Mitochondria-mediated apoptosis induced by 5-aminolevulinic acid-based photodynamic therapy in HL-60 cells / 中国实验血液学杂志

This study was purposed to investigate the changes of mitochondrial membrane potential (MMP) and apoptosis-related gene Bcl-2 expression of HL-60 cells treated with 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT). HL-60 cell line was used as a model and divided into 4 groups: ALA group, PDT group, ALA+PDT group and control group. The change of MMP was detected by flow cytometry with JC-1 (lipophilic cation 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethyl-benzimidazol-carbocyanine iodide); the mRNA expression of Bcl-2 was determined by semi-quantitative RT-PCR and real-time PCR. The results demonstrated that MMP significantly decreased after treatment with ALA-PDT and the ratio of cells with disrupted MMP obviously increased in ALA+PDT group in time-dependence manner, as compared with control, ALA and PDT groups (P < 0.05), while no difference between ALA and PDT groups was found. The semi-quantitative RT-PCR and real-time PCR showed that the expression level of Bcl-2 was obviously down regulated at 2 h after ALA-PCT, further down-regulated at 4 h, and lasted in low level at 24 h. It is concluded that ALA-PDT-induced apoptosis of HL-60 cells is associated with its effect on MMP, that is ALA-PDT promotes cell apoptosis through effect on mitochondrial function.

Preparation and identification of monoclonal antibody against PNAS-2 protein / 中国实验血液学杂志

This study was purposed to prepare and primarily identify the specific monoclonal antibodies (McAbs) against the apoptosis related protein PNAS-2 so as to provide the essential tool for study of PNAS-2 function. The McAbs against PNAS-2 were prepared via the immunization of mice, cell fusion and cloning using synthetic peptide of PNAS-2 as immunogen; the specificity, titer and subtype of McAb were detected by Western blot, ELISA and immunofluorescence. The results showed that the stable hybridoma cell line S-31-7 producing McAbs against PNAS-2 protein was successfully obtained. The immunoglobulin of the McAb was identified to be IGg1lambda. The titer of ascetic fluid fled McAb were 1:8,000. A single specific band with 28 kD was shown in Western blot test, and the antigen recognized was present in cell cytoplasm by immunofluorescence. In conclusion, the obtained McAb against PNAS-2 displays strong specificity and high titer, which may be applied to the advanced research on PNAS-2 protein.

Research on mechanism of chloroquine phosphate-induced U937 cell apoptosis / 上海第二医科大学学报

Objective To observe the effects of chloroquine phosphate on apoptosis of leukemic cell line U937, and investigate whether chloroquine phosphate induces leukemic cell apoptosis by normalizing protein PNAS-2's abnormal subcellular location. Methods Chloroquine phosphate of different concentrations were added into culture fluid of leukemic cell line U937 at logarithmic phase. MTr was used to measure cell proliferation, flow cytometry and laser confocal microscopy were applied to detect cell apoptosis, and immunofluorescence technology was employed to observe the effects of chloroquine phosphate on the changes of subcellular location of protein PNAS-2. Results Apoptosis of leukemic cell line U937 was significantly induced by 50 μg/mL chloroquine phosphate, and subcellular location of protein PNAS-2 was changed. Conclusion Chlorequine phosphate can induce apoptosis of leukemic cell line U937, and the mechanism may be related to the normalization of PNAS-2's abnormal subcellular location in U937 cell line. Chloroquine phosphate has the potential to be used in leukemic therapy.

