Low-dose methotrexate enhances aminolevulinate-based photodynamic therapy in skin carcinoma cells in vitro and in vivo.
Low-dose methotrexate enhances aminolevulinate-based photodynamic therapy in skin carcinoma cells in vitro and in vivo.
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DOI：
10.1158/1078-0432.ccr-08-3054
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发表时间：
2009-05-15
期刊：
影响因子：
--
通讯作者：
Maytin EV
中科院分区：
文献类型：
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作者：
Anand S;Honari G;Hasan T;Elson P;Maytin EV
目的通过甲氨蝶呤（MTX）预处理细胞和肿瘤，提高细胞内光敏剂水平，提高δ-氨基乙酰丙酸（ALA）光动力疗法（PDT）的治疗效果和肿瘤细胞选择性。体外和体内的皮肤癌细胞作为模型系统。将培养的人SCC 13和HEK 1细胞、正常角质形成细胞和体内皮肤肿瘤模型（见下文）用MTX预处理72小时，然后用ALA孵育4小时。评估光暴露后PpIX水平和细胞存活率的变化。与正常角质形成细胞相比，MTX预处理的单层培养物优先提高癌细胞内PpIX水平2至4倍。光动力杀伤协同增强的联合治疗，相比，光动力疗法。在宽的MTX浓度范围（0.0003 - 1.0 mg/L; 0.6 nM - 2 mM）内实现了MTX对PpIX水平的增强。PpIX增强与关键卟啉途径酶的蛋白质表达变化相关，即粪卟啉原氧化酶增加~4倍，亚铁螯合酶表达稳定或略有下降。分化标志物（E-钙粘蛋白，外皮蛋白，聚丝蛋白）也选择性地诱导MTX在癌细胞。通过显示MTX预处理在三种模型中增强PpIX积累来建立体内相关性：永生化角质形成细胞的器官型培养物;小鼠中的化学诱导的皮肤肿瘤;和皮下植入小鼠中的人A431鳞状细胞肿瘤。联合治疗使用短期暴露于低剂量MTX，然后ALA-PDT应进一步研究作为一种新的组合方式，以提高效率和选择性的PDT上皮癌。
To improve treatment efficacy and tumor cell selectivity of δ-aminolevulinic acid (ALA)-based photodynamic therapy (PDT), via pretreatment of cells and tumors with methotrexate (MTX) to enhance intracellular photosensitizer levels. Skin carcinoma cells, in-vitro and in-vivo, served as the model system. Cultured human SCC13 and HEK1 cells, normal keratinocytes, and in-vivo skin tumor models (see below) were preconditioned with MTX for 72 h, then incubated with ALA for 4 h. Changes in PpIX levels and in cell survival after light exposure were assessed. MTX-preconditioning of monolayer cultures preferentially raised intracellular PpIX levels 2- to 4-fold in carcinoma cells versus normal keratinocytes. Photodynamic killing was synergistically enhanced by the combined therapy, compared to PDT alone. MTX enhancement of PpIX levels was achieved over a broad MTX concentration range (0.0003 – 1.0 mg/L; 0.6 nM – 2 mM). PpIX enhancement correlated with changes in protein expression of key porphyrin pathway enzymes, i.e. ~4-fold increase in coproporphyrinogen oxidase, and stable or slightly decreased expression of ferrochelatase. Differentiation markers (E-cadherin, involucrin, filaggrin) were also selectively induced by MTX in carcinoma cells. In-vivo relevance was established by showing that MTX preconditioning enhances PpIX accumulation in three models: organotypic cultures of immortalized keratinocytes; chemically-induced skin tumors in mice; and human A431 squamous cell tumors implanted subcutaneously in mice. Combination therapy using short-term exposure to low-dose MTX followed by ALA-PDT should be further investigated as a new combination modality to enhance efficacy and selectivity of PDT for epithelial carcinomas.