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.

Expression of alternatively spliced human tissue factor in acute leukemia cells / 中国实验血液学杂志

The high expression of tissue factor (TF) is related to the coagulation disorder in acute leukemia. TF in blood circulation is mainly expressed in cells, microparticles (MP) and alternatively spliced human tissue factor (asHTF). To elucidate the role of TF in the coagulation disorder of acute myeloid leukemia (AML), RT-PCR was performed on 6 common AML cell lines NB4, HL-60, Kasumi-1, U937, K562 and THP-1. The results showed that only NB4 and U937 cells expressed baseline full-length TF and asHTF which were proved by sequencing. The flow cytometric detection, TF activity and TF antigen tests in NB4 and U937 cells revealed that the asHTF was expressed in trace amount and almost had no activity, while the TF antigen and activity in microparticles were significantly higher than that in asHTF. It is concluded that asHTF may play an unimportant role in the coagulation disorder of AML. Microparticle associated tissue factor (MP-TF) is the predominant source of TF activity released from AML cells.

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.

Expression spectra of apoptosis-related gene pnas-2 / 中国实验血液学杂志

To explore the expression spectra of apoptosis-related gene pnas-2 in normal tissues and acute leukemia (AL) patient tissues, the expressions of pnas-2 gene in tissues including heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, spleen, lymph node, thymus, leukocyte, bone marrow and fetal liver were detected by Northern blot. The expressions of pnas-2 in samples including 44 de novo, 9 non-CR, 27 CR and 12 relapsed AL patients were measured by real-time RT-PCR and Northern blot, and the expression levels of pnas-2 in normal and tumor tissues from 31 patients with malignancies were also detected. The results showed that pnas-2 was not expressed in the most tissues except in placenta. The results of real-time PCR indicated that pnas-2 expressions in samples of de novo, non-CR and relapsed patients ware significantly higher than that in CR, tumor tissues and normal tissues. In serial monitoring of 7 AL patients, the expression level of pnas-2 was high at first visit examination, but remarkably decreased after remission, and the pnas-2 expression level increased again when relapsed. It is concluded that the pnas-2 is specifically up-regulated in acute leukemia patients, which might be an oncogene and participate in leukemogenesis.

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.

Correlation between expression of apoptosis-related gene pnas-2 and leukemia / 中国实验血液学杂志

The study was purposed to explore the correlation between apoptosis-related gene pnas-2 and leukemia. The RT-PCR was performed to detect the expression levels of pnas-2 gene in NB4, K562, U937 cells before and after treatment with AS(4)S(4), and to analysis the expression change of pnas-2 gene in bone marrow cells from patients with acute leukemia before and after chemotherapy. The results showed that the expression of pnas-2 gene in arsenic sulfide treated NB4 cells was down regulated in time-dependent manner, but the same outcome in K562 and U937 cells after being treated with AS(4)S(4) was not found. The positive expression rate of pnas-2 in cells from untreated patients with acute leukemia was 100%, and was significantly higher than that in normal control group. After chemotherapy, the expression was negative in complete remission patients, whereas in no-remission patients there were no significant differences of expression of pnas-2 before and after treatment. It is concluded that the pnas-2 gene may be closely related with apotosis of arsenic sulfide treated APL cells, and may consider as a molecular biological remission marker in acute leukemia.

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.

Effect of recombinant human granulocyte colony-stimulating factor on neutrophil morphology, function and phenotype in patients with acute leukemia undergoing chemotherapy / 中国实验血液学杂志

This study was to explore the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on neutrophil morphology, function and phenotype in patients with acute leukemia undergoing chemotherapy. Neutrophil morphology was observed under microscope with oil immersion; phagocytotic function was examined by measuring the amount of hydrogen peroxide produced by neutrophil; chemotaxis was analyzed by agarose method; oxidative burst was analyzed by flow cytometry using immunofluorescence technique; neutrophil phenotype was analyzed by flow cytometry and immunofluorescence techniques. The results showed that after rhG-CSF administration, the increased "toxic" granulation, vacuoles and Döhle bodies were observed in neutrophils of patients with acute leukemia. Compared with normal control, the functions of phagocytosis, chemotaxis, oxidative burst of neutrophil were impaired after chemotherapy, while these functions were enhanced and returned to normal level or even to be exceeded after administration of rhG-CSF. In patients with acute leukemia the neutrophil presented significantly higher expression of CD64 and CD62L than that in normal control, and a mild increase of CD64 expression and significant increase of CD62L expression were found in patients after rhG-CSF treatment. No modifications of CD16, CD32, CD14 and CD11b expression were detected in these patients before or after G-CSF administration. It is concluded that rhG-CSF administration can modify the morphology, function and phenotype of neutrophils in the patients with acute leukemia undergoing chemotherapy, and these modifications of neutrophil behavior may be supposed to be a reason for the enhancement of organism anti-infection ability.

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>