title: Expression of pro-urokinase cDNA in Chinese hamster ovary cell line.
abstract: Expression vectors containing the pro-urokinase (pro-UK) cDNA (pSV2-proUK) and a dihydrofolate reductase cDNA (pSV2-dhfr or MMTV-dhfr) were cotransfected into CHO-dhfr- cells by the calcium phosphate precipitation technique. The dhfr+ transformants were selected by fibrinolytic agarose plate assay. Two colonies, named CLF-14 and CLF-8, exhibited significantly high expression levels of the biological activity of urokinase-type plasminogen activator (mu-Pa). They reached more than 24 IU/10(6) cells/48 h and 16 IU/10(6) cells/48 h, respectively. Examination of the cell supernatants for mu-Pa antigenicity using ELISA method also showed strong positive results, and the quantities of expression were about 0.14-0.22 micrograms/10(6) cells/48 h and 0.08-0.14 micrograms/10(6) cells/48 h, respectively. The mu-Pa secreted by stable transformed cells could be completely inhibited by UK anti-serum, but not by tissue-type plasminogen activator (t-PA) antiserum nor by normal rabbit serum.
authors.affiliation: Laboratory of Genetic Engineering, Molecular Genetics Center, Beijing.
authors.forename: F Z
authors.initials: FZ
authors.lastname: Li
authors.forename: X Z
authors.initials: XZ
authors.lastname: Li
authors.forename: H Q
authors.initials: HQ
authors.lastname: Zhang
authors.forename: B C
authors.initials: BC
authors.lastname: Hu
authors.forename: W Y
authors.initials: WY
authors.lastname: Yu
authors.forename: J M
authors.initials: JM
authors.lastname: Fang
authors.forename: C F
authors.initials: CF
authors.lastname: Huang
mesh_terms: D000818:Animals; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D004247:DNA / Q000378:metabolism; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D006801:Humans; D010957:Plasmids; D011498:Protein Precursors / Q000235:genetics*; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics*
chemical_list: D011498:Protein Precursors; D004247:DNA; D014568:Urokinase-Type Plasminogen Activator