Cloning of Endostatin and Secreted Expression in COS-7 Cells

Objective From the mouse liver, the endostatin cDNA was cloned and secretorily expressed in the recreted form in the COS-7 cells. This is a basis for tumor antiangiogenesis gene therapy. Methods Mouse endostatin cDNA was amplified from the liver cells of BABL/c mouse by means of RT-PCR, then cloned into sequencing vector puc-T. After verified by sequencing, secreting expression vector pSEC-endo was constructed. With the DEAE-dextran, the COS-7 cells were transfected by the plasmid pSEC-endo, monitoring the expression of endostatin gene by means of RT-PCR and Western analysis. Results The mouse endostatin cDNA sequence is identical to that reported in literature reference. And there's with mRNA transcribed in the transfected COS-7 cells. The results of Western blot showed that the supernatant and cytoplasmic of the COS-7 cells transduced with pSEC-endo had the expression of 20 kd objective protein. Conclusion The results suggested that cDNA of mouse endostatin could be expressed successfully cloned in COS-7 and secreted form COS-7.