title: Expression of amplified human beta interferon genes using heavy metal induction in Chinese hamster ovary cells.
abstract: An expression cassette consisting of the human beta-interferon (beta-IFN) cDNA fused to the human metallothionein (MeT)IIA promoter has been linked to a selectable mouse dihydrofolate reductase gene (dhfr) and used to transform dhfr-deficient Chinese hamster ovary (CHO) cells. Transformants resistant to increasing concentrations of methotrexate (Mtx) were isolated and found to secrete beta-IFN either constitutively or upon induction with cadmium (up to 325 000 units beta-IFN/10(6) cells/24 h). Molecular analysis demonstrates a large increase in beta-IFN-specific DNA sequences and beta-IFN mRNA levels in amplified cell lines, with initiation of transcription occurring at the authentic start point for the MeT promoter.
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004720:Endonucleases; D005260:Female; D005784:Gene Amplification; D005786:Gene Expression Regulation / Q000187:drug effects; D005818:Genetic Engineering; D007370:Interferon Type I / Q000235:genetics*; D008668:Metallothionein / Q000235:genetics*; D008670:Metals / Q000494:pharmacology; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012315:RNA Caps; D012333:RNA, Messenger / Q000235:genetics; D015719:Single-Strand Specific DNA and RNA Endonucleases
chemical_list: D007370:Interferon Type I; D008670:Metals; D012315:RNA Caps; D012333:RNA, Messenger; D008668:Metallothionein; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases