[Enhancement of all-trans retinoic acid induced HL-60 leukemia cell differentiation by human umbilical cord mesenchymal stem cells].

This study was aimed to investigate the enhancement of all-trans retinoic acid-induced HL-60 leukemia cell differentiation by human umbilical cord mesenchymal stem cells (hucMSC). The HL-60 cells were divided into 4 groups: control group (HL-60 cells treated without ATRA), hucMSC group (HL-60 cells co-cultured with hucMSCs), ATRA group (HL-60 cells treated with ATRA) and ATRA + hucMSC group (HL-60 cells treated with ATRA and co-cultured with hucMSCs). The proliferations of control group and hucMSC group were compared by Cell Counting Kit-8 (CCK8). The morphology of HL-60 cells and NBT positive rate in 4 groups were observed and compared by means of microscopy, the c-myc expression of HL-60 cells in different groups was evaluated by real-time PCR, and the CD11b expression on HL-60 cells in different groups were detected by flow cytometry. The results showed that in the co-culturing system, hucMSCs could inhibit the proliferation of HL-60 (hucMSC:HL-60 is 1:1, 48 hours p < 0.05, 72 hours p < 0.01; hucMSC:HL-60 is 1:5, 72 hours p < 0.05). In condition of stimulation with 2 micromol/L ATRA, the neutrophil like HL-60 cells and NBT positive rate in ATRA + hucMSC group were higher than those in ATRA group (p < 0.05). The c-myc expression of HL-60 cells in ATRA + hucMSC group was lower than that in ATRA group (p < 0.05). Furthermore, HL-60 cells in ATRA + hucMSC group had stronger CD11b expression than ATRA group (48 hours p < 0.05, 72 hours p < 0.01). It is concluded that hucMSC not only can inhibit the proliferation of HL-60 cells, but also can enhance the differentiation effect of HL-60 cells induced by ATRA.

[Biological characteristics of Wt1 gene in relation to Ph(+) leukemia cell line K562].

Wt1 is a dual-function gene involved in hematopoiesis, leukemogenesis and prognosis for leukemia. This gene is highly expressed in acute myeloid leukemia (AML) and the progression of chronic myelogenous leukemia (CML). It was reported elsewhere that high level of wt1 expression indicated worse prognosis for leukemia. Wt1 gene functions are different due to its subcellular localization. This study was aimed to investigate the expression and localization of wt1 mRNA and WT1 protein, and explore the effects of wt1 inhibitor, curcumin, on K562 cell proliferation, cell cycle and its possible mechanisms. MTT method was used to detect cell proliferation; flow cytometry was used to analyze the alteration of cell cycle, and the immunofluorescence and Western blot technology were performed to observe the subcellular localization of WT1 protein. The transcripts of wt1 and bcr/abl p210 was analyzed by real-time PCR. The results showed that wt1 mRNA and its protein were both highly expressed in K562 cells. The curcumin and imatinib (Glevec) both inhibit the cell proliferation resulting in the G(2)/M and G(0)/G(1) phase arrest respectively. Meanwhile, the transcripts of wt1 and bcr/ablp210 genes decreased greatly after being treated with the two inhibitors above. It is concluded that the alteration of wt1 gene affects the biological characteristics of Ph(+) K562 cells, such as cell proliferation, cell cycle and so on. Gene wt1 is expected to be further studied as a new therapy target in Ph(+) leukemias.

[IL-27 regulates the expression of Mac-1, fMLP-R and IL-1beta in human neutrophils through p38 MAPK and PI3K signal pathways].

The present study was aimed to investigate the pathways, by which IL-27 regulates the expression of adherent molecule Mac-1, chemotactic factor receptor fMLP-R and pro-inflammatory cytokine IL-1beta in human neutrophils. Highly purified human neutrophils were isolated from peripheral blood using Ficoll-Hypaque gradients centrifugation and erythrocyte lysis. The mRNA expression of IL-27 receptor components (WSX-1/TCCR and gp130) in human neutrophils was detected by reverse transcription polymerase chain reaction (RT-PCR). After incubation with IL-27 and specific inhibitors (p38 MAPK inhibitor SB203580, PI3K inhibitor LY294002 and ERK inhibitor U0126), the mRNA levels of fMLP-R and IL-1beta were determined by real time RT-PCR, and the adherent molecule Mac-1 expression in human neutrophils was determined by flow cytometry. The IL-1beta level in culture supernatant of human neutrophils was assayed by radioimmunoassay. The results showed that IL-27 receptor components (WSX-1/TCCR and gp130) were constitutively expressed in human neutrophils. IL-27 down-regulated Mac-1 expression in human neutrophils (p<0.05). After incubation with specific inhibitors, SB203580, not LY294002 and U0126, inhibited the down-regulation of Mac-1 expression by IL-27. However, IL-27 up-regulated the mRNA expression of fMLP-R and IL-1beta, and increased the release of IL-1beta (p<0.05). Interestingly, LY294002, not SB203580 and U0126, inhibited the up-regulation of fMLP-R and IL-1beta by IL-27. It is concluded that the IL-27 may regulate the expression of Mac-1, fMLP-R and IL-1beta in human neutrophils through p38 MAPK and PI3K signal pathways.

