Differences between human embryonic stem cell lines

Abstract

The promise of human embryonic stem cell (hESC) lines for treating injuries and degenerative diseases, for understanding early human development, for disease modelling and for drug discovery, has brought much excitement to scientific communities as well as to the public. Although all of the lines derived worldwide share the expression of characteristic pluripotency markers, many differences are emerging between lines that may be more associated with the wide range of culture conditions in current use than the inherent genetic variation of the embryos from which embryonic stem cells were derived. Thus, the validity of many comparisons between lines published thus far is difficult to interpret. This article reviews the evidence for differences between lines, focusing on studies of pluripotency marker molecules, transcriptional profiling, genetic stability and epigenetic stability, for which there is most evidence. Recognition and assessment of environmentally induced differences will be important to facilitate the development of culture systems that maximize stability in culture and provide lines with maximal potential for safety and success in the range of possible applications.

Safety paradigm: genetic evaluation of therapeutic grade human embryonic stem cells

“…Despite wide interest in defining the properties of hESCs, comprehensive characterization has been done with only a subset of lines. The popularity of some of the earliest lines derived, such as H1 and H9, both for research and for the generation of clinical grade banks, arises not necessarily because they are superior lines, as these cells were derived on mouse feeders in the presence of serum, but because by default (Adewumi et al 2007;Allegrucci & Young 2007;Lefort et al 2008;Närvä et al 2010). Although many of such studies have been useful in identifying 'master' genes of pluripotency, no consistent clustering could be ascribed to variations in chromosomal stability or differentiation propensity of the hESC lines.…”

“…Hanson & Caisander 2005;Allegrucci & Young 2007;Baker et al 2007;Catalina et al 2008). These karyotypic changes emerged beyond passage 13 and were in general losses or gains of whole chromosomes (aneuploidy), rather than structural rearrangements within a diploid karyotype.…”

Multiparameter flow cytometry for the characterization of human embryonic stem cells

“…This in mind, it is difficult not to consider the possibility that under different culture conditions the recorded loss of expression between passages may have been greatly reduced if not totally eradicated and similarly the gate shift to 99% may not have been so detrimental to the marker expression in general. This paper lends weight to the opinions of Young (2007) andthe International Stem Cell Initiative (2007), that the regulation and standardization of human embryonic culture conditions among research laboratories could be the first steps required to limit expression marker variation in embryonic cell lines. Perhaps also by extension the first steps towards defining a universal phenotypic marker panel for human embryonic stem cells.…”

“…This is predominantly due to the fact that of the numerous embryonic cell lines that have been established (167 lines approved for use in UK alone (MRC UK Stem Cell Line Registry), for the limited number of these that have been compared at least, the expression levels for the reported pluripotency markers have been shown to be similar but not identical (International Stem Cell Initiative 2007;Carpenter et al 2004). The contribution of divergent culture techniques in different laboratories to this diversity is debatable (Carpenter et al 2004;Allegrucci et al 2005;Allegrucci and Young 2007). Additionally, the lack of knowledge about documented target markers has also hindered the selection of a universal marker panel.…”

“…Additionally, the lack of knowledge about documented target markers has also hindered the selection of a universal marker panel. This is particularly true for surface markers where for most, their physiological function remains unclear (Henderson et al 2002;Allegrucci et al 2005;Allegrucci and Young 2007) especially considering some are not exclusive to hESCs and are expressed on various other cell types (Allegrucci and Young 2007;Barraud et al 2007;Linju-Yen et al 2005;Gang et al 2007). Still, given the potential of non-invasive FACS, surface markers are the ideal standard marker panel candidate.…”