Induced pluripotent stem cells are sensitive to DNA damage.

Area of Science:

• Stem cell biology
• Genomics
• Radiation biology

Background:

• Induced pluripotent stem cells (iPSCs) hold promise for personalized medicine due to their similarity to embryonic stem cells (ESCs).
• Genomic instability and DNA damage response in iPSCs remain critical concerns for clinical translation.

Purpose of the Study:

• To investigate the genomic state and DNA damage response of iPSCs following ionizing radiation (IR).
• To compare the radiosensitivity and DNA repair capacity of an iPSC line with its primary somatic cell counterpart.

Main Methods:

• Exposure of iPSC line 3FB4-1 and mouse embryonic fibroblast (MEF) cells to ionizing radiation (IR).
• Quantification of DNA damage using γ-H2AX foci assay.
• Whole-genome sequencing to identify point mutations post-IR.

Main Results:

• The iPSC line (3FB4-1) demonstrated significantly lower DNA damage repair ability compared to MEF cells.
• IR induced a modest increase in γ-H2AX foci in iPSCs, contrasting with a larger increase in MEFs.
• Whole-genome sequencing revealed more widespread point mutations in iPSCs than in MEFs after IR exposure.

Conclusions:

• iPSCs exhibit heightened sensitivity to ionizing radiation, likely due to compromised DNA damage repair mechanisms.
• The findings underscore the importance of addressing the DNA repair capacity of iPSCs before their clinical application.