Effects of photodeoxygenation on cell biology using dibenzothiophene S-oxide derivatives as O(P-3)-precursors

Photodeoxygenation of dibenzothiophene S-oxide and its derivatives have been used to generate atomic oxygen [O(P-3)] to examine its effect on proteins, nucleic acids, and lipids. The unique reactivity and selectivity of O(P-3) have shown distinct oxidation products and outcomes in biomolecules and cell-based studies. To understand the scope of its global impact on the cell, we treated MDA-MB-231 cells with 2,8-diacetoxymethyldibenzothiophene S-oxide and UV-A light to produce O(P-3) without targeting a specific cell organelle. Cellular responses to O(P-3)-release were analyzed using cell viability and cell cycle phase determination assays. Cell death was observed when cells were treated with higher concentrations of sulfoxides and UV-A light. However, significant differences in cell cycle phases due to UV-A irradiation of the sulfoxide were not observed. We further performed RNA-Seq analysis to study the underlying biological processes at play, and while UV-irradiation itself influenced gene expression, there were 9 upregulated and 8 downregulated genes that could be attributed to photodeoxygenation. [GRAPHICS]

Automated summary

Photodeoxygenation of dibenzothiophene S-oxide and its derivatives generates atomic oxygen to examine its effect on biomolecules and cells. Cell death can occur when exposed to higher concentrations of sulfoxides and UV-A light, while UV-irradiation influences gene expression with specific upregulated and downregulated genes related to photodeoxygenation.