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ALA‐PDT results in phenotypic changes and decreased cellular invasion in surviving cancer cells
Author(s) -
Tsai Tsuimin,
Ji Hong Tai,
Chiang PeiChi,
Chou RueyHwang,
Chang WunShaing Wayne,
Chen ChinTin
Publication year - 2009
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20761
Subject(s) - phenotype , cancer , biology , cancer cell , cancer research , medicine , pathology , genetics , gene
Background and Objectives The mechanisms of photodynamic therapy (PDT) have been studied on the cellular and tissue levels. However, the cellular behaviors of cancer cells survived from PDT are still not clear. This study attempted to investigate the influence of 5‐aminolevulinic acid (ALA)‐based PDT on the invasion ability as well as molecular changes in surviving cancer cells and their progeny. Materials and Methods The systematic effects of ALA‐PDT were evaluated using human invasive carcinoma cells (lung adenocarcinoma CL1‐5 cells, melanoma A375 cells and breast carcinoma MDA‐MB‐231 cells). To study the cellular behaviors of surviving cancer cells, PDT‐derived variants were established as stable cell lines after consecutive treatment with ALA‐PDT. Scratch wound assay and invasion assay were performed to evaluate the migration and invasion ability in the surviving cancer cells and the established PDT‐derived variants. RT‐PCR and immunoblot analysis were performed to examine the expression levels of epidermal growth factor receptor (EGFR). Results Though ALA‐PDT caused differential phototoxicity among these invasive carcinoma cells, reduced migration was found in all the surviving cancer cells Compared to parental cancer cells, the established PDT‐derived variants exerted significant phenotypic changes of cellular morphology, reduced mitochondrial function and a suppressed cellular invasiveness. Furthermore, correlated with the reduced invasion ability, expression of EGFR was downregulated in these established PDT‐derived variants. Conclusions Except for direct cell killing, ALA‐PDT could reduce EGFR expression and invasion ability of the surviving cancer cells and these effects could further pass to the progeny. The results from this study provide insights into a new mechanism by which PDT might affect cellular behaviors and tumor metastasis. Lasers Surg. Med. 41:305–315, 2009. © 2009 Wiley‐Liss, Inc.