Abstract
Human Induced pluripotent stem cells (hiPSCs) and embryonic stem cells (hESCs) gain great attentions as cell sources for regenerative medicine. Since hiPSCs and hESCs have ability to grow eternally (self-renewal) and to differentiate into any types of cells comprising human body (pluripotency), even a small number of cells could form teratoma inside recipients. To solve this subject, I have focused on cell surface glycans of hiPSCs and hESCs. In 2007, just after hiPSCs were developed, I performed comprehensive glycome analysis of hiPSCs derived from various origins. I could not only clarify structural features of cell surface glycans of hiPSCs/hESCs, but also discover a lectin, called rBC2LCN, which is specific to hiPSCs/hESCs. rBC2LCN was also named as AiLecS1, since this lectin was the first lectin specific to stem cells developed at AIST (rBC2LCN/AiLecS1). Based on this finding, I developed two technologies to provide solutions to the tumorigenicity of hiPSCs/hESCs. One is the GlycoStem test to quantitate hiPSCs/hESCs using cell culture supernatants and another is a drug conjugate of rBC2LCN/AiLecS1 to eliminate hiPSCs/hESCs. In this review, I describe the discovery of rBC2LCN/AiLecS1 and its installation to regenerative medicine.
