In order to further investigate the effect of annexin II (Ann-II) on tissue plasminogen activator (t-PA)-dependent plasminogen (PLG) activation and its interactive mechanism, recombinant native Ann-II bound t-PA, PLG and plasmin with high affinity was examined. The flow cytometric assay showed that the ann-II expression rate was higher in the human umbilical vein endothelial cell (HUVEC) (87.65%) than in the HL-60 cells as controls (35.79%). Two irrelevant proteins, bovine serum albumin (BSA) and equine IgG (EIG) had no effect on the production of plasmin. Ann-II-mediated enhancement of t-PA-dependent PLG activation was inhibited by epsilon-aminocaproic acid or by pretreatment of Ann-II with carboxypeptidase B with the inhibitive rate being 77.8% and 77.0%, respectively. It was revealed that the effect of Ann-II on PLG activation was specific for t-PA. Urokinase didn't bind to Ann-II, demonstrating the role of receptor-related lysine residues on activation of PLG, showing that the Ann-II-PLG interaction was dependent upon carboxyl-terminal lysine residues. These findings suggest that annexin II-mediated co-assembly of t-PA and PLG may promote plasmin generation and play a key role in modulating fibrinolysis on the endothelial surface.
Annexin A2 ; pharmacology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; metabolism ; Fibrinolysis ; Humans ; Plasminogen ; metabolism ; Recombinant Proteins ; pharmacology ; Tissue Plasminogen Activator ; metabolism ; Umbilical Veins ; cytology

In order to further investigate the effect of annexin II (Ann-II) on tissue plasminogen activator (t-PA)-dependent plasminogen (PLG) activation and its interactive mechanism, recombinant native Ann-II bound t-PA, PLG and plasmin with high affinity was examined. The flow cytometric assay showed that the ann-II expression rate was higher in the human umbilical vein endothelial cell (HUVEC) (87.65%) than in the HL-60 cells as controls (35.79%). Two irrelevant proteins, bovine serum albumin (BSA) and equine IgG (EIG) had no effect on the production of plasmin. Ann-II-mediated enhancement of t-PA-dependent PLG activation was inhibited by epsilon-aminocaproic acid or by pretreatment of Ann-II with carboxypeptidase B with the inhibitive rate being 77.8% and 77.0%, respectively. It was revealed that the effect of Ann-II on PLG activation was specific for t-PA. Urokinase didn't bind to Ann-II, demonstrating the role of receptor-related lysine residues on activation of PLG, showing that the Ann-II-PLG interaction was dependent upon carboxyl-terminal lysine residues. These findings suggest that annexin II-mediated co-assembly of t-PA and PLG may promote plasmin generation and play a key role in modulating fibrinolysis on the endothelial surface.
Annexin A2/*pharmacology ; Cells, Cultured ; Endothelium, Vascular/cytology ; Endothelium, Vascular/*metabolism ; Fibrinolysis ; Plasminogen/*metabolism ; Recombinant Proteins/pharmacology ; Tissue Plasminogen Activator/*metabolism ; Umbilical Veins/cytology

OBJECTIVETo study the effects of interferon-gamma (IFN-gamma) on the adhesiveness and invasiveness of prostate cancer cells.

METHODSWe determined the effect of IFN-gamma on the adhesiveness of prostate cancer cell lines LNCaP and PC-3 by treating the plate with fibronectin and laminin, on the invasiveness of prostate cancer cells into the artificial basal membrane consisting of Matrigel and fibronectin using the Transwell chamber, and on the expression of annexin-2 in these cells by Western blot.

RESULTSThe adhesion rates of prostate cancer cell lines LNCaP and PC-3 were 21% and 23% in the IFN-gamma treatment group, significantly lower than 46% and 40% in the untreated group (P < 0.05). The invasiveness of the cells was markedly decreased in the former as compared with the latter (P < 0.05). IFN-gamma significantly inhibited the expression of annexin-2 in prostate cancer cell lines LNCaP and PC-3 (P < 0.05).

CONCLUSIONIFN-gamma can decrease the adhesiveness and invasiveness of the prostate cancer cell line by down-regulating the expression of annexin-2.

Annexin A2 ; biosynthesis ; Blotting, Western ; Cell Adhesion ; drug effects ; Cell Line, Tumor ; Cell Movement ; drug effects ; Humans ; Interferon-gamma ; pharmacology ; Male ; Neoplasm Invasiveness ; Prostatic Neoplasms ; metabolism ; pathology

The study was designed to investigate annexin II resulting in molecular pathological mechanism of the primary fibrinolysis and establish annexin II vector model for further research on disturbance of coagulation. A target gene was amplified from human umbilical vein endothelial cells (HUVEC) by RT-PCR. Annexin II gene fragment was purified and ligated with molecular biological recombinant technology. The recombinant of plasmid annexin II was transfected into HL-60 cells and its distribution in the cell and structure characteristics of annexin II protein were evaluated by multi-photon excitation laser scanning microscope. By means of flow cytometry (FCM) and Werstern blot technique, the protein expression was qualitatively and quantitatively analyzed. Transfected cells were treated in vitro with annexin II antisense oligonucleotide (AS) targeting to the start site of annexin II cDNA. The results showed that the recombinant pZeoSV2(+)/ANN II was constructed successfully and expressed in HL-60 cells. The protein expression was distributed on the surface of cell by fluorescence assay. After transfection for 48 hours, the cells occurred higher level of expression. The level of the plasmin was significantly enhanced in the present of annexin II. The FCM and Western blot analysis showed the annexin II expression was similar both in transiently and stably transfected in HL-60 cells. Annexin II antisense oligonucletide and McAb significantly inhibited the activity of plasminogen. It was concluded that annexin II plays an important role in the fibrinotysis. Annexin II vector was defined as a expression tool for further studying fibrinolysis and coagulopathy in malignant disease.
Annexin A2 ; genetics ; physiology ; Endothelium, Vascular ; chemistry ; cytology ; Fibrinolysis ; Genetic Vectors ; HL-60 Cells ; Humans ; Oligonucleotides, Antisense ; pharmacology ; Polymerase Chain Reaction ; Recombinant Proteins ; biosynthesis

OBJECTIVETo investigate the effect of thalidomide on Annexin II (AnxA2) gene regulation in multiple myeloma cell line RPMI8226 and human microvascular endothelial cell line HMEC-1 cells in vitro, and explore the potential mechanism of thrombosis induced by thalidomide.

METHODSRPMI8226 and HMEC-1 cells were cultivated in vitro. Real time quantitative PCR (RQ-PCR) was used to detect the influence of thalidomide at different concentration on the expression of AnxA2 mRNA, flow cytometry (FCM) and confocal microscopy were used to detect the cell surface protein level after the samples were stimulated with different concentrations of thalidomide.

RESULTSAnxA2 mRNA level in RPMI8226 cells treated with thalidomide at 12.5 microg/ml, 25.0 microg/ml and 50.0 microg/ml was decreased compared with the control group (0.60+/-0.15, 0.33+/-0.14, 0.42+/-0.16, vs 1.07+/-0.16, respectively, P<0.05) and did so in HMEC-1 cells (0.21+/-0.20, 0.08+/-0.08, 0.17+/-0.16 vs 1.16+/-0.24, respectively, P<0.05). The AnxA2 protein level in RPMI8226 cells treated with above mentioned concentrations of thalidomide was also decreased compared with the control (3.39+/-0.32, 2.82+/-0.28, 3.21+/-0.23 vs 5.53+/-0.32, respectively, P<0.05) and that did so in HMEC-1 cells (0.72+/-0.11, 0.64+/-0.08, 0.67+/-0.08 vs 1.40+/-0.15, respectively, P<0.05).

CONCLUSIONSThalidomide can inhibit the expression of AnxA2 mRNA and protein in RPMI8226 and HMEC-1 cells, which may be one of the mechanisms for the development of thrombosis induced by thalidomide in multiple myeloma patients.

Annexin A2 ; genetics ; metabolism ; Cell Line ; Endothelial Cells ; metabolism ; Endothelium, Vascular ; cytology ; Humans ; Multiple Myeloma ; metabolism ; pathology ; RNA, Messenger ; genetics ; Thalidomide ; pharmacology

OBJECTIVESTo study the fibrinolytic activity and the expression of uPAR and Annexin II in leukemic cell lines and their alterations on all-trans retinoic acid ( ATRA) treatment.

METHODSThe fibrinolytic activity was measured by chromogenic assay in NB4, SHI-1, K562, Jurkat and Raji cell lines. The protein expression of uPAR and Annexin II on cells surface and the mRNA expression of uPAR and Annexin II in cells of these cell lines were detected using flow cytometry and RT-PCR method respectively.

RESULTSThe plasmin activity in supernatant was increased significantly after incubation of SHI-1 and NB4 cells with plasminogen. The plasmin activity of NB4 cells was obviously decreased by ATRA. The plasmin activity of NB4 and SHI-1 cells was significantly decreased by uPAR monoclonal antibodies. The expressions of uPAR and Annexin II and their mRNA in SHI-1 and NB4 cells were higher than that in other cell lines. ATRA could remarkably decrease the expressions of Annexin II and uPAR and their mRNA in NB4 cells.

