Endothelial Cell-Derived Microparticles in the Pathogenesis of Chemotherapy-Associated Hypercoagulability.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1457-1457
Author(s):  
Daniel Lechner ◽  
Marietta Kollars ◽  
Sabine Eichinger ◽  
Paul Alexander Kyrle ◽  
Ansgar Weltermann
Keyword(s):  
Thrombin Generation ◽  
Culture Media ◽  
Annexin V ◽  
Membrane Vesicles ◽  
Procoagulant Activity ◽  
Dependent Manner ◽  
Thrombin Generation Assay ◽  
Apoptotic Effect ◽  
Mitochondrial Dehydrogenase Activity

Abstract Background: Cisplatin-based chemotherapy is a risk factor of venous thromboembolism in cancer patients. The underlying pathogenesis remains unclear. We hypothesized an apoptotic effect of cisplatin on endothelial cells (EC) inducing a release of small membrane vesicles, so-called microparticles (MP) which are known to cause hemostasis activation. Objectives: To quantify the release of MP from EC following administration of cisplatin and to investigate MP-associated procoagulant mechanisms. Methods: Two EC lines (HUVEC, HMVEC-L) were exposed to cisplatin (1, 2.5, 5, 10, and 20 μM) for up to 120 h. Cell viability was assessed by quantification of mitochondrial dehydrogenase activity, counts and procoagulant activity of MP were measured by flow cytometry and a thrombin generation assay, respectively. Tissue factor (TF) antigen levels were determined by ELISA. Results: EC viability decreased in a dose- and time-dependent manner and was accompanied by an increasing release of MP into culture media (maximum: HUVEC + 544%; HMVEC-L + 1738%). In parallel, procoagulant activity of media increased by up to 150% (HUVEC) and 493% (HMVEC-L), respectively. The procoagulant activity was almost abolished by annexin V but was not suppressed by a monoclonal TF-antibody. TF antigen levels on MP were persistently low even at high cisplatin concentrations. Conclusion: At pharmacologically relevant concentrations, cisplatin induced a marked release of procoagulant MP from EC. Negatively charged phospholipids but not TF on MP were decisive for total thrombin generation. Further studies are warranted to investigate the cisplatin-induced release of EC-derived MP in vivo.

scholarly journals Monitoring Compound-Related Effects on Coagulability in Rats and Cynomolgus and Rhesus Monkeys by Thrombin Generation Kinetic Measurement

2020 ◽  
Vol 39 (3) ◽  
pp. 207-217
Author(s):  
F. Poitout-Belissent ◽  
D. Culang ◽  
D. Poulin ◽  
R. Samadfan ◽  
S. Cotton ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Thrombin Generation ◽  
In Vivo Studies ◽  
Coagulation Cascade ◽  
Dependent Manner ◽  
Kinetic Assay ◽  
Thrombin Generation Assay ◽  
Coefficients Of Variation

Thrombin generation assay (TGA) is a sensitive method for the assessment of the global clotting potential of plasma. This kinetic assay can detect both hypocoagulable and hypercoagulable conditions: delayed or reduced thrombin generation leading to a prolonged clotting time, or induced thrombin activity, shifting the coagulation cascade toward thrombosis. The purpose of this study is to qualify the TGA in nonhuman primates (NHP) and rats for its use during nonclinical in vivo and in vitro studies. Blood was drawn from nonanesthetized animals, and platelet-poor plasma was obtained after double centrifugation; coefficients of variation were <10% for all derived parameters of thrombin generation assessed with 5 pM of tissue factor. Thrombin generation was evaluated in vitro in rat and NHP plasmas with ascending doses of unfractionated heparin (UFH), recombinant tissue factor, and anticoagulant compounds. Thrombin generation was decreased with UFH and anticoagulant compounds, but was increased in the presence of tissue factor, in a dose-dependent manner. In a rat model of inflammation, animals were administered a low dose of lipopolysaccharides. Thrombin generation measurements were decreased 3 hours post-LPS administration with a nadir at 24 hours, while thrombin–antithrombin complexes reached a peak at 8 hours, supporting an earlier production of thrombin. In conclusion, these data demonstrated that TGA can be performed in vitro for screening of compounds expected to have effects on coagulation cascade, and thrombin generation can be measured at interim time points during nonclinical in vivo studies in rats and NHP.

The Effects of Heparin and Annexin V on Fibrin Accretion after Injury in the Jugular Veins of Rabbits

1993 ◽  
Vol 69 (03) ◽  
pp. 227-230 ◽  
Author(s):  
J Van Ryn-McKenna ◽  
H Merk ◽  
T H Müller ◽  
M R Buchanan ◽  
W G Eisert
Keyword(s):  
Vessel Wall ◽  
Thrombin Generation ◽  
Antithrombin Iii ◽  
Specific Effect ◽  
Annexin V ◽  
Inhibitory Effect ◽  
Jugular Veins ◽  
Prothrombinase Complex ◽  
Wall Injury

SummaryWe compared the relative abilities of unfractionated heparin and annexin V to prevent fibrin accretion onto injured jugular veins in vivo. Heparin was used to accelerate the inhibition of thrombin by antithrombin III, and annexin V was used to inhibit the assembly of the prothrombinase complex on phospholipid surfaces, thereby blocking thrombin generation. Rabbit jugular veins were isolated in situ, a 2 cm segment was injured by perfusing it with air, and then blood flow was re-established. Five minutes later, each rabbit was injected with heparin (20 U/kg) or annexin V (0.3 mg/kg) and then with 125I-fibrinogen. The amount of 125I-fibrin accumulation onto each injured vessel wall segment was measured 4 h later. Each injured vessel was completely deendothelialized as a result of the air perfusion as demonstrated by electron microscopy. 125I-fibrin accretion onto the injured jugular veins was enhanced 2.4-fold as compared to the uninjured veins in sham-operated animals. Heparin treatment did not reduce fibrin accretion, whereas, annexin V treatment decreased fibrin accretion by 60%, p <0.05. This latter effect was achieved without sustained circulating anticoagulation. Additional experiments confirmed that the inhibitory effect of annexin V on fibrin accretion was associated with a surface specific effect, since more annexin V bound to the injured jugular vein segments as compared to the non-injured jugular veins. We conclude that, i) mild vessel wall injury (selective de-endothelialization) in veins results in a thrombogenic vessel wall; ii) the thrombogenecity of which is not inhibited by prophylactic doses of heparin; but iii) is inhibited by annexin V, which binds to injured vessel wall surface, and inhibits thrombin generation independently of antithrombin III.

Increased Procoagulant Activity of Red Blood Cells from Patients with Homozygous Sickle Cell Disease and β-Thalassemia

1996 ◽  
Vol 76 (03) ◽  
pp. 322-327 ◽  
Author(s):  
Dominique Helley ◽  
Amiram Eldor ◽  
Robert Girot ◽  
Rolande Ducrocq ◽  
Marie-Claude Guillin ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Red Blood Cells ◽  
Sickle Cell ◽  
Blood Cells ◽  
Annexin V ◽  
Mean Value ◽  
Procoagulant Activity ◽  
Dependent Manner ◽  
Cell Disease ◽  
Homozygous Sickle Cell Disease

SummaryIt has recently been proved that, in vitro, red blood cells (RBCs) from patients with homozygous β-thalassemia behave as procoagulant cells. The procoagulant activity of β-thalassemia RBCs might be the result of an increased exposure of procoagulant phospholipids (i. e. phosphatidylserine) in the outer leaflet of the membrane. In order to test this hypothesis, we compared the catalytic properties of RBCs of patients with β-thalassemia and homozygous sickle cell disease (SS-RBCs) with that of controls. The catalytic parameters (Km, kcat) of prothrombin activation by factor Xa were determined both in the absence and in the presence of RBCs. The turn-over number (kcat) of the reaction was not modified by normal, SS- or (3-thalassemia RBCs. The Km was lower in the presence of normal RBCs (mean value: 9.1 µM) than in the absence of cells (26 µM). The Km measured in the presence of either SS-RBCs (mean value: 1.6 µM) or β-thalassemia RBCs (mean value: 1.5 pM) was significantly lower compared to normal RBCs (p <0.001). No significant difference was observed between SS-RBCs and p-thalassemia RBCs. Annexin V, a protein with high affinity and specificity for anionic phospholipids, inhibited the procoagulant activity of both SS-RBCs and (3-thalassemia RBCs, in a dose-dependent manner. More than 95% inhibition was achieved at nanomolar concentrations of annexin V. These results indicate that the procoagulant activity of both β-thalassemia RBCs and SS-RBCs may be fully ascribed to an abnormal exposure of phosphatidylserine at the outer surface of the red cells.

