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

OBJECTIVETo study the influence of CD147 gene silencing on the expression of ANXA2, MMP-2 and TIMP-2 of thyroid medullary carcinoma TT cells and related biological characteristics.

METHODSProtein expression of CD147, ANXA2, MMP-2 and TIMP-2 was detected by immunocytochemistry.RNAi technology was used to identify the specific siRNA sequences and the optimal time point of effective inhibition of CD147 gene. The expression of ANXA2, MMP-2 and TIMP-2 at mRNA and protein levels was detected with RT-PCR and Western blot, respectively. MTT method was used to detect the proliferation of the TT cells, flow cytometry (FCM) to detect the cell cycle and apoptosis changes of TT cells and transwell chamber assays to document the influence of CD147 gene silencing on migration and invasion of the TT cells.

RESULTSThe protein expression of CD147, ANXA2, MMP-2 and TIMP-2 proteins was variable in the TT cells. Two siRNA sequences were identified to effectively silence CD147 gene in the TT cells, in which relative expression of MMP-2 was reduced at both mRNA and protein levels; although the expression of ANXA2 mRNA and protein did not change significantly. TIMP-2 protein expression markedly decreased in an absence of its mRNA expression. The proliferation of the TT cells was inhibited upon the CD147 gene silencing along with a significant increase of G(0)/G(1) phase cells and a decrease of G(2)/M phase cells.However, the proportion of the apoptotic cells in all experimental groups did not change. The number of the penetrating cells through the membrane filters did not show significant changes in all experimental groups in the Transwell chamber assays.

CONCLUSIONSThrough RNAi technology, two CD147 siRNA sequences are identified and shown to effectively inhibit CD147 gene expression of the TT cells. CD147 gene silencing leads to growth inhibition of the TT cells and alteration of the cell cycle. However, silencing CD147 does not significantly affect the apoptosis, migration and invasion of the TT cells.

Annexin A2 ; genetics ; metabolism ; Basigin ; genetics ; metabolism ; Carcinoma, Medullary ; metabolism ; pathology ; Cell Cycle ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Gene Silencing ; Humans ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Thyroid Neoplasms ; metabolism ; pathology ; Tissue Inhibitor of Metalloproteinase-2 ; genetics ; metabolism ; Transfection ; Tumor Cells, Cultured

OBJECTIVETo investigate the effects of Annexin A2 (ANXA2) deficiency on the malignant biological behaviour of hepatoma cells.

METHODSThe human hepatocellular carcinoma (HCC) cells lines MHCC97-H, HepG2, SMMC-7721, SMMC-7402 and L02 were evaluated. The expression and distribution of ANXA2 were analysed by western blotting, real-time PCR, immunofluorescence and immunohistochemistry.Cell cycle was assessed by flow cytometry and propidium iodide staining. Effects of ANXA2 silencing on invasion and migration potential were assessed by transwell assay and wound healing assay, respectively. Proliferative potential was assessed by CCK-8 kit in vitro and xenograft tumour-growth assay in vivo. The t-test, chi square test, rank sum test, q-test and F-test were used for statistical analyses.

RESULTSThe expression level of ANXA2 was markedly higher in the MHCC97-H cells with high metastasis potential than in the HepG2, SMMC-7721, SMMC-7402 and L02 cells. The efficiency of shRNA-mediated ANXA2 deficiency was more than 80%. Immunofluorescence analysis of the MHCC97-H cells indicated that ANXA2 expression was mainly localized to the cellular membrane and cytoplasm, with some nuclear localization. Down-regulation of ANXA2 led to S-phase arrest of HCC cells (q =8.001, P =0.002) and an inhibition of proliferation (q =17.140, P less than 0.01), migration (q =12.808, P less than 0.01) and invasion potential (q =9.069, P =0.002). Xenograft tumour-growth assay indicated that shRNA targeting of ANXA2 led to lower tumour weight (q =11.968, P < 0.001) and down-regulated ANXA2 expression (Z =2.530, P =0.011).

CONCLUSIONDown-regulation of Annexin A2 gene transcription effectively changes the biological behaviours of hepatoma cells, and may represent a potential target of HCC molecular therapies.