[Inhibition of leukemia cell proliferation by G-rich oligonucleotides].

G-rich oligonucleotides (GROs) belong to a novel class of phosphodiester oligonucleotides. They can form G-tetramer structure which contributes to cell cycle arrest and growth inhibitory effects by non-antisense pathway. This study was aimed to investigate the biological effects of GRO-26B on leukemia cell lines. Cell proliferation of different cell lines were detected by using MTT method and trypan blue incorporation assay. Alteration of cell cycle was analyzed by using flow cytometry. Apoptosis was detected by using Annexin V/PI kit. Western blot was used to detect the expression level of cyclins and CDKs. Morphological features of GRO-26B-treated cells was observed by light microscopy and transmission electron microscopy (TEM). The results showed that GRO-26B could inhibit the proliferation of AML cell lines, such as U937 and NB4 cells in a dose-dependent manner. GRO-26B induced the cell cycle to be arrested at S phase in time-dependent manner, which was associated with the alteration of cyclin A, cyclin B, CDC2 and CDK2. The morphology of cells treated by GRO-26B also showed a distinct change as compared to the untreated cells. It is concluded that GRO-26B can inhibit AML cell proliferation, which is partially associated to cell cycle arrest at S phase. The S phase arrest is related to cyclins/CDKs. The regulation mechanism of cell cycle and proliferation is complicated. All of the above-mentioned phenomena need to be studied in the future.

[Up-regulation of CD86 and cytokine expression in acute leukemia cells by Ara-C].

AIM: To observe the effects of Ara-c on the expression of CD86 molecule on acute leukemia cells and explore the possible mechanisms. METHODS: The expression of CD86 on U937, HL-60 and NB4 cell lines treated with or without Ara-C wa assayed by flow cytometry. The mRNA expression of CD86, NF-kappaB, IFN-gamma was examined by semiquantitative RT-PCR. RESULTS: UP-regulation of CD86 was observed on those cells treated by Ara-c. The level of CD86 and NF-kappaB mRNA in Ara-c treated cells was significantly enhanced. IFN-gamma was detectable 72 hours after T cell activation. CONCLUSION: Ara-C can enhance CD86 and NF-kappaB expression on acute leukemia cells, which may play critical role in T cell activation and differentiation.

[The quantity, subsets and expression of costimulatory molecules of circulating dendritic cells in the patients with myelodysplastic syndromes].

OBJECTIVE: To investigate the quantity, subset of dendritic cells (DC) and their costimulatory molecule expression in peripheral blood (PB) of the patients with myelodysplastic syndromes (MDS). METHODS: Total DC (Lin1(+) HLA-DR(+)), myeloid DC (mDC) (Lin1(-) HLA-DR(+) CD11c(+)) and plasma DC (pDC) (Lin1(-) HLA-DR(+) CD123(+)) in fresh PB samples of 38 MDS patients and 19 normal controls were assayed by flow cytometry with the monoclonal antibodies. The expressions of costimulatory molecules CD80, CD86 and CD40 on these DCs were also assayed in the same way. RESULTS: The number of total DC in PB of low-risk and high-risk MDS patients was significantly higher than that in normal controls [(33.7 +/- 7.0) x 10(6)/L, (56.3 +/- 29.0) x 10(6)/L vs (12.1 +/- 1.4) x 10(6)/L, respectively] (P < 0.05), that of mDC in PB of low-risk and high-risk MDS patients was higher than that of normal controls too [(16.7 +/- 6.3) x 10(6)/L, (28.7 +/- 17.6) x 10(6)/L vs (5.5 +/- 0.9) x 10(6)/L] (P < 0.05), but pDC in low-risk and high-risk MDS patients was not significantly higher than that in normal controls (P > 0.05). The percentage of total DC in PB mononuclear cells (PBMNC) of low-risk and high-risk MDS patients [(2.37 +/- 0.53)% and (3.58 +/- 1.39)% respectively and that of mDC (0.90 +/- 0.35)%, (1.51 +/- 0.70)% respectively] were higher than that of normal controls [(0.68 +/- 0.08)%, and (0.32 +/- 0.05)% respectively] (P < 0.05), but that of pDC in MDS cases was not higher than that of normal controls (P > 0.05). The expressions of CD80 and CD86 between MDS patients and normal controls had significant difference (P < 0.05). CONCLUSIONS: Total DC and mDC were increased significantly in MDS, but pDC did not. The costimulatory molecules (CD80 and CD86) except CD40 expressed higher on the DC of MDS patients. It suggested that the inflammatory injury related APC increased in MDS, but the antitumour immunity related APC did not . What found here might be one of the mechanisms involved in the pathogenesis of MDS.

