Craft in Biomedical Research by Mianna Meskus

Author:Mianna Meskus
Language: eng
Format: epub, pdf
Publisher: Palgrave Macmillan US, New York

A year later, the same principle used in mouse models was applied successfully in adult human cells. Two independent research teams published their studies, one led by Yamanaka and colleagues (Takahashi et al. 2007) and another led by James Thomson at University of Wisconsin-Madison (Yu et al. 2007) which proved that human fibroblasts, that is, skin cells, could be reprogrammed to regain the state of pluripotency . Thomson’s group used slightly different transcription factors from their Japanese colleagues, Oct4, Sox2, Nanog, and Lin28, in order to avoid using the proto-oncogene c-Myc, which has been found in human cancers. Both papers conveyed the excitement that iPS cells would make it possible to generate cell lines from individuals predisposed to specific diseases. Equally appealing in the new technology was that it would remove the ethical controversy that had hampered this field of science due to the use of human embryos in stem cell generation (Takahashi et al. 2007; Yu et al. 2007; see also Chap. 6).

A little over a year after I had begun this study, the scientific importance of the SCNT and iPS cell technologies received prestigious international acknowledgment. In 2012, the Nobel Prize in Physiology or Medicine was jointly bestowed to Gurdon and Yamanaka for their achievements in the field of cellular reprogramming. According to the Nobel Assembly at Karolinska Institutet, the discovery that mature, specialized cells can be reprogrammed to become immature cells capable of developing into all tissues of the body has “revolutionized our understanding of how cells and organisms develop” because they show that it is indeed possible to “turn back the developmental clock” (Nobel Prize press release 2012). In a stem cell symposium I participated some years later, one presenter described the exciting state of iPS cells as “I am open for anything, I am open to who I am”.3

Presently, the iPS cell technology is considered both promising and challenging because these cells come into existence through substantial manipulation—human activities due to which the defining biological characteristics of the original cells are fundamentally altered. IPS cells are thus biological material that does not exist in nature but is instead created in laboratory conditions from donated tissue . Initially iPS cells were thought as identical to the hES cells, sharing several characteristics from similar morphology to the self-renewing capacity. As researchers accumulated evidence on the epigenetic changes and differences in gene expression profile in the iPS cells, the field however agreed that the latter demonstrate some significant differences from the hES cells, and they do not attain as “perfect” state of pluripotency as the hES cells (Krupalnik and Hanna 2014; Mattout et al. 2011; Toivonen et al. 2013).4

Despite the observed differences between the two stem cell types, iPS cells became the new “tool for the job”, as Joan Fujimura (1996) put it, for several reasons already hinted at. They provide a more accessible source for research material than hES cells, which have been derived from “surplus embryos” and oocytes donated by women undergoing IVF . Furthermore iPS

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