Development of Novel Drugs from Patient-Derived iPS Cells

iPS cells have attracted great attention from basic science to clinical medicine. In particular in the field of clinical medicine, iPS cells are expected to be very good tools for transplantation into diseased organs after differentiation. Actually in 2014, iPS cell-derived retinal cells have been transplanted into the patient of age-related macular degeneration in Japan. iPS cells are also expected to be good tools for dissecting molecular mechanisms of the disease and for developing novel drugs. It has been impossible to use alive cardiomyocytes of patients for investigating the disease mechanisms. iPS cell-derived cardiomyocytes, which are originated from patients of genetic diseases such as cardiomyopathy and long QT syndrome, should express abnormal genes same as cardiomyocytes of the patient heart. Thus, it is possible to understand the pathophysiology of the disease heart and develop novel drugs by using the iPS-derived cardiomyocytes. Although iPS-derived cardiomyocytes are immature and express genes less abundantly than, or genes different from cardiomyocytes of the patient heart, it is a big progress to be able to use alive human cardiomyocytes for experiments. We will discuss present status and issues of patient-derived iPS cells as a tool of dissecting pathophysiology and developing drugs.