Thioredoxin upregulation by 5-aminolaevulinic acid-based photodynamic therapy in human skin squamous cell carcinoma cell line.
OBJECTIVE
5-aminolaevulinic acid-based photodynamic therapy (ALA-PDT) is widely performed in the clinical setting for superficial skin cancers, giving favorable results, but residual tumor and recurrence occur occasionally. Thioredoxin is a common antioxidant that suppresses apoptosis and facilitates cell growth. We investigated the expression of thioredoxin following ALA-PDT in human skin squamous cell carcinoma cell line, HSC-5.


METHODS
ALA-PDT was performed in HSC-5 cells using low-dose (5 J/cm(2), 100 mW/cm(2)) or high-dose (30 J/cm(2), 100 mW/cm(2)) irradiation, and the expression of thioredoxin was measured by Western blotting. An MTT assay was used to assess cell growth following a low dose of multiple irradiations. Cell death was examined by Western blotting for caspase-3 and PARP. Immunofluorescence double staining using annexin V and propidium iodine was also performed.


RESULTS
Expression of thioredoxin was only observed following low-dose exposure ALA-PDT. Multiple low-dose exposure ALA-PDT significantly proliferated cell growth. With high-dose exposure ALA-PDT, caspase-3 and PARP expression were seen, and cell death due to apoptosis and/or necrosis was observed, but thioredoxin was barely detected.


CONCLUSIONS
Low-dose exposure ALA-PDT increased the expression of thioredoxin and facilitated the growth of HSC-5 cells.
Kuhara
Tomoe
T
Department of Dermatology, Aichi Medical University School of Medicine, Aichi, Japan. tomoe@aichi-med-u.ac.jp
Watanabe
Daisuke
D
Akita
Yoichi
Y
Takeo
Tomohiro
T
Ishida
Natsuko
N
Nakano
Aki
A
Yamashita
Noriko
N
Ohshima
Yuichiro
Y
Kawada
Morihiro
M
Yanagishita
Takeshi
T
Tamada
Yasuhiko
Y
Matsumoto
Yoshinari
Y
D000622:Aminolevulinic Acid / Q000009:adverse effects / Q000494:pharmacology*; D000704:Analysis of Variance; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects* / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D024161:Collagen Type XI / Q000378:metabolism; D006801:Humans; D054025:Lasers, Dye; D008856:Microscopy, Fluorescence; D009364:Neoplasm Recurrence, Local / Q000139:chemically induced; D010778:Photochemotherapy / Q000009:adverse effects / Q000379:methods; D017319:Photosensitizing Agents / Q000009:adverse effects / Q000494:pharmacology*; D011829:Radiation Dosage; D013879:Thioredoxins / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
C499319:COL11A2 protein, human; D024161:Collagen Type XI; D017319:Photosensitizing Agents; D013879:Thioredoxins; D000622:Aminolevulinic Acid; D053148:Caspase 3