Chen Baoan, Yin Li, Cheng Jian, Ding Jiahua, Gao Chong, Sun Yunyu, Zhao Gang, Wang Jun, Bao Wen, Xia Guohua, Gao Feng, Wang Xuemei
Department of Hematology, Zhongda Hospital affiliated to Southeast University, Nanjing, China.
Hematology. 2011 Jan;16(1):24-30. doi: 10.1179/102453311X12902908411797.
In this study, we applied D, L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) hydrochloride as a chemical inhibitor for glucosylceramide synthase (GCS) and tetrandrine (Tet) for P-glycoprotein (P-gp) to reverse daunorubicin (DNR) resistance of human leukemia cell line K562/A02. Cytotoxicity assays showed that either PDMP or Tet enhanced cytotoxic effect of DNR on K562/A02 cells, while cotreatment of these two drugs had a more significant effect on chemosensitization. Using flow cytometric analysis, we confirmed that the enhancement effect was accompanied by elevated cellular DNR accumulation and DNR-induced apoptosis. According to reverse transcription-polymerase chain reaction and western blot, the reversal effect of that composite might owe to the significant downregulation of mdr1 and GCS gene expressions. Importantly, PDMP diminished mdr1 gene expression and Tet also downregulated GCS gene expression. Moreover, a positive correlation was observed between GCS and P-gp. Thus, our results suggest that a potential clinical application of PDMP in combination with Tet may enhance chemosensitivity in leukemia.
在本研究中，我们应用盐酸D，L-苏式-1-苯基-2-癸酰氨基-3-吗啉代-1-丙醇（PDMP）作为葡萄糖神经酰胺合酶（GCS）的化学抑制剂，以及粉防己碱（Tet）作为P-糖蛋白（P-gp）的抑制剂，以逆转人白血病细胞系K562/A02对柔红霉素（DNR）的耐药性。细胞毒性试验表明，PDMP或Tet均可增强DNR对K562/A02细胞的细胞毒性作用，而这两种药物联合处理对化学增敏作用更显著。通过流式细胞术分析，我们证实增强作用伴随着细胞内DNR积累增加和DNR诱导的细胞凋亡。根据逆转录-聚合酶链反应和蛋白质印迹法，该复合物的逆转作用可能归因于mdr1和GCS基因表达的显著下调。重要的是，PDMP降低了mdr1基因表达，Tet也下调了GCS基因表达。此外，观察到GCS和P-gp之间呈正相关。因此，我们的结果表明，PDMP与Tet联合应用在临床上可能增强白血病的化疗敏感性。
