In vitro effect of bortezomib alone or in combination with harringtonine or arsenic trioxide on proliferation and apoptosis of multidrug resistant leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of bortezomib alone or combined with harringtonine (HT) or arsenic trioxide (As2O3) on the proliferation capacity and apoptosis of HL-60/ADM cell line and fresh cells from refractory/relapse acute leukemia patients.</p><p><b>METHODS</b>HL-60/ADM cells or refractory/relapse leukemia cells were incubated with bortezomib at different doses alone and in combination with HT or As2O3. The proliferation capacity was observed by MTT assay, cell apoptosis by fluorescence microscopy and flow cytometry. Intracellular concentration of daunorubicin (DNR) was determined by flow cytometry.</p><p><b>RESULTS</b>In bortezomib-treated HL-60/ADM cells, the proliferation inhibition rate and apoptotic cells increased in a time- and dose-dependent manner. 40 nmol/L bortezomib could maximally inhibit the proliferation of HL-60/ADM cells at 48 hours. 15 micromol/L As2O3 or 752 nmol/L HT combined with different doses of bortezomib could inhibit proliferation and induce apoptosis of HL-60/ADM cells. The As2O3 plus bortezomib or HT plus bortezomib showed a greater anticancer efficacy than either of the drugs alone (P < 0.05, P < 0.01). Bortezomib (10 nmol/L) could markedly enhance the intracellular accumulation of DNR in HL-60/ADM cells (P < 0.05).</p><p><b>CONCLUSIONS</b>Bortezomib can inhibit proliferation and induce apoptosis of HL-60/ADM cells and fresh refractory/relapse acute leukemia cells, especially combined with HT or As2O3.</p>

Effect of bortezomib used alone or in combination with arsenic trioxide on HL-60 cell xenograft in nude mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the antitumor efficacy and adverse effects of bortezomib either used alone or in combination with arsenic trioxide for transplanted tumor in nude mice.</p><p><b>METHODS</b>Nude mice bearing HL-60 cell xenografts were randomized into 4 groups to receive treatment with normal saline, bortezomib, arsenic trioxide, bortezomib plus arsenic trioxide. The tumor growth inhibition and general condition of the nude mice were observed, and in situ TUNEL assay and immunohistochemistry were performed on the transplanted tumors.</p><p><b>RESULTS</b>Bortezomib alone and in combination with arsenic trioxide could both inhibit the growth of the transplanted tumors, prolong the survival of the nude mice, and induce cell apoptosis and growth inhibition of the HL-60 cells in vivo, and the combined administration exhibited even better effects. The administration was well tolerated with causing manifest vital organ damages in the mice.</p><p><b>CONCLUSION</b>Bortezomib in combination with arsenic trioxide has significant antitumor effect in nude mice bearing HL-60 cell xenografts possibly by inducing HL-60 cell apoptosis and growth inhibition without producing no significant adverse effects.</p>

HL-60 cell apoptosis induced by bortezomib alone or in combination with arsenic trioxide in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of bortezomib alone and in combination with arsenic trioxide on apoptosis of HL-60 cells.</p><p><b>METHODS</b>HL-60 cells were treated with bortezomib alone or in combination with arsenic trioxide for 12 to 48 h and the cell proliferation was analyzed with MTT assay, and cell apoptosis detected by DNA gel electrophoresis, fluorescence microscopy and flow cytometry.</p><p><b>RESULTS</b>At the concentrations of 10 to 50 nmol/L, bortezomib effectively inhibited HL-60 cell proliferation, and induced cell apoptosis. A 12-hour bortezomib treatment at 10 nmol/L was sufficient to induce cell apoptosis, and prolonged treatment or increased concentration significantly increased HL-60 cell apoptotic rate. Combined treatment of the cells with bortezomib (10 nmol/L) and arsenic trioxide (15 micromol/L) resulted in an even higher cell apoptosis rate than that induced by the respective agent alone.</p><p><b>CONCLUSION</b>Bortezomib can induce HL-60 cell apoptosis in a time- and dose-dependent manner, and a synergistic effect can be observed of bortezomib and arsenic trioxide in apoptosis induction.</p>

