Studies of the significance of functional and structural changes in mitochondria in PhotofrinTM-photodynamic-therapy-resistant cells

Brian C. Wilson; Malini Olivo; Roger Moorehead; Gurmit Singh

doi:10.1117/12.179985

19 July 1994 Studies of the significance of functional and structural changes in mitochondria in PhotofrinTM-photodynamic-therapy-resistant cells

Brian C. Wilson, Malini Olivo, Roger Moorehead, Gurmit Singh

Author Affiliations +

Proceedings Volume 2133, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy III; (1994) https://doi.org/10.1117/12.179985
Event: OE/LASE '94, 1994, Los Angeles, CA, United States

Abstract

This paper reports further studies of Radiation Induced Fibrosarcoma (RIF-1) tumor cells which have been made resistant to Photodynamic Therapy by multiple treatment and regrowth in vitro using the hematoporphyrin derivative photosensitizer Photofrin. Previous work has shown both structural and functional changes in the mitochondria of the resistant (RIF-8A) cells. Colocalization of Photofrin and the mitochondrial localizer Rhodamine-123 was assessed by double-label confocal fluorescence microscopy (CFM). At 18h Photofrin incubation, there was strong correlation in discrete subcellular sites between Photofrin and Rhodamine fluorescence. However, in RIF-8A cells there were also discrete regions of Rhodamine localization which showed weak or no Photofrin fluorescence. This was not observed in RIF-1 cells. CFM measurements also showed that the Photofrin fluorescence after 18h incubation was reduced by increasing concentration of Rhodamine (30 min. incubation), and that this dependence was different for the two cell types. The RIF-8A cells were also shown to be cross-resistant to cisplatin and to have an associated reduced level of Pt-DNA adducts, suggesting the possibility of increased repair capacity. Cross-resistance was not observed, however, with a ruthenium phthalocyanine photosensitizer nor, as previously reported, with other chemotherapeutic agents such as Adriamcyin. Thus, there is a complex pattern of cross-resistance with these cells. Preliminary observations of the effects of a respiratory chain inhibitor (oligomycin) and an uncoupler of oxidative phosphorylation (FCCP) indicate differences between RIF-8A and RIF-1 which may be related to the condensed mitochondrial structure of the RIF-8A cells.

Citation Download Citation

Brian C. Wilson, Malini Olivo, Roger Moorehead, and Gurmit Singh "Studies of the significance of functional and structural changes in mitochondria in PhotofrinTM-photodynamic-therapy-resistant cells", Proc. SPIE 2133, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy III, (19 July 1994); https://doi.org/10.1117/12.179985

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available