Biomedical subjects

Guan-Jun Wang

Publications and source records attributed to Guan-Jun Wang.

9 recordsLinked to original sources

PubMed2006

[Analysis of the different proteomes between the acute leukemia cells and normal white blood cells].

This study was aimed to analyze the different proteomes between human acute leukemia (AL) cells and normal white blood cells by proteomic technology in order to lay the basis for diagnosing AL and understanding the mechanism of leukemogenesis. The proteins from AL cells of 40 AL patients identified by FAB classification and proteins from normal lymphocytes and granulocytes of 20 normal volunteers were separated by two-dimensional electrophoresis (2-DE), and the differentially expressed proteins between the two groups were identified by both matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electronspray ionization (ESI)-MS/MS. The results showed that among the differentially expressed proteins between AL cells and normal lymphocytes and granulocytes, some proteins involved in the process of malignant transformation (such as Op18, NM23-H1), cell proliferation (such as PCNA) and apoptosis inhibition (such as tumor necrosis factor inhibitor protein) were found to be up regulated in AL cells. However, some proteins involved in differentiation and physiological functions of normal cells were down regulated in AL cells. It is concluded that there are many events involved in the process of leukemogenesis, expression of some proteins relating to the malignant transformation, cell proliferation and apoptosis inhibition are up-regulated in AL cells. The proteome analysis may provide a new approach to explaining the molecular mechanism underlying the pathogenesis of AL.

Adolescent↗

PubMed2006

[Using real-time polymerase chain reaction to quantitate bcr-abl mRNA].

BACKGROUND & OBJECTIVE: When leukemia patients achieve complete remission after chemotherapy, a few tumor cells still exist in other tissues outside bone marrow, which is called minimal residual disease (MRD), and it is the base of relapse. To cure leukemia, we should not only find MRD in time, but also quantitate MRD for instructing treatment and predicting prognosis. This study was to establish a real-time reverse transcription-polymerase chain reaction (RT-PCR) system to quantitate bcr-abl mRNA. METHODS: bcr-abl mRNA in leukemia cell line K562 was amplified by RT-PCR. T-A clone was used to construct the combined plasmid to be standard template; the standard curve of bcr-abl oncogene was drawn. bcr-abl mRNA in bone marrow samples of 16 chronic myelocytic leukemia (CML) patients was quantitated by this method. The sensitivity, stability, and repetition of this method were evaluated. RESULTS: The sensitivity is 10 copies of the recombined plasmid. The coefficient variations (CV) of repetition and stability were 2.19% and 3.21%. The correlation (R) of the standard curve was 0.984. The median bcr-abl level of the 16 CML patients was 4.58x10(4) kb/microg RNA. CONCLUSIONS: Real-time PCR has high sensitivity, repetition, and specificity. It can quantitate the copy number of bcr-abl oncogene.

Bone Marrow↗

PubMed2006

[The proteomics study of apoptotic NB4 cells induced by sodium butyrate].

OBJECTIVE: To explore the molecular mechanisms of apoptotic NB4 cells induced by the histone deacetylase inhibitor, sodium butyrate(SB). METHODS: SB was exposed to NB4 cells at a final concentration of 1.0 mmol/L. The untreated and treated cells were analysed with FACS and 2-dimensional electrophoresis (2-DE) at 0, 12, 24, 48 and 72 h. The changed protein spots were identified with MALDI-TOF-MS and ESI-TOF-MS/MS. RESULTS: SB induced apoptosis of NB4 cells. Twenty-one changed proteins involving apoptotic signal transduction, immunological regulation, transcriptional control, cellular metabolism, molecular transport and so on were identified. Thirteen of them had been reported to be related to apoptosis. CONCLUSION: SB can induce apoptosis and many functional protein changes in tumor cells. These results pave the way to further explore the anti-tumor mechanism of SB.

Apoptosis↗

PubMed2005

Two-dimensional electrophoresis protein profiling as an analytical tool for human acute leukemia classification.

Two-dimensional electrophoresis (2-DE) was used to profile the proteins of leukemic cells from 61 cases of akute leukemia (AL) characterized by the French-American-British (FAB) classification. The differentially expressed protein spots were identified by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electrospray ionization-tandem MS (ESI-MS/MS). The distinct protein profiles (DPPs) of AL FAB subtypes were explored successfully, including acute myeloid leukemia (AML), its subtypes (M2, M3, and M5), and acute lymphoid leukemia (ALL), which were homogeneous within different samples of the same subgroup but clearly differed from all other subgroups. We also found a group of proteins differentially expressed between AL cells and normal white blood cells. Among the DPPs of AL subtypes, some proteins have been reported, but most of them were first reported here to mark AML differentiation and to discriminate AML from ALL. These data show that 2-DE protein profiling could be used as an analytical tool for facilitating molecular definition of human AL classification and understanding the mechanism of leukemogensis, and the extension of the present analysis to the currently less well-defined AL will identify additional subgroups and may promote the identification of new targets for specific treatment approaches.

Acute Disease↗

PubMed2004

Proteomic analysis of human acute leukemia cells: insight into their classification.