The Effect of Active Site-inhibited Factor VIIa on Tissue Factor-initiated Coagulation Using Platelets before and after Aspirin Administration

1997 ◽  
Vol 78 (04) ◽  
pp. 1202-1208 ◽  
Author(s):  
Marianne Kjalke ◽  
Julie A Oliver ◽  
Dougald M Monroe ◽  
Maureane Hoffman ◽  
Mirella Ezban ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Active Site ◽  
Large Scale ◽  
Thrombin Generation ◽  
Factor Viia ◽  
Dependent Manner ◽  
Antithrombotic Agent ◽  
Before And After ◽  
Ic50 Values

SummaryActive site-inactivated factor VIIa has potential as an antithrombotic agent. The effects of D-Phe-L-Phe-L-Arg-chloromethyl ketone-treated factor VIla (FFR-FVIIa) were evaluated in a cell-based system mimicking in vivo initiation of coagulation. FFR-FVIIa inhibited platelet activation (as measured by expression of P-selectin) and subsequent large-scale thrombin generation in a dose-dependent manner with IC50 values of 1.4 ± 0.8 nM (n = 8) and 0.9 ± 0.7 nM (n = 7), respectively. Kd for factor VIIa binding to monocytes ki for FFR-FVIIa competing with factor VIIa were similar (11.4 ± 0.8 pM and 10.6 ± 1.1 pM, respectively), showing that FFR-FVIIa binds to tissue factor in the tenase complex with the same affinity as factor VIIa. Using platelets from volunteers before and after ingestion of aspirin (1.3 g), there were no significant differences in the IC50 values of FFR-FVIIa [after aspirin ingestion, the IC50 values were 1.7 ± 0.9 nM (n = 8) for P-selectin expression, p = 0.37, and 1.4 ± 1.3 nM (n = 7) for thrombin generation, p = 0.38]. This shows that aspirin treatment of platelets does not influence the inhibition of tissue factor-initiated coagulation by FFR-FVIIa, probably because thrombin activation of platelets is not entirely dependent upon expression of thromboxane A2.

Panax notoginseng Inhibits Tumor Growth through Activating Macrophage to M1 Polarization

2018 ◽  
Vol 46 (06) ◽  
pp. 1369-1385 ◽  
Author(s):  
Bosung Kim ◽  
Eun-Yeong Kim ◽  
Eun-Ji Lee ◽  
Jung Ho Han ◽  
Chung-Hwan Kwak ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Culture Media ◽  
Tumor Model ◽  
Annexin V ◽  
Panax Notoginseng ◽  
Raw264.7 Cells ◽  
M1 Polarization ◽  
Chemotactic Protein ◽  
M1 Phenotype

Among the herbal ingredients of HangAmDan-B, a medicinal formula that redirects macrophages to become tumoricidal effectors, we found that Panax notoginseng (Burk.) F. H. Chen is the active component responsible for its macrophage-mediated antitumor activity. The water extracted roots of P. notoginseng (PN) did not affect the viability of RAW264.7 murine macrophage-like cells and murine Lewis lung carcinoma (LLC) cells up to a concentration of 100[Formula: see text][Formula: see text]g/mL. However, the transfer of culture media from PN-treated RAW264.7 cells suppressed the growth of LLC cells. The expression of classically activated (M1) markers, such as interleukin (IL)-1[Formula: see text], monocyte chemotactic protein (MCP)-1, tumor necrosis factor (TNF)-[Formula: see text], and inducible nitric oxide synthase (iNOS), was increased by PN treatment. The expression of alternatively activated (M2) markers including CD206, IL-10, and [Formula: see text]-[Formula: see text]-acetylhexosaminidases (YM-1) was reduced by PN treatment in the presence of IL-4. Flow cytometry also revealed that PN drives M1 activation of RAW264.7 cells. The transfer of culture media from PN-treated RAW264.7 cells induced the apoptosis of LLC cells as measured by flow cytometry using Annexin-V staining and western blot analysis for caspase cascade-related proteins. In addition, the results from in vivo tumor allograft model demonstrated that PN reduced both tumor volume and weight. The activation of macrophages toward an M1 phenotype was confirmed in the tumor allograft tumor model. These results collectively show that PN can serve as a potent anticancer agent through reeducation of macrophages toward an M1 phenotype.

scholarly journals An Intramolecular Association between Two Domains of the Protein Kinase Fused Is Necessary for Hedgehog Signaling

2004 ◽  
Vol 24 (23) ◽  
pp. 10397-10405 ◽  
Author(s):  
Manuel Ascano ◽  
David J. Robbins
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Hedgehog Signaling ◽  
Membrane Vesicles ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Dependent Manner ◽  
Intramolecular Association

ABSTRACT The protein kinase Fused (Fu) is an integral member of the Hedgehog (Hh) signaling pathway. Although genetic studies demonstrate that Fu is required for the regulation of the Hh pathway, the mechanistic role that it plays remains largely unknown. Given our difficulty in developing an in vitro kinase assay for Fu, we reasoned that the catalytic activity of Fu might be highly regulated. Several mechanisms are known to regulate protein kinases, including self-association in either an intra- or an intermolecular fashion. Here, we provide evidence that Hh regulates Fu through intramolecular association between its kinase domain (ΔFu) and its carboxyl-terminal domain (Fu-tail). We show that ΔFu and Fu-tail can interact in trans, with or without the kinesin-related protein Costal 2 (Cos2). However, since the majority of Fu is found associated with Cos2 in vivo, we hypothesized that Fu-tail, which binds Cos2 directly, would be able to tether ΔFu to Cos2. We demonstrate that ΔFu colocalizes with Cos2 in the presence of Fu-tail and that this colocalization occurs on a subset of membrane vesicles previously characterized to be important for Hh signal transduction. Additionally, expression of Fu-tail in fu mutant flies that normally express only the kinase domain rescues the fu wing phenotype. Therefore, reestablishing the association between these two domains of Fu in trans is sufficient to restore Hh signal transduction in vivo. In such a manner we validate our hypothesis, demonstrating that Fu self-associates and is functional in an Hh-dependent manner. Our results here enhance our understanding of one of the least characterized, yet critical, components of Hh signal transduction.

Nicotinamide Enhances the Polyploidization of Primary Megakaryocytes.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1366-1366
Author(s):  
Lisa M. Giammona ◽  
Eleftherios Papoutsakis ◽  
William M. Miller
Keyword(s):  
Dna Content ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Annexin V ◽  
Dependent Manner ◽  
Vitamin B3 ◽  
Ploidy Levels ◽  
High Ploidy

Abstract Megakaryocyte (Mk) maturation includes the development of polyploid cells via endomitosis. In vitro models of Mk differentiation can be used to gain a better understanding of the molecular mechanisms controlling this process. However, it is challenging to achieve ploidy levels in cultured human cells that are as high as those observed in vivo. Others have recently reported the use of chemical inhibitors to increase Mk ploidy (Lannutti et al., Blood 105:3875, 2005). Here, we show that nicotinamide (NIC), a form of vitamin B3, enhances the normal process of Mk polyploidization and leads to both a greater fraction of high ploidy cells and a greater degree of polyploidization. Human mobilized peripheral blood CD34+ cells were cultured in serum-free medium supplemented with thrombopoietin (TPO) to induce Mk differentiation. Beginning on day 5 of culture, cells were treated with nicotinamide (3 and 6.25 mM) and monitored for DNA content, growth, apoptosis, and surface marker expression. NIC treatment resulted in a greater fraction of Mks with high ploidy (DNA content greater than or equal to 8N). The ploidy of NIC treated cells continued to increase over the duration of the 13-day culture, whereas the ploidy of untreated cells peaked at day 9. On day 13 (8 days of NIC exposure), the percentages of high ploidy Mks for the untreated, 3 mM NIC, and 6.25 mM NIC conditions were 23%, 48%, and 63%, respectively. Furthermore, cells treated with NIC reached ploidy levels of 64N and 32N for 6.25 and 3 mM NIC, respectively, compared to 16N for untreated cells. NIC-treated cells also displayed dramatic differences in morphology - characterized by an increase in cell size, the presence of a more highly lobated nucleus, and an increased frequency of proplatelet-forming cells. Nicotinamide is known to inhibit poly(ADP-ribose) polymerase (PARP) and Sir2, which are both NAD+ dependent enzymes. Preliminary experiments show that PARP activity is low in cultured Mks and is not affected by addition of 6.25 mM NIC. Continued exposure (beginning at day 5) to the PARP inhibitors (and nicotinamide analogs) 3-aminobenzamide (3-AB) and benzamide at concentrations of 1, 3, and 6.25 mM was toxic to cells in a dose dependent manner. Interestingly, high doses of NIC (25 and 50 mM) were also toxic to cells. Remarkably, while Mk polyploidization and apoptosis are typically correlated, the increase in DNA content observed for NIC-treated cells occurred without significantly affecting the percentage of apoptotic Mks (assessed by Annexin V staining). These data suggest that it may be possible to partially decouple Mk apoptosis and polyploidization. Furthermore, while 6.25 mM NIC inhibited cell proliferation by ~35%, total expansion of cells cultured with 3 mM NIC was similar to that of untreated cells. This, combined with similar Mk commitment, as defined by a similar percentage of CD41+ cells, resulted in a greater overall number of high ploidy Mks in cultures treated with NIC. Since there is a direct correlation between Mk DNA content and platelet production (Mattia et al., Blood 99:888, 2002), these results suggest a possible therapeutic benefit of NIC for the management of thrombocytopenia. Similarly, NIC could also be used as an additive to ex vivo Mk cultures destined for transplantation. Figure Figure

