Pterins, heterocyclic compounds widespread in biological systems, participate in relevant biological processes and are able to act as photosensitizers. In the present study, we ascertained that 2-aminopteridin-4(3H)-one, abbreviated as Ptr, is readily incorporated into and/or onto cervical cancer cells (HeLa) and that these cells die upon UV-A irradiation of Ptr. Cell death was assessed using two tests: (1) the Rhodamine 123 fluorescence assay for mitochondrial viability and (2) the Trypan Blue assay for membrane integrity. The data suggest that, for Ptr-dependent photoinitiated cell death, events related to mitochondrial failure precede those associated with the failure of the cell membrane.
© 2011 The Authors. Photochemistry and Photobiology © 2011 The American Society of Photobiology.