-Original-

Effects of Iron on Efficacy of Photodynamic Therapy Using Photolon in a Mouse Model of CT26 Colon Cancer

Jung In Lee¹, Tae-Gyu Ahn² and Ji Hyun Choi²

¹Department of Internal Medicine, Chosun University College of Medicine, Gwangju, Korea
²Department of Obstetrics and Gynecology, Chosun University College of Medicine, Gwangju, Korea

Background: Photodynamic therapy (PDT)-a minimally invasive anti-cancer therapy-is undergoing experimental studies to increase its anti-cancer effects. This study investigated the influence of iron on the anti-cancer effects of PDT.
Methods: PDT was performed in a cancer-bearing mouse model, which was created by using a murine colon carcinoma (CT26) cell line after administration of Photolon and iron. Tumor volume and the results of TdT-mediated dUTP-biotin nick end labeling (TUNEL), 8-OHdG, and TBARS assays were used to measure anti-cancer effect.
Results: On day 14, tumor volume had increased by 49% in the PDT group and decreased by 72% in the iron+PDT group. The percentage of TUNEL-positive cells in tumor tissues was 45% in the PDT group and 69% in the iron+PDT group, suggesting that the proportion of TUNEL-positive cells had increased in the iron+PDT group. The 8-OHdG content in tumor tissues was 33% higher in the iron+PDT group than in the PDT group. The TBARS content in tumor tissues was 46% higher in the iron+PDT group than in the PDT group.
Conclusions: Iron enhances the anti-cancer effect of PDT using Photolon, most likely by increasing oxidative damage.

J Nippon Med Sch 2023; 90: 41-49

Keywords
photodynamic therapy, iron, anti-cancer

Correspondence to
Ji Hyun Choi, Department of Obstetrics and Gynecology, Chosun University College of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Korea
choijh@chosun.ac.kr

Received, March 4, 2022
Accepted, August 24, 2022