bp, its sequence is correct and the expressed protein is 20 kDa. The protein possesses the anti-angiogenesis activity. Hypodermic injection of endostatin at the dose of 5 mg/kg/d, 10 mg/kg/d or 20 mg/kg/d can inhibit the human glioma angiogenesis and tumor growth(the inhibition rate of the tumor are seperately 34.5%, 76.1% and 80.2%).
Conclusion: The cloning, expression and preliminary application of human endostatin protein lay the foundation for the antiangiogenesis therapy of glioma and the other solid tumors.