CONCLUSIONIn leukemia cell lines, NB4 and SHI-1 cells have stronger fibrinolytic activity. Both Annexin II and uPAR on the leukemic cell membranes might contribute to this activity. The high fibrinolytic activity can be corrected by ATRA by down-regulating Annexin I and uPAR mRNA and protein expression in NB4 cells.

Annexin A2 ; biosynthesis ; genetics ; Cell Line, Tumor ; Fibrinolysis ; drug effects ; Humans ; Leukemia ; metabolism ; pathology ; RNA, Messenger ; genetics ; Receptors, Cell Surface ; biosynthesis ; genetics ; Receptors, Urokinase Plasminogen Activator ; Reverse Transcriptase Polymerase Chain Reaction ; Tretinoin ; pharmacology

AIMTo determine the cellular distribution of secretory phospholipase A(2) (sPLA(2)) in dependence on the acrosomal state and under the action of elastase released under inflammatory processes from leukocytes.

METHODSAcrosome reaction of spermatozoa was triggered by calcimycin. Human leukocyte elastase was used to simulate inflammatory conditions. To visualize the distribution of sPLA(2) and to determine the acrosomal state, immunofluorescence techniques and lectin binding combined with confocal laser scanning fluorescence microscopy and flow cytometry were used.

RESULTSAlthough sPLA(2) was detected at the acrosome and tail regions in intact spermatozoa, it disappeared from the head region after triggering the acrosome reaction. This release of sPLA(2) was associated with enhanced binding of annexin V-fluoroscein isothiocyanate (FITC) to spermatozoa surfaces, intercalation of ethidium-homodimer I, and binding of FITC-labelled concanavalin A at the acrosomal region. Spermatozoa from healthy subjects treated with elastase were characterized by release of sPLA(2), disturbance of acrosome structure, and loss of vitality.

CONCLUSIONThe ability of spermatozoa to release secretory phospholipase A(2) is related to the acrosomal state. Premature destabilization of the acrosome and loss of sPLA(2) can occur during silent inflammations in the male genital tract. The distribution pattern of sPLA(2) in intact spermatozoa might be an additional parameter for evaluating sperm quality.

Acrosome ; drug effects ; physiology ; Acrosome Reaction ; drug effects ; Annexin A5 ; metabolism ; Anti-Bacterial Agents ; pharmacology ; Calcimycin ; pharmacology ; Ethidium ; Flow Cytometry ; Fluorescent Dyes ; Humans ; In Vitro Techniques ; Male ; Microscopy, Confocal ; Pancreatic Elastase ; metabolism ; Phosphatidylserines ; metabolism ; Phospholipases A2, Secretory ; metabolism ; Semen ; cytology ; drug effects ; Spermatozoa ; drug effects ; enzymology

BACKGROUNDMost patients with acute myelogenous leukemia (AML) suffer from disordered hemostasis. We have previously shown that annexin II (Ann II), a high-affinity co-receptor for plasminogen/tissue plasminogen activator, plays a central role in primary hyperfibrinolysis in patients with acute promyelocytic leukemia (APL). The expression of Ann II in cells from patients with major subtypes of AML and the effect of arsenic trioxide (As2O3) on Ann II expression in AML cells were investigated to determine whether As2O3-mediated downregulation of Ann II could restore hemostatic stability.

METHODSA total of 103 patients (48 females and 55 males; age, 19 - 58 years) were included. Plasma samples were collected before and after treatment as well as after complete remission. Ann II and plasminogen activation were measured in leukemic cells during treatment with 1 micromol/L As2O3.

RESULTSBefore As2O3 treatment, Ann II mRNA expression (real-time PCR) was the highest in M3 cells (P < 0.05), higher in M5 cells than that in M1, M2, M4, and M6 cells (P < 0.001), and positively correlated with Ann II protein expression (flow cytometry) (r = 0.752, P < 0.01). Exposure for up to 120 hours to As2O3 (1 micromol/L) had no significant effect on Ann II protein in M1 and M2 leukemic cells, but decreased Ann II protein expression twofold within 48 hours of exposure in M3 cells (P < 0.05) and twofold within 96 hours in M5 cells (P < 0.05). The rate of plasmin generation was higher in APL, M5, and M4 cells than in M1, M2, and M6 cells.

CONCLUSIONSAs2O3 may reduce hyperfibrinolysis in AML by downregulation of Ann II. Furthermore, As2O3 affects more than one form of AML (APL, M4 and M5), suggesting its potential role in their management.

