Heat shock protein70 (HSP70) is expressed plentifully in tumor cells, and it could regulate tumor immunity. Recent studies show that PDT induces cell surface expression and release HSPs from the treated cells. HSPs have critical role in the PDT-induced immune responses, but the dynamic of HSP70 in living cells induced by PDT has not been reported. In present study, YFP-HSP70 was used to monitor the dynamic distribution of HSP70 in living cells in real time. With confocal laser scanning microscope, we detected the dynamic distribution of HSP70 after PDT treatment. The results show that HSP70 most localize in the cytoplasm of tumor cells, but few localize on cell surface, and that the cytoplasmic HSP70 immediately translocated to the cell surface after Photofrin-PDT treatment. In addition, the surface-expressed HSP70 remain unchanged and did not release from tumor cells during apoptotic process. Our data suggest that HSP70, expressing on the cell surface after PDT treatment , may serves as a surface targets for immune cells and induced immune responses to regulate the efficacy of PDT.

Date Published: 1 May 2007
PDF: 8 pages
Proc. SPIE 6534, Fifth International Conference on Photonics and Imaging in Biology and Medicine, 65341G (1 May 2007); doi: 10.1117/12.741578

Published in SPIE Proceedings Vol. 6534:
Fifth International Conference on Photonics and Imaging in Biology and Medicine
Qingming Luo; Lihong V. Wang; Valery V. Tuchin; Min Gu, Editor(s)