OBJECTIVETo investigate the effect of SHIP gene mutation on the cell cycle and its related gene expression in K562 cells.

METHODSThe recombined green fluorescent protein (GFP) containing FIV-SHIP gene was transfected into K562 cells. The transfection efficiency and cell cycle of K562/SHIP were assessed by flow cytometry (FCM). The proliferation of K562 cells was detected by MTT assay, the mRNA levels of SHIP by real-time fluorescent relative-quantification reverse transcriptional PCR (FQ-PCR), and the protein levels of SHIP, Cyclin D1, p21(WAF1/CIPI) and p27(KIP1) by Western blot.

RESULTSWild type SHIP inhibited K562 cell proliferation and caused a G(0)/G(1) arrest \[(34.2 +/- 7.8)% vs (0.7 +/- 8.3)% (P < 0.01)\]; while the point mutation of SHIP gene did not show such effect. Western blot results showed that the Akt phosphorylation and cyclin D1 expression was significantly decreased (P < 0.01), and the expression of p27(KIP1) and p21(WAF1/CIPI) increased. Site-directed mutation of SHIP gene SH2 domain (TTC-->CTC, Phe-->Leu) did not influence the Akt phosphorylation and cyclins (P > 0.05).

CONCLUSION(1) wtSHIP gene can down-regulate Akt phosphorylation and result in inhibition of cyclin D1 expression, up-regulating p27(KIP1) and p21(WAF1/CIPI) expression, finally leading to the reduction of K562 cell proliferation, and inducing G(0)/G(1) phase arrest. (2) SHIP gene suppresses the proliferation of K562, being dependent on its intact structure and function.

Cell Cycle Proteins ; metabolism ; Humans ; Inositol Polyphosphate 5-Phosphatases ; K562 Cells ; Mutation ; Phosphoric Monoester Hydrolases ; genetics ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Transfection

The src homology 2 (SH2)-domain containing inositol-5-phosphatase (SHIP) is another recently identified lipid phosphatase after phosphatase and tensin homology deleted on chromosome ten gene (PTEN). It plays an important role in negatively regulating the proliferation of hematopoietic cells. The relationship between SHIP and the inhibition of tumor proliferation is rarely reported. The purpose of this study is to evaluate the apoptosis induced by SHIP gene in K562 cell line and to explore the involved signaling pathway. The K562 cells were transfected with human SHIP gene by using the lentiviral vector containing SHIP, and the transfection was verified by fluorescent quantitative PCR (FQ-PCR) and Western blot. Then the effects of SHIP protein expression on cell growth and apoptosis were measured. The levels of p-Akt, bcl-2 family, caspase and the activity of NFkappaB were assayed by Western blot and ELISA, respectively. The results are as follows: (1) Human leukemia cell line K562 was SHIP-negative; (2) Transfection with SHIP gene led to the re-expression of SHIP mRNA and protein in K562, as shown by FQ-PCR and Western blot; (3) The expression of SHIP protein inhibited cell growth and significantly increased apoptosis in K562 cells; (4) Compared to that in control group, the expression level of p-Akt-308 and p-Akt-473 in SHIP-expressing cell group decreased significantly (P<0.01); SHIP activated caspase-9, caspase-3, up-regulated protein levels of bad, p27, down-regulated expression of bcl-xL, while it had no effect on the expression of bcl-2 and bax. Furthermore, the inhibition of NF-kappaB was achieved along with the inactivation of Akt. These data suggest that SHIP gene has potential abilities to inhibit K562 leukemic cell proliferation and induce its apoptosis via inactivating PI3K/Akt pathway. The loss of SHIP might be the explanation of aberrant high-level p-Akt in human leukemia. It may be at least one of the mechanisms by which the loss of SHIP expression contributes to leukemia progression.
Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Cell Proliferation ; Down-Regulation ; Genetic Vectors ; Humans ; Inositol Polyphosphate 5-Phosphatases ; K562 Cells ; NF-kappa B ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphoric Monoester Hydrolases ; genetics ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; Transfection

OBJECTIVETo explore the effect of mutation in PxxP domain of SHIP on migration and invasion of leukemia cells and its mechanism.

