Yamanaka team finds genes to identify defective iPS cells


A research team led by Nobel laureate and Kyoto University professor Shinya Yamanaka, the discoverer of induce pluripotent stem cells, has turned up genes that can help identify defective human iPS cells lacking differentiation ability.

The discovery could make it easier to remove such inferior cells before clinical application of regenerative medicine using iPS cells, which can theoretically develop into any type of tissue, experts say.

According to a report published online by the U.S. journal Proceedings of the National Academy of Sciences, Yamanaka’s team converted 40 human iPS cells into neural cells.

After the neural culture differentiation, seven human iPS cell clones retained “a significant number of undifferentiated cells,” the proportion of which stood at more than 10 percent.

The team then found three common genes in the seven defective iPS cell clones and all of the genes had the so-called LTR-7 sequences.

The researchers also reported neural cells derived from the defective iPS cells formed teratoma when transplanted into mouse brains.