[Differential study on the in vivo homing potential of human hematopoietic stem/progenitor cells from different sources in xenotransplanted NOD/SCID mouse model].

OBJECTIVE: To compare the in vivo homing potential of human hematopoietic stem/progenitor cells (HS/PCs) derived from fresh umbilical cord blood (UCB), cryopreserved UCB, mobilized peripheral blood (mPB) and bone marrow (BM) in xenotransplanted NOD/SCID mouse model, and to explore the relationship between the homing potential of HS/PCs and their expression levels of membrane receptor CXCR4. METHODS: The expression levels of membrane CXCR4 on HS/PCs were assessed by flow cytometric analysis (FACS). CFSE-labeled human HS/PCs from different sources were transplanted into irradiated NOD/SCID mice. Human CD34 cells home in bone marrow and spleen of recipient mice were determined 20 hours after xenotransplantation by FACS and the homing efficiencies were calculated. Tissue sections of the recipient mice femurs were made and the distribution of CFSE-labeled human CD34 cells were observed under fluorescence microscope. RESULTS: The expression levels of membrane CXCR4 on CD34+ cells from fresh UCB, cryopreserved UCB, mPB and BM were (49.52 +/- 1.12)%, (46.12 +/- 2.29)%, (48.50 +/- 2.48)% and (65.39 +/- 1.27)%, respectively. The homing efficiencies of CD34+ cells from fresh UCB, cryopreserved UCB, mPB and BM in recipient mice BM were (3.00 +/- 0.44)%, (2.84 +/- 0.46)%, (4.06 +/- 0.70)% and (5.76 +/- 0.52)% , respectively. Human CD34+ cells mainly located within endosteal region of recipient mice femurs. CONCLUSION: CD34+ cells from UCB express lower levels of membrane CXCR4 than those from mPB and BM. The level of membrane CXCR4 on UCB CD34+ cells is down-regulated after freezing and thawing procedures. The homing efficiency of human CD34 cells from UCB in recipient mice is lower than that of mPB and BM.

[Expressions of c-mpl proteins on CD34+ bone marrow cells and platelets of the patients with polycythemia vera].

The objective of this study was to investigate the expressions of TPO receptor (c-mpl) proteins on CD34 positive bone marrow cells (CD34+ BMCs), platelets and the expression of c-mpl mRNA in bone marrow cells of the patients with polycythemia vera (PV). The expressions of c-mpl proteins on CD34+ bone marrow hematopoietic cells of 13 PV patients and 15 normal controls were assessed by bicolor flow cytometry and the expressions of c-mpl proteins on platelets of 15 PV patients and 15 normal controls were assessed by monocolor flow cytometry, and the expressions of c-mpl mRNA in bone marrow hematopoietic cells (BMHCs) were assessed by RT-PCR. The results showed that no difference was found between the expression of c-mpl proteins on CD34+ BMHCs of PV patients (0.99% +/- 0.14%) and that of normal controls (0.92% +/- 0.12%) (p > 0.05). There was no difference too between the expression of c-mpl protein on platelets in PV patients (20.33% +/- 4.84%) and that in normal controls (23.50% +/- 3.64%) (p > 0.05). No difference between the expression of c-mpl mRNA in BMHCs of PV patients and that in normal controls was seen. In conclusion, the expressions of c-mpl proteins on CD34+ BMHCs, platelets and c-mpl mRNA in BMHCs of PV patients were not obviously abnormal.

Subtypes of B lymphocytes in patients with autoimmune hemocytopenia.

OBJECTIVE: To investigate the quantities of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia and the relationship between quantities of CD5+ B lymphocytes and clinical or laboratorial parameters. METHODS: Quantities of CD5+ B lymphocytes in the bone marrow of 14 patients with autoimmune hemolytic anemia (AIHA) or Evans syndrome, 22 immunorelated pancytopenia (IRP) patients, and 10 normal controls were assayed by flow cytometry. The correlation between their clinical or laboratorial parameters and CD5+ B lymphocytes was analyzed. RESULTS: The quantity of CD5+ B lymphocytes of AIHA/Evans syndrome (34.64% +/- 19.81%) or IRP patients (35.81% +/- 16.83%) was significantly higher than that of normal controls (12.00% +/- 1.97%, P < 0.05). However, there was no significant difference between AIHA/Evans syndrome and IRP patients (P > 0.05). In all hemocytopenic patients, the quantity of bone marrow CD5+ B lymphocytes showed significantly negative correlation with serum complement C3 level (r = -0.416, P < 0.05). In the patients with AIHA/Evans syndrome, the quantity of bone marrow CD5+ B lymphocytes showed significantly positive correlation with serum indirect bilirubin level (r = 1.00, P < 0.05). In Evans syndrome patients, the quantity of CD5+ B lymphocytes in bone marrow showed significantly positive correlation with platelet-associated immunoglobulin G (r = 0.761, P < 0.05) and platelet-associated immunoglobulin M ( r = 0.925, P < 0.05). The quantity of CD5+ B lymphocytes in bone marrow of all hemocytopenic patients showed significantly negative correlation with treatment response (tau-b = -0.289, P < 0.05) , but had no correlation with colony forming unit-erythroid (r = -0.205, P > 0.05) or colony forming unit-granulocyte-macrophage colonies (r = -0.214, P > 0.05). CONCLUSIONS: The quantity of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia significantly increases and is correlated with disease severity and clinical response, which suggest that CD5+ B lymphocytes might play an important role in the pathogenesis of autoimmune hemocytopenia.

Burden of abnormal hematopoietic clone in patients with myelodysplastic syndromes.

OBJECTIVE: To investigate the role of the burden of abnormal hematopoietic clone in the development of myelodysplastic syndromes (MDS). METHODS: The ratio of the bone marrow cells with abnormal chromosomes to the total counted bone marrow cells was regarded as the index of MDS clone burden. The disease severity related parameters including white blood cell count, hemoglobin, platelet count, lactate dehydrogenase level, bone marrow blast, myeloid differentiation index, micromegakaryocyte, transfusion, interleukin-2, tumor necrosis factor (TNF), CD4+ and CD8+ T cells of MDS patients were assayed, and the correlations between those parameters and MDS clone burden were also analyzed. RESULTS: The clone burden of MDS patients was 67.4% +/- 36.2%. MDS clone burden positively correlated with bone marrow blasts (r = 0.483, P < 0.05), negatively with hemoglobin level (r = -0.445, P < 0.05). The number of blasts, hemoglobin, and erythrocytes in high clone burden (> 50%) and low clone burden ( < or = 50%) groups were 7.78% +/- 5.51% and 3.45% +/- 3.34%, 56.06 +/- 14.28 g/L and 76.40 +/- 24.44 g/L, (1.82 +/- 0.48) x 10(12)/L and (2.32 +/- 0.66) x 10(12)/L, respectively (all P < 0.05). CD4+ T lymphocytes of MDS patients and normal controls were (0.274 +/- 0.719) x 10(9)/L and (0.455 +/- 0.206) x 10(9)/L, respectively (P < 0.05). CD8+ T lymphocytes of MDS patients and normal controls were (0.240 +/- 0.150) x 10(9)/L and (0.305 +/- 0.145) x 10(9)/L, respectively. The serum level of interleukin-2 of MDS patients (6.29 +/- 3.58 ng/mL) was significantly higher than normal control (3.11 +/- 1.40 ng/mL, P < 0.05). The serum level of TNF of MDS patients and normal control group were 2.42 +/- 1.79 ng/mL and 1.68 +/- 0.69 ng/mL, respectively. The ratio of CD4 to CD8 was higher in high clone burden MDS patients (1.90 +/- 0.52) than that in low clone burden patients (0.97 +/- 0.44, P < 0.05). CONCLUSION: The quantitive clonal karyotype abnormalities and deficient T cell immunity are important parameters for evaluating MDS severity and predicting its progression.

[The prognostic value of quantitative chromosomal abnormality in myelodysplastic syndromes].

OBJECTIVE: To investigate the prognostic value of quantitative chromosomal abnormality in myelodysplastic syndromes (MDS). METHODS: Chromosomal karyotypes in seventy-one MDS patients' were analyzed quantitatively. Based on the number of abnormal metaphase in 20 counted metaphases, the patients were divided into three groups: no abnormal karyotypes, abnormal metaphases less than or equal to five, and that more than five. The leukemia transformation rate, death rate and survival time between these three groups were compared. RESULTS: Forty-four cases (62.0%) had abnormal karyotypes. The incidences of abnormal karyotypes in RA, RCMD and RAEB were 76.9%, 55.8% and 75.0%, respectively, being no significant difference (P > 0.05). Among the abnormal karyotypes, complex abnormality with two or more abnormal karyotypes was most common and accounted for 47.7%. The frequencies of trisomy 8, monosomy 7 and del 20q were 18.2%, 4.5% and 4.5%, respectively. Other kinds of abnormal karyotypes totally accounted for 25%. There were 27 cases of group 1, 28 of group 2 and 16 of group 3. Eighteen cases (25.4%) transformed to acute leukemia. The incidences of leukemia transformation in group 1, 2 and 3 were 18.5%, 25% and 37.5%, and the death rates were 29.6%, 42.9% and 56.3%, respectively. The median survival times were 60, 47 and 24 months respectively. CONCLUSION: The quantitative chromosome abnormality has prognostic value in MDS.

[Study on the burden of abnormal hematopoietic clone of the patients with myelodysplastic syndromes and its implications].

OBJECTIVE: To investigate the abnormal hematopoietic clone burden of the patients with myelodysplastic syndromes (MDS) and its clinical implication. METHODS: The ratio of the metaphase with abnormal karyotypes to the total was regarded as the index of MDS clonal burden. Thirteen parameters were assayed and the correlations between these parameters and MDS clone burden were analysed. RESULTS: The clonal burden of MDS patients was (67.4 +/- 36.2)%. It correlated positively with bone marrow blasts (r = 0.483, P < 0.05), negatively with hemoglobin level (r = -0.445, P < 0.05). The number of blasts, hemoglobin and erythrocytes in high clonal burden (>50%) and low clonal burden (< or = 50%) groups were significantly different (P < 0.05). CD4+ T lymphocytes of MDS patients and normal controls were (274.18 +/-71.85) x 10(6)/L and (454.82 +/- 205.88) x 10(6)/L (P < 0.05) respectively. CD8+ T lymphocytes between MDS patients and normal controls had no difference. The serum level of IL-2 of MDS patients and normal control groups were (6.29 +/- 3.58) g/L and (3.11 +/- 1.40) microg/L (P < 0.05) respectively; but no difference in the serum level of TNF between MDS and control groups. The ratio of CD4+ to CD8+ in high clonal burden patients was 1.90 + 0.52, and in low clonal burden patients was 0.97 +/- 0.44 (P < 0.05). CONCLUSION: The clonal burden and deficient T cell immunity are the indicators for predicting MDS patients clinical progression.

[Expression of apoptosis-related proteins in bone marrow neutrophils of patients with paroxysmal nocturnal hemoglobinuria].