METHODSThe lentiviral vector mediated wild type SHIP (wtSHIP) and mutant SHIP (muSHIP) plasmids were transfected into K562 cells through gene transfection techniques. Expression of SHIP at mRNA and protein level was detected by real-time PCR and Western blot, respectively. Transwell assay was used to analyze the difference between the migration and invasion ability of the K562/wtSHIP and the K562/muSHIP cells after transfection. Primary migration associated factor FAK, MMP and NF-κB were assayed by Western blot.

RESULTSAfter transfection, the SHIP expression in transfected K562 cells were significantly increased. Compared with the migration ability of K562/wtSHIP\[(15.8 ± 1.4)%\], that of K562/muSHIP cells \[(54.3 ± 2.4)% \] increased greatly and almost at the same level of that of K562/pFIV\[(50.3 ± 3.8)%\] (P < 0.01). The invasion assay also showed that K562/wtSHIP\[(32 ± 6)/HP\] has a lower invasion ability than that of the K562/muSHIP group \[(83 ± 16)/HP\] and K562/pFIV group \[(78 ± 13)/HP\] (P < 0.01). Western blot analysis showed that the expression of p-FAK and NF-κB was up-regulated in K562/muSHIP group compared to that of the K562/wtSHIP group.

CONCLUSIONSThe results confirmed that mutation in PxxP domain of SHIP gene played an important role in negative regulating function of SHIP gene. The mutation affects the cell migration and invasion ability through increase in MMP-9 expression, FAK phosphorylation and NF-κB activation. It suggested that the mutation of PxxP domain in SHIP gene might be pathogenic, and be one of the reasons for SHIP abnormality in leukemia.

Cell Movement ; Genetic Vectors ; Humans ; Inositol Polyphosphate 5-Phosphatases ; K562 Cells ; Leukemia ; pathology ; Mutation ; Phosphoric Monoester Hydrolases ; genetics ; Plasmids

OBJECTIVETo observe the expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with mesial temporal lobe epilepsy (MTLE) and to investigate the roles of dynamin-1 and phosphor-dynamin-1 in the development of MTLE.

METHODSMale Sprague-Dawley rats (aged 25 days) were randomly divided into acute control (AC), acute seizure (AS), latent control (LC), latent seizure (LS), chronic control (CC) and chronic spontaneous seizure (CS) groups. Lithium chloride-pilocarpine was used to induce a rat model of MTLE. The hippocampus samples of 5 children with a pathologically confirmed hippocampal sclerosis who received surgical operation were collected as a human model (HM) group, and the hippocampus samples of 4 dead children (without organic lesion of the hippocampus) were collected by autopsy as a human control (HC) group. The expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with MTLE was measured by Western blot and immunohistochemistry.

RESULTSThe Western blot showed that the expression of phosphor-dynamin-1 was significantly lower in the AS and CS groups than in the corresponding control groups (AC and CC groups) (P<0.05). The expression of phosphor-dynamin-1 was significantly lower in the HM group than in the HC group (P<0.05). There were no significant differences in the expression of dynamin-1 among the AS, LS and CS groups and between the HM and HC groups (P>0.05). The immunohistochemical results showed that phosphor-dynamin-1 was highly expressed in the cytoplasm of hippocampal neurons of AC, CC and HC groups, but its expression was significantly reduced in the AS, CS and HM groups (P<0.05).

CONCLUSIONSThe expression of phosphor-dynamin-1, not dynamin-1, is downregulated in the hippocampus of children and rats with MTLE during seizures, which suggests that the phosphorylation/dephosphorylation of dynamin-1 may be involved in the development of MTLE.

Animals ; Blotting, Western ; Child ; Dynamin I ; analysis ; metabolism ; Epilepsy, Temporal Lobe ; metabolism ; Female ; Hippocampus ; chemistry ; metabolism ; Humans ; Immunohistochemistry ; Male ; Phosphorylation ; Rats ; Rats, Sprague-Dawley

