Effect of Montelukast on T-lymphocyte subsets and advanced oxidation protein products in immune thrombopenic purpura model mice / 中国免疫学杂志

Objective:To investigate the effect of Montelukast on T-lymphocyte subsets, cytokines and advanced oxidation protein products ( AOPP ) in immune thrombopenic purpura ( ITP ) model mice. To analyze the principle of the treatment by Montelukast. Methods: Forty ITP mice were randomly divided into control group,model group,Montelukast low dose group(3 mg/kg) and Montelukast high dose group(12 mg/kg). ITP model mice were successive administration for 14 days after building models for 7 days. Platelet counts,the index of thymus and spleen were calculated. T-lymphocyte subsets were detected by flow cytometry. IL-6,TNF-α,AOPP were detected by enzyme linked immunosorbent assays. Results: Comparison with control group,the PLT,thymus index and spleen index,CD8+,IL-6,TNF-α,AOPP of model group mice were significantly increased (P＜0. 05) while CD3+,CD4+,CD4+/CD8+were significantly decreased (P＜0. 05). Comparison with model group,PLT,thymus index and spleen index,CD8+,IL-6,TNF-α,AOPP of low dose group and high douse group mice were significantly decreased (P＜0. 05) while CD3+,CD4+,CD4+/CD8+were significantly increased (P＜0. 05). Conclusion: Montelukast can cure ITP regulate immune disorders,eliminate accumulation of AOPP and reduce level of IL-6 and TNF-α.

One Case of Multiple Myeloma with Central Never System Infiltration / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To analyses and summarize a case of multiple myeloma with disseminated infiltration in central nervous system.</p><p><b>METHODS</b>The results of laboratorial examination and clinical data were analyzed and compared in the light of published literatures.</p><p><b>RESULTS</b>The headache and diplopia were caused by infiltration of multiple myeloma cells to the central nervous system. Unlike those reported in the literatures, this case was a rare case of disseminated infiltration inside the brain, and plasma cells were CD56+, this patient has not yet accepted any multiple myeloma-associated treatment as like that reported in the literatures. And different from cases reported, this patient showed a good response to the intrathecal chemotherapy.</p><p><b>CONCLUSION</b>Whether this good response is due to a heterogeneity of MM or effect of treatment-associated drug is still to be decided.</p>

BMMSC from blastic phase CML down-regulate leukemia cell apoptosis / 中国实验血液学杂志

The purpose of this study was to investigate the effect of bone marrow mesenchymal stem cells (BMMSC) from patients with chronic myeloid leukemia (CML) in blastic phase (Bp) on K562 cells and the primary CML-Bp cells, and to explore its potential mechanisms. K562 cells and primary CML-Bp cells were co-cultured with BMMSC of different groups; the cell proliferation was detected by MTT method, the cell apoptosis rate and mitochondrial membrane potential were measured by flow cytometry, the expression levels of Caspase-8, Caspase-9, and activated Caspase-3 in cells were measured by Western blot. The results showed that the CML-Bp BMMSC could enhance the survival rate of K562 cells treated with adviamycin (ADM) and display protective effect on K562 cells and primary CML-Bp mononuctear cells, inhibited ADM-induced leukimia cell apoptosis (P < 0.05); as compared with CML-chronic phase (CML-Cp) BMMSC and normal BMMSC, the CML-Bp BMMSC showed the highest protective effect on leukemic cells, the mitochondrial membrane potential of co-cultured cells slightly droped (P < 0.05). In the CML-Bp BMMSC cultured with K562 cells, the expression level of caspase-3 was more down-regulated than that in K562 alone plus ADM group, while the expression of caspase-9 significantly increased (P < 0.05). It is concluded that the CML-Bp BMMSC down-regulates ADM-induced leukemia cell appoptosis, its mechanism may relate with the inhibition of mitochondrial membrane potential drop, the stabilization of unactive expression of caspase-9 and down-regulation of caspase-3 expression.