This study was aimed to evaluate expression levels of CD166, Fas and apoptosis-related proteins in bone marrow neutrophils of PNH patients and normal controls, and to analyze their correlation in order to explore whether exist apoptosis abnormality in BM neutrophils of PNH patients. The expression levels of CD16b, Fas and Bax, Bcl-2 in BM neutrophils of PNH patients and normal controls were assayed by flow cytometry; the difference of expression levels between patients and controls, and expression correlation between CD16b and apoptosis-related proteins were compared. The results showed that (1) the expression levels of CD16b on BM neutrophils of patients and controls were (20.36 +/- 9.05)% and (71.34 +/- 26.8)% respectively (P = 0.01); (2) the expression levels of CD95 on BM neutrophils of patients and controls were (62.83 +/- 32.11)% and (48.00 +/- 38.52)% respectively, there were no significant difference between CD95 expressions in BM neutrophils of PNH patients and controls and no significant correlation between expression of CD95 and CD16b on BM neutrophils of PNH patients (P > 0.05); (3) the expression levels of Bcl-2 in BM neutrophil cytoplasma of patients and controls were (8.64 +/- 5.40)% and (16.82 +/- 15.39)% respectively, there were no significant difference between Bcl-2 expression of patients and controls, and no significant correlation between the expression of Bcl-2 and CD16b in BM neutrophil cytoplasma of PNH patients (P > 0.05); (4) the expression levels of Bax in BM neutrophil cytoplasma of patients and control were (30.47 +/- 22.15)% and (48.47 +/- 15.99)% respectively, there were no significant difference between the Bax expressions of patients and controls, and no significant correlation between the Bax and CD16b expressions in BM neutrophil cytoplasma of PNH patients. In conclusion, BM neutrophils of PNH patients expressed apoptosis-related CD95, Bcl-2 and Bax without significant difference from the normal controls, and without significant correlation with the CD16b expression. It is suggested that the cell growth and decrease of PNH patients possibly are independent of abnormal apoptosis.

[The response of bone marrow hematopoietic cells to G-CSF in paroxysmal nocturnal hemoglobinuria patients].

OBJECTIVE: To study the response of hematopoietic cells (HSC) to granulocyte colony stimulating factor (G-CSF) in paroxysmal nocturnal hemoglobinuria (PNH) patients. METHODS: (1) Bone marrow mononuclear cells (BMMNC) from 17 PNH patients and 12 normal subjects were inoculated into semisolid culture media containing or not G-CSF (50 ng/ml). The cluster/colony forming unit-granulocyte/monocyte (CFU/cFU-GM) were counted and compared. (2) BMMNC of 20 PNH patients and 12 normal controls were triply stained for CD34, CD59 and G-CSF receptor CD114/stem cell factor receptor (C-KIT) CD117 and assessed by FCM. The CD34(+) cells were identified as CD34(+)/CD59(+) and CD34(+)/CD59(-). Percentage of CD114 and CD117 expression in each cell population was calculated. RESULTS: (1) PNH cFU-GM without G-CSF were (112.41 +/- 22.74)/10(5) BMMNC, while with G-CSF: (133.82 +/- 25.85)/10(5) BMMNC and normal cFU-GM were (190.33 +/- 36.05)/10(5) BMMNC, (309.42 +/- 92.94)/10(5) BMMNC, respectively. Whether with or without G-CSF, PNH BMMNC formed less cFU-GM than control did, both of the two kinds of BMMNC responded to G-CSF well (P < 0.05), but the increment of PNH cFU-GM yields was less than that of the normal control (P < 0.05). CFU-GM yields of PNH BMMNC without G-CSF were (24.29 +/- 9.05)/10(5) BMMNC, with G-CSF were (27.53 +/- 10.65)/10(5) BMMNC, while normal control were (77.42 +/- 36.01)/10(5) BMMNC and (98.00 +/- 43.14)/10(5) BMMNC, respectively. Whether with or without G-CSF, PNH BMMNC showed less CFU-GM yields than that of control (P < 0.05). (2) The percentage of CD114 positive cells in PNH CD34(+)CD59(+) BMMNC was (73.34 +/- 29.40)% and that in PNH CD34(+)CD59(-) BMMNC and in control CD34(+)CD59(+) BMMNC were (32.70 +/- 6.89)% and (58.52 +/- 29.99)%, respectively. The percentage of CD114 expression in PNH CD34(+) CD59(-) BMMNC was less than that in the other two groups (P < 0.05). The percentages of CD117 positivities on the PNH CD34(+)CD59(+) BMMNC were (76.90 +/- 22.08)%, PNH CD34(+) CD59(-) (36.03 +/- 7.69)% and control CD34(+) CD59(+) (80.28 +/- 13.36)%, respectively (P < 0.01). CONCLUSION: In vitro, BMMNC of normal control grow better, and respond better to G-CSF than PNH BMMNC do. PNH CD34(+)CD59(-) BMMNC express less G-CSF receptor and C-KIT than PNH CD34(+)CD59(+) and normal CD34(+)CD59(+) BMMNC do, which may be the reason that abnormal PNH clone grow worse than the normal clones do.

[Expression of cell cycle control genes in myelodysplastic syndromes].