Adult ; Annexin A2 ; metabolism ; Arsenicals ; pharmacology ; Bone Marrow Cells ; cytology ; drug effects ; metabolism ; Cell Survival ; drug effects ; Cells, Cultured ; Down-Regulation ; drug effects ; Female ; Humans ; Leukemia, Promyelocytic, Acute ; metabolism ; physiopathology ; Male ; Middle Aged ; Oxides ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; Young Adult

This study was aimed to investigate the effects of bortezomib on VEGF gene expression of endothelial cell line HMEC-1, and to determine the changes of the transcriptional regulation activity of hypoxia-inducible factor 1 (HIF-1alpha) and expression intensity of Annexin A2, so as to analyze the possible mechanisms of the above expression of VEGF gene. Expression intensity of VEGF gene was determined by real-time quantitative PCR; the relative proliferation activity of cells was assayed by cell count kit CCK-8; the expression intensity of carbonic anhydrase IX (CA IX) gene was detected by RT-PCR; expression of Annexin A2 at gene and protein levels were determined by real-time quantitative PCR and Western blot respectively. The results showed that after being treated by bortezomib with 2.5, 5.0, 10 nmol/L for 12 hours, the expression intensity of VEGF gene of endothelial cell line HMEC-1 was as follows: 0.730 +/- 0.106, 0.673 +/- 0.153, 0.767 +/- 0.090 (as 1.0 was made in 0 nmol/L) (p < 0.05); the proliferation activity of cells was not significantly suppressed by bortezomib in 2.5, 5.0 nmol/L (p > 0.05), while that was significantly suppressed by bortezomib of 10 nmol/L (p = 0.024), The results from RT-PCR showed that expression intensity of CA IX gene was conspicuously down-regulated by bortezomib in different concentrations, which suggested that the transcriptional regulation activity of HIF-1alpha was inhibited by bortezomib. And down-regulated expression of Annexin A2 protein by bortezomib in different concentrations was confirmed by real-time quantitative PCR and Western blot. It is concluded that low doses of bortezomib has no significant inhibition effect on the activity of proteasome. Bortezomib may down-regulate the expression of VEGF gene of endothelial cell through regulating the activity of HIF-1alpha and the expression of Annexin A2.
Annexin A2 ; genetics ; metabolism ; Antigens, Neoplasm ; genetics ; metabolism ; Boronic Acids ; pharmacology ; Bortezomib ; Carbonic Anhydrase IX ; Carbonic Anhydrases ; genetics ; metabolism ; Cell Line ; Down-Regulation ; Endothelial Cells ; drug effects ; metabolism ; Gene Expression ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Pyrazines ; pharmacology ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

Annexin A2, a multifunctional tumor associated protein, promotes nuclear factor-kappa B (NF-κB) activation by interacting with NF-κB p50 subunit and facilitating its nuclear translocation. Here we demonstrated that two ginsenosides Rg5 (G-Rg5) and Rk1 (G-Rk1), with similar structure, directly bound to Annexin A2 by molecular docking and cellular thermal shift assay. Both Rg5 and Rk1 inhibited the interaction between Annexin A2 and NF-κB p50 subunit, their translocation to nuclear and NF-κB activation. Inhibition of NF-κB by these two ginsenosides decreased the expression of inhibitor of apoptosis proteins (IAPs), leading to caspase activation and apoptosis. Over expression of K302A Annexin A2, a mutant version of Annexin A2, which fails to interact with G-Rg5 and G-Rk1, effectively reduced the NF-κB inhibitory effect and apoptosis induced by G-Rg5 and G-Rk1. In addition, the knockdown of Annexin A2 largely enhanced NF-κB activation and apoptosis induced by the two molecules, indicating that the effects of G-Rg5 and G-Rk1 on NF-κB were mainly mediated by Annexin A2. Taken together, this study for the first time demonstrated that G-Rg5 and G-Rk1 inhibit tumor cell growth by targeting Annexin A2 and NF-κB pathway, and G-Rg5 and G-Rk1 might be promising natural compounds for targeted cancer therapy.
Active Transport, Cell Nucleus ; drug effects ; Annexin A2 ; chemistry ; deficiency ; genetics ; metabolism ; Antineoplastic Agents ; chemistry ; metabolism ; pharmacology ; Apoptosis ; drug effects ; Biological Products ; chemistry ; metabolism ; pharmacology ; Cell Nucleus ; drug effects ; metabolism ; Down-Regulation ; drug effects ; Drug Discovery ; Gene Knockdown Techniques ; Ginsenosides ; chemistry ; Hep G2 Cells ; Humans ; Molecular Docking Simulation ; Molecular Targeted Therapy ; NF-kappa B p50 Subunit ; metabolism ; Protein Conformation