光动力疗法对乳腺癌细胞株MDA-MB-231的体外实验研究

Effect of photodynamic therapy on human breast cancer cell line MDA-MB-231 in vitro

目的观察光动力疗法(PDT)对乳腺癌细胞株MDA-MB-231的杀伤效果,选择最佳作用参数(光敏剂浓度和光照强度);探讨PDT的作用机制,为PDT在乳腺癌的动物荷瘤模型和临床运用提供理论依据。方法实验分为空白对照组、单纯激光组、单纯光敏剂组和实验组(照光+光敏剂)。对体外培养的人乳腺癌细胞株MDA-MB-231进行HpD-PDT实验,应用MTT法检测其光密度值OD492,观察不同实验条件下对人乳腺癌细胞在体外的抑制作用,并绘制其抑制曲线和观察其形态学变化。结果HpD-PDT组(HpD2μg/ml,5J/cm2)于治疗后24h明显抑制体外培养的人乳腺癌细胞,而空白对照组、单纯使用光敏剂组(HpD2μg/ml)及单纯激光照射组(5J/cm2)对细胞增殖均无明显影响。HpD-PDT后12h,透射电镜可见:实验组细胞内出现大量的核碎裂、核融解、核消失等坏死征象。结论HpD-PDT可明显抑制体外培养的人乳腺癌细胞株MDA-MB-231的生长,光动力疗法为乳腺癌新的治疗手段提供了理论及实验依据。

Objective To observe the effect of photodynamie therapy （PDT） on human breast cancer cell line MDA-MB-231 in vitro, and to select the optimization parameters （concentration of photosensitizer and intensity of illumination ）;meanwhile to investigate possible mechanisms of PDT,furthermore to offer foundation theory in hearing cancer model and the clinical therapy for breast cancer. Methods The cells were divided into four groups：the normal control before radiation without HpD,HpD alone,laser alone,and HpD in combination with laser radiation. The breast cancer cell line MDA-MB-231 cultured in vitro were treated with different concentrations of HpD and different dosages of laser,then MTT assay was applied to measure the OD492. Then growth curve was described according above ideal parameters. The morpheus of cells was observed under the light microscope and electron microscope after PDT at different time. Results HpD-PDT （ HpD 2 μg/ml,5 J/cm^2 ） could inhibit obviously the growth of breast cancer after 24 hours ,but there were no obviously influence on the growth among blank control group, single photosensitive group （ HpD 2 μg/ml ） and single laser group （5 J/cm^2 ）. After HpD-PDT 12 hours, it could be seen commonly the phenomenon that intra-cellular filled with nuclear fragmentation, nuclear thawing, nuclear abolition in experimental group through transmission electron microscope. Conclusion The growth of breast cancer cell line MDA-MB-231 is obviously inhibited in HpD-PDT. photodynamic therapy can provide new treatment for the breast cancer in theory and experiment.