Figure 3.

Restoring Abbreviated XPC Gene Expression in Patient-Derived Fibroblasts

(A) Scheme for ABE-induced read through of an XPC-associated PTC. (B) Targeted deep-sequencing data showing the A-to-G substitution rate induced by ABEmax treatment at the PTC site in the XPC gene. (C) Expression level of the XPC protein in XPC mutant cells rescued by treatment with ABEs (ABEmax or xABE), compared with the expression level in untreated cells and cells treated with ataluren or gentamicin for 48 h. (D) Cell viability of WT skin fibroblasts (BJ-5ta), XPC mutant cells (GM14867), and XPC mutant cells treated with ABEs (ABEmax or xABE), ataluren, or gentamicin at 3 days after exposure to 254 nm ultraviolet radiation at a dose of 25 J/m². p values were calculated by one-way ANOVA with post-hoc Bonferroni’s multiple comparison tests (n = 6). p value indicators from a comparison with GM14867 cell viability are shown above each treatment group. NS, not significant (p > 0.05); *p < 0.05; ***p < 0.001. (E) Prolonged expression of the XPC protein after CRISPR-pass treatment. Significant and stable XPC protein expression was observed until at least 4 weeks after ABEmax treatment. However, XPC protein expression declined after removal of ataluren and gentamycin. Proteins were also prepared from ABEmax-treated XPC mutant cells at 2 and 4 weeks (subculturing twice per week) for comparison. Blue and red arrowheads indicate the positions of XPC protein.