皮肤癌细胞的5-氨基酮戊酸光动力效应研究

目的研究AIA－PpIX在皮肤癌细胞中的药代动力学规律，分析ALA—PDT对皮肤癌细胞的光动力作用机制。方法利用荧光光谱技术测量皮肤癌细胞A431和A375的ALA—PpIX的荧光强度。利用激光共聚焦显微技术研究ALA—PpIX在皮肤癌细胞中的分布。用倒置相差显微镜观察ALA－PDT作用后细胞的形态学变化。使用CCK－8（CellCounting Kit-8）比色法测定AIA-PDT后细胞的存活率。结果两种皮肤癌细胞内ALA—PpIX的含量随着ALA浓度的增大而增加，当ALA浓度为0．6mM时，ALA-PpIX的含量已基本达到饱和，0．6mM为最佳的药物孵育浓度。给予细胞0．6mMALA孵育4h后，检测到AIA—PpIX弥散分布于两种皮肤癌细胞的胞浆内和细胞膜上。两种细胞经AIA－PDT后的形态发生显著变化。在光剂量增加到1．74J／cm^2时，A431和A375细胞的存活率均下降到25％以下。结论两种皮肤癌细胞吸收ALA后合成PpIX的特性没有显著差异。在相同孵育时间条件下，A431合成PpⅨ的含量比A375高。A431和A375对ALA-PpIX的最佳药物孵育浓度为0．6mM。ALA—PDT对两株皮肤癌细胞均有明显的抑制作用，A431对ALA-PDT更敏感。

Efficacy of 5-Aminolevulinic Acid Mediated Photodynamic Therapy for A431 and A375 Cells

Objective To analyze the ALA-PDT efficacy for two types of skin cancer cells, and the pharmacokinetics of ALA-PpIX was also studied. Methods Fluorescence spectroscopy and laser scanning confocal microscopy were used to measure the fluorescence intensity and subcellular distribution of ALA-PpIX in A431 and A375 cells, respectively. Morphological changes of A431 and A375 cells after ALA-PDT were observed with an inverted phase contrast microscope. The survival rate of A431 and A375 cells after ALA-PDT was evaluated with CCK-8 （Cell Counting Kit-8） colorimetrie assay. Results ALA-PpIX content in cells increased with incubated ALA concentration, and reached saturation at 0. 6 mM ALA. ALA-PpIX fluorescence was detected within cells and on the cytomembrane of the two types of skin cancer cells after incubation with 0. 6 mM ALA. Significant morphological changes of A431 and A375 cells were observed after ALA-PDT. The survival rate of A431 and A375 cells dramatically decreased with the increasing of light dose, and the survival rate less than 25% at the given light dose of 1.74 J/ 2 cm . Conclusions The synthesis characteristics of ALA-PpIX in A431 and A375 ceils were very similar. The ALA-Pp IX concentration in A431 was higher than that in A375 under the same concentration and time for incubation. The optimal concentration for the two types of skin cancer cells was 0. 6 mM. The sensitivity of A431 ceils to ALA-PDT was higher than that of A375 cells.