Department of Oral Medicine, Peking University School and Hospital of Stomatology, Beijing 100081, PR China.
Department of Oral Medicine, Peking University School and Hospital of Stomatology, Beijing 100081, PR China.
Photodiagnosis Photodyn Ther. 2020 Mar;29:101554. doi: 10.1016/j.pdpdt.2019.08.036. Epub 2019 Aug 31.
The clinical effect of 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) may be correlated with the degree of dysplasia of cancer tissues, but much is still unknown regarding the differences in its effectiveness, especially in oral cancer and precancerous lesions. The aim of this study is to compare the effects of ALA-PDT on a human oral precancerous cell line (DOK) and an oral squamous cell carcinoma cell line (CAL-27).
First, we explored the dose- and time-dependent responses of DOK and CAL-27 cells to ALA-PDT. DOK and CAL-27 cells were incubated with various concentrations of ALA (from 0.25 to 2 mM), followed by PDT using laser irradiation at 635 nm. The resulting photocytotoxicity was assessed in both cell lines using MTT assays. Further, apoptosis was assessed using flow cytometry, reactive oxygen species (ROS) generation was evaluated with 2,7-dichlorofluorescein diacetate (DCFH2-DA), and the response to treatment was examined via RT-qPCR and Western blotting to measure the mRNA and protein expression levels of matrix metallopeptidase 2 (MMP-2) and MMP-9.
ALA-PDT inhibited the proliferation of DOK and CAL-27 cells in a dose- and time-dependent manner. Dose-effect and inhibition-time relationships were also found. The rates of DOK and CAL-27 cell apoptosis when the ALA dose was 1 mM were 30.66 ± 3.10% and 75.40 ± 1.29%, respectively (P < 0.01). Following PDT, compared with DOK cells, the ROS level in CAL-27 cells was significantly increased and was correlated with an increase in the ALA concentration. Mechanistically, both the mRNA and protein expression levels of MMP-2 and MMP-9 were found to be regulated in both cell types after ALA-PDT.
ALA-PDT effectively killed DOK and CAL-27 cells in a dose- and time-dependent manner in vitro. However, under the same conditions, the susceptibilities of these cell lines to ALA-PDT were different. Further studies are necessary to confirm whether this difference is present in clinical oral cancer and precancerous lesions.
5-氨基酮戊酸介导的光动力疗法（ALA-PDT）的临床效果可能与癌症组织的异型程度相关，但对于其疗效的差异，尤其是在口腔癌和癌前病变中，仍有许多未知之处。本研究旨在比较 ALA-PDT 对人口腔癌前细胞系（DOK）和口腔鳞状细胞癌细胞系（CAL-27）的作用。
首先，我们探索了 DOK 和 CAL-27 细胞对 ALA-PDT 的剂量和时间依赖性反应。将 DOK 和 CAL-27 细胞分别用不同浓度的 ALA（0.25 至 2mM）孵育，然后用 635nm 激光照射进行 PDT。用 MTT 法评估两种细胞系的光细胞毒性。进一步通过流式细胞术评估细胞凋亡，用 2,7-二氯二氢荧光素二乙酸酯（DCFH2-DA）评估活性氧（ROS）的产生，通过 RT-qPCR 和 Western 印迹法检测基质金属蛋白酶 2（MMP-2）和 MMP-9 的 mRNA 和蛋白表达水平，以检测治疗反应。
ALA-PDT 以剂量和时间依赖性方式抑制 DOK 和 CAL-27 细胞的增殖。还发现了剂量-效应和抑制时间关系。ALA 剂量为 1mM 时，DOK 和 CAL-27 细胞的凋亡率分别为 30.66±3.10%和 75.40±1.29%（P<0.01）。与 DOK 细胞相比，在 PDT 后，CAL-27 细胞中的 ROS 水平显著增加，且与 ALA 浓度的增加相关。在机制上，ALA-PDT 后两种细胞类型中 MMP-2 和 MMP-9 的 mRNA 和蛋白表达水平均受到调节。
ALA-PDT 可有效杀死体外 DOK 和 CAL-27 细胞，呈剂量和时间依赖性。然而，在相同条件下，这些细胞系对 ALA-PDT 的敏感性不同。需要进一步的研究来证实这种差异是否存在于临床口腔癌和癌前病变中。
