OBJECTIVETo test the effect of bifunctional molecule IL2-GMCSF in promoting the activation of dendritic cells (DCs) cultured in tumor conditioned medium.

METHODSWe prepared a tumor conditioned medium using mouse melanoma cell line B16F10 supplemented with IL2-GMCSF, GM-CSF, IL-2, or the combination of the latter two. After culturing mouse DC cell line DC2.4 in the conditioned medium for 24 h, the DCs were examined for phagocytosis, proliferation, maturation phenotype, cytokine secretion, and signal pathway activation.

RESULTSDC2.4 cells displayed characteristics of immature DCs. After cell culture in the conditioned medium, the cells showed enhanced phagocytosis but significantly suppressed cell proliferation activity. Culture in the conditioned medium also promoted DC cell maturation and secretion of macrophage-derived chemokine (MDC), but inhibited IL-12 secretion. Supplementation of the conditioned medium with IL2-GMCSF promoted phagocytosis, proliferation, maturation, and cytokine (including both IL-12 and MDC) secretion of DC2.4 cells. Compared with GM-CSF, IL2-GMCSF induced a higher level of NF-κB signal pathway activation but suppressed STAT3 activation.

CONCLUSIONCompared with GM-CSF, IL2-GMCSF can better promote DC activation in the context of tumor-induced immune suppression, and thus shows potentials in anti-tumor therapy.

Animals ; Cell Differentiation ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Chemokine CCL22 ; metabolism ; Culture Media, Conditioned ; chemistry ; Dendritic Cells ; cytology ; drug effects ; Gene Expression Regulation, Neoplastic ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Immune Tolerance ; Interleukin-12 ; metabolism ; Interleukin-2 ; pharmacology ; Melanoma, Experimental ; pathology ; Mice ; NF-kappa B ; metabolism ; Phagocytosis ; STAT3 Transcription Factor ; metabolism ; Signal Transduction

In order to enhance the antitumor efficacy of recombinant Newcastle disease virus, rNDV-IL15 was rescued in this study. Recombinant plasmid prNDV-IL15 was constructed, and BHK21 cells were transfected with the recombinant plasmid. Finally, the recombinant Newcastle disease virus rNDV-IL15 was successfully rescued. The growth curves of these two recombinant viruses were determined. Murine melanoma B16F10 cells were infected with rNDV-IL15 at MOI of 0.1, and the expression level of IL15 in the supernatant was detected by ELISA. The antitumor efficacy of rNDV-IL15 and rNDV was compared in vitro and in vivo. Results showed that prNDV-IL15 was constructed and recombinant virus rNDV-IL15 was successfully rescued. The growth curve of rNDV-IL15 showed that the growth of rNDV-IL15 had not been changed after insertion of IL15 gene. Results showed that there was high level of IL15 expression in the supernatant of rNDV-IL5-infected B16F10 cells (1 044.3 +/- 27.7 ng x mL(-1)). rNDV-IL15 and rNDV significantly inhibited the growth of B16F10 cells in vitro in a time-dependent manner. However, there was no significant difference between them. In animal experiments, rNDV-IL15 efficiently suppressed tumor growth in vivo when compared with rNDV, and the difference was statistically significant. The results suggested that rNDV-IL15 is a more effective antitumor agent.
Animals ; Body Weight ; Cell Line, Tumor ; Cell Proliferation ; Chick Embryo ; Cytotoxicity, Immunologic ; Female ; Genetic Therapy ; Interleukin-15 ; genetics ; metabolism ; Melanoma, Experimental ; pathology ; therapy ; Mice ; Neoplasm Transplantation ; Newcastle disease virus ; genetics ; Plasmids ; Recombinant Proteins ; genetics ; metabolism ; Transfection ; Tumor Burden

CD146 is a newly identified endothelial biomarker that has been implicated in angiogenesis. Though in vitro angiogenic function of CD146 has been extensively reported, in vivo evidence is still lacking. To address this issue, we generated endothelial-specific CD146 knockout (CD146(EC-KO)) mice using the Tg(Tek-cre) system. Surprisingly, these mice did not exhibit any apparent morphological defects in the development of normal retinal vasculature. To evaluate the role of CD146 in pathological angiogenesis, a xenograft tumor model was used. We found that both tumor volume and vascular density were significantly lower in CD146(EC-KO) mice when compared to WT littermates. Additionally, the ability for sprouting, migration and tube formation in response to VEGF treatment was impaired in endothelial cells (ECs) of CD146(EC-KO) mice. Mechanistic studies further confirmed that VEGF-induced VEGFR-2 phosphorylation and AKT/p38 MAPKs/NF-κB activation were inhibited in these CD146-null ECs, which might present the underlying cause for the observed inhibition of tumor angiogenesis in CD146(EC-KO) mice. These results suggest that CD146 plays a redundant role in physiological angiogenic processes, but becomes essential during pathological angiogenesis as observed in tumorigenesis.
Animals ; CD146 Antigen ; genetics ; metabolism ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; Female ; Fibrosarcoma ; metabolism ; pathology ; Male ; Melanoma, Experimental ; metabolism ; pathology ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NF-kappa B ; metabolism ; Neovascularization, Physiologic ; drug effects ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Retinal Vein ; growth & development ; pathology ; Signal Transduction ; drug effects ; Transplantation, Homologous ; Vascular Endothelial Growth Factor A ; pharmacology ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism

OBJECTIVETo evaluate the therapeutic effect of MHSP65-TCL on melanoma and its effect on the activity of the immunocytes.