STI571 enhances the effect of arsenic trioxide and Velcade on bcr/abl+-CD34+ cell proliferation and apoptosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of STI571, arsenic trioxide (As2O3) and Velcade, used alone or in combination, on the proliferation and apoptosis of bcr/abl+-CD34+ cells.</p><p><b>METHODS</b>bcr/abl+-CD34+ cells isolated from the bone marrow of patients with chronic myeloid leukemia (CML) were treated for 96 h with STI571, As2O3 and Velcade either alone and in combination, and the cell proliferation and apoptosis were analyzed by CCK-8 assay and flow cytometry. The morphological changes of the apoptotic cells were observed by Hoechst33342 staining and fluorescent microscope. The inhibitory effects of the drugs on normal CD34+ cells were also observed.</p><p><b>RESULTS</b>Low-concentration STI571, As2O3 or Velcade all dose-dependently inhibited bcr/abl+-CD34+ cell proliferation without obvious apoptosis-inducing effects. STI571 at 0.25-2 micromol/L combined with As2O3 at 2.5 micromol/L and with Velcade at 15 nmol/L both significantly increased the cell inhibition and apoptosis rates, showing obvious additive or synergistic effects of the drugs without further enhancement of normal CD34+ cell inhibition.</p><p><b>CONCLUSION</b>Combination with STI571 enhances the effects of As2O3 and Velcade on bcr/abl+-CD34+ cells, suggesting the potential clinical value of this regimen.</p>

Effect of G-CSF on the proliferation and differentiation of bcr/abl(+)-CD34+ cells from CML patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the effect of granulocyte colony-stimulating factor (G-CSF) on the proliferation and differentiation of bcr/abl(+)-CD34+ cells.</p><p><b>METHODS</b>bcr/abl(+)-CD34+ cells were isolated from bone marrow of chronic myelocytic leukemia (CML) patients and were treated with 0, 10, 100, 1000 ng/ml of G-CSF for 48, 96, 144 hs. CD34 cells from normal bone marrow were used as controls. Cell proliferation was determined by trypan blue dye exclusion, cell-cycle and antigen differentiation were determined by flow cytometry and cell morphology was observed under light microscope.</p><p><b>RESULTS</b>The number of bcr/abl(+)-CD34+ cells was increased obviously in all groups. After cultured for 48 and 96 h, the number of bcr/abl(+)-CD34+ cells at G-CSF 10 ng/ml group was significantly higher than that in G-CSF 0 ng/ml group (P < 0.05) , the number of normal CD34 cells was increased only in the presence of G-CSF. After cultured for 48, 96 and 144 h, the cell number in G-CSF 100 ng/ml group was significantly higher than that in G-CSF 0 ng/ml group (P < 0.05, P < 0.01, P < 0.01, respectively). After cultured for 144 h, the cell percentages in G0/G1 phase for bcr/abl(+)-CD34+ cells in G-CSF 10, 100, 1000 ng/ml groups were significantly less than that in G-CSF 0 ng/ml group (P < 0. 05), and that for normal CD34 cells in G-CSF 10, 100, 1000 ng/ml groups were significantly less than that of G-CSF 0 ng/ml group after cultured for 48 and 96 h. The expressions of CD34 on bcr/abl(+)-CD34+ cells and normal CD34+ cells were decreased along with the culture duration, accompanied by the expression of CD33 and CD13 increased first and decreased later, which was not correlated with the concentration of G-CSF. Both bcr/abl(+)-CD34+ cells and normal CD34+ cells showed mature morphology along with proliferation and differentiation.</p><p><b>CONCLUSIONS</b>G-CSF promotes proliferation of both bcr/abl(+)-CD34+ cells and normal CD34+ cells, but not necessary for the former, and the former differentiates more rapidly than the latter does, but both was independent of G-CSF.</p>

Induction of apoptosis in HL-60 cells by bortezomib alone or in combination with harringtonine in vitro / 中国实验血液学杂志