Polymorphisms of CYP3A5 gene in acute leukemia patients and their role in chemotherapy and prognosis / 中国实验血液学杂志

The objective of study was to investigate the role of the polymorphisms and protein expression of CYP3A5 gene in the therapy and prognosis of acute leukemia (AL) patients, the polymorphisms of CYP3A5 gene and the expression of protein CYP3A5 were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and immunohistochemistry method respectively. The results showed that there were three CYP3A5 genotypes in the 88 cases, namely CYP3A5*1/*1, CYP3A5*1/*3 and CYP3A5*3/*3 with frequencies of 26%, 50% and 24%, respectively. There were no significant differences in clinic data between the three groups, but the expressions of CYP3A5 of three groups were (36.6+/-19.2)%, (7.8+/-9.2)%, (0.5+/-0.9)%, the OS were (11.6+/-2.1) months, (30.5+/-12.2) months, (52.3+/-8.5) months, and the DFS were (7.5+/-1.8), (27+/-15.8), (52.3+/-8.1) months, respectively (p<0.05). It is concluded that the polymorphism of CYP3A5 gene is not related with the morbidity of AL, but closely associated with the expression of CYP3A5 in AL patients, and the latter are closely associated with the chemotherapeutic effect and prognosis. CYP3A5 genotype may be used as a new predictor to the chemotherapeutic effect and prognosis in AL cases.

Effect of daunorubicin and cytarabine on cell line NB4 / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore whether daunorubicin (DNR) combined with cytosine arabinoside (Ara-C) and DNR alone have similar effect on acute promyelocytic leukemia (APL) cell line NB4 and acute myeloblastic leukemia cell line HL-60 in vitro.</p><p><b>METHODS</b>Cell morphology, cells viability, and cell apoptosis (Annexin-V by flow cytometry assay) were analysed.</p><p><b>RESULTS</b>After incubation with DNR plus Ara-C for 24 hours,NB4 cell viability [(36.75 +/- 3.82)%] (n = 6) and cell apoptosis rate [(21.24 +/- 5.82)%] (n = 3) did not change significantly compared to that treated with DNR alone for 24 hours [(35.73 + 6.28 )%, (22.55 +/- 3.26)%, respectively] (P > 0.05). However, HL-60 cell viability [(67.17 +/- 2.07)%] and cell apoptosis rate [(48.05 +/- 0.92)%] changed significantly in DNR plus Ara-C group compared with DNR alone [(63.31 +/- 1.80)% ,(41.51 +/- 0.89)%, respectively] (P < 0.01 and < 0.05, respectively).</p><p><b>CONCLUSION</b>DNR plus Ara-C and DNR alone have similar effect on NB4 cells, but have different effect on HL-60 cells.</p>

The changes of mRNA expression of telomerase subunits induced by Ara-C in HL-60 cells / 中国癌症杂志

Background and purpose:Ara-C is one of the most effective and common agents in the treatment of acute nonlyphocytic leukemia. Telomerase is a unique complex of ribonucleoprotein. It plays an important role in the pathogenesis and development of cancer. In this study, we investigate the changes of mRNA expression of telomerase subunits in HL-60 cells induced by Ara-c and try to come up with a theory that could help to assess the efficacy of Ara-C. Methods:The combinations of various Ara-C concentration and the incubation time were used to treat HL-60. The ratios of apoptotic cell to necrosis cell were determined by flow cytometry and the expressions of telomerase subunits mRNA were evaluated by RT-PCR.Results:① There was no influence on transcription of telomerase subunits gene after HL-60 cells was cultured with 0~0.2ug/ml Ara-C for 12 hours;② 2ug/ml and 10ug/ml of Ara-C could down regulate the expression of hTERT from 0.80+0.07 to 0.50+0.04 and 0.39+0.03, not hTR and hTP1;③ with longer incubation with 10ug/ml of Ara-C, the percentage of apoptosis could be increased. The maximal induction of apoptosis (18.16+4.25%) could be reached at 12hrs treatment of Ara-C, then gradually decreased later on. The rate of necrosis increased with time, the maximal percentage(57.94+12.03%) of necrosis was observed at 48hrs of incubation time with drug. The mRNA level of hTERT gene also decreased along with the cultured time , the lowest value (0.18+0.03) has been documented at 48hrs time point, but not hTR、TP1.Conclusions:① Ara-C could down-regulate the expression of hTERT mRNA in a dose-and time-dependent manner, but not hTR、hTP1;② There might be no relationship between the percentage of apoptosis induced by Ara-C apoptosis and the expression of telomerase hTERT gene mRNA, but a close relationship between necrosis and the expression of hTERT mRNA has been found.

