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DNA repair in human pluripotent stem cells is distinct from that in non-pluripotent human cells.

Luo LZ, Gopalakrishna-Pillai S, Nay SL, Park SW, Bates SE, Zeng X, Iverson LE, O'Connor TR - PLoS ONE (2012)

Bottom Line: The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability.Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use.Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Biology, Beckman Research Institute, City of Hope National Medical Center, Duarte, California, United States of America.

ABSTRACT
The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability. Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use. In this study, a comparison of DNA repair pathways in pluripotent cells, as compared to those in non-pluripotent cells, demonstrated that DNA repair capacities of pluripotent cell lines were more heterogeneous than those of differentiated lines examined and were generally greater. Although pluripotent cells had high DNA repair capacities for nucleotide excision repair, we show that ultraviolet radiation at low fluxes induced an apoptotic response in these cells, while differentiated cells lacked response to this stimulus, and note that pluripotent cells had a similar apoptotic response to alkylating agent damage. This sensitivity of pluripotent cells to damage is notable since viable pluripotent cells exhibit less ultraviolet light-induced DNA damage than do differentiated cells that receive the same flux. In addition, the importance of screening pluripotent cells for DNA repair defects was highlighted by an iPSC line that demonstrated a normal spectral karyotype, but showed both microsatellite instability and reduced DNA repair capacities in three out of four DNA repair pathways examined. Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use.

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Summary of DNA repair rates/capacity in multiple DNA repair pathways in all cell lines investigated.Y axis shows the logarithmic phase of fold difference of pluripotent cells over IMR90 fibroblasts. Dotted lines are used to separate the repair pathways and direct comparisons should be limited to within the pathways. Values are mean±SD. DNA repair capacities were evaluated at 24 h after treatment or transfection.
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pone-0030541-g008: Summary of DNA repair rates/capacity in multiple DNA repair pathways in all cell lines investigated.Y axis shows the logarithmic phase of fold difference of pluripotent cells over IMR90 fibroblasts. Dotted lines are used to separate the repair pathways and direct comparisons should be limited to within the pathways. Values are mean±SD. DNA repair capacities were evaluated at 24 h after treatment or transfection.

Mentions: We have shown that the DNA repair capacities of hESCs and iPSCs are greater for nucleotide excision repair and base excision repair, than are those of non-pluripotent cells. However, when evaluating DSB repair, the DNA repair capacities of non-homologous end-joining in pluripotent cells were statistically indistinguishable from those for non-pluripotent cells, except for one iPSC line. In contrast, the DNA repair capacity for single-strand annealing, which is inherently mutagenic, was lower for all pluripotent cell lines and highest in the fibroblast lines. Moreover, induction of DNA-damage in pluripotent cells by UVC and H2O2 was lower than in fibroblasts. However, in pluripotent cells, despite the reduced level of DNA damage and the rapid repair kinetics in the global genome-nucleotide excision repair pathway, exposure to UVC and DMS initiated apoptotic cell death, resulting in cell detachment at doses that are non-lethal to fibroblasts. The summarized data, comparing only data for each cell line for each assay (Figure 8), demonstrate the complexity of studying DNA repair in different pluripotent cell lines, and the need for characterization of these lines prior to experimental use.


DNA repair in human pluripotent stem cells is distinct from that in non-pluripotent human cells.

Luo LZ, Gopalakrishna-Pillai S, Nay SL, Park SW, Bates SE, Zeng X, Iverson LE, O'Connor TR - PLoS ONE (2012)

Summary of DNA repair rates/capacity in multiple DNA repair pathways in all cell lines investigated.Y axis shows the logarithmic phase of fold difference of pluripotent cells over IMR90 fibroblasts. Dotted lines are used to separate the repair pathways and direct comparisons should be limited to within the pathways. Values are mean±SD. DNA repair capacities were evaluated at 24 h after treatment or transfection.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3295811&req=5

pone-0030541-g008: Summary of DNA repair rates/capacity in multiple DNA repair pathways in all cell lines investigated.Y axis shows the logarithmic phase of fold difference of pluripotent cells over IMR90 fibroblasts. Dotted lines are used to separate the repair pathways and direct comparisons should be limited to within the pathways. Values are mean±SD. DNA repair capacities were evaluated at 24 h after treatment or transfection.
Mentions: We have shown that the DNA repair capacities of hESCs and iPSCs are greater for nucleotide excision repair and base excision repair, than are those of non-pluripotent cells. However, when evaluating DSB repair, the DNA repair capacities of non-homologous end-joining in pluripotent cells were statistically indistinguishable from those for non-pluripotent cells, except for one iPSC line. In contrast, the DNA repair capacity for single-strand annealing, which is inherently mutagenic, was lower for all pluripotent cell lines and highest in the fibroblast lines. Moreover, induction of DNA-damage in pluripotent cells by UVC and H2O2 was lower than in fibroblasts. However, in pluripotent cells, despite the reduced level of DNA damage and the rapid repair kinetics in the global genome-nucleotide excision repair pathway, exposure to UVC and DMS initiated apoptotic cell death, resulting in cell detachment at doses that are non-lethal to fibroblasts. The summarized data, comparing only data for each cell line for each assay (Figure 8), demonstrate the complexity of studying DNA repair in different pluripotent cell lines, and the need for characterization of these lines prior to experimental use.

Bottom Line: The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability.Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use.Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Biology, Beckman Research Institute, City of Hope National Medical Center, Duarte, California, United States of America.

ABSTRACT
The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability. Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use. In this study, a comparison of DNA repair pathways in pluripotent cells, as compared to those in non-pluripotent cells, demonstrated that DNA repair capacities of pluripotent cell lines were more heterogeneous than those of differentiated lines examined and were generally greater. Although pluripotent cells had high DNA repair capacities for nucleotide excision repair, we show that ultraviolet radiation at low fluxes induced an apoptotic response in these cells, while differentiated cells lacked response to this stimulus, and note that pluripotent cells had a similar apoptotic response to alkylating agent damage. This sensitivity of pluripotent cells to damage is notable since viable pluripotent cells exhibit less ultraviolet light-induced DNA damage than do differentiated cells that receive the same flux. In addition, the importance of screening pluripotent cells for DNA repair defects was highlighted by an iPSC line that demonstrated a normal spectral karyotype, but showed both microsatellite instability and reduced DNA repair capacities in three out of four DNA repair pathways examined. Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use.

Show MeSH
Related in: MedlinePlus