OBJECTIVE: To study aberrant expression of cell cycle control genes in patients with myelodysplastic syndromes (MDS). METHODS: Reverse transcription polymerase chain reaction (RT-PCR) was used to investigate the expression of cell cycle control genes (cyclin D2, cyclin D3, cyclin A1, cyclin E, CDK2, CDK4, CDK6, p21, p27, p57, Rb and E2F1) in bone marrow mononuclear cells (BMMNCs) from 29 normal control, 27 MDS and 19 de novo acute myeloid leukemia (AML). RESULTS: The expression levels of cyclin D3 (0.65 +/- 0.17, P < 0.05) and cyclin A1 (0.48 +/- 0.04, P < 0.05) in MDS were higher than those in normal control and significantly lower than those in AML. The expression rates and levels of cyclin D2 (40.7% and 0.78 +/- 0.21) and cyclin E (51.9% and 0.52 +/- 0.10) in MDS were statistically higher than those in normal control and AML. The expression level of CDK2 in MDS (0.66 +/- 0.19, P < 0.01) was higher than that in normal control (0.42 +/- 0.04) and the expression rate of CDK6 in MDS (25.9%) higher than in normal control (3.4%, P < 0.05). There was no significant difference of the expression rates and levels of CDK4 in MDS, AML and normal control. The expression rates and levels of p21 (77.8% and 1.18 +/- 0.21) and p27 (48.1% and 1.14 +/- 0.40) in MDS were statistically higher than those in normal control and AML. The expression level of p57 in MDS (0.69 +/- 0.06) was higher than that (0.53 +/- 0.05, P < 0.01) in normal control but lower than in AML (0.96 +/- 0.16, P < 0.01). The expression rate (55.6%) and level (0.85 +/- 0.17) of Rb in MDS were significantly higher than those in normal control and AML. The expression rate (7.4%) and level (0.39 +/- 0.04) of E2F1 in MDS were comparable to those in normal control but lower than those in AML. CONCLUSION: MDS clones have aberrant mechanism of cell cycle control: high expressions of cyclin family members, CDK2 and CDK6 may lead to high proliferation; high expression of p21 and p27 may cause the G1 phase arrest.

[Study of Th cell subsets in bone marrow of myelodysplastic syndromes patients].

OBJECTIVE: To study the quantity and ratio of Th1, Th2 cells in the bone marrow of myelodysplastic syndromes (MDS) patients, and to evaluate the correlation between the ratio of the blast cells and the number of the Th1 cells in the bone marrow of MDS patients. METHODS: By FACS, the quantity and ratio of IFN-gamma producing CD4(+) T cell (Th1) and IL-4 producing CD4(+) T cell (Th2) cells in the bone marrow were detected in 21 MDS patients, 18 normal controls and 13 severe aplastic anemia (SAA) patients respectively. The karyotypes of 18 MDS patients and 15 normal controls were assayed. The correlation between the ratio of the blast cells in the bone marrow and the number of the Th1 cells in the MDS patients were analyzed. RESULTS: The percentages of Th1 cells, Th2 cells and ratio of Th1/Th2 in the bone marrow of normal controls were (0.48 +/- 0.10)%, (0.24 +/- 0.19)% and 2.31 +/- 0.76 respectively, while those of the MDS patients were (0.36 +/- 0.11)%, (0.76 +/- 0.35)% and 0.51 +/- 0.13. The percentage of Th1 cells of patients with MDS was reduced and the Th1/Th2 ratio was significantly lower than that of normal controls (P < 0.01). Those of the patients with SAA were (4.75 +/- 0.49)%, (0.40 +/- 0.28)% and 26.5 +/- 8.79 respectively, their Th1 cells and Th1/Th2 ratio were markedly higher than those of normal controls (P < 0.01). In all of the 15 normal controls the karyotypes were normal, but that of MDS patients was (50.00 +/- 0.10)%. The lower ratio of the Th1 cells in the bone marrow of the patients with MDS and the AML which progressed from MDS was negatively correlated with the higher percentage of the blast cells (r = -0.563, P < 0.01). CONCLUSIONS: (1) The immune function of T lymphocytes in MDS is abnormal: the balance between Th1 and Th2 cells is broken. (2) With descending of the number of Th1 cells in the bone marrow of the MDS patients, the disease is progressing to leukemia.

[Isolation of single chain antibodies against cell surface molecules by pathfinder selection].

