Patent ID: 6399377
Filing Date: 2002-06-04
Classification: C07K,C12N,C12Y

Abstract:
A transformed mammalian cell, in cell culture, for expressing a protein of interest, said mammalian cell comprising:a directly amplifiable gene sequence, in expressible form, which when expressed renders said cell more resistant to a toxic agent, said sequence being exogenous to said cell; a gene of interest, in expressible form, which encodes a desired protein foreign to said cell; and an anti-sense gene sequence, in transcribable form, encoding an anti-sense RNA which selectively hybridizes in said cell to at least a portion of the mRNA transcribed from said directly amplifiable gene sequence so as to inhibit the translation of said mRNA, such that a higher level of amplification of said directly amplifiable gene and said gene of interest can be achieved, if the cell is exposed to a sufficient level of the toxic agent, than in the absence of said anti-sense RNA, wherein the directly amplifiable gene encodes a dihydrofolate reductase (DHFR) and the toxic agent is methotrexate (MTX).