5-ALA-PDT联合放疗对常氧与乏氧人卵巢癌SKOV3细胞的杀伤作用

Killing effects of 5-ALA-PDT combined with radiotherapy on human ovarian carcinoma SKOV3 cells under normoxia and hypoxia

目的：探讨5-氨基酮戊酸（5-ALA）介导的LED-光动力疗法（photodynamic therapy,PDT）联合放疗对人卵巢癌SKOV3细胞的杀伤作用。方法：常氧与乏氧下SKOV3细胞各实验组经不同浓度的5-ALA培养4 h后,由不同功率密度的635nm红光和6 Gy X线照射,48 h后MTT法检测细胞存活率。结果：常氧与乏氧下0.1-0.7 mmol·L^-1范围内,5-ALA无细胞毒性与放射增敏性（P〉0.05）;5-ALA〉0.1 mmol·L^-1,随着药物浓度与红光功率密度的增加,细胞存活率呈明显的下降趋势;X线与5-ALA-PDT联用,Ra×Rb/Rc比值分别为2.13、1.49,且常氧下联用与顺序无关,乏氧下有关（P〈0.01）。结论：常氧与乏氧下X线与PDT联用都是协同作用,但乏氧下联用效果弱于常氧,且先X线照射后PDT可能会是一个更好的联用方式。

OBJECTIVE To study combined effects of radiotherapy and 5-aminolevulinic acid （5-ALA）-mediated LED-photo-dynamic therapy （PDT） on human ovarian carcinoma SKOV3 cells. METHODS SKOV3 cells were incubated with 5-ALA at different concentrations for 4 h and exposed to different fluence rates of 635 nm red light and 6 Gy X-ray radiation in independent treatment groups. After 48 h, percent cell survival rate was investigated using MTT assay. RESULTS 5-ALA had no cytotoxicity or radiosensitivity in range of 0. 1-0. 7 mmol· L^-1 under normoxia or hypoxia （P〉0. 05）. When 5-ALA concentration was over 0. 1 mmol· L^-1 , SKOV3 cell survival rate showed a significant decreasing trend as 5-ALA concentration and red light fluence rates increased. Rates of Ra×Rb/Rc were 2. 13 and 1.49 respectively under normoxia and hypoxia when X-ray combined with 5-ALA-PDT. Combination was not related with sequence under normoxia, but not under hypoxia （P〈0. 01）. CONCLUSION X-ray combined with PDT has synergistic effects under normoxia and hypoxia, but effects of hypoxia were weaker than that of normoxia. It may be a better way for X-ray radiation following PDT.