1. Far-Ultraviolet Light at 222 nm Affects Membrane Integrity in Monolayered DLD1 Colon Cancer Cells
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Jun Nishikawa, Yuta Tamura, Tomohiro Fujii, Soichiro Fukuda, Shoma Yoneda, Nanami Yamaura, Shinichi Takahashi, Takeshi Yamamoto, Junzo Nojima, Yutaka Suehiro, Takahiro Yamasaki, and Taro Takami
- Subjects
far-ultraviolet ,222 nm ,membrane damage ,monolayer cells ,cell death ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
222 nm far-ultraviolet (F-UV) light has a bactericidal effect similar to deep-ultraviolet (D-UV) light of about a 260 nm wavelength. The cytotoxic effect of 222 nm F-UV has not been fully investigated. DLD-1 cells were cultured in a monolayer and irradiated with 222 nm F-UV or 254 nm D-UV. The cytotoxicity of the two different wavelengths of UV light was compared. Changes in cell morphology after F-UV irradiation were observed by time-lapse imaging. Differences in the staining images of DNA-binding agents Syto9 and propidium iodide (PI) and the amount of cyclobutane pyrimidine dimer (CPD) were examined after UV irradiation. F-UV was cytotoxic to the monolayer culture of DLD-1 cells in a radiant energy-dependent manner. When radiant energy was set to 30 mJ/cm2, F-UV and D-UV showed comparable cytotoxicity. DLD-1 cells began to expand immediately after 222 nm F-UV light irradiation, and many cells incorporated PI; in contrast, PI uptake was at a low level after D-UV irradiation. The amount of CPD, an indicator of DNA damage, was higher in cells irradiated with D-UV than in cells irradiated with F-UV. This study proved that D-UV induced apoptosis from DNA damage, whereas F-UV affected membrane integrity in monolayer cells.
- Published
- 2024
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