TY  - JOUR
AU  - Schmalz, Michael
AU  - Liang, Xiao-Xuan
AU  - Wieser, Ines
AU  - Gruschel, Caroline
AU  - Muskalla, Lukas
AU  - Stöckl, Martin Thomas
AU  - Nitschke, Roland
AU  - Linz, Norbert
AU  - Leitenstorfer, Alfred
AU  - Vogel, Alfred
AU  - Ferrando-May, Elisa
TI  - Dissection of DNA damage and repair pathways in live cells by femtosecond laser microirradiation and free-electron modeling.
JO  - Proceedings of the National Academy of Sciences of the United States of America
VL  - 120
IS  - 25
SN  - 0027-8424
CY  - Washington, DC
PB  - National Acad. of Sciences
M1  - DKFZ-2023-01165
SP  - e2220132120
PY  - 2023
N1  - #LA:W650#
AB  - Understanding and predicting the outcome of the interaction of light with DNA has a significant impact on the study of DNA repair and radiotherapy. We report on a combination of femtosecond pulsed laser microirradiation at different wavelengths, quantitative imaging, and numerical modeling that yields a comprehensive picture of photon-mediated and free-electron-mediated DNA damage pathways in live cells. Laser irradiation was performed under highly standardized conditions at four wavelengths between 515 nm and 1,030 nm, enabling to study two-photon photochemical and free-electron-mediated DNA damage in situ. We quantitatively assessed cyclobutane pyrimidine dimer (CPD) and γH2AX-specific immunofluorescence signals to calibrate the damage threshold dose at these wavelengths and performed a comparative analysis of the recruitment of DNA repair factors xeroderma pigmentosum complementation group C (XPC) and Nijmegen breakage syndrome 1 (Nbs1). Our results show that two-photon-induced photochemical CPD generation dominates at 515 nm, while electron-mediated damage dominates at wavelengths ≥620 nm. The recruitment analysis revealed a cross talk between nucleotide excision and homologous recombination DNA repair pathways at 515 nm. Numerical simulations predicted electron densities and electron energy spectra, which govern the yield functions of a variety of direct electron-mediated DNA damage pathways and of indirect damage by •OH radicals resulting from laser and electron interactions with water. Combining these data with information on free electron-DNA interactions gained in artificial systems, we provide a conceptual framework for the interpretation of the wavelength dependence of laser-induced DNA damage that may guide the selection of irradiation parameters in studies and applications that require the selective induction of DNA lesions.
KW  - DNA strand breaks (Other)
KW  - nonlinear photodamage (Other)
KW  - oxidative DNA damage (Other)
KW  - reductive DNA damage (Other)
KW  - wavelength selectivity (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:37307476
DO  - DOI:10.1073/pnas.2220132120
UR  - https://inrepo02.dkfz.de/record/276790
ER  -