摘要
目的:研究蓖麻毒素的提取方法和对肿瘤细胞的杀伤作用。方法:根据Nicolson和Blaustein的方法稍加改良,通过PBS提取、硫酸铵分段盐析、Sephrose4B亲和层析和SephadexG100凝胶过滤等步骤,从去壳蓖麻籽中提取天然蓖麻毒素;采用细胞培养,以MTT法分析不同浓度蓖麻毒素对肿瘤细胞的杀伤作用。结果:用亲和层析和凝胶过滤等步骤提纯的蓖麻毒素,分子量为63kD,由2个亚基组成。细胞毒性分析:蓖麻毒素在高浓度下(5×10-8mol/L～5×10-10mol/L)对正常细胞和结肠癌细胞的杀伤效率无差异(P>0.05),而在低浓度下(5×10-11mol/L～5×10-13mol/L)两者有显著性差异(P<0.01);各种浓度蓖麻毒素对白血病细胞K562和大肠癌细胞SW480的杀伤作用无统计学上的差别(P>0.05)。结论:蓖麻毒素在低浓度下对肿瘤细胞的杀伤有选择性,对白血病细胞K562和大肠癌细胞SW480的杀伤作用在各种浓度下无选择性。
<Abstrcat> Objective: To extract and purify ricin from castor beans and to evaluate its anti-cancer activity. Methods: Ricin was purified from castor beans according the modified method of Nicolson and Blaustin.The lectins were extracted in 0.01 mol/L phosphate buffered saline and isolated in the 40% to 80% fraction of ammonium sulfate precipitation.The dialyzed fractionated preparation was applied with a Sepharose 4B column.Thelectins were eluted with a linear lactose gradient (0.01 mol/L ～0.5 mol/L).Ricin wasseparated from the ricinus agglutinin by gel filtration on a Sephadex G-100.MTT was applied to analyze the cytotoxicity with different dosage of ricin in different cancer cell lines. Results: There was no difference between the killing effect of normal cells and that of colon cancer cells by using thehigh dosage of ricin(5×10^(-8) mol/L^5×10^(-10) mol/L).However,the cytotoxicity was significant different in those cells with the low dosage of ricin(5×10^(-11) mol/L^5×10^(-13) mol/L).Meanwhile ricin had the similar cytotoxicity to leukemia cell K562 and colon cancer cell SW480. Conclusion: Ricin is able to kill tumor cells selectively at low concentration,but the selectivity does not appear at high concentrations.
出处
《浙江大学学报（医学版）》
CAS
CSCD
2005年第3期217-219,共3页
Journal of Zhejiang University(Medical Sciences)
基金
国家自然科学基金(30270294和30070166)
浙江省自然科学基金(301057).