METHODSMHSP65-TCL was prepared by mixing MHSP65 with TCL derived from B16 melanoma cell lysate by repeated freezing and thawing. The MHSP65-TCL vaccine was administered in mice bearing B16 melanoma, and the changes in melanoma growth was observed. To investigate the influence of TCL in MHSP65-TCL on the activity of the immunocytes, we co-cultured TCL and mouse spleen cells in vitro, and analyzed CD69 expression on the cells, cell apoptosis, and levels of IL-10 and IFN-γ in the cell culture supernatant.

RESULTSThe MHSP65-TCL vaccine showed an anti-melanoma effect in the tumor-bearing mice. In the in vitro experiment, TCL in MHSP65-TCL strongly stimulated the activation of mouse spleen cells while causing apoptosis in some of the immunocytes and promoting cellular IL-10 secretion, but not IFN-γ.

CONCLUSIONSMHSP65-TCL derived from B16 melanoma cells has an anti-melanoma effect mediated by the activation of immunocytes. TCL in MHSP65-TCL also has immunosuppressive effect on immunocytes possibly due to the presence of suppressive components in TCL, and identifying and eliminating these components may potentially improve the anti-tumor actovoty of MSHP65-TCL vaccine.

Animals ; Antigens, CD ; metabolism ; Antigens, Differentiation, T-Lymphocyte ; metabolism ; Apoptosis ; Bacterial Proteins ; administration & dosage ; immunology ; Cancer Vaccines ; Cell Extracts ; administration & dosage ; immunology ; Cell Line, Tumor ; Chaperonin 60 ; administration & dosage ; immunology ; Female ; Interferon-gamma ; metabolism ; Interleukin-10 ; metabolism ; Lectins, C-Type ; metabolism ; Melanoma, Experimental ; immunology ; pathology ; Mice ; Mice, Inbred C57BL ; Random Allocation ; Spleen ; cytology ; immunology ; metabolism ; Tumor Burden ; immunology

The anti-melanogenesis effect of glyceollins was examined by melanin synthesis, tyrosinase activity assay in zebrafish embryos and in B16F10 melanoma cells. When developing zebrafish embryos were treated with glyceollins, pigmentation of the embryos, melanin synthesis and tyrosinase activity were all decreased compared with control zebrafish embryos. In situ expression of a pigment cell-specific gene, Sox10, was dramatically decreased by glyceollin treatment in the neural tubes of the trunk region of the embryos. Stem cell factor (SCF)/c-kit signaling pathways as well as expression of microphthalmia-associated transcription factor (MITF) were determined by western blot analysis. Glyceollins inhibited melanin synthesis, as well as the expression and activity of tyrosinase induced by SCF, in a dose-dependent manner in B16F10 melanoma cells. Pretreatment of B16F10 cells with glyceollins dose-dependently inhibited SCF-induced c-kit and Akt phosphorylation. Glyceollins significantly impaired the expression and activity of MITF. An additional inhibitory function of glyceollins was to effectively downregulate intracellular cyclic AMP levels stimulated by SCF in B16F10 cells. Glyceollins have a depigmentation/whitening activity in vitro and in vivo, and that this effect may be due to the inhibition of SCF-induced c-kit and tyrosinase activity through the blockade of downstream signaling pathway.
Animals ; Embryo, Nonmammalian/drug effects ; Melanins/*biosynthesis ; Melanoma, Experimental/metabolism/pathology ; Mice ; Monophenol Monooxygenase/metabolism ; Phosphorylation/drug effects ; Pigmentation/drug effects ; Proto-Oncogene Proteins c-kit/*metabolism ; Pterocarpans/chemistry/*pharmacology ; SOXE Transcription Factors/metabolism ; Sesquiterpenes/chemistry/*pharmacology ; Signal Transduction/*drug effects ; Soybeans/*chemistry ; Stem Cell Factor/*pharmacology ; Zebrafish/embryology/metabolism

In order to increase the plasma half-life and tissue specificity of IL-1 receptor antagonist, a recombinant fusion protein IL-1Ra-HSA, linked by a rigid peptide linker PAPAP, was engineered and expressed by the Pichia pastoris host cells. The fusion protein was secreted to the host cells culture, identified by Western blot, and purified by affinity chromatography. This was followed by a further examination of its bioactivity and pharmacokinetics. Our results demonstrated that the fusion protein retained the antagonist activity of IL-1Ra, capable of binding specifically to the IL-1 receptor on human melanoma A375.S2 cells, and inhibits the cytolytic effect of IL-1beta to A375.S2 cells. Albumin fusion dramatically extended the half-life of IL-1Ra and resulted in a specific accumulation of IL-1Ra in the arthritic paws and a lower distribution of IL-1Ra in other organs such as liver, kidney, spleen and lung in mice with collagen-induced arthritis. The findings reported herein indicate that the fusion protein is likely to have greater clinical applications in areas such as the treatment of rheumatoid arthritis.
Animals ; Apoptosis ; drug effects ; Arthritis, Experimental ; metabolism ; Cell Line, Tumor ; Forelimb ; metabolism ; Half-Life ; Humans ; Interleukin 1 Receptor Antagonist Protein ; genetics ; metabolism ; pharmacokinetics ; pharmacology ; Interleukin-1beta ; toxicity ; Male ; Melanoma ; pathology ; Mice ; Mice, Inbred DBA ; Pichia ; genetics ; metabolism ; Plasmids ; Recombinant Fusion Proteins ; genetics ; metabolism ; pharmacokinetics ; pharmacology ; Serum Albumin ; genetics ; metabolism ; pharmacokinetics ; pharmacology ; Tissue Distribution

Malignant melanoma still remains to be a serious health threat. Overexpression of focal adhesion kinase (FAK) in melