Effects of Dasatinib on the Maturation of Monocyte-Derived Dendritic Cells Derived from Healthy Donors and Chronic Myelogenous Leukemia Patients / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of dasatinib on the maturation of monocyte-derived dendritic cells (moDCs) derived from healthy donors (HDs) and chronic myelogenous leukemia (CML) patients.@*METHODS@#Peripheral blood mononuclear cells (PBMCs) were isolated from HDs (n=10) and CML patients (n=10) who had got the remission of MR4.5 with imatinib treatment. The generation of moDCs from PBMCs was completed after 7 days of incubation in DC I culture medium, and another 3 days of incubation in DC II culture medium with or without 25 nmol/L dasatinib. On the 10th day, cells were harvested and expression of molecules of maturation related marker were assessed by flow cytometry. The CD80+CD86+ cell population in total cells was gated as DCs in the fluorescence-activated cell storting (FACS) analyzing system, then the expression of CD83, CD40 or HLA-DR in this population was analyzed respectively.@*RESULTS@#The proportion of CD80+CD86+ cells in total cells didn't show a statistical difference between HD group and patient group (89.46%±9.70% vs 87.39%±9.34%, P=0.690). Dasatinib significantly enhanced the expression of the surface marker CD40 (P=0.008) and HLA-DR (P=0.028) on moDCs derived from HDs compared with the control group, while the expression of CD83 on moDCs didn't show a significant difference between dasatinib group and the control group (P=0.428). Meanwhile, dasatinib significantly enhanced the expression of the surface marker CD40 (P=0.023), CD83 (P=0.038) and HLA-DR (P=0.001) on moDCs derived from patients compared with the control group.@*CONCLUSION@#For CML patients, the same high proportion of moDCs as HDs can be induced in vitro, which provides a basis for the application of DC-based immunotherapy strategy. Dasatinib at the concentration of 25 nmol/L can efficiently promote the maturation of moDCs derived from HDs and CML patients in vitro. Dasatinib shows potential as a DC adjuvant to be applied in DC-based immunotherapy strategies, such as DC vaccine and DC cell-therapy.

Effects of Tyrosine Kinase Inhibitors on the Th1 and Treg Cells of CML Patients / 中国实验血液学杂志

OBJECTIVE@#To compare the immunomodulatory effects of the 2nd generation of tyrosine kinase inhibitors (TKIs)-dasatinib and nilotinib as well as the 1st generation of TKI-imatinib on chronic myeloid leukemia (CML) patients.@*METHOD@#To evaluate the T cell subtypes by flow cytometry on the CML patients of our center who received the treatment with dasatinib (n=10), nilotinib (n=26) or imatinib (n=44) for more than 3 months, and to analyze and correlate these data with the clinical remission situations and prognosis.@*RESULTS@#80.0% of the patients in dasatinib group, 16.6% of the patients in nilotinib group and 27.5% of the patients in imatinib group respectively had a Th1 proportion in the peripheral blood (Th1/CD4 T) above the upper limit of normal. More specifically, the Th1 proportion in dasatinib group (30.86%±9.75%) was significantly higher than that in nilotinib group(17.37%±9.35%) (P<0.001) and that in imatinib group (20.79%±9.01%) (P<0.001). Among the 3 groups, both the CD8 T cell proportion (CD8 T/Lymphocyte) and the Th2 proportion (Th2/CD4 T) in the peripheral blood did not show a statistically significant difference. The Treg proportion (Treg/CD4 T) in dasatinib group (1.31%±0.10%) was significantly lower than that in nilotinib group (2.65%±0.97%) (P<0.001) and that in imatinib group(2.99%±1.40%) (P<0.001).Among all the CML patients analyzed, for CML patients who had a Th1 proportion above the upper limit of normal(25.8%) (n=28), 84.62% of these patients obtained CCyR (complete cytogenetic response), 71.43% of these patients obtained MMR (major molecular response), 71.43% of these patients obtained MR4.5; for CML patients who had the Th1 proportion in the normal range(11.8%-25.8%) (n=45), 90.7% of these patients obtained CCyR, 75.56% of these patients obtained MMR, and 75.56% of these patients obtained MR4.5; for CML patients who had the Th1 proportion below the lower limit of normal (11.8%) (n=21), 57.14% of these patients obtained CCyR, 47.62% of these patients obtained MMR, and 47.62% of these patients obtained MR4.5. The above-mentioned data shows that the patients in high Th1 group and the normal Th1 group obtained the higher remission rate as well as the deeper remission level.@*CONCLUSION@#This study shows that during the CML treatment with TKIs, the increased or normal Th1 proportion indicates a bigger chance for CCyR, MMR, and MR4.5. Dasatinib may significantly increase the level of Th1 while decrease the level of Treg in the patients, as compared with nilotinib and imatinib.

Mechanisms of tetrandrine and 5-bromotetrandrine in reversing multidrug resistance may relate to down-regulation of multidrug resistance associated protein 7 expression / 中国实验血液学杂志

Both tetrandrine (Tet) and 5-bromotetrandrine (BrTet) can effectively reverse P-glycoprotein (P-gp)-mediated multidrug resistance (MDR). The structure of multidrug resistance associated protein 7 (MRP7) has its own specificity and difference compared with other members of the MRP family. This study was aimed to investigate whether Tet and BrTet can inhibit the expression level of MRP7 so as to further look into the mechanisms of the reversal effects of Tet and BrTet on MDR. The inhibitory effects of daunorubicin (DNR) used alone on the proliferation of K562 and K562/A02 cells were evaluated by MTT assay, the IC(50) of DNR and drug resistant folds were calculated. The mRNA level of MRP7 was tested by real-time PCR, and the protein levels of MRP7 and P-gp were tested by Western blot. The DNR accumulation was analyzed by flow cytometry (FCM). The results showed that the resistance of K562/A02 cells to DNR was 23.65-folds of that of K562 cells. After administration of 1 µmol/L Tet or 2 µmol/L BrTet, the mRNA level of MRP7 in the K562/A02 cells decreased to 2% and 12% respectively, and the protein level of MRP7 decreased by 53.2% and 83.7% respectively. The protein level of P-gp decreased by 58.47% and 52.20% in the 1 µmol/L Tet and 2 µmol/L BrTet groups. FCM detection showed that 1 µmol/L Tet and 2 µmol/L BrTet significantly increased the accumulation of DNR in K562/A02 cells by 94.32% and 271% respectively. It is concluded that Tet and BrTet both can reverse MDR in vitro. The mechanisms may be related to the inhibition of MRP7 overexpression and the increase of anticancer drug concentration in cells. At the same molar concentration, the effects of Tet and BrTet in inhibiting the protein level of MRP7 expression do not show significant difference.