INTRODUCTION OF HUMAN ADENOMATOUS POLYPOSIS-COLI GENE INTO MIN MICE VIA CATIONIC LIPOSOMES

Background. The adenomatous polyposis coli (APC) gene is a tumour-supp ressor gene involved in familiar polyposis coli (FAP), a hereditary di sease 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 introd ucing normal human APC as a means of either preventing or reversing po lyp formation, we describe a method of in vivo transfection of APC int o colonic epithelium of the Min mouse. Methods. 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 anti then eu thanized at 24, 48, and 72 hours after the last treatment. Polymerase chain reaction (PCR) was used to detect the presence of the plasmid DN A. Results. PCR on the extracted colonic epithelial DNA showed the pre sence of plasmid DNA up to 72 hours after the last treatment. Expressi on of the plasmid construct was confirmed by reverse transcriptase-PCR . Conclusions. We have demonstrated the repented introduction and dete ction of normal human APC in the colonic epithelium of the Min Mouse i n vivo during an extended period of time with no toxic side effects by means of our prolonged therapy.