Berndt-Paetz Mandy, Weimann Annett, Sieger Nadine, Schastak Stanislaw, Riyad Yasser M, Griebel Jan, Arthanareeswaran Vinodh K A, Stolzenburg Jens-Uwe, Neuhaus Jochen
Department of Urology, Research Laboratories, University of Leipzig, Leipzig, Germany.
Department of Urology, University Hospital Leipzig, Leipzig, Germany.
Photodiagnosis Photodyn Ther. 2017 Jun;18:244-251. doi: 10.1016/j.pdpdt.2017.02.017. Epub 2017 Mar 6.
Efficacy of PDT in muscle-invasive bladder cancer is hampered by low tissue penetration of most photosensitizers by short excitation wavelength. THPTS is excitable at near-infrared (760nm) allowing tissue penetration up to 15mm. We examined the cellular effects of THPTS-PDT in human bladder cancer cells.
We used four human transitional carcinoma cell lines, epithelial bladder progenitors (HBLAK) and bladder smooth muscle cells (HBSMC). We used flow cytometry to examine pharmacokinetics of THPTS, confocal laser scanning microscopy to analyze subcellular localization and production of reactive oxidative species (ROS), examined cytotoxicity and cell death pathways (qRT-PCR).
Total uptake varied between cell lines and was significantly high in HBLAK and HBSMC. Lysosomal localization was mainly seen in cancer cells and HBLAK, while THPTS was distributed throughout the cytoplasm in HBSMC. Significant ROS production was detected 30min after THPTS-PDT. Growth arrest occurred within 4h and resulted in apoptotic and necrotic cytotoxicity after 24h. Cytotoxicity was dose-dependent and specifically high in cancer cells and HBLAK and significantly low in HBSMC.
THPTS-PDT induces cellular mechanisms leading to cellular growth arrest, apoptosis and necrosis in human bladder cancer cells. These effects are only partly dependent on the total amount of THPTS uptake and rather dependent on its subcellular compartmentalization. HBSMC are hardly affected by THPTS-PDT confirming tumor specificity and safety. THPTS is a promising new photosensitizer with the unique advantage of deep tissue penetration allowing the treatment of solid tumors and warranting further animal studies.
光动力疗法（PDT）在肌肉浸润性膀胱癌中的疗效受到大多数光敏剂激发波长较短导致组织穿透性低的限制。四羟基苯基二氢卟吩（THPTS）可在近红外（760nm）激发，组织穿透深度可达15mm。我们研究了THPTS-PDT对人膀胱癌细胞的细胞效应。
我们使用了四种人移行癌细胞系、膀胱上皮祖细胞（HBLAK）和膀胱平滑肌细胞（HBSMC）。我们使用流式细胞术检测THPTS的药代动力学，利用共聚焦激光扫描显微镜分析亚细胞定位和活性氧（ROS）的产生，检测细胞毒性和细胞死亡途径（qRT-PCR）。
细胞系之间的总摄取量有所不同，在HBLAK和HBSMC中显著较高。溶酶体定位主要见于癌细胞和HBLAK，而THPTS在HBSMC中分布于整个细胞质。THPTS-PDT后30分钟检测到显著的ROS产生。4小时内出现生长停滞，24小时后导致凋亡和坏死性细胞毒性。细胞毒性呈剂量依赖性，在癌细胞和HBLAK中特异性较高，在HBSMC中显著较低。
THPTS-PDT诱导细胞机制，导致人膀胱癌细胞发生细胞生长停滞、凋亡和坏死。这些效应仅部分依赖于THPTS摄取的总量，而更依赖于其亚细胞区室化。HBSMC几乎不受THPTS-PDT的影响，证实了肿瘤特异性和安全性。THPTS是一种有前景的新型光敏剂，具有深层组织穿透的独特优势，可用于实体瘤治疗，值得进一步开展动物研究。
