Gene and cell-based therapy for diabetes mellitus: endocrine gene therapeutics.

Recently, islet transplantation in the treatment of type 1 diabetes has been revisited with improved results. This approach has the potential to restore the regulatory unit of endocrine pancreas, but it cannot be a definite solution because of its limitation for the use of toxic immune-suppressive agents and limited number of donors. One possible way to restore the insulin secretion safely is with cell therapy using tissue engineering of a patient's own somatic cells by transduction of the corresponding gene of interest, in which extrapancreatic cells are engineered to secrete insulin. We constructed a somatic cell therapy system using a furin-cleavable insulin gene and somatic cells of mesenchymal origin. We also tested a semipermeable chamber that can contain allo- or xenogeneic insulin-secreting cells and found that the device could be helpful for cell therapy. This novel approach should provide a feasible method for treatment of diabetes mellitus without the use of any toxic agent or of embryonic stem cells that involve ethical implications.