Development of Stem Cell Research
Tissue stem cells have been used therapeutically for many years in the contexts of Haematopoietic Stem Cell Transplantation (HSCT), in order to treat many types of blood cancer; stem cell-based skin grafting (Green et al.,1979, Green, 1989), and corneal damage (Rama et al, 2010). In HSCT, stem cells are harvested from the patient or donor and are transplanted back into the patient to restore damaged cells. However, the need for transplantable tissues and organ is far outweighs the available supply.(2, 5)
In 1998, Dr. James Thomson was able to derive the first Embryonic Stem Cells in human. This invention is hoped to solve the limited donated organs and tissues supply. Moreover, studying ES cells seemed to offer limitless possibilities because its pluripotency makes hESC possible to generate every cell type within human. Narsinh et al (2011) argue that the opportunity to model disease, discover disease mechanism and, ultimately, use cell therapy for previously untreatable conditions was particularly alluring. On the other hand, the derivation of human ES cells apparently sparked controversy because their derivation involved the destruction of a human embryo. There were heated debates regarding the moral status of the embryo (EuroStemCell, 2011). According to Barfoot (2013), some countries take a tightly regulated but permissive approach to research involving the use of human embryos to generate ES cell lines. Others have placed some restrictions on research in this area, either through direct legislation, patentability or by limiting the uses of research funding (Barfoot, 2013; The Hinxton Group, 2013).
Another obstacle that hESCs research face is logistical problem. According to Narsinh et al (2011), the limited supply of donor human embryo made this research application somewhat challenging. In particular, Narsinh et al (2011) also argue the products derived from hESCs for transplantation purposes would face rejection by the transplant recipient’s immune system or necessitate that the recipient receive lifelong therapy with toxic immunosuppressive medication. All of these reasons explain the relatively low compound annual growth rate (CAGR) of hESCs global publications (Table 1& Figure 2). (2, 6, 7)
Despite the hindrances to the study of human ES cells over the past decade, great strides were being made in understanding the pathway that regulate the maintenance and pluripotency of ES cells. In 2006 Takahashi and Yamanaka announced the successful alternative sources of personalized patient-specific stem cells called Induced Pluripotent Stem Cells (IPSCs). The iPS cells are derived from adult mouse fibroblast through the reprogramming of only four genes: OCT4 (also known as POU5F1), SOX2, Kruppel-like factor 4(KLF4) and c-MYC. Just a year later, this finding was replicated in human cells (Takahashi et al.,2007, Yu et al., 2007). This groundbreaking work was awarded the Nobel Prize in Physiology or Medicine in...