Animals ; Annexin A2 ; genetics ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Liver Neoplasms ; pathology ; Neoplasm Transplantation ; RNA, Small Interfering ; genetics ; Signal Transduction ; Transcription, Genetic

This study was purposed to investigate the apoptosis-inducing effect of Annexin A2 gene (AnxA2) on multiple myeloma (MM) cells and its mechanisms. The human MM cell lines U266 and RPMI8226 were transfected by using siRNA targeting at AnxA2; the expressions of AnxA2 mRNA and protein in the siRNA-transfected cells were detected by real-time PCR and Western blot, respectively; the cell apoptosis was assayed by flow cytometry. The results showed that silencing AnxA2 gene by siRNA resulted in decreased expressions of AnxA2 gene and protein, increased apoptosis of U266 and RPMI8226 cell lines (P < 0.05), at the same time resulted in down-regulation of apoptosis-related gene expressions including p65NF-κB, IL-2, IL-6 (P < 0.05), and up-regulation of P53 gene expression (P < 0.05). It is concluded that the AnxA2 silence plays a promoting role in apoptosis of MM cell lines U266 and RPMI8226.
Annexin A2 ; genetics ; Apoptosis ; genetics ; Cell Line, Tumor ; Humans ; Multiple Myeloma ; genetics ; pathology ; RNA, Small Interfering ; genetics

BACKGROUNDChoroidal neovascularization (CNV) is a common cause of visual loss in the elderly patients with age-related macular degeneration and represents the growth of subretinal new vessels in the macular region. This study aimed to investigate the relationship between annexin A2 (ANXA2) and vascular endothelial growth factor (VEGF) in CNV.

METHODSIn a rat model of argon laser coagulation-induced CNV, the mRNA expressions of the annexins and VEGF protein expression in the retina were detected using fluorescent real-time polymerase chain reaction (PCR) and immunohistochemistry, respectively. The interactions between ANXA2 and VEGF in both a retinal pigment epithelial cell line RPE-J and the rat model of CNV were examined by means of RNA interference, real-time PCR, Western blotting, enzyme-linked immunosorbent assay (ELISA) and histopathological examinations.

RESULTSFundus fluorescein angiography (FFA) showed that argon laser coagulation of the retina induced stable CNV models in the rats. Two to three weeks after the coagulation, ANXA2 and VEGF expressions in the coagulated area in the retina and choroid increased to the peak level, while the other annexin members (ANXA4, ANXA5, ANXA7 and ANXA11) showed no obvious changes. In RPE-J cells and the CNV model, RNA interference of ANXA2 gene significantly lowered the VEGF protein and mRNA expressions, and application of an adenoviral vector containing ANXA2 gene markedly increased VEGF expressions in the rat model of CNV, but produced no significant effects on the expressions of the kinase insert domain-containing receptor (KDR) or the fms-like tyrosine kinase (Flt-1). The expression of KDR inhibited the increment in ANXA2 expression, but VEGF and Flt-1 did not directly affect ANXA2 expression.

CONCLUSIONBesides the role as a plasminogen and the receptor of tissue plasminogen activator, ANXA2, which is under regulation of KDR via a negative feedback mechanism, also participates in neovascularization by regulating VEGF expression through a positive feedback mechanism.

Animals ; Annexin A2 ; analysis ; genetics ; physiology ; Cells, Cultured ; Choroidal Neovascularization ; etiology ; metabolism ; Disease Models, Animal ; Immunohistochemistry ; Laser Coagulation ; Lasers, Gas ; RNA, Messenger ; analysis ; Rats ; Rats, Inbred BN ; Vascular Endothelial Growth Factor A ; analysis ; genetics ; physiology

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

OBJECTIVETo investigate the effects of bortezomib on the migration of endothelial cells and the expression of angiogenesis-related molecules, and explore the mechanism of its antiproliferation of tumor cells.

METHODSCell count kit CCK-8 was used to detect the relative proliferation activity of cells after treated by bortezomib at different concentrations for 12 h and 24 h, respectively. Transwell model was uesd to detect the migration rate of cells. Expression levels of VEGF and Annexin A2 genes were determined by real-time quantitative PCR. Annexin A2 protein was validated by Western blot.

