Introduction of human adenomatous polyposis coli gene into Min mice via cationic liposomes

The adenomatous polyposis coli (APC) gene is a tumor-suppressor gene involved in familial polyposis coli (FAP), a hereditary disease heralded by the development of hundreds of colorectal adenomas. A mouse model for FAP, the multiple intestinal neoplasia (Min) mouse, develops multiple adenomatous polyps of the large and small intestine similar to their human counterparts. To test the feasibility of introducing normal human APC as a means of either preventing or reversing polyp formation, we describe a method of in vivo transfection of APC into colonic epithelium of the Min mouse.

Anesthetized young (4 weeks) Min mice were treated with enemas containing lipofectant and a normal human APC cDNA plasmid every 72 hours for 2 months and then euthanized at 24, 48, and 72 hours after the last treatment. Polymerase chain reaction (PCR) was used to detect the presence of the plasmid DNA.

PCR on the extracted colonic epithelial DNA showed the presence of plasmid DNA up to 72 hours after the last treatment. Expression of the plasmid construct was confirmed by reverse transcriptase-PCR.

We have demonstrated the repeated introduction and detection of normal human APC in the colonic epithelium of the Min Mouse in vivo during an extended period of time with no toxic side effects by means of our prolonged therapy.