Apoptotic Mechanism of Human Leukemia K562/A02 Cells Induced by Magnetic Ferroferric Oxide Nanoparticles Loaded with Wogonin / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Traditional Chinese medicine wogonin plays an important role in the treatment of leukemia. Recently, the application of drug-coated magnetic nanoparticles (MNPs) to increase water solubility of the drug and to enhance its chemotherapeutic efficiency has attracted much attention. Drugs coated with MNPs are becoming a promising way for better leukemia treatment. This study aimed to assess the possible molecular mechanisms of wogonin-coated MNP-Fe3O4 (Wog-MNPs-Fe3O4) as an antileukemia agent.</p><p><b>METHODS</b>After incubated for 48 h, the antiproliferative effects of MNPs, wogonin, or Wog-MNPs-Fe3O4on K562/A02 cells were determined by methyl thiazolyl tetrazolium (MTT) assay. The apoptotic rates of K562/A02 cells treated with either wogonin or Wog-MNPs-Fe3O4were determined by flow cytometer (FCM) assay. The cell cycle arrest in K562/A02 cells was determined by FCM assay. The elementary molecular mechanisms of these phenomena were explored by Western blot and reverse transcriptase polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>With cell viabilities ranging from 98.76% to 101.43%, MNP-Fe3O4was nontoxic to the cell line. Meanwhile, the wogonin and Wog-MNPs-Fe3O4had little effects on normal human embryonic lung fibroblast cells. The cell viabilities of the Wog-MNPs-Fe3O4group (28.64-68.36%) were significantly lower than those of the wogonin group (35.53-97.28%) in a dose-dependent manner in 48 h (P < 0.001). The apoptotic rate of K562/A02 cells was significantly improved in 50 μmol/L Wog-MNPs-Fe3O4group (34.28%) compared with that in 50 μmol/L wogonin group (23.46%; P< 0.001). Compared with those of the 25 and 50 μmol/L wogonin groups, the ratios of G0/G1-phase K562/A02 cells were significantly higher in the 25 and 50 μmol/L Wog-MNPs-Fe3O4groups (all P< 0.001). The mRNA and protein expression levels of the p21 and p27 in the K562/A02 cells were also significantly higher in the Wog-MNPs-Fe3O4group compared with those of the wogonin group (all P< 0.001).</p><p><b>CONCLUSIONS</b>This study demonstrated that MNPs were the effective drug delivery vehicles to deliver wogonin to the leukemia cells. Through increasing cells arrested at G0/G1-phase and inducing apoptosis of K562/A02 cells, MNPs could enhance the therapeutic effects of wogonin on leukemia cells. These findings indicated that MNPs loaded with wogonin could provide a promising way for better leukemia treatment.</p>

Polymorphisms of dihydropyrimidine dehydrogenase gene and clinical outcomes of gastric cancer patients treated with fluorouracil-based adjuvant chemotherapy in Chinese population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Dihydropyrimidine dehydrogenase (DPD), a key enzyme involved in the catabolism of 5-fluorouracil (5-FU), is the attractive candidate for pharmacogenetic research on efficacies and toxicities of 5-FU. The aim of this study is to explore the association between polymorphisms of dihydropyrimidine dehydrogenase gene (DPYD) and clinical outcomes of gastric cancer patients treated with fluorouracil-based adjuvant chemotherapy in the Chinese population.</p><p><b>METHODS</b>Three hundred and sixty-two patients with gastric cancer in the Chinese population were treated with fluorouracil-based adjuvant chemotherapy. The single nucleotide polymorphic genotypes of DPYD were determined by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) using DNA samples isolated from peripheral blood collected before treatment.</p><p><b>RESULTS</b>The average response rate for chemotherapy was 46.7%. A significantly different distribution of the rs1801159 (c2=8.76, P=0.012) genotypes was observed. Homozygous genotype rs1801159A/A was over-represented in responsive patients. Conversely, carriers of the rs1801159A/G genotype were prevalent in non-responsive patients. In the haplotype association analysis, there was significant difference in global haplotype distribution between the groups (c2=3.96, P=0.0465).</p><p><b>CONCLUSIONS</b>These results suggest that polymorphisms of rs1801159 in DPYD may be used as valuable predictors of the response to fluorouracil-based chemotherapy for gastric cancer patients in the Chinese population. Well-designed, comprehensive, and prospective studies on determining these polymorphisms of DPYD as predictive markers for gastric cancer in response to fluorouracil-based therapies are warranted.</p>