Phenotypic and Functional Effects of Perifosine on Dendritic Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4803-4803
Author(s):  
Weihua Song ◽  
Teru Hideshima ◽  
Yu-Tzu Tai ◽  
Kenneth C. Anderson ◽  
Nikhil C. Munshi
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Annexin V ◽  
Antitumor Agent ◽  
Dependent Manner ◽  
Immune Functions ◽  
Akt Inhibitor ◽  
Antitumor Effects

Abstract Perifosine is a synthetic novel alkylphospholipid, a new class of antitumor agent which targets cell membranes and inhibits Akt activation. Perifosine inhibits multiple myeloma (MM) cell growth in vitro and in vivo mouse model. Currently perifosine is under the evaluation of phase II clinical trail in MM. Although perifosine has shown significant direct antitumor effects, its effect on immune system has not yet been clarified. The objective of this study is to evaluate the effects of perifosine on the activity of antigen presenting cells (APCs). Monocyte-derived dendritic cells (DCs) from normal human donors were used as the APCs, and mature DCs were obtained by the treatment of TNF-α and IL-1β. Perifosine was used at the concentrations of 2.5 uM, 5 uM and 10 uM for the treatment with DCs. We first evaluated the effect of perifosine on the survival of DCs. We observed that the perifosine treatment up to 48 hours had no effect on viability (>90%) of DCs, assessed by annexin V and PI staining. Alteration of phenotype by perifosine on DCs was further examined by flow cytometry. Our results demonstrated that with dose-dependent manner, perifosine led to a significant down-regulation of surface antigens on immature DCs at 24 and 48 hours, which associated to costimulation (CD40, CD80 and CD86), antigen presentation (HLA-ABC, HLA-DPQR) and maturation (CD83). However, we did not observed significant effect of perifosine on above surface markers on mature DCs. Since DCs play a crucial role on the regulation of Th1/Th2 immune responses by the production of IL-12, we next evaluated IL-12 secretion by DCs with and without perifosine treatment. Importantly, treatment with perifosine significantly decreased LPS-induced-IL-12 production, compared to untreated DCs (untrt vs. trt = 192.29 vs. 166.23 pg/ml (2.5uM), 111.19 pg/ml (5uM) and 44.886 pg/ml (10uM)) at 24 hours. To assess the effect of perifosine on DCs function on the regulation of T cell responses, we stimulated allogenic T cells with mature DCs with or without the pre-treatment of perifosine. The proliferation assay by 3H-TdR incorporation and IFN-γ production by ELISA indicated perifosine-treated DCs had no significant effect on the regulation of T cells function. Taken together, these results showed that DCs function are influenced by the treatment of perifosine. Our pre-clinical data therefore indicates the need to monitor immune functions in patients under the Akt inhibitor treatment.

