蛋白激酶C对Pgp介导的K562细胞耐药性的影响  

REGULATORY EFFECT OF PROTEIN KINASE C ON P-GLUCOPROTEIN MEDIATED DRUG RESISTANCE IN HUMAN LEKEMIA K_562 CELLS

作　　者：尚世丽[1] 刘云鹏[2] 罗颖[2] 卢香兰[2] 张敬东[2] 车晓芳[2] 于秉治[2] 翟明[2] 

机构地区：[1]鞍山市鞍钢铁东医院血液科,鞍山114002 [2]中国医科大学

出　　处：《肿瘤》2001年第4期260-262,共3页Tumor

基　　金：辽宁省自然科学基金资助 (编号 962 3 2 )

摘　　要：目的　研究蛋白激酶C(PKC)在P 糖蛋白 (Pgp)介导的人类白血病K5 6 2细胞多药耐药中的作用。方法　用苔盼蓝拒染法检测药物敏感性 ,用免疫组织化学法检测Pgp的表达 ,用流式细胞仪检测细胞内柔红霉素 (DNR)积聚 ,用Takai法及Westernblot法分别检测PKC活性和PKCα含量。结果　耐药株K5 6 2 /D细胞对DNA及多种抗癌药物显示多药耐药性 ,并存在Pgp过度表达。K5 6 2 /D与敏感株K5 6 2 /S细胞相比 ,PKC总活性无明显差别 ,但PKCα含量显著增高。PKC激活剂TPA增加K5 6 2 /S和K5 6 2 /D细胞的PKC活性 ,使PKC和PKCα由胞质向胞膜转位 ,K5 6 2 /D细胞内DNA积聚减少。PKC抑制剂staurosporine减少K5 6 2 /S和K5 6 2 /D细胞的PKC活性及PKCα含量 ,增加K5 6 2 /D细胞内DNA积聚。结论　PKCα在K5 6 2 /D细胞中显著增高 ,上调PKC ,使K5 6 2 /D细胞内DNA积聚减少 ,下调PKC ,使K5 6 2 /D细胞内的DNA积聚增加 。Objective To study the effect of protein kinase C (PKC) on P -glycoprotein (Pgp) mediated multidrug resistance (MDR) in human leukemia K562 cells.Methods The drug sensitivity was tested by trypanblau dye exclusion method. The Pgp phenotype was analyzed by immunohistochemical method. The intracellular DNR accumulation was measured by Flow cytometer. PKC activity and PKC α content were assayed by Takai's methods and Western blot analysis, re spectively. Results Resistant cell line K562/D cells were resis tant to DNR and many antitumour drugs. There was no significant difference of th e PKC total activity between K562/D and sensitive cell line K562/S cells, but th e PKC α content in K562/D cells was obviously higher than that in K562/S cells. PKC activator TPA increased the PKC activity and promoted translocation of PKC and PKC α from cytosol to membrane in K562/S and K562/D cells. Furthermore, TPA decreased the intracellular DNR accumulation in K562/D cells. PKC inhibitor sta urosporine reduced the PKC ativity and PKC α content in K562/S and K562/D cells , and then increased the intracellular DNA accumulation in K562/D cells, but not in K562/S cells.Conclusion PKC α is obviously increased in K5 62/D cells. Up-regulating PKC decreases the intracellular DNR accumulation, whi le down-regulating PKC partly increases the drug accumulation in K562/D cells. These results suggest that PKC is probably involved in Pgp mediated MDR via regu lating funciton of Pgp.

关 键 词：多药耐药 P-糖蛋白 蛋白激酶C K562细胞 

分 类 号：R730.53[医药卫生—肿瘤] R969.4[医药卫生—临床医学]