CAJ | 학술논문

目的：探讨低剂量白桦脂酸对 K562/A02细胞对阿霉素敏感性的影响及其相关机制。方法单用阿霉素和低剂量白桦脂酸联用阿霉素处理 K562/A02细胞，分别采用 MTT 法和流式细胞术检测低浓度白桦脂酸对阿霉素诱导的 K562/A02细胞增殖、凋亡及胞内 pH 值的影响；通过 real-time PCR 和 Western Blot 分别检测低浓度白桦脂酸对阿霉素诱导的 K562/A02细胞 NHE1及 MDR1 mRNA 及蛋白表达的影响。结果低浓度的白桦脂酸可以显著提高阿霉素诱导的 K562/A02细胞的增殖抑制效应（P<0.05），使其凋亡显著增强（P<0.05）。低浓度白桦脂酸联合阿霉素作用 K562/A02细胞后，胞内 pH 值降低（P<0.05），同时 NHE1和 MDR1 mRNA 的表达减少（P<0.05），NHE1和 P-gp 蛋白表达下降（P<0.05）。给予 NHE1抑制剂Amiloride 处理 K562/A02细胞后，再用白桦脂酸联合阿霉素处理，P-gp 的表达与单用 Amiloride 处理 K562/A02细胞相比无明显变化，而 BA 处理组、Amiloride 处理组、BA 联合 Amiloride 处理组的 NHE1和 P-gp 的表达均较对照组显著下降（P<0.05）。结论低浓度白桦脂酸可以增强 K562/A02细胞株对阿霉素的敏感性，这可能与其降低 NHE1表达，进而减少 P-gp 的表达，改变细胞内 pH 值有关。
목적：탐토저제량백화지산대 K562/A02세포대아매소민감성적영향급기상관궤제。방법단용아매소화저제량백화지산련용아매소처리 K562/A02세포，분별채용 MTT 법화류식세포술검측저농도백화지산대아매소유도적 K562/A02세포증식、조망급포내 pH 치적영향；통과 real-time PCR 화 Western Blot 분별검측저농도백화지산대아매소유도적 K562/A02세포 NHE1급 MDR1 mRNA 급단백표체적영향。결과저농도적백화지산가이현저제고아매소유도적 K562/A02세포적증식억제효응（P<0.05），사기조망현저증강（P<0.05）。저농도백화지산연합아매소작용 K562/A02세포후，포내 pH 치강저（P<0.05），동시 NHE1화 MDR1 mRNA 적표체감소（P<0.05），NHE1화 P-gp 단백표체하강（P<0.05）。급여 NHE1억제제Amiloride 처리 K562/A02세포후，재용백화지산연합아매소처리，P-gp 적표체여단용 Amiloride 처리 K562/A02세포상비무명현변화，이 BA 처리조、Amiloride 처리조、BA 연합 Amiloride 처리조적 NHE1화 P-gp 적표체균교대조조현저하강（P<0.05）。결론저농도백화지산가이증강 K562/A02세포주대아매소적민감성，저가능여기강저 NHE1표체，진이감소 P-gp 적표체，개변세포내 pH 치유관。
Objective To explore the effects and mechanism of low dose of Betulinic on the sensitivity to Adriamycin in Adriamycin-re-sistant cells line K562/A02. Methods The chronic myeloid leukemia cells line K562 and Adriamycin-resistant cells line K562/A02 treated with low dose of Betulinic acid, NHE1 inhibitor (Amiloride) alone or plus Adriamycin. The effects of low dose of Betulinic acid on prolifera-tion inhibition, apoptosis and intracellular pH values induced by Adriamycin were tested by MTT assay and flow cytometry separately in K562 and K562/A02 cells, and the mRNA and protein levels of NHE1 and MDR1 expression were detected by real-time PCR, and western blot respectively. Results The effects on proliferation inhibition induced by Adriamycin can be significantly enhanced when it was combined with low dose of Betulinic acid in K562/A02 cells(P<0.05). In addition, the apoptotic rate of K562/A02 cells treated with Betulinic acid plus Amiloride was also significantly increased(P<0.05). After treatment of Adriamycin combined with low dose of Betulinic acid in K562/A02 cells, the intracellular pH value significantly decreased(P<0.05), the mRNA levels of NHE1 and MDR1 expression and the protein levels of NHE1 and P-gp expression all were significantly downregulated(P<0.05). After K562/A02 cells treated with NHE1 inhibitor (Amiloride), and then treated with low dose of Betulinic acid with Adriamycin again, the P-gp expression showed no obvious changes when compared with that after treatment of Adriamycin alone. However, when compared with control group, both NHE1 and P-gp expression levels de-creased significantly in BA , Amiloride, and BA plus Amiloride group(P<0.05). Conclusion Low dose of Betulinic acid can significantly enhance the sensitivity to Amiloride in K562/A02 cells. This may be associated with down-regulation of NHE1 expression ,and further de-crease of P-gp expression and pH value.