To evaluate the expression of cytoplasmic CD79a (CyCD79a) and other commonly used B-lymphoid immunomarkers including cytoplasmic CD22 (CyCD22), CD19, CD20 and CD10 in various acute leukemia cells and to define the most sensitive and specific markers in the diagnosis of precursor B-cell acute lymphoblastic leukemia (pB-ALL), the immunophenotypic data from 221 de novo adult and pediatric acute leukemia patients as studied using multi-parameter flow cytometry in addition to routine morphologic and enzyme cytochemical assay, were retrospectively analyzed. Cytogenetic and/or molecular biological data in all 45 cases of acute promyelocytic leukemia (APL) and 13 cases of acute leukemia suspected as AML with the fusion genes such as AML1/ETO and CBFbeta/MYH11 were investigated. The results showed that CyCD79a and CyCD22 were the most sensitive and specific markers respectively for pB-ALL. Expression of CyCD79a was seen in 100% of 58 cases of pB-ALL. At the same time, none (0%) of all 147 cases of acute myeloid leukemia (AML) and 15 cases of precursor T-cell acute leukemia (pT-ALL) was positive for CyCD22. The conclusion is made that united detection of CyCD79a and CyCD22 is the optimal immune combination for the diagnosis pB-ALL and the distinguishing pB-ALL with AML and pT-ALL.
Acute Disease ; B-Lymphocytes ; immunology ; Biomarkers, Tumor ; immunology ; CD79 Antigens ; immunology ; Cytoplasm ; immunology ; Flow Cytometry ; Humans ; Immunophenotyping ; Karyotyping ; Leukemia, Myeloid ; genetics ; immunology ; pathology ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma ; immunology ; metabolism ; pathology ; Sialic Acid Binding Ig-like Lectin 2 ; immunology

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.
Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Drug Synergism ; Humans ; K562 Cells ; Oxides ; pharmacology ; Recombinant Proteins ; pharmacology ; TNF-Related Apoptosis-Inducing Ligand ; pharmacology

OBJECTIVETo investigate the methylation of CpG island in the SHP-1 gene promoter and its significance in lymphoma. To evaluate the effects of As2O3 on demethylation of SHP-1 in human lymphoma cell line T2 and on proliferation of T2 cells.

METHODST2 cells were treated with AsO3. Methylation specific PCR was used to detected the status of SHP-1 methylation in newly diagnosed lymphoma tissues and the T2 cells. The mRNA and protein expression of SHP-1 were determined by FQ-PCR and Western blot. The expression of phospha-c-kit was examined by Westren blot. MTT and flow cytometry were used to determine the growth and apoptosis in T2 cells.

RESULTST2 cells contained completely methylated SHP-1. Furthermore, there was constitutive c-kit phosphorylation. The expression of SHP-1 was recoverd when the cells exposed to AsO3, and concomitant with increasing SHP-1, a parallel down-regulation of phosphorylated c-kit occurred, so that by day 3 phosphorylated c-kit was barely detectable. As2O3 inhibited the cell growth, and the effects were dose- and time-dependent. As2O3 also increased apoptosis rate of T2 cells in a dose- and time-dependent manner, too, and on the 1, 2, 3 d treatment with AsO3 (2.5 micromol/L), the apoptosis rates were 6.12%, 26.53%, 50.90%, respectively. The frequency of methylation in SHP-1 gene promoter in lymphoma tissues was 87.5% (28/32). In the control group, however, 12 specimens of benign lymph node proliferation showed no methylation in CpG island of SHP-1 gene promoter.

CONCLUSIONHypermethylation of SHP-1 gene promoter in lymphoma indicates the inactivation of SHP-1 gene and its possible role in the tumorigenesis of lymphoma. As2O3 can effectively cause demethylation and inhibit the growth of tumor by reactivating the SHP-1 gene transcription. SHP-1 methylation leading to epigenetic activation of c-kit may have a tentative role in the pathogenesis of lymphoma. Therefore, As2O3 is potentially useful in the treatment of lymphoma as a demethylating agent.

Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Arsenicals ; administration & dosage ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; CpG Islands ; DNA Methylation ; drug effects ; Dose-Response Relationship, Drug ; Gene Expression Regulation, Neoplastic ; Humans ; Lymphoma ; metabolism ; pathology ; Lymphoma, Non-Hodgkin ; genetics ; metabolism ; pathology ; Oxides ; administration & dosage ; pharmacology ; Protein Tyrosine Phosphatase, Non-Receptor Type 6 ; genetics ; metabolism ; Proto-Oncogene Proteins c-kit ; metabolism ; RNA, Messenger ; metabolism ; Transcriptional Activation ; drug effects ; Up-Regulation

OBJECTIVETo study the influence of lipopolysaccharide (LPS) on the permeability of rat brain microvascular endothelial cells (BMECs) and possible molecular mechanism.

