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
目的观察人类急性单核细胞白血病(AML-M5)细胞系THP-1与骨髓间充质干细胞(BM-MSCs)之间隧道纳米管(TNTs)结构的形成;探讨TNTs中线粒体转运对THP-1细胞凋亡的影响及线粒体在TNTs中转运的分子机制。方法使用特异性荧光染料分别对线粒体、...目的观察人类急性单核细胞白血病(AML-M5)细胞系THP-1与骨髓间充质干细胞(BM-MSCs)之间隧道纳米管(TNTs)结构的形成;探讨TNTs中线粒体转运对THP-1细胞凋亡的影响及线粒体在TNTs中转运的分子机制。方法使用特异性荧光染料分别对线粒体、细胞骨架蛋白F-Actin和细胞核进行荧光标记,共聚焦显微镜观察BM-MSCs与THP-1细胞间TNTs的形成及TNTs中线粒体的传递。BM-MSCs与THP-1细胞共培养5 d后运用流式细胞术检测THP-1细胞凋亡;共培养体系分为4组:直接共培养(SC组)、Transwell透膜共培养(TC组)、直接共培养体系中加入细胞松弛素(TNTs抑制剂)Latrunculin B(LC组)、无BM-MSCs而仅有培养液(MC组);Western blot检测细胞器转运相关马达蛋白(KIF5B)表达水平。结果 BM-MSCs与THP-1细胞间可观察到TNTs形成,BM-MSCs中线粒体通过TNTs单向传递到THP-1细胞,并未观察到线粒体逆向传递。Annexin V-FITC/PI检测THP-1细胞凋亡结果显示,SC组跟LC组凋亡率较MC组明显减低( P <0.01),LC组高于SC组( P <0.01),TC组较SC组和LC组明显升高( P <0.01),TC组与MC组凋亡率无明显差异( P >0.05)。BM-MSCs中 KIF5B表达水平明显高于THP-1细胞( P <0.001),Rotenone处理BM-MSCs后显著抑制KIF5B的表达( P <0.01)。结论 BM-MSCs线粒体通过TNTs向THP-1细胞单向传递,THP-1细胞摄取BM-MSCs线粒体后可能诱导凋亡抵抗;细胞间线粒体转运可能与马达蛋白KIF5B相关。展开更多
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.
文摘目的观察人类急性单核细胞白血病(AML-M5)细胞系THP-1与骨髓间充质干细胞(BM-MSCs)之间隧道纳米管(TNTs)结构的形成;探讨TNTs中线粒体转运对THP-1细胞凋亡的影响及线粒体在TNTs中转运的分子机制。方法使用特异性荧光染料分别对线粒体、细胞骨架蛋白F-Actin和细胞核进行荧光标记,共聚焦显微镜观察BM-MSCs与THP-1细胞间TNTs的形成及TNTs中线粒体的传递。BM-MSCs与THP-1细胞共培养5 d后运用流式细胞术检测THP-1细胞凋亡;共培养体系分为4组:直接共培养(SC组)、Transwell透膜共培养(TC组)、直接共培养体系中加入细胞松弛素(TNTs抑制剂)Latrunculin B(LC组)、无BM-MSCs而仅有培养液(MC组);Western blot检测细胞器转运相关马达蛋白(KIF5B)表达水平。结果 BM-MSCs与THP-1细胞间可观察到TNTs形成,BM-MSCs中线粒体通过TNTs单向传递到THP-1细胞,并未观察到线粒体逆向传递。Annexin V-FITC/PI检测THP-1细胞凋亡结果显示,SC组跟LC组凋亡率较MC组明显减低( P <0.01),LC组高于SC组( P <0.01),TC组较SC组和LC组明显升高( P <0.01),TC组与MC组凋亡率无明显差异( P >0.05)。BM-MSCs中 KIF5B表达水平明显高于THP-1细胞( P <0.001),Rotenone处理BM-MSCs后显著抑制KIF5B的表达( P <0.01)。结论 BM-MSCs线粒体通过TNTs向THP-1细胞单向传递,THP-1细胞摄取BM-MSCs线粒体后可能诱导凋亡抵抗;细胞间线粒体转运可能与马达蛋白KIF5B相关。
