Yun-Yu Sun

Synergistic effect of the combination of nanoparticulate Fe3O4 and Au with daunomycin on K562/A02 cells

In this study, we have explored the possibility of the combination of the high reactivity of nano Fe3O4 or Au nanoparticles and daunomycin, one of the most important antitumor drugs in the treatment of acute leukemia clinically, to inhibit MDR of K562/A02 cells. Initially, to determine whether the magnetic nanoparticle Fe3O4 and Au can facilitate the anticancer drug to reverse the resistance of cancer cells, we have explored the cytotoxic effect of daunomycin (DNR) with and without the magnetic nano-Fe3O4 or nano-Au on K562 and K562/A02 cells by MTT assay. Besides, the intracellular DNR concentration and apoptosis of the K562/A02 cells was further investigated by flow cytometry and confocal fluorescence microscopic studies. The MDR1 gene expression of the K562/A02 cells was also studied by RT-PCR method. Our results indicate that 5.0 × 10−7 M nano-Fe3O4 or 2.0 × 10−8 M nano-Au is biocompatible and can apparently raise the intracellular DNR accumulation of the K562/A02 cells and increase the apoptosis of tumor cells. Moreover, our observations illustrate that although these two kinds of nanoparticles themselves could not lower the MDR1 gene expression of the K562/A02 cells, yet they could degrade the MDR1 gene level when combining with anticancer drug DNR. This raises the possibility to combine the nano-Fe3O4 or nano-Au with DNR to reverse the drug resistance of K562/A02 cells, which could offer a new strategy for the promising efficient chemotherapy of the leukemia patients.

Effect of magnetic nanoparticles of Fe3O4 and 5-bromotetrandrine on reversal of multidrug resistance in K562/A02 leukemic cells.

This study aims to evaluate the multidrug resistance (MDR) reversal activity by magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4) and 5-bromotetrandrine (BrTet) MDR cell line K562/A02 solitarily or symphysially. The proliferation of K562 and K562/A02 cells and the cytotoxicity on peripheral blood mononuclear cells (PMBCs) were evaluated by MTT assay. Cellular accumulation of daunorubicin (DNR) was analyzed by flow cytometry. Real-time polymerase chain reaction and Western blotting analyses were performed to examine the mRNA and protein levels of mdr1, respectively. The results showed that the combination of MNPs-Fe3O4 and BrTet with effective concentrations significantly increased cytotoxicity against MDR cell line K562/A02. Both BrTet and MNPs-Fe3O4 increased the intracellular DNR accumulation in the K562/A02 cell line, and downregulated the level of mdr1 gene and expression of P-glycoprotein. Furthermore, the combination did not have significant cytotoxicity in PMBCs. We propose that MNPs-Fe3O4 conjugated with DNR and BrTet probably have synergetic effects on MDR reversal.

Effect of D, L-threo-1-phenyl-2-decanoylamino- 3-morpholino-1-propanol and tetrandrine on the reversion of multidrug resistance in K562/ A02 cells

Abstract 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.