{"title":"KDM6A deficiency promotes 5-aminolevulinic acid-mediated photodynamic therapy resistance in bladder cancer by suppressing ROS accumulation.","authors":"Ryo Tasaka, Kohei Kobatake, Yuki Kohada, Kenshiro Takemoto, Takafumi Fukushima, Kento Miura, Ryoken Yamanaka, Takashi Babasaki, Yohei Sekino, Hiroyuki Kitano, Keisuke Goto, Akihiro Goriki, Keisuke Hieda, Osamu Kaminuma, Nobuyuki Hinata","doi":"10.1016/j.urolonc.2025.07.022","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Non-muscle invasive bladder cancer (NMIBC) frequently recurs after transurethral resection of bladder tumors, necessitating a novel therapeutic approach. 5-Aminolevulinic acid-based photodynamic therapy (ALA-PDT) has emerged as a minimally invasive therapeutic approach; however, its long-term efficacy remains limited, and the mechanisms underlying ALA-PDT resistance are unclear. Lysine-specific demethylase (KDM) 6A, a tumor suppressor frequently mutated in NMIBC, has been implicated in cancer stemness and therapy resistance.</p><p><strong>Objective: </strong>This study aimed to investigate the role of KDM6A deficiency in modulating ALA-PDT efficacy in bladder cancer.</p><p><strong>Methods: </strong>KDM6A-knockout (KO) bladder cancer cell lines were established using CRISPR/Cas9-based gene editing. Cancer stemness was evaluated via sphere formation assays and expression of stem cell markers, while the cytotoxic effects of ALA-PDT were assessed through cell viability analysis. Protoporphyrin IX (PpIX) accumulation and reactive oxygen species (ROS) generation were examined using fluorescence microscopy and flow cytometry.</p><p><strong>Results: </strong>KDM6A-KO cells exhibited significantly increased sphere-forming ability, enhanced stem cell marker expression, and greater resistance to ALA-PDT-induced cytotoxicity. Despite elevated PpIX accumulation in KDM6A-KO cells, ROS levels following ALA-PDT were significantly reduced. A negative correlation between KDM6A expression and ROS-scavenging enzymes expression, particularly SOD2 and GPX1, was confirmed both in public database analyses and in KDM6A-deficient cells.</p><p><strong>Conclusions: </strong>These findings indicate that KDM6A deficiency promotes cancer stemness and confers resistance to ALA-PDT in bladder cancer cells by suppressing ROS generation despite increased PpIX levels. This study provides new insights into the role of KDM6A in ALA-PDT resistance and may contribute to developing novel therapeutic and diagnostic strategies for NMIBC.</p>","PeriodicalId":23408,"journal":{"name":"Urologic Oncology-seminars and Original Investigations","volume":" ","pages":""},"PeriodicalIF":2.3000,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Urologic Oncology-seminars and Original Investigations","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.urolonc.2025.07.022","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ONCOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Non-muscle invasive bladder cancer (NMIBC) frequently recurs after transurethral resection of bladder tumors, necessitating a novel therapeutic approach. 5-Aminolevulinic acid-based photodynamic therapy (ALA-PDT) has emerged as a minimally invasive therapeutic approach; however, its long-term efficacy remains limited, and the mechanisms underlying ALA-PDT resistance are unclear. Lysine-specific demethylase (KDM) 6A, a tumor suppressor frequently mutated in NMIBC, has been implicated in cancer stemness and therapy resistance.
Objective: This study aimed to investigate the role of KDM6A deficiency in modulating ALA-PDT efficacy in bladder cancer.
Methods: KDM6A-knockout (KO) bladder cancer cell lines were established using CRISPR/Cas9-based gene editing. Cancer stemness was evaluated via sphere formation assays and expression of stem cell markers, while the cytotoxic effects of ALA-PDT were assessed through cell viability analysis. Protoporphyrin IX (PpIX) accumulation and reactive oxygen species (ROS) generation were examined using fluorescence microscopy and flow cytometry.
Results: KDM6A-KO cells exhibited significantly increased sphere-forming ability, enhanced stem cell marker expression, and greater resistance to ALA-PDT-induced cytotoxicity. Despite elevated PpIX accumulation in KDM6A-KO cells, ROS levels following ALA-PDT were significantly reduced. A negative correlation between KDM6A expression and ROS-scavenging enzymes expression, particularly SOD2 and GPX1, was confirmed both in public database analyses and in KDM6A-deficient cells.
Conclusions: These findings indicate that KDM6A deficiency promotes cancer stemness and confers resistance to ALA-PDT in bladder cancer cells by suppressing ROS generation despite increased PpIX levels. This study provides new insights into the role of KDM6A in ALA-PDT resistance and may contribute to developing novel therapeutic and diagnostic strategies for NMIBC.
期刊介绍：
Urologic Oncology: Seminars and Original Investigations is the official journal of the Society of Urologic Oncology. The journal publishes practical, timely, and relevant clinical and basic science research articles which address any aspect of urologic oncology. Each issue comprises original research, news and topics, survey articles providing short commentaries on other important articles in the urologic oncology literature, and reviews including an in-depth Seminar examining a specific clinical dilemma. The journal periodically publishes supplement issues devoted to areas of current interest to the urologic oncology community. Articles published are of interest to researchers and the clinicians involved in the practice of urologic oncology including urologists, oncologists, and radiologists.
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