Method for expressing inducible rna [in cells, nucleic acid molecules therefor and cells transformed by said molecules

A method of expressing RNAi in cells, comprising:

• introducing into eukaryotic cells a molecule of nucleic acid comprising sense and antisense sequences of RNAi placed under control of a promoter of single transcription, the sense and antisense sequences being separated by a sequence of DNA comprising a sequence for stopping transcription, wherein the DNA sequence is framed at each end thereof by a lox sit, and
• placing Cre in contact with the lox sites to obtain by site-specific recombination elimination of the DNA sequence and the stop sequence of the transcription such that the sense and antisense sequences are no longer separated except by a remaining lox sequence and thereby permit transcription of the RNAi in its entirety with the remaining lox sequence as a loop.

A molecule of nucleic acid comprising sense and antisense sequences of RNAi placed under control of a promoter of single transcription, the sense and antisense sequences being separated by a sequence of DNA comprising a sequence for stopping transcription, wherein the DNA sequence is framed at each end thereof by a lox site.

A pharmaceutical composition comprising a therapeutically effective amount of an active substance of at least a cell or cell line in accordance with claim 8 and a compatible excipient.