RESULTSAfter treated with bortezomib at concentrations of 2.5, 5.0 and 10 nmol/L for 12h, respectively, the HMEC-1 cell proliferation activity was 1.004 ± 0.002, 0.793 ± 0.021 and 0.874 ± 0.062, respectively, being no statistical difference from that of control group (1.000) P < 0.05); while the migration rates of them were 0.697 ± 0.060, 0.597 ± 0.090 and 0.874 ± 0.062, respectively, being significantly lower than that of control group (1.000) (P < 0.05) and so did for the expression of VEGF and Annexin A2 genes. After treated with 5 nmol/L bortezomib for 12 h, the Annexin A2 and VEGF gene relative expression level of HMEC-1 cells was 0.540 ± 0.001 and 0.793 ± 0.153, respectively, being of statistical difference from that of control group (1.000) P < 0.05). The conspicuous downregulation of Annexin A2 protein was also confirmed by Western Blot.

CONCLUSIONSBortezomib can inhibit migration of endothelial cell HMEC-1 by downregulating the expression of VEGF and Annexin A2, displaying a new mechanism of bortezomib for inhibition of tumor proliferation.

Annexin A2 ; metabolism ; Bortezomib ; Cell Proliferation ; drug effects ; Endothelial Cells ; metabolism ; Humans ; RNA, Messenger ; genetics ; Vascular Endothelial Growth Factor A ; metabolism

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

OBJECTIVETo investigate the effects of Annexin II (AnxA2) gene silencing by siRNA on proliferation and invasive potential of lymphoma cell line Jurkat cells.

METHODSA synthesized siRNA duplex targeting to AnxA2 was transfected into Jurkat cells. Transfection efficiency was analyzed by real-time PCR and flow cytometry. MTT assay for cell proliferation and transwell plates for invasive potential were performed.

RESULTSCompared with the negative controls, the cell proliferation inhibitory rate of the AnxA2 siRNA transfected Jurkat cells was significantly increased at 24 h, 48 h and 72 h [(17.4 +/- 2.3)%, (22.4 +/- 3.8)%, (37.6 +/- 1.5)% vs (-1.3 +/- 5.1)%, (-5.5 +/- 4.4)%, (-10.8 +/- 5.5)%, respectively, P<0.05]. The cell invasive potential of the transfected Jurkat cells was inhibited remarkably at 48 h (11.3 +/- 4.2 vs 54.3 +/- 8.7, P<0.01).

CONCLUSIONAnxA2 gene silenced by siRNA can inhibit the proliferation and the invasive potential of Jurkat cells remarkably.

Annexin A2 ; genetics ; metabolism ; Cell Proliferation ; Chemotaxis ; genetics ; Gene Silencing ; Humans ; Jurkat Cells ; RNA, Small Interfering ; genetics ; Transfection

OBJECTIVETo study the fibrinolytic activity in patients with acute promyelocytic leukemia (APL) and its alteration in all-trans retinoic acid (ATRA) and/or arsenic trioxide (ATO) treatment.

METHODSPlasma fibrinogen concentration was determined with the conventional method, and the levels of fibrin degradation products (FDP) and D-dimer were quantified with ELISA. Plasminogen was measured by chromogenic assay. Cell surface expression of Annexin II and u-PAR and their mRNA levels were measured by flow cytometry and real time-PCR, respectively.

RESULTSThe levels of FDP and D-dimer in APL were remarkably higher in APL patients than that in normal controls, while fibrinogen and plasminogen were lower. Both Annexin II and u-PAR were highly expressed on APL cells, which declined after treatment with ATRA and/or ATO, but remained higher than those on normal bone marrow mononuclear cells.

CONCLUSIONAbnormally high levels of Annexin II and u-PAR expression on APL cells may contribute to the increased production of plasmin, leading to primary hyperfibrinolysis in APL. ATRA and ATO therapy induces down-regulation of Annexin II and u-PAR expression, which may be contribute, at least in part, to the relief of the hemorrhagic complications in APL.

Adolescent ; Adult ; Aged ; Annexin A2 ; analysis ; Arsenicals ; therapeutic use ; Female ; Fibrinolysis ; Humans ; Leukemia, Promyelocytic, Acute ; drug therapy ; physiopathology ; Male ; Middle Aged ; Oxides ; therapeutic use ; RNA, Messenger ; genetics ; Tretinoin ; therapeutic use ; Urokinase-Type Plasminogen Activator ; analysis ; Young Adult