【目的】探讨中药复方君子汤(FFJZ)联合阿霉素(DOX)逆转白血病K562/VCR细胞多药耐药及诱导凋亡的机制。【方法】采用CCK8法检测细胞耐药性及耐药性逆转作用;采用流式细胞术检测细胞总凋亡率和早期凋亡率;采用实时荧光定量逆转录—聚合...【目的】探讨中药复方君子汤(FFJZ)联合阿霉素(DOX)逆转白血病K562/VCR细胞多药耐药及诱导凋亡的机制。【方法】采用CCK8法检测细胞耐药性及耐药性逆转作用;采用流式细胞术检测细胞总凋亡率和早期凋亡率;采用实时荧光定量逆转录—聚合酶链反应(RT-PCR)检测多药耐药基因1(MDR1)、P糖蛋白(P-gp)、乳腺癌耐药相关蛋白(BCRP)、B淋巴细胞瘤-2相关X蛋白(Bax)和B淋巴细胞瘤-2(Bcl-2)的基因表达水平;Western blot法检测Bax、Bcl-2蛋白表达。【结果】CCK-8检测结果显示:无细胞毒性的FFJZ(6 mg/m L)、DOX(5 mg/m L)单独用药可显著降低K562/VCR的半数抑制浓度指数(IC_(50))(P<0.05),两药联合应用对K562/VCR逆转指数显著高于单独应用(P<0.05)。流式细胞术结果显示:作用浓度为4、6 mg/m L的FFJZ联合DOX(5 mg/m L)能够提高K562/VCR细胞总凋亡率和早期凋亡率,与DOX对照组比较差异有统计学意义(P<0.05)。RT-PCR结果显示:FFJZ联合DOX应用可下调MDR1、BCRP、P-gp m RNA表达,与DOX对照组比较,差异无统计学意义(P>0.05);FFJZ联合DOX应用可上调Bax m RNA、下调Bcl-2 m RNA表达,与DOX对照组比较,差异有统计学意义(P<0.01)。Western blot结果显示:FFJZ联合DOX与对照组比较,Bax蛋白表达显著上调(P<0.05),Bcl-2蛋白表达显著下调(P<0.05),与Bax、Bcl-2 m RNA表达一致。【结论】无细胞毒性的FFJZ、DOX对K562/VCR细胞耐药性均有逆转作用,两药联合应用具有明显的协同效应,其机制可能与其上调促凋亡基因Bax和下调抗凋亡基因Bcl-2的表达有关。展开更多
OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI)...OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.展开更多
文摘【目的】探讨中药复方君子汤(FFJZ)联合阿霉素(DOX)逆转白血病K562/VCR细胞多药耐药及诱导凋亡的机制。【方法】采用CCK8法检测细胞耐药性及耐药性逆转作用;采用流式细胞术检测细胞总凋亡率和早期凋亡率;采用实时荧光定量逆转录—聚合酶链反应(RT-PCR)检测多药耐药基因1(MDR1)、P糖蛋白(P-gp)、乳腺癌耐药相关蛋白(BCRP)、B淋巴细胞瘤-2相关X蛋白(Bax)和B淋巴细胞瘤-2(Bcl-2)的基因表达水平;Western blot法检测Bax、Bcl-2蛋白表达。【结果】CCK-8检测结果显示:无细胞毒性的FFJZ(6 mg/m L)、DOX(5 mg/m L)单独用药可显著降低K562/VCR的半数抑制浓度指数(IC_(50))(P<0.05),两药联合应用对K562/VCR逆转指数显著高于单独应用(P<0.05)。流式细胞术结果显示:作用浓度为4、6 mg/m L的FFJZ联合DOX(5 mg/m L)能够提高K562/VCR细胞总凋亡率和早期凋亡率,与DOX对照组比较差异有统计学意义(P<0.05)。RT-PCR结果显示:FFJZ联合DOX应用可下调MDR1、BCRP、P-gp m RNA表达,与DOX对照组比较,差异无统计学意义(P>0.05);FFJZ联合DOX应用可上调Bax m RNA、下调Bcl-2 m RNA表达,与DOX对照组比较,差异有统计学意义(P<0.01)。Western blot结果显示:FFJZ联合DOX与对照组比较,Bax蛋白表达显著上调(P<0.05),Bcl-2蛋白表达显著下调(P<0.05),与Bax、Bcl-2 m RNA表达一致。【结论】无细胞毒性的FFJZ、DOX对K562/VCR细胞耐药性均有逆转作用,两药联合应用具有明显的协同效应,其机制可能与其上调促凋亡基因Bax和下调抗凋亡基因Bcl-2的表达有关。
基金Shanghai Municipal Health Bureau:Traditional Chinese Medicine in Treating with Advanced Hepatocellular Carcinoma(No.ZYSNXD-CC-ZDYJ032)
文摘OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.