MNPs-Fe₃O₄mediates malignant Hematolpoectic cell apoptosis / 中国实验血液学杂志

This study was purposed to evaluate whether the safe concentration of magnetic nanoparticles of Fe₃O₄(MNPs-Fe₃O₄) for monocytes could induce the SKM-1 cell apoptosis. The average size and Zeta potential of MNPs-Fe₃O₄were determined by transmission electron microscopy and the Malvern Zetasizer 3000 HS, respectively. The cell viability after being exposed to MNPs-Fe₃O₄for 12, 24, 48, and 72 hours was detected by using cell count Kit-8. The cell apoptosis was evaluated by flow cytometry with Annexin V/PI double staining and Wright-Giemsa staining. The cell cycle was measured by flow cytometry. The levels of active caspase-3, survivin and bcl-rambo in cells treated with MNPs-Fe₃O₄and/or trolox for 48 hours were detected with Western blot. The results showed that the cell viability decreased in SKM-1 cells after exposure to 50 µmol/L and 100 µmol/L MNPs-Fe₃O₄(P < 0.05), but did not in monocytes (P > 0.05), compared with that of each non-MNPs-Fe₃O₄-treated group. This exposure also induced the SKM-1 cells to be arrested in G0/G1. Annexin V/PI staining assay showed that cell apoptotic rate induced by 100 µmol/L MNPs-Fe₃O₄was significantly high in SKM-1 cells while not so high in monocytes, and the pretreatment with trolox could attenuate the apoptosis. Moreover, the active caspase-3 increased in SKM-1 cells after the exposure to MNPs-Fe₃O₄, while that was not in monocytes, and the increased expression of BCL-rambo and the decreased expression of survivin involved in the process were also observed. It is concluded that MNPs-Fe₃O₄can induce the caspase 3-dependent SKM-1 cell apoptosis by increasing the BCL-rambo expression and decreasing the survivin expression, but this cytotoxic effect can not be observed in monocyte's.

Preliminary study on the effect of TRAIL on adhesion and apoptosis of multiple myeloma cell line RPMI8226 and its mechanism / 中国实验血液学杂志

The present study was purposed to investigate the inhibition effect of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) on growth of RPMI8226 cells and adhesion between RPMI8226 cells and bone marrow stroma cells (BMSC), and to explore its mechanism as well. The inhibition effects of TRAIL on cells growth and adhesion were assayed by MTT; cell apoptosis was detected by Annexin V and PI; expression of genes bax, bcl-2, mcl-1, CARP1, CARP2, XIAP and cFLIP were determined by semi-quantitative RT-PCR; apoptosis-related protein expression was detected by Western blot. The results showed that TRAIL inhibited the proliferation of RPMI8226 cells in dose- and time-dependent manners. TRAIL induced apoptosis in RPMI8226 cells, the expression level of genes bcl-2, mcl-1, CARP1, CARP2, XIAP and cFLIP decreased, while the expression level of Bax increased, but the expression level of caspase-3 and NF-kappaB P65(RelA) proteins decreased. Moreover, TRAIL up-regulated the expression level of adherent molecule CXCR4 in RPMI8226 cells significantly. It is concluded that TRAIL up-regulated the expression level of adherent molecule CXCR4 in RPMI8226 cells significantly, and induced the apoptosis of RPMI8226 cells. Growth inhibition effect of TRAIL on RPMI8226 cells is in dose- and time-dependent manners.

Effect of a methylation inhibitor 5-aza-2'-deoxycytidine on SHP-1 gene expression, proliferation and apoptosis in K562 cells / 中国实验血液学杂志

The aim of this study was to investigate the regulation of 5-aza-CdR on transcription of SHP-1 gene and effects on the proliferation and apoptosis of K562 cells. Methylation-specific PCR (MSP) was used to detect CpG island methylation in SHP-1 promoter. MTT and flow cytometry were used to detect the growth and apoptosis of K562 cells after treatment with different concentration of 5-aza-CdR. The expressions of SHP-1 mRNA and protein were determined by FQ-PCR and Western blot. The expression of p-JAK2 was assayed by Western blot. The result showed that methylation of SHP-1 gene promoter was detected in K562 cells, and the SHP-1 mRNA and protein were expressed again in K562 cells after treatment with 5-aza-CdR, meanwhile the expression of phosphorylated P-JAK2 was down-regulated; 5-aza-CdR significantly inhibited the cell growth in dose and time dependent manners. AG490 inhibited the cell proliferation. 5-aza-CdR increased the apoptosis rate of K562 cells also in dose- and time-dependent manners. The apoptosis rates of K562 cells treated with 5-aza-CdR for 1, 3 and 5 days were 9.3%, 24.2% and 37.7% respectively. After treatment with 2 micromol/L 5-aza-CdR for 24 hours, cells in G(0)/G(1) phase increased gradually, cells in G(2)/M phase decreased gradually, cells were arrested in G(0)/G(1) phase. The cell ratios in G(2)/M phase at 1, 3 and 5 days after treatment with 5-aza-CdR were 30.7%, 23.45 and 19.3% respectively. It is concluded that the 5-aza-CdR, inhibitor of specific methylation transferase, can re-express the silent SHP-1 gene in K562 cells, inhibits the proliferation of leukemia cells and induces cell apoptosis by activating JAK/STAT pathway.