Prognostic values of lactate dehydrogenase and ?_2 microglobulin levels in adult acute myeloid leukemia / 上海第二医科大学学报

Objective To investigate the prognostic values of serum lactate dehydrogenase(LDH) and beta-2 microglobulin(?2-MG) levels in patients with acute myeloid leukemia(AML). Methods The associations of serum LDH and ?2-MG levels at diagnosis,remission and relapse with treatment and prognosis in 68 patients with AML were retrospectively analysed. Results There were no difference in LDH and ?2-MG between AML subtypes patients.The level of serum LDH and ?2-MG at diagnosis and relapse were much higher than those at remission.Patients with lower level of LDH and ?2-MG got higher CR rate and longer term overall survival and disease-free survival.Patients with higher level of both LDH and ?2-MG got lower CR rate,shorter term of overall survival and disease-free survival than those with higher level of LDH or ?2-MG or those with normal level of LDH and ?2-MG. Conclusion LDH and ?2-MG is a singificant prognostic indicator for AML.While combined LDH and ?2-MG are more definite for the treatment and diagnosis.

Effects of quercetin on morphology and VEGF secretion of leukemia cells NB4 in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effects of quercetin on cell morphology and VEGF expression of acute myeloblastic leukemia cells NB4 in vitro.</p><p><b>METHODS</b>The cytomorphology of NB4 cells was assessed by Wright-stain, apoptosis rate by apoptotic marker Annexin V, and VEGF secretion level by ELISA.</p><p><b>RESULTS</b>Typical apoptosis was found in NB4 cells after treatment with quercetin. Apoptotic marker Annexin V analysis showed that the apoptotic rate of NB4 cells was increased after treatment with quercetin. The secretion of VEGF of NB4 cells was significantly decreased after treatment with quercetin.</p><p><b>CONCLUSION</b>Quercetin can induce apoptosis and inhibit secretion of VEGF in NB4 leukemia cells.</p>

Reversal of multidrug resistance of HL-60 adriamycin resistant leukemia cell line by quercetin and its mechanisms / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Quercetin, a widely distributed natural flavonoid with a variety of biological functions, can reverse multidrug resistance (MDR) in leukemia according to recent researches. The aim of this study was to investigate the mechanisms of reversal of multi-drug resistance by quercetin mainly in respect of membrane transporters.</p><p><b>METHODS</b>MTT cell viability assay was used to verify the chemo-sensitization to daunorubicin (DNR) by quercetin in HL-60/ADM cell line and determine the effective reversal concentration, the expression of MRP(1) gene and its protein product, multidrug resistant associated protein 1 by RT-PCR and flow cytometry By confocal laser scanning microscopy, the subcellular distribution of DNR in HL-60/S and HL-60/ADM cells was examined before and after quercetin exposure.</p><p><b>RESULTS</b>Compared with HL-60/S, 20-40 micromol/L quercetin in vitro remarkably enhanced the sensitivity of HL-60/ADM cells to daunorubicin, down-regulated the expression of MRP(1) gene and its protein product MRP(1), restored the abnormal subcellular distribution of daunorubicin, so as to reverse MDR. Moreover, such an effective concentration of quercetin was non-toxic to the cells.</p><p><b>CONCLUSION</b>Quercetin could be a candidate of effective multidrug resistance-reversing agent with low toxicity in leukemia chemotherapy.</p>

