Cloning, Expression and Tumor Suppression of Human Endostatin.

Human endostatin cDNA was cloned from total RNA of normal Chinese liver cell line L02 by RT-PCR. Endostatin DNA sequence encoded 184 amino acid residues. Five base pairs and 3 amino acid residues are different from that reported, it may be due to interspecies difference. The endostatin cDNA was inserted into the pET-28a(+) containing T7 promoter. The recombinant plasmid was transformed the E.coli BL21(DE3). Recombinant human endostatin was highly expressed as inclusion body when the expression strain BL-ENDO was induced with 1 mmol/L IPTG. Result of SDS-PAGE analysis revealed that recombinant human endostatin was accounted for up to 25% of soluble protein in E.coli. Purified and refolded recombinant human endostatin was active in inhibiting tumor growth and metastasis.