Construction of expression plasmid for fused idiotypic DNA vaccine of B-cell lymphoma / 中国实验血液学杂志

The idiotypic determinant of surface immunoglobulin of B-cell lymphoma, as a tumor-specific antigen, has proved to be able to induce immune responses. To analyze whether an idiotypic vaccine fused with cytokine can elicit more effectively protective antitumor immunity, an eukaryotic expression plasmid was constructed, which encoded the fusion gene of single-chain variable fragment as a tumor specific antigen against B-cell lymphoma with monocyte chemotactic protein-3 (MCP3) as immunogen to elicit T-cell-dependent protective antitumor immunity, and EGFP (Enhanced Green Fluorescent Protein) gene as a marker to trace the survival, growth, differentiation and expression of the former exogenetic genes. The cDNAs for immunoglobulin (Ig) VH and IgVL were amplified by RT-PCR and assembled into the single-chain variable fragment (scFv) connected with a (Gly(4)Ser)(3) linker by recombinant PCR method. Then, the fragments of scFv and MCP3 were ligated with a NDAQAPKS spacer by the same method. The results showed that the fusion genes of scFv and MCP3-scFv were inserted into an eukaryotic expression vector pTARGET, and EGFP was cloned into the downstream of scFv and MCP3-scFv respectively. Finally the constructed plasmids were confirmed by sequencing and restriction analysis. In conclusion, a tumor-derived idiotypic DNA vaccine, encoding the fusion gene of single-chain variable fragment and monocyte chemotactic protein-3 (MCP3) to elicit a T-cell dependent, antitumor immunity, and the EGFP gene was inserted correctly. The DNA vaccine could be used for further study of DNA vaccine against B cell lymphoma in vivo.

Apoptosis of the adriamycin-resistant leukemia cell line induced by the recombinant mutant human TNF-related apoptosis-inducing ligand combined with arsenic trioxide / 中国实验血液学杂志

This study was aimed to investigate the effect of recombinant mutant human TNF-related apoptosis-inducing ligand (rmhTRAIL) combined with As(2)O(3) on inducing apoptosis of adriamycin-resistant leukemia cell line K562/A02 (mdr-1(+)). The morphologic changes of cells treated with rmhTRAIL were observed by inverted microscope, taking adriamycin-sensitive cell line K562 (mdr-1(-)) as control; the inhibitory rate of cell proliferation after being treated with rmhTRAIL, As(2)O(3) alone or combined was assayed by MTT method; the apoptosis peaks of K562/AO2 and K562 were quantitatively detected by flow cytometry with PI staining after being treated with rmhTRAIL, As(2)O(3) alone or in combination. The results indicated that the inhibition effect of rmhTRAIL and As(2)O(3) in combination on K562/AO2 and K562 cells was higher than that of riTRAIL and As(2)O(3) alone (p < 0.01), rmhTRAIL combined with As(2)O(3) had synergistic effect in killing K562/AO2 and K562 cells by king's formula. The apoptosis rates of K562/AO2 and K562 cells were 34.93 +/- 0.10% and 10.53 +/- 0.16% (p < 0.01), as well as 5.95 +/- 0.07%, and 3.50 +/- 0.01% (p < 0.05), 50.95 +/- 0.91% and 20.75 +/- 0.95% (p < 0.05) respectively when their cells were treated by rmhTRAIL and As(2)O(3) alone. The apoptosis rate in K562/AO2 group was higher than that in K562 group. It is concluded that rmhTRAIL can induce K562/A02 and K562 cell apoptosis; rmhTRAIL combined As(2)O(3) had synergistic effects; the efficacy of on rmhTRAIL or As(2)O(3) inducing K562/AO2 cell apoptosis is higher than that on their parental cell line K562.

