Effect of tetrandrine combined with daunorubicin on expressions of P21 and P-gp in K562/A02 cells / 中国实验血液学杂志

This study was aimed to investigate the reversal effect of Tetrandrine (TET) combined with daunorubicin (DNR) on multidrug resistance (MDR) of K562/A02 cells and its relation to P21, P-gp and their genes so as to provide the new theoretic evidence for clinical use of TET. The experiments were divided into 4 groups: control group (DNR alone), combined 1 group (DNA+0.5 mg/L TET), combined 2 group (DNR+1.0 mg/L TET) and combined 3 group (DNR+2.0 mg/L TET). The expressions of P21, P-gp and mdr-1 gene in K562/A02 cells of different groups were detected by Western blot, flow cytometry and semi-quantitative PCR respectively. The results showed that the expression of P21 was enhanced along with increasing of TET concentration, the expression of P-gp was reduced along with increasing of TET concentration and expression of mdr-1 gene was almost not observed in K562 cells, but the high expression of mdr-1 gene was seen in K562/A02 cells, furthermore, the expression of mdr-1 gene in K562/A02 cells increasingly was reduced along with increasing of TET concentration. It is concluded that the TET possesses the reversal effect on multiple drug resistance of K562/A02 cells with concentration dependence, the reversal effect of TET may be related to up-regulation of P21 expression and down-regulation of P-gp and mdr-1 gene expressions in K562/A02 cells.

Influence of tetrandrine on SORCIN gene expression in K562/A02 cell line / 中国实验血液学杂志

This study was aimed to explore the changes of soluble resistance-related calcium binding protein (sorcin) expression in reversion of multidrug resistance of K562/A02 leukemic cell line with different concentrations of tetrandrine (Tet), so as to provide a new theoretic evidence for clinical application of Tet. The inhibition of K562/A02 cell line by daunorubicin (DNR) was assayed by MTT method. The changes of SORCIN gene expression were assayed by RT-PCR. The changes of SORCIN protein expressed were assayed by Western blot. The results showed that Tet could enhance the cytotoxicity of DNR to K562/A02 cells (the IC(50) of DNR + Tet was 11.3+/-0.17 mg/L, 5.15+/-0.10 mg/L, 3.91+/-0.06 mg/L, and 2.52+/-0.04 mg/L, when concentrations of Tet were 0 mg/L, 0.5 mg/L, 1.0 mg/L, and 2.0 mg/L respectively). The gene encoding sorcin was highly expressed in K562/A02 cells, the expression of which was firstly enhanced in Tet concentration 0.5 mg/L, then attenuated in Tet concentration of 1.0, 2.0 mg/L (p<0.05). Sorcin protein expressed lowly in K562 cells and highly in K562/A02 cells, but the expression of SORCIN protein in K562/A02 cells was enhanced in Tet concentration of 0.5 mg/L, then was attenuated in Tet concentration of 1.0, 2.0 mg/L (p<0.05). It is concluded that the effect of Tet on reversal of K562/A02 drug-resistance shows concentration dependence by MTT assay. Tet reverses multidrug-resistance of K562/A02 cells through regulation of expression of SORCIN gene and protein, but not fully correlates to the reversing effect.

Purging effects of CD3AK/iNOS in vitro on primary leukemic cells from chronic myeloid leukemia patients / 中国实验血液学杂志

To investigate the purging effect of CD3AK/iNOS on primary leukemic cells from chronic myeloid leukemia patients in vitro, amphotropic packaging cell line PA317 transfected with the whole length of iNOS gene was cultivated, amplified and screened by G418. The viral titer was determined by the NIH3T3 cells. Human peripheral blood mononuclear cells were isolated and activated by anti-CD3 monoclonal antibody in vitro. CD3AK cells were incubated with viral supernatant and selected by G418. Resistant clones were assayed for iNOS gene expression by RT-RCR. The content of nitric oxide and the activity of iNOS in the culture supernatant of CD3AK/iNOS were evaluated by the method of Griess. After BMMNC or PBMNC from CML patients were co-cultured with CD3AK/iNOS, CD3AK/Neo and CD3AK/iNOS respectively, the expression of bcr/abl fusion gene was detected by serial dilution semi-quantitative net RT-PCR assay. The results showed that anti-G418 positive packaging cell line PA317 transfected with the whole length of iNOS gene clones could stably synthesize and excrete recombinant retroviral vectors. The titer of recombinant retroviral vectors was 1.0 x 10(5) CFU/ml. After being transfected by recombinant retroviral supernatant, the iNOS cDNA was expressed in CD3AK/iNOS. The content of NO and activity of iNOS that synthesized and excreted by CD3AK/iNOS were notably increased, compared with those of CD3AK. There were statistically significant differences in NO content and iNOS activity between two groups. After BMMNC or PBMNC from CML patients were co-cultured with CD3AK/iNOS, CD3AK/Neo and CD3AK/iNOS respectively, the expression of bcr/abl fusion gene in all of them was down-regulated by serial dilution semi-quantitative RT-PCR assay. It is concluded that construction of CD3AK/iNOS can markedly increase the content of NO and the activity of iNOS, which can be more efficient in in vitro purging leukemia cells for autologous hematopoietic stem cell transplantation.