Feedback Activation of Factor XI by Thrombin Is Essential for Hemostasis In Vivo.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2127-2127
Author(s):  
Henri M. H. Spronk ◽  
Sabine Wilhelm ◽  
Rene Van Oerle ◽  
Menno L. Knetsch ◽  
David Gailani ◽  
...  
Keyword(s):  
Thrombin Generation ◽  
Conflicts Of Interest ◽  
Factor Viia ◽  
Fibrin Clot ◽  
Intrauterine Death ◽  
Factor Xii ◽  
Dependent Manner ◽  
Factor Xi ◽  
Feedback Activation

Abstract Abstract 2127 Poster Board II-102 Background: The revised model of coagulation proposes that factor XI (FXI) can be activated by thrombin, which is generated upon activation of the tissue factor (TF) pathway. This concept, however, has not been tested in vivo. A recent study questioned the existence of this feedback loop and suggested that factor XII (FXII) is the sole activator of FXI. Here, we analyze the feedback activation of FXI in plasma and in genetically altered mice. Methods and results: Fluorescence-based assays indicated that particle-bound thrombin caused thrombin generation in plasma both in the absence of TF and in the presence of active site inhibited factor VIIa. Thrombin failed to activate FXII and thrombin generation was almost completely abolished by an anti-FXIa antibody and in FXI-deficient plasma. Surface bound thrombin induced complex formation of FXI, with its major inhibitor C1 inhibitor, even in FXII-deficient plasma in a time and dose dependent manner. To determine if thrombin-driven FXI activation is important for hemostasis in vivo we used TF deficient mice (low TF), which have severely reduced thrombin formation. Low TF mice were crossed with mice deficient in one of the intrinsic pathway proteases FXII, FXI, or FIX. Double deficiency in TF and either FIX or FXI resulted in the intrauterine death of embryos due to hemorrhage. In contrast low TF/FXII-null mice were viable and the bleeding phenotype was unchanged from low TF animals. Conclusions: Surface-bound thrombin, a model for fibrin clot-protected thrombin, generates thrombin in a FXI dependent manner, independently from FXII. In addition to corroborating an amplifying role of FXI in thrombin generation, we provide the first evidence that at low TF levels FXI is essential in generating a sufficient ambient level of thrombin to permit embryonic development. Disclosures: No relevant conflicts of interest to declare.

Inhibition Effects of baicalin on Lymphoma Cell Line CA46 in Vitro and in Vivo

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5053-5053
Author(s):  
Jian Da Hu ◽  
Yi Huang ◽  
Yingyu Chen ◽  
Tiannan Wei ◽  
Tingbo Liu ◽  
...  
Keyword(s):  
Cell Line ◽  
Biological Effects ◽  
Annexin V ◽  
Lymphoma Cell ◽  
Control Group ◽  
Dependent Manner ◽  
Lymphoma Cell Line ◽  
Proliferation Inhibition

Abstract Baicalin is a traditional Chinese medicine with multiple biological effects. Some researches showed baicalin has anti-tumor effects in solid tumor, such as prostate cancer. In order to investigate its effects on proliferation inhibition and apoptosis induction in human lymphoma cell, we treated Burkitt lymphoma cell line CA46 with baicalin in vitro and in vivo of CA46 xenograft. Baicalin remarkably inhibited the cell proliferation, with an IC50 value of 10μM. Apoptosis was remarkably induced by baicalin in a dose-dependent manner, which was detected by Annexin V FITC/PI double staining analysis, TUNEL labeling method and DNA fragmentation respectively. Furthermore, RT-PCR showed that the mRNA expressions of c-myc and bcl-2 in treated CA46 cell decreased in a time-dependent manner. Western-Blot showed that the protein expressions of c-myc, bcl-2, procaspase-3 and PARP(116KD) in baicalin treated CA46 cell were down-regulated, while the expression of PARP(85KD) increased. Based on the results in vitro, we investigated in vivo efficacy of baicalin, alone or in combination with cytotoxic drug VP16, for treatment in CA46 nude mice xenograft. Baicalin with the dosage of 40mg/kg/d and 80kg/mg/d could remarkably inhibit the growth of the tumor compared with control group. Combination of baicalin and VP16 had better anti-tumor effects. Histological examination of tumor samples showed more necrotic cells in treated groups. And obvious apoptosis could be observed by electron microscope. No adverse events were found in treated groups. From above we could conclude that baicalin could efficiently induce proliferation inhibition and apoptosis of CA46 cells in vitro and in vivo, which may be related with the down-regulation of c-myc and bcl-2 expressions, as well as the up-regulation of caspase-3 activity.

Sign in / Sign up

Export Citation Format

Share Document