Immunoglobulin D lambda multiple myeloma: a case report / 中国实验血液学杂志

To improve the recognition of immunoglobulin D multiple myeloma and explore its clinical feature and laboratory examination characteristics, so as to reduce the the missed diagnosis and misdiagnosis, a case of IgD multiple myeloma (MM) with myelofibrosis and bone marrow necrosis is reported. The clinical feature, treatment and prognosis of IgDlambda MM were discussed. Immunoglobulin D multiple myeloma is a rare disease and predominantly occurs in young male patients, which shows an aggressive clinical course with poor response to conventional treatment and unfavorable prognosis. Immunoglobulin D multiple myeloma was usually misdiagnosed as a light chain type multiple myeloma by using routine laboratory examination. Immunoglobulin D monoclonal protein is not easy to be detected owing to its low protein level, resulting in missed diagnosis. Immunofixation electrophoresis is highly sensitive and specific for diagnosis of IgD MM, can enhance accuracy of diagnosis for this rare disease.

Angioimmunoblastic T-cell lymphoma with autoimmune hemolytic anemia and pure red cell aplasia / 中国实验血液学杂志

Angioimmunoblastic T-cell lymphoma (AILT) is a peripheral T-cell lymphoma often complicated autoimmune phenomena such as autoimmune cytopenia, and is a truly rare type of NHL. In order to investigate the clinical features, pathological manifestation of this lymphoma, and to explore its therapy protocol, a 37-years old patient with AILT was investigated. The routine blood examination, bone marrow smear, lymphonodus biopsy, Coombs test, flow cytometry for bone marrow mononuclear cells, serological test, immunochemistry method etc were performed for this patient. The results showed that the systemic lymphadenectasis and hepatosplenomegaly were seen in patient, the cervical lymphonode biopsy revealed AITL. The hematoglobin level and number of reticulocytes were very low. Coombs test was positive. Simultaneously, the bone marrow aspirate revealed erythroid aplasia. The warm type autoimmune hemolytic anemia (AIHA) and pure red cell aplasia (PRCA) were co-existed. After one course of chemotherapy with CHOP-E, infiltration sign of AITL patient with AIHA and PRCA disappeared. In conclusion, the AITL patient complicated with AIHA and PRCA was successfully diagnosed, the lymphonode biopsy and bone marrow smear showed more significant, the chemotherapy protocol of CHOP-E can give some effect to cure such angioimmunoblastic T cell lymphoma.

Expression and clinical value of SHP-1 and c-kit in acute leukemia / 中国实验血液学杂志

The aim of study is to investigate the expression of hematopoietic cell phosphatase (SHP-1) gene and c-kit pro-oncogene in acute leukemia (AL) and its impact on prognosis in AL. Semi-quantity reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the expression of SHP-1 mRNA and c-kit mRNA in 60 AL patients and 33 normal controls (NC). The results showed that the positive rates of SHP-1 expression from high to low level were found orderly in complete remission group, newly diagnosed group and relapsed group, there was significance difference between each group and NC group (P < 0.05). The positive rates of c-kit expression were opposite order in each groups as compared with SHP-1. there was also significance difference between each group and NC group (P < 0.05). The positive rate of SHP-1 and c-kit expressions in AML was higher than that in ALL (P < 0.05), there was negative correlation between expressions of SHP-1 and c-kit (r = -0.502, P < 0.05); The difference between the complete remission rate in SHP-1 positive and in SHP-1 negative patients from 30 newly diagnosed AML patients was significant (P < 0.05), the same result was found between c-kit(+) complete remission and c-kit(-) complete remission. It is concluded that SHP-1 gene is a potentially anti-oncogene and inhibits the growing of tumor by negatively modulating c-kit gene. Simultaneous detection of SHP-1 and c-kit gene may act as a factor for predicting prognosis in AL.

