Postgraduate Program in Biophotonics Applied to Health Sciences, Nove de Julho University, UNINOVE, São Paulo, Brazil.
Postgraduate Program in Biophotonics Applied to Health Sciences, Nove de Julho University, UNINOVE, São Paulo, Brazil.
J Photochem Photobiol B. 2022 Oct;235:112552. doi: 10.1016/j.jphotobiol.2022.112552. Epub 2022 Sep 6.
The aim of the present study was to investigate the effects of PDT using the photosensitizer 5-aminoulevulinic acid (5-ALA) in oral squamous cell carcinoma (OSCC) behavior, mainly regarding its role on the cancer stem cell (CSC) phenotypes and in maintenance of the stem cell properties. Two OSCC cell lines were used and divided in the groups: Control, 5-ALA, LED 6 J/cm and PDT. MTT and Neutral red assays were used to access cellular viability, cell migration was evaluated by the wound healing assay. The stem cell phenotype was analyzed by flow cytometry to evaluate the CD44/ESA, CD44/ESA and CD44 populations, by the clonogenic and tumor sphere formation assays as well as by RT-qPCR. The presence of Protoporphyrin IX in each CSC fraction was evaluated by flow cytometry. The OSCC cell lines showed a significant decrease in cell viability and migration after PDT. The percentage of CD44/ESA cells decreased after PDT, which was associated with an increase in the CD44 cells and with a functional decrease in the colony and sphere formation capacity. CD44/ESA cells showed increased PpIX, which contributed for their greater sensitivity to PDT. INV gene increased significantly after PDT, indicating cellular differentiation. Altogether, our results demonstrate that 5-ALA mediated PDT decreases not only the fraction of oral CSC but also their functional capabilities, inducing their differentiation.
本研究旨在探讨使用光敏剂 5-氨基酮戊酸（5-ALA）的 PDT 对口腔鳞状细胞癌（OSCC）行为的影响，主要关注其对癌症干细胞（CSC）表型的作用以及对干细胞特性的维持。使用了两种 OSCC 细胞系，并将其分为以下几组：对照组、5-ALA 组、LED 6 J/cm 组和 PDT 组。通过 MTT 和中性红测定法来评估细胞活力，通过划痕愈合试验评估细胞迁移。通过流式细胞术分析干细胞表型，以评估 CD44/ESA、CD44/ESA 和 CD44 群体，通过集落形成和肿瘤球体形成试验以及 RT-qPCR 进行评估。通过流式细胞术评估每个 CSC 亚群中 Protoporphyrin IX 的存在。PDT 后，OSCC 细胞系的细胞活力和迁移明显下降。PDT 后 CD44/ESA 细胞的百分比下降，与 CD44 细胞增加以及集落和球体形成能力的功能下降相关。CD44/ESA 细胞的 PpIX 增加，这有助于它们对 PDT 的更高敏感性。INV 基因在 PDT 后显著增加，表明细胞分化。总之，我们的结果表明，5-ALA 介导的 PDT 不仅降低了口腔 CSC 的比例，而且降低了它们的功能能力，诱导其分化。