OBJECTIVE: To isolate single chain antibody fragments (scFv) against cell surface molecules by pathfinder selection from an anti-KG1a cell scFv phage library. METHODS: The anti-KG1a scFv library was enriched by KGla cell panning for three rounds, or unenriched, then processed for pathfinder selection respectively using anti-CD34 monoclonal antibody as pathfinder molecule. ScFv phage clones were randomly picked and identified by binding KG1a cells using immunofluorescein and flow cytometry. The KG1a+ clones were further identified by KG1a, HL60, U937, and CEM cell lines and ELISA. Their antigenic molecules on cell surface were digested by chymopapain and analyzed by flow cytometry. DNAs from ten positive clones were sequenced. The scFv clones with different primary structure were used to analyze the molecular weight of their antigens by Western blot. RESULTS: One hundred and two KG1a+ scFv phage clones were isolated from 144 enriched and 96 unenriched scFv phage library respectively, among which 47 bound KG1a, HL60, U937, and CEM cells, 55 bound KG1a cells exclusively. None of 28 KG1a+, HL60-, U937-, and CEM- scFv clones bound to the CD34 antigen, as confirmed by ELISA, although most of their antigens were sensitive to chymopapain digestion. DNA sequences from ten positive clones showed that they were from four different clones. They bound antigens with different molecular weight. CONCLUSIONS: One hundred and two scFv phage clones specific for hematopoietic stem and progenitor cells have been isolated from an anti-KG1a cell scFv phage library. The pathfinder selection has showed advantages to improve the screening efficacy of scFv phage clones against antigens, which present at very low densities on the cell surface.

[Apoptosis and proliferation of CD34 positive bone marrow cells in patients with polycythemia vera].

OBJECTIVE: To study the apoptosis and proliferation of CD(34) positive (CD(34)(+)) bone marrow cells (BMC) in patients with polycythemia vera (PV). METHODS: The expression of Annexin V and Ki67 of the CD(34)(+) BMC in 20 PV patients and control cases [10 essential thrombocythemia (ET), 12 normal persons] were assessed by bicolor flow cytometry (FCM), and the correlation between apoptosis and clinical situation was analysed in PV patients. RESULTS: The Annexin V expressions of CD(34)(+) BMC were (15.96 +/- 1.45)% in PV patients and (15.53 +/- 1.76)% in ET patients which were lower than that in normal subjects [(23.61 +/- 3.89)%, (P < 0.05)]. The Ki67 expression of CD(34)(+) BMC was (48.79 +/- 11.68)% in PV patients and (49.60 +/- 9.98)% in ET patients, which were significantly higher than that in normal controls (33.87 +/- 6.82)%. The ratio of apoptosis/proliferation in PV patients was 0.33 +/- 0.10 and in ET patients 0.32 +/- 0.02 which were significantly lower than that in normal controls 0.72 +/- 0.11 (P < 0.01). The apoptosis of CD(34)(+) BMC was negatively correlated with the hemoglobin (Hb) levels (r = -0.481, P = 0.037), white blood cells (WBC) (r = -0.538, P = 0.026) and the numbers of endogenous erythroid colony (EEC) (r = -0.632, P = 0.50), and the ratio of apoptosis/proliferation was negatively correlated with the Hb (r = -0.537, P = 0.018) and WBC (r = -0.667, P = 0.003) in PV patients. CONCLUSION: There were lower apoptosis and higher proliferation in CD(34)(+) BMC of PV patients. Lower apoptosis was correlated with the severity of the disease.

[Preliminary study of DA or HA regimen chemotherapy for the treatment of refractory and relapsed paroxysmal nocturnal hemoglobinuria].

OBJECTIVE: To observe the efficacy and side effect of DA/HA regimen chemotherapy for the treatment of refractory and relapsed paroxysmal nocturnal hemoglobinuria (PNH). METHODS: Eight patients with refractory and relapsed PNH were treated with DA/HA regimen chemotherapy. Three patients were treated with DA (DNR 40 mg/d, i.v.drip, the first and the second day; 20 mg/d, i.v.drip, the third day; Ara-C 100 mg/d, i.v.drip, for 5 days) and 5 patients with HA (HHT 2 - 3 mg/d, i.v.drip, for 5 days; Ara-C 100 mg/d, i.v.drip, for 5 days). RESULTS: All the 8 patients responded well: the PNH clone was diminished in five patients. Hemolysis was remitted in 6 cases. Five patients showed improvement in hematological parameters. The dosage of corticosteroid was decreased in all of them. No serious side effect was revealed. CONCLUSION: DA/HA regimen chemotherapy was safe and effective for refractory and relapsed PNH patients.