Combined effect of recombinant mutant human TRAIL and daunorubicin in inducing apoptosis of leukemia cell and its mechanism / 中国实验血液学杂志

The aim of study was to investigate the combined effect of recombinant mutant human TRAIL (rmhTRAIL) with daunorubicin (DNR) or alone on K562 and U937 leukemia cell lines and its mechanism. The fibroblasts (MRC-5) of normal-human embryonic lung were used as control cells. After being treated with rmhTRAIL and DNR or only with rmTRAIL, the cytotoxic effect and the apoptosis rate in K562, U937 cells were measured by MTT assay. The expression levels of TRAIL death receptor and TRAIL decoy receptor mRNA in these three cell lines were assayed by semiquantitive RT-PCR before and after treatment with DNR. The results indicated that K562 and U937 were sensitive to rmhTRIAL. DNR had synergistic inhibitory effect with rmhTRAIL on the growth of K562 and U937 cell lines (P < 0.05). The expression level of DR4 and DR5 mRNA was significantly higher in K562 and U937 with combined treatment of rmhTRAIL and DNR than that in those alone, while the expressions of DcR1 and DcR2 mRNA were not influenced. It is concluded that in vitro, rmhTRAIL alone or in combination with DNR can obviously inhibit the growth of leukemia cell lines and induce cell apoptosis, DNR and rmhTRAIL have a synergistic inhibitory effect on growth of K562 and U937. The mechanism may correlate with the up-regulation of DR4 and DR5 of K562 and U937.

Construction and expression of a prokaryotic expression plasmid of idiotypic vaccine against B cell lymphoma: encoding the fusion genes of single-chain variable fragment and MCP-3 / 中国实验血液学杂志

The aim was to construct a prokaryotic expression plasmid encoding the fusion gene of single-chain variable fragment and monocyte chemotactic protein-3 (MCP-3). The cDNAs of immunoglobulin (Ig) VH and Ig VL were amplified by RT-PCR and assembled into the single-chain variable fragment (scFv) by recombinant PCR method. The cDNAs of Ig VH and Ig VL were connected by a (Gly4Ser)3 linker. Then, the fragments of scFv and MCP-3 were connected with a NDAQAPKS spacer, using recombinant PCR method again. The results indicated that the fusion gene of scFv-MCP-3 were constructed correctly and cloned into the prokaryotic expression plasmid successfully identified by sequencing and restriction endonucleases examination. Finally, the fusion protein was expressed in E coli DH5alpha under induction by arabinose. And the fusion protein was 65 kD and account for 30% of the total protein of the bacteria. In conclusion, a prokaryotic plasmid, encoding the fusion gene of single-chain variable fragment with MCP-3 and expressing idiotype protein vaccination against B cell lymphoma, was constructed correctly.

A case of hepatosplenic gammadelta T cell lymphoma / 中国实验血液学杂志

Hepatosplenic gammadelta T cell lymphoma represents rare, often aggressive type of malignant peripheral T-cell lymphoma, which is characterized by expressing T-cell-associated markers CD2, CD3 and gammadelta T-cell receptor, and nonactivated cytotoxic cell phenotype (TIA-1+, granzyme B-). The pathological findings of a liver biopsy specimen revealed the diffuse infiltration of lymphocytes in the sinusoids and the aspiration biopsy from spleen revealed the diffuse infiltration of lymphocytes in the red pulp, not shaped to the nodes, often resulted in the misdiagnosis. Recently, by analyzing the immunophenotype and TCR rearrangement from liver, spleen and bone marrow, a case of adult hepatosplenic gammadelta T cell lymphoma was diagnosed. In combination with references, It is belived that immunophenotype and TCR rearrangement are necessary means to diagnosis hepatosplenic gammadelta T cell lymphoma.

Mutation analysis of SHIP gene in acute leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>The SH2 domain containing inositol 5'-phosphatase (SHIP) is predominately expressed in hematopoietic cells, and is a crucial negative regulator in the development of hematopoietic cells. This paper is to evaluate the role of the SHIP gene in human leukemogenesis.</p><p><b>METHODS</b>Expression of SHIP gene in bone marrow and/or peripheral blood from 32 patients with acute myeloid leukemia (AML), 9 with acute lymphoblastic leukemia (ALL), as well as human hematopoietic cell lines was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), single strand conformational polymorphism (SSCP) and DNA sequencing.</p><p><b>RESULTS</b>RT-PCR showed that all samples expressed SHIP gene. Mutations of SHIP gene were detected in 7 (22%) of 32 AML patients and one (12%) of 9 ALL patients. Interestingly, two missense mutations that had been observed in a AML patient at diagnosis disappeared after complete remission (CR). In addition, in vitro Akt phosphorylation was prolonged and increased following IL-3 stimulation of this patient's cells.</p><p><b>CONCLUSION</b>Our data demonstrate for the first time the mutation of SHIP gene in acute leukemia and suggest a possible role of the mutation of this gene in the development of acute leukemia. SHIP may serve as a tumor suppressor by negatively regulating the PI3K/Akt signaling pathway in hematopoietic cells.</p>

Mutation analysis of hematopoietic cell phosphatase gene in acute leukemia / 中国实验血液学杂志

The hematopoietic cell phosphatase (HCP or SHP-1), the SH2 domain contain protein tyrosine phosphatase, is a crucial negative regulator in the process of hematopoietic cell development, proliferation and receptor-mediated mitogenic signaling pathways, and its mutation is responsible for the over-expansion and inappropriate activation of myelomonocytic population in motheaten mice. The aim of the study was to evaluate the role of the HCP gene in leukemogenesis. Bone marrow and/or peripheral blood from 32 acute myeloid leukemia (AML) patients, 9 acute lymphocytic leukemia (ALL) patients, 8 leukemia cell lines and 50 normal controls were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) based on single strand conformation polymorphism (SSCP) and sequencing. RT-PCR showed that all samples expressed HCP gene, only one missense mutation at codon 225 (AAC to AGC, Asn to Ser) within N-terminal SH2 domain was found in an ALL patient. In addition, four polymorphic base substitutions were detected in codon 69, 85, 86 and 266, respectively. In conclusion, mutation of HCP gene is an infrequent genetic aberration which may only play a role in pathogenesis of a small part of leukemia, however, its significance needs to be further clarified.

In vitro effects of mevastatin on the proliferation and apoptosis in human multiple myeloma cell line U266 / 中国实验血液学杂志

In order to investigate the anti-tumor activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and the mechanism underlying the cell proliferation and apoptosis modulated in myeloma cells, the effects of mevastatin, an HMG-CoA reductase inhibitor, on cell growth, cell cycle progression and apoptosis in U266 human multiple myeloma (MM) cell line in vitro were explored by MTT colorimetric assay, morphologic observation, flow cytometry, DNA gel electrophoresis, and RT-PCR. The results demonstrated that mevastatin inhibited the growth of U266 cells in time- and dose-dependent manners. Cell cycle analysis showed that U266 cells underwent G(0)/G(1) arrest under exposure to mevastatin, but it did not affect p27 expression at both mRNA and protein level. Morphologic observations revealed cytoplasm shrinkage, nuclear condensation and fragmentation in mevastatin-treated cells, and fraction of annexin V(+)PI(-) cells increased significantly in the presence of the agent as determined by flow cytometric assay. In addition, mevastatin caused the collapse of mitochondrial transmembrane potential (Deltapsim), induced DNA fragmentation, and down-regulated the mRNA expression of bcl-2. The growth-inhibitory, cell cycle arresting, and proapoptotic effects of mevastatin in U266 cells could be effectively reversed by the addition of mevalonate (MVA), the immediate endproduct of the reaction catalyzed by HMG-CoA reductase. It is concluded that mevastatin suppresses proliferation by inducing G(0)/G(1) phase arrest and triggering apoptosis via down-regulation of bcl-2 and reduction of Deltapsim, which may be attributed to the inhibition of MVA pathway by mevastatin. Statins including mevastatin may find their future application in the treatment of MM.

