蓖麻毒素温敏型凝胶间质化疗对H22肝癌荷瘤小鼠的影响

目的：探讨蓖麻毒素温敏型凝胶经皮瘤内注射间质化疗治疗小鼠H22肝癌的有效性及可行性。 方法：采用色谱方法纯化蓖麻毒素,高效液相色谱法和蛋白印迹法进行纯度和性质鉴定。建立小鼠皮下移植肝癌模型,分为模型组、空白凝胶组、游离蓖麻毒素组、蓖麻毒素温敏型凝胶组,瘤体内注射相应药物。治疗后第15天,剥离肿瘤称取质量并计算抑瘤率;光学显微镜下观察肿瘤组织坏死情况;透射电子显微镜观察肿瘤组织细胞的超微结构变化及凋亡的形态学改变;分光光度计法检测肿瘤组织半胱氨酸蛋白酶3（caspase-3）活性;取血检测小鼠肝肾功能。 结果：蓖麻毒素温敏型凝胶瘤体内注射间质化疗对小鼠肝肾功能无明显影响;局部给药一次抑瘤率达71.31%;光学显微镜观察结果提示,肿瘤组织大片坏死;透射电子显微镜观察结果显示肿瘤细胞染色质边集、凋亡小体形成等典型的凋亡形态学改变;肿瘤细胞caspase-3活性亦明显升高。 结论：蓖麻毒素温敏型凝胶间质化疗可抑制荷瘤小鼠肿瘤生长,且具有较高的安全性。

Effects of interstitial chemotherapy using thermosensitive gel-coated ricin on hepatoma H22-bearing mice

Objective： To explore the efficacy and feasibility of interstitial chemotherapy using thermosensitive gel-coated ricin in hepatoma H22-bearing mice.
Metheds： Ricin was purified by chromatography method. The purified ricin was identified by Western blot assay and the purity was determined by high-performance liquid chromatography. BALB/c mice were inoculated subcutaneously in right flank with hepatoma H22 ceils. When the tumor size reached about 1.0 cm in diameter, 40 mice were randomly divided into untreated group, thermosensitive gel group, ricin group and thermosensitive gel-coated ricin group. Mice in each group were administered different agents by percutaneous intratumoral injection, including normal saline, thermosensitive hydrogel, ricin and thermosensitive gel-coated ricin. Fifteen days after treatment, the tumors were removed to calculate inhibition rate of tumor growth. The tumor tissues were made into pathological sections to perform histopathological examination. The ultrastructure of tumor tissue was examined by electron microscope examination as well. Blood was collected to detect the hepatic and renal functions. The caspase-3 activity of tumor tissue was determined by using zymologic method with a spectrophotometer.
Results： After intratumoral therapy, tumor weight in the thermosensitive gel-coated ricin group was lower than that in the untreated group, with a tumor growth inhibition rate of 71. 31%. No obvious hepatic or renal toxicities were detected after thermosensitive gel-coated ricin treatment. Histopathologic observation of the tumor tissue showed massive necrosis and typical apop!osis phenomena, including chromatin margination and apoptotic body. Meanwhile, thermosensitive gel-coated ricin resulted in a significant increase in the caspase- 3 activity as compared with the untreated group and the ricin group （P〈0. 01, P〈0.05）.
Conclusion： The above findings indicate that intratumoral therapy with thermosensitive gel-coated ricin has strong antitumor effect and can obviously lessen systemic toxicity, which may provide an effective and feasible method for hepatocellular carcinoma treatment.