Transfection of HL-60 cells with CYP3A5 gene induces drug-resistant phenotype / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate if CYP3A5 gene is involved in the molecular mechanisms for multiple drug resistance in leukemia cells.</p><p><b>METHODS</b>A full length cDNA of CYP3A5 gene was cloned, and a recombinant eukaryotic expression plasmid was constructed, then stably transfected cell lines were established. Furthermore, the sensitivity of those cell lines to several anticancer drugs were assessed by MTT and FCM assay.</p><p><b>RESULTS</b>The recombinant plasmid was designated as pcDNA3-CYP3A5. Transfecting HL-60 cells (which didn't show transcript of CYP3A5 gene) with recombinant plasmid pcDNA3-CYP3A5 generated HL-60/CYP3A5 cell line, and transfecting of HL-60 cells with the parental pcDNA3 vector served as control HL-60/pc cell line. Daunorubicin induced remarkable apoptosis peaks in HL-60 and HL-60/pc cells, while such effect did not occur in HL-60/CYP3A5 cells (apoptosis cell percentage were 7.3%, 6.3% and 1.2%, respectively). Compared with HL-60 and HL-60/pc cells, HL-60/CYP3A5 cells were statistically significantly resistant to daunorubicin, aclacinomycin A, vincristine and harringtonine (resistance multiples were 2.89, 2.01, 4.05 and 2.79 times, respectively, P < 0.05), however the sensitivity to teniposide didn't change (resistance multiple was 1.04 times).</p><p><b>CONCLUSION</b>Transcription of CYP3A5 gene in leukemia cells directly induces resistance to anthracyclines and alkaloids, however the cells are still sensitive to epipodophyllotoxins. Therefore, our findings confirmed a new mechanism of multidrug resistance.</p>

Effect of ATRA and DNR on the expression and secretion of VEGF in leukemic cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of VEGF mRNA and secretion of VEGF protein in NB4 and HL-60 cells affected by all-trans retinoic acid (ATRA) and daunorubincin (DNR) respectively.</p><p><b>METHODS</b>Semi-quantitative RT-PCR and ELISA were used to study the expression of VEGF mRNA and secretion of VEGF protein in NB4 and HL-60 cell lines treated by ATRA and DNR respectively.</p><p><b>RESULTS</b>VEGF was expressed in both NB4 and HL-60 cells. The expression of VEGF mRNA and secretion of VEGF protein could be down-regulated by ATRA and DNR respectively in a time and dose dependent manner.</p><p><b>CONCLUSION</b>Besides inducing apoptosis and restraining proliferation of leukemic cells, ATRA and DNR exerted their anti-leukemia effects by reducing angiogenesis via reduction of angiogenic reaction stimulating signals.</p>

Effects of Red Orpiment on Cell Morphology and Expression of PML mRNA and Protein in NB4, and HL-60 Cells / 中国实验血液学杂志

In this study the effects of red orpiment on NB4 and HL-60 cells were tried to determine. Semi-quantitative RT-PCR to determine the PML mRNA expression, immuno-fluorcscence study, together with the fluorescence stain and morphological observations were used. The results showed that: (1) red orpiment induces apoptosis morphologically in NB4 and HL-60 cells, the morphology of typical apoptosis can be seen in NB4 and HL-60 cells after 12 hours of treatment with red orpiment. Through the Wright's stain, we can see the extensive membrane blebbing, condensation of heterochromatin, and cell fragmentation, apoptotic body appearing. Many dead cells can be found on the second day. (2) in NB4 cells, red orpiment is shown to induce the PML-RARalpha chimera disappearance and to reorganize then to degradation of PML nuclear bodies which also seen in HL-60 cells, indirect immunofluorescence staining of PML with a specific monoclonal antibody was performed in control and treated cells. In NB4 cells, the control was diffusely microspeckled pattern of immunoreactivity. Upon red orpiment treatment, the microspeckled pattern disappeared, PML protein reversed into normal location. and the the size and the brightness of the particles were increased obviously. The normal nuclear distribution of PML protein was seen in untreated HL-60 cells. After treatment with red orpiment, in the nuclei of HL-60 cells, the size and the brightness of the particles were also increased. After two days of treatment with red orpiment, the immunofluorescent particles in cells almost disappeared. (3) the expression of PML mRNA is not changed in red orpiment-treated cells, RT-PCR to determine the PML mRNA expression in NB4 and HL-60 cells treated with red orpiment, the expression results are similar to the controls, that to say, the PML mRNA lever is unaffected. It was concluded that, red orpiment induced PML to play the effects of induce apoptosis in leukemia cells at the translational level and inhibited the proliferation of leukemia cells.