METHODSMonolayers of primary rat BMECs were separated and cultured, and then treated with (LPS group) or without LPS (control group). The barrier integrity was measured by transendothelial electrical resistance (TEER) assay. The degrees of RhoA activation were determined by Pull-down assay. The expression levels of p115RhoGEF, zonula occludens-1 (ZO-1), occludin and claudin-5 proteins were detected by Western blot analysis.

RESULTSThe average TEER values of rat BMECs in the LPS group were 108.3±4.2 Ω•cm2 and 85.4±2.5 Ω•cm2 respectively 3 and 12 hrs after LPS treatment, which were significantly lower than that in the control group (159.0±8.6 Ω•cm2). Compared with the control group, the activity of RhoA started to increase 5 minutes after LPS treatment, and the expression of p115RhoGEF protein started to increase 1 hr after LPS treatment and the cellular protein levels of ZO-1, occludin and claudin-5 decreased significantly 3 hrs after LPS treatment in the LPS group (P<0.05).

CONCLUSIONSLPS may activate the p115RhoGEF/RhoA pathway and decrease protein expression of ZO-1, occludin and claudin-5, resulting in an increased permeability of rat BMECs.

Animals ; Brain ; blood supply ; Capillary Permeability ; drug effects ; Electric Impedance ; Endothelial Cells ; drug effects ; metabolism ; Guanine Nucleotide Exchange Factors ; analysis ; Lipopolysaccharides ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Rho Guanine Nucleotide Exchange Factors ; Tight Junctions ; chemistry ; rhoA GTP-Binding Protein ; analysis

OBJECTIVETo study the in vitro antitumor activity of bcl-2 fully phosporothioated antisense oligodeoxynucleotide (bcl-2 ASODN) to malignant lymphoblastic cells.

METHODSProliferation 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.

RESULTSMTT 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%).

CONCLUSIONbcl-2 ASODN induced Raji cells apoptosis by downregulating bcl-2 protein.

Apoptosis ; drug effects ; Cell Division ; drug effects ; Dose-Response Relationship, Drug ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Oligonucleotides, Antisense ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tumor Cells, Cultured ; drug effects ; metabolism

The aim of this study was to investigate whether and how phosphodiesterase (PDE) inhibitors modulate the proliferation, cell cycle and apoptosis in lymphoma cells. The effects of aminophylline (AM), a non-specific PDE inhibitor, on Raji cells were explored in vitro. MTT assay, light and transmission electron microscopy and annexin V staining were used to observe cell proliferation, morphologic changes and apoptosis rate in AM-treated cells, and FCM and RT-PCR techniques were adopted to detect the effect on cell cycle, the expression of cyclin B1 and Bcl-2 and mitochondrial transmembrane potential in AM-treated cells. The results showed that AM inhibited the growth of Raji cells in a concentration-dependent manner. Morphologic observations showed apoptosis changes in AM-treated cells, including cytoplamic shrinkage, cytoplasmic bubbling, karyopyknosis and nuclear fragmentation. FCM and RT-PCR detection showed that AM intervention increased the fraction of annexin V(+) cells, reduced the value of mitochondrial transmembrane potential, induced S phase arrest, and down-regulated the expression of Bcl-2 at both mRNA and protein level and cyclin B1 protein in a concentration-dependent manner. It is concluded that PDE inhibitor aminophylline may induce Raji cell growth inhibition, S phase arrest, apoptosis via down-regulation of Bcl-2 and reduction of mitochondrial transmembrane potential.
Aminophylline ; pharmacology ; Apoptosis ; drug effects ; Burkitt Lymphoma ; drug therapy ; genetics ; pathology ; Cell Division ; drug effects ; Cyclin B ; genetics ; metabolism ; Cyclin B1 ; Dose-Response Relationship, Drug ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Intracellular Membranes ; drug effects ; physiology ; Membrane Potentials ; drug effects ; Mitochondria ; drug effects ; physiology ; Phosphodiesterase Inhibitors ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; drug effects ; genetics ; metabolism ; S Phase ; Tumor Cells, Cultured ; drug effects ; metabolism ; ultrastructure