重组人类核心蛋白聚糖对白血病K562细胞增殖的影响

 【摘要】　目的　观察重组人类核心蛋白聚糖（rhDCN）对白血病 K562细胞生长抑制、凋亡的影响，并探讨可能的作用机制。方法　通过Lipofectamine 2000脂质体介导转染对数生长期的白血病K562细胞，实验分组为0.9 % NaCl溶液组、pcDNA3.1（+）／K562组、pcDNA3.1（+）-DCN／K562组和脂质体组。经瑞特染色观察转染后细胞形态的改变，MTT法检测细胞增殖活性，流式细胞术（FCM）分析细胞凋亡，Western blot法检测细胞凋亡相关蛋白bcl-xl、Mcl-1及Bax的表达。结果　pcDNA3.1（+）-DCN／K562组瑞特染色呈现典型的凋亡形态学改变。MTT结果显示，pcDNA3.1（+）-DCN／K562组转染24 h细胞增殖抑制率为（16.14±1.08）%，转染48 h为（14.07±1.01）%，转染72 h为（20.29±1.19）%，明显高于对应时间点其他组增殖抑制率，差异均有统计学意义（均P＜0.05）。FCM检测结果显示，pcDNA3.1（+）-DCN／K562组凋亡率为（20.15±1.31）%、细胞的G0／G1期细胞百分率为（51.15±0.57）%，与其他各组比较增加明显，差异有统计学意义（均P＜0.05）。Western blot结果显示，pcDNA3.1（+）-DCN／K562组与其他各组比较bcl-xl、Mcl-1蛋白表达减低，Bax蛋白表达升高。结论　rhDCN重组质粒可有效抑制K562细胞增殖，并诱导其凋亡，rhDCN对细胞周期及凋亡相关蛋白bcl-xl、Mcl-1、Bax的影响可能是其发挥作用的机制。

Effect of rhDCN on proliferation of leukemic cell line K562

Objective To investigate the anti-tumorigenesis function of rhDCN on the leukemia K562 cells in vitro and analyze the possible mechanism. Methods Exponential phase of K562 cells were transfected with pcDNA3.1（＋）-DCN, and PBS, liposome alone, and pcDNA3.1（＋） vector were as control groups. Morphology change of K562 ceils was detected by Wright stain, and cell proliferation activity was detected by MTT. Cell cyele and apoptosis of K562 cells were assessed by FCM. The expression of apoptosis-related protein, including bcl-xl, Mcl-1 and Bax were detected by Western blot. Results Wright stain showed that typical apoptotic morphology of K562 cells were observed in DCN transfected group. There were no morphological changes of apoptosis in other groups. MTT method results showed that proliferation inhibition rate of the transfected cells 24 h （16.14±1.08） %, 48 h （14.07±1.01） %, 72 h （20.29±1.19） %] was higher than that of the other control groups （P 〈 0.05）. FCM results showed that the apoptosis index （20.15±1.31） % of the DCN transfected group was higher than that of the other groups （P 〈 0.05）, and most of cells arrested in the Gc/GI phase （51.15±0.57） % （P 〈 0.05）. Western blot results showed the expression levels of Bax were increased while bcl-xl and Mcl-1 were decreased in pcDNA3.1（＋）-DCN/K562 group. Conclusion rhDCN can inhibit the growth of K562 cells and induce the apoptosis. The effect of DCN on bcl-xl, Mcl-1, Bax may play a role in its mechanism.