The aim of this study was to investigate the effect of bortezomib alone and in combination with harringtonine on apoptosis of HL-60 cells. HL-60 cells were treated with bortezomib, harringtonine in different concentrations for 12 - 48 hours. Cell proliferation was analyzed by MTT assay; the apoptosis of HL-60 cells was observed by DNA gel electrophoresis, fluorescence microscopy and flow cytometry. The results showed that 10 - 50 nmol/L bortezomib could effectively inhibit HL-60 cell proliferation, and induced its apoptosis. After treating for 12 hours, 10 nmol/L bortezomib could trigger cells apoptosis. With time prolongation or dose increase, HL-60 cell apoptotic rate significantly increased. Furthermore, co-administration of bortezomib (10 nmol/L) with harringtonine (30 nmol/L) resulted in a higher cell apoptotic rate when compared with that induced by those agents used alone. It is concluded that the bortezomib can induce HL-60 cells apoptosis in a time-and-dose-dependent manner and synergistic effectiveness can be found when bortezomib combined with harringtonine.

Labeling of CDTPA-dianhydride-coupled CD45 monoclonal antibody with yttrium-90 / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the methods for labeling CDTPA-coupled CD45 monoclonal antibody (mAb) with yttrium-90 ((90)Y) for potential acute myeloid therapy.</p><p><b>METHODS</b>CD45 mAb was labeled with (90)Y by CDTPA and the labeling rate, radiochemical purity, final specific activity, and immunological activity of the mAb were detected.</p><p><b>RESULTS</b>With the optimal molar ratio of CDTPA/Ab at 20:1, the labeling rate was 95%, radiochemical purity 99.8%, and final specific activity 1.9 mCi/mg. This conjugate was stable in vitro with comparable immunological activity in comparison with unlabeled CD45 mAb.</p><p><b>CONCLUSION</b>(90)Y-CDTPA-CD45 mAb possesses good properties as an ideal targetting therapeutic agent for acute leukemia.</p>

Proliferation-inhibiting effect of indomethacin on chronic myeliod leukemia cells is related to the supression of STAT signal transduction pathway / 中国实验血液学杂志

This study was aimed to observe whether expressions of JAK2, STAT1, STAT5 proteins in indomethacin-treated CML cells involved in the proliferation inhibition of CML cells, and elucidate the pharmacological mechanism of indomethacin anti-leukemia. MTT assay and trypan blue dye exclusion test were used to detect the inhibitory effect of indomethacin on CML cells proliferation. JAK2, STAT1, STAT5 proteins were analyzed by Western blot; the subcellular distribution of STAT1, STAT5 were detected with indirect immunofluorescence technique. The results showed that indomethacin at >or= 400 micromol/L significantly inhibited the proliferation of CML cells and down-regulated the expression of STAT1, STAT5 protein, no JAK2 change was observed. STAT1 and STAT5 were located in cytoplasm. It is concluded that indomethacin inhibits the proliferation of CML cells and the mechanism may be related to down-regulated expression of STAT, or blockage of cells growth signals.

Proliferation inhibition effect of indomethacin on CML cells associated with down-regulation of phosphorylated STAT1/STAT5 and inhibition of COX-2 expression / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the mechanism of anti-proliferative effect of indomethacin (IN) on chronic myelogenous leukemia (CML) cells.</p><p><b>METHODS</b>MTT was applied to assay CML cells viability under IN intervention. STAT1, STAT5 proteins were analyzed by Western blot, the expressions of phosphorylated STAT1 or STAT5 by immunoprecipitation combined with Western blot, the cellular localization of p-STATs proteins by indirect immunofluorescence technique, and the detection of Bcl-X(L) and COX-2 protein by Western blot.</p><p><b>RESULTS</b>IN could significantly inhibit the viability of CML cells. 0 approximately 400 micromol/L of IN could down-regulate the expression of p-STAT1 or p-STAT5 in a dose-response manner, p-STATs were distributed mainly in the nucleus as scattering spots. The expression of COX-2 protein could be detected in K562 cells. Both Bcl-X(L) and COX-2 proteins could be inhibited by IN in a dose-dependent manner.</p><p><b>CONCLUSIONS</b>IN could significantly inhibit the proliferation of CML cells, the mechanism of which might be related to the suppression of STATs/Bcl-X(L) signal transduction pathway. There exists COX-2 protein expression in K562 cells, the anti-leukemia effect of IN was possibly dependent on COX-2 pathway.</p>