藻蓝蛋白色素肽光动力学抗肿瘤作用的实验研究

Antitumor Studies of C-Phycocyanin Chromophore Peptides Mediated Photodynamic Therapy

目的 :探讨藻蓝蛋白色素肽的理化特性及光动力疗法 (PDT)抗肿瘤效果。方法 :用柱层析法从螺旋藻藻蓝蛋白酶介产物中分离色素肽 ,并用 MTT法及口丫啶橙染色法检测色素肽对体外培养的小鼠肉瘤细胞 S180及荷瘤小鼠 PDT作用效果。结果 :分离出三种色素肽的分子量分别为 17.4KD、7.72 KD及 6 .6 KD,它们的吸收光谱峰值分别位于 6 18nm ,5 80 nm ,6 0 5 nm,荧光发射峰均在 6 85 nm处。 MTT法检测证明 ,在浓度为 10 0︼g/ m l,用波长为 5 80 nm、6 0 0 nm,照射剂量为 2 8.8J/ cm2染料激光 (氩离子为激发光源 )照射 ,对肿瘤细胞的杀伤率达 6 9.2 %～ 80 .2 %;在色素肽CCP1 、CCP3 介导的 PDT对小鼠移植瘤生长影响的实验发现 ,色素肽易被瘤细胞吸收 ,当激光照射剂量为 12 0 J/cm2 ,肿瘤直径在 0 .5～ 0 .7cm范围内 ,瘤体旁注射剂量为 5 0 ︼g的 CCP1 及 CCP3 光敏剂时 ,藻胆蛋白酶介产物的抑瘤率可达 46 %～ 81%,且被 PDT作用后的细胞表现了典型的凋亡细胞特征。结论 :藻蓝蛋白色素肽具良好的 PDT效果 ,有可能通过诱发凋亡途径导致细胞死亡。

Objective: to study the antitumor effects and mechanisms of C-Phycocyanin chromophore peptides mediated Photodynamic therapy in vitro and in vivo.Methods: Chromophore peptides CCP 1～CCP 3 were isolated by DEAE-Sepharose Fast Flow, chracterized with respect to spectroscope properties and molecular weight. The PDT effects of CCP 1～CCP 3 on S180 cell and tumor bearing mice were assessed with MTT method and acridine orange staining. Result: CCP 1 has a molecular weight of 17400, CCP 2 7720, CCP 3 6600, their absorption spectra with maximum are located at 618 nm, 580 nm and 600 nm separately. In vitro test, the highest inhibited rates of of S180 cells were 19.8 % ～30.8 %, when concentration of chromophore peptides was 100μg / mL, irradiated by dying laser with dose of 28.8 J/cm 2. In vivo test, in the condition of tumor diameter between 0.5 cm～ 0.7 cm and the irradiation dose of 120 J/cm 2, the tumor inhibited rates were 46 %～81 % , the tumor cells inhibited by PDT showed typical apoptosis character. Conclusion: With the advantage in special fluorescence activity?Low molecular weight?good light absorbent character, C-PC chromophore peptides are the attractive option for improving the selectivity of PDT. Tumor death may be the result of inducing of cell apoptosis.