Methods and compositions for use in selectively producing a protein in telomerase expressing cells

A method of selectively expressing a protein in telomerase expressing cells present in a population of cells that includes cells that do not express telomerase, said method comprising:

• introducing into said cells of said population an effective amount of an expression cassette comprising a coding sequence for said protein operably linked to a Site C repressor site and a promoter to selectively produce said protein in said telomerase expressing cells of said population of cells, wherein said expression cassette does not include the TERT minimal promoter.

A method of selectively expressing a protein in telomerase expressing cells present in a multicellular organism which includes cells that do not express telomerase, said method comprising:

• administering to said organism an effective amount of an expression cassette comprising a coding sequence for said protein operably linked to a Site C repressor site and a promoter to selectively produce said protein in said telomerase expressing cells of said multicellular organism, wherein said expression cassette does not include the TERT minimal promoter.

A method of diagnosing the presence of telomerase expressing cells in a host, said method comprising:

• administering to said host an effective amount of an expression cassette comprising a coding sequence for a marker protein operably linked to a Site C repressor site and a promoter to selectively produce said marker protein in said telomerase expressing cells of said host, wherein said expression cassette does not include the TERT minimal promoter;
• and
• detecting the presence of said marker protein in said host to diagnose the presence of telomerase expressing cells in said host.

A method of treating a host for a cellular proliferative disease, said method comprising:

• administering to said host an effective amount of an expression cassette comprising a coding sequence for a therapeutic protein operatively linked to a Site C repressor site and a promoter to selectively produce said therapeutic protein in said telomerase expressing cells of said host, wherein said expression cassette does not include the TERT minimal promoter.