PURPOSE: French-American-British (FAB) classification of acute leukemia with genetic heterogeneity is important for treatment and prognosis. However, the distinct protein profiles that contribute to the subtypes and facilitate molecular definition of acute leukemia classification are still unclear. EXPERIMENTAL DESIGN: The proteins of leukemic cells from 61 cases of acute leukemia characterized by FAB classification were separated by two-dimensional electrophoresis, and the differentially expressed protein spots were identified by both matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) and tandem electrospray ionization MS (ESI-MS/MS). RESULTS: The distinct protein profiles of acute leukemia FAB types or subtypes were successfully explored, including acute myeloid leukemia (AML), its subtypes (M2, M3, and M5) and acute lymphoid leukemia (ALL), which were homogeneous within substantial samples of the respective subgroups but clearly differed from all other subgroups. We found a group of proteins that were highly expressed in M2 and M3, rather than other subtypes. Among them, myeloid-related proteins 8 and 14 were first reported to mark AML differentiation and to differentiate AML from ALL. Heat shock 27 kDa protein 1 and other proteins that are highly expressed in ALL may play important roles in clinically distinguishing AML from ALL. Another set of proteins up-regulated was restricted to granulocytic lineage leukemia. High-level expression of NM23-H1 was found in all but the M3a subtype, with favorable prognosis. CONCLUSIONS: These data have implications in delineating the pathways of aberrant gene expression underlying the pathogenesis of acute leukemia and could facilitate molecular definition of FAB classification. The extension of the present analysis to currently less well-defined acute leukemias will identify additional subgroups.

Acute Disease↗

PubMed2004

[Study on bone marrow microvascular density in hematological diseases].

To investigate the state and significance of bone marrow angiogenesis in hematological diseases, bone marrow microvascular density (BM-MVD) in plastic-embedded section was examined using acetone-fixed bone marrow tissues embedded in glycol-methacrylate (GMA) resin and by the method of immunohistochemistry. The results showed that bone marrow MVD increased greatly in newly diagnosed hematological malignancies before treatment. BM-MVD in patients with acute leukemia decreased down to the normal range as the controls at the time of complete remission. In the non-remission group, BM-MVD decreased less, but when relapsed it increased again up to the same range as the newly diagnosed hematological malignancies, significant increase of BM-MVD was found in patients with anemia, but in less degree than that in hematological malignancies. It is concluded that bone marrow angiogenesis plays a key role in the pathogenesis and development of hematological malignancy. Antiangiogenic therapy may be able to constitute a novel strategy for the treatment of hematological malignancies including leukemia.

Acute Disease↗

PubMed2003

[Monitoring of the therapeutic response of interferon to chronic myeloid leukemia by duel-color fluorescence in situ hybridization].

To investigate the significance of duel-color fluorescence in situ hybridization (D-FISH) in monitoring the response to interferon alpha (IFN-alpha) therapy in patients with chronic myeloid leukemia (CML), the D-FISH method was employed to detect the proportion of the interphase nuclei cells with bcr/abl fusion gene in the bone marrow of patients with CML before and after IFN-alpha therapy, and the results were compared with those of bcr/abl fusion mRNA by RT-PCR and Philadephia chromosome (Ph) by conventional cytogenetic analysis. The results showed that the mean detectable rate of bcr/abl fusion gene before and after IFN-alpha therapy was 96.4% and 58.6% respectively, in 22 patients who were bcr/abl-positive before IFN-alpha therapy by D-FISH method, was 94.0% and 70.1% respectively, in 2 patients of Ph-negative before treatment. Major, minor and no responses were seen respectively in 4, 4 and 14 cases from 22 patients by D-FISH method. The results also showed a good correlation with the analysis of RT-PCR and conventional cytogenetics. In conclusion, D-FISH method could directly detect the bcr/abl fusion gene of the interphase cells in bone marrow of patients with CML. It can overcome the defect of conventional cytogenetic methods which analyze only the cells in metaphase and the drawback of RT-PCR unable to quantify the bcr/abl fusion gene. D-FISH provides a more convenient and reliable method for evaluating the degree of clone remission to patients with CML after IFN-alpha therapy.

Adolescent↗

PubMed2003

[Progress in the studies of acute myelogenous leukemia stem cell].

Acute myelogenous leukemia (AML) cells are organized in a hierarchical fashion, with only the most primitive rare population (leukemia stem cell, LSC) of AML cells capable of maintaining the leukemic clone. A broad range of studies has indicated that AML results from mutations at the level of the stem cells of AML cells. The changes of cellular and molecular features in these malignant stem cells determine the features of leukemic clone and give rise to different subtypes of AML. LSCs share some similar characteristics with normal hematopoietic stem cells (HSC) including the ability to self-renew, and also have the potential of limited differentiation. LSCs, also have some features that are not found in normal HSC. LSCs have unique phenotype such as CD90-, CD117- and CD123+. Tumor-suppressor protein-death associated protein kinase and interferon regulatory factor 1 were overexpressed in LSCs, but not in normal HSC. Due to a predominantly G0 cell-cycle status, LSCs may not be responsive to conventional chemotherapeutic agents, compared with leukemia blasts. It is proposed that surviving LSCs are a major contributing factor to leukemic relapse. Although LSC population is likely to be drug-resistant, quiescent LSCs are preferentially susceptible to apoptosis induction while sparing normal HSC, with the appropriate stimulus such as proteasome inhibitor MG-132. This article reviewed the data emerging from the study of LSCs, and elucidated the distinct cellular and molecular characteristics of the LSC population, which may shed new light on AML therapy and leukemogenesis study.

Cell Count↗

PubMed2001

[Generation of Dendritic Cells from Human Cord Blood CD34(+) Cells and Their Activation of T Cell-Dependent Antitumor Immune Response In Vitro]

To induce the growth and differentiation of dendritic cells (DCs) from human cord blood, CD34(+) cells isolated from human cord blood by mini-MACS were cultured in a liquid culture system with rhSCF, rhGM-CSF, rhTNF-alpha and rhFL for 10 days. Then the induced cells were characterized by DC's morphological and phenotypic properties. In addition, they stimulated the proliferation of allogeneic T cells and possessed an efficient capacity for initiating T cell-dependent antitumor immune responses in vitro. It is concluded that mature DCs could be obtained from human cord blood CD34(+) cells.

Journal Article↗