Mutation analysis of SHIP gene in acute leukemia / 中国实验血液学杂志

The SH2 domain containing inositol 5'-phosphatase (SHIP) was initially described as a 145 kD protein phosphorylated on tyrosines upon growth factor and cytokine stimulation. SHIP is predominately expressed in hematopoietic cells, and is a crucial negative regulator in the development of hematopoietic cells. To evaluate the role of the SHIP gene in human leukemogenesis, expression and mutation of SHIP gene in bone marrow and/or peripheral blood from 32 patients with acute myeloid leukemia (AML), 9 patients with acute lymphoblastic leukemia (ALL), as well as human hematopoietic cell lines were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), single strand conformational polymorphism (SSCP) and sequencing. The RT-PCR showed that all samples expressed SHIP gene. Mutations of SHIP gene were detected in 7 out of 32 AML patients (22%) and one out of 9 ALL patients (12%). Interestingly, two missense mutations that had been observed in one AML patient at diagnosis disappeared after complete remission (CR). In addition, Akt phosphorylation was prolonged and increased following IL-3 stimulation in this patient sample. In conclusion, data of this study demonstrate the mutation of the SHIP gene in acute leukemia for the first time and suggest a possible role of the mutation of this gene in the development of acute leukemia. SHIP serves as a tumor suppressor by negatively regulating the PI3K/Akt signaling pathway in hematopoietic cells.

mitochondrial ceramidase overexpression up-regulates Bcl-2 protein level in K562 cells, probably through its metabolite sphingosine-1-phosphate / 中国实验血液学杂志

Recently, a mitochondrial ceramidase has been identified and cloned, whose mitochondrial localization strongly suggests the existence of an unexpected mitochondrial pathway of ceramide metabolism that may play a key role in mitochondrial functions, especially in the regulation of apoptosis. To explore the biological effect of mitochondrial ceramidase on cells, pcDNA 3.1/His-CDase plasmid, containing mitochondrial ceramidase cDNA sequence, was transducted into K562 cells mediated by liposome, and G418 was used to screen for positive colonies. A stable transfected K562 cell line was established and named as 'K562TC'. The difference between K562 and K562TC cells in chemotheraputic cytotoxicity response and serum-withdrawal resistance and Bcl-2 protein expression were evaluated by MTT assay, annexin V/PI test, flow cytometry or Western blotting, respectively. The results showed that although survival was comparable between K562 and K562TC cells after exposed to adriamycin, etoposide or arsenious acid, K562TC cells with elevated Bcl-2 protein expression level as identified by FCM or Western blotting revealed stronger resistance to apoptosis induced by serum withdrawal than their parental cells. Inhibition of mitochondrial ceramidase expression in K562TC cells by its specific antisense oligodeoxynucleotide was correlated with a decrease in Bcl-2 protein level. N, N-dimethylsphingosine, a sphingosine kinase inhibitor, depleted intracellular sphingosine-1-phosphate production, also abrogated Bcl-2 protein expression in K562TC cells, while Bcl-2 protein level in K562 cells was up-regulated by exogenous sphingosine-1-phosphate. It is concluded that mitochondrial ceramidase overexpression in K562 cells leads to markedly elevated level of Bcl-2 protein and results in more resistance to serum withdrawal. This effect is initiated not by sphingosine, the direct metabolite of mitochondrial ceramidase, but via sphingosine-1-phosphate, its phosphorylated form. This is the first evidence that mitochondrial ceramidase, through its sphingoid metabolite sphingosine-1-phosphate, up-regulates Bcl-2 protein expression in K562 cells.

Effects of bcl-2 antisense oligodeoxynucleotide on proliferation and apoptosis of Raji cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the in vitro antitumor activity of bcl-2 fully phosporothioated antisense oligodeoxynucleotide (bcl-2 ASODN) to malignant lymphoblastic cells.</p><p><b>METHODS</b>Proliferation and apoptosis of Raji cells incubated with bcl-2 ASODN were evaluated by MTT assay, flow cytometry (FCM) and electron microscopy, and the level of bcl-2 protein and mRNA expression were assessed by FCM and RT-PCR, respectively.</p><p><b>RESULTS</b>MTT assay demonstrated that bcl-2 ASODN could partially inhibit the growth of Raji cells. After incubated with ASODN for 48 hours, Raji cells exhibited characteristic morphologic changes of apoptosis, including cytoplasm membrane blebbing, chromatin condensation crescents formation and nuclear fragmentation. The apoptosis rate of Raji cells treated with 20 micromol/L bcl-2 ASON for 72 hrs was 43.86% which is significantly higher than that of control (10.05%). The bcl-2 ASODN induced apoptosis of Raji cells was accompanied by declined expression of bcl-2 mRNA, which decreased to 0.88% at 72 hrs and was significantly lower than that of control (79.54%).</p><p><b>CONCLUSION</b>bcl-2 ASODN induced Raji cells apoptosis by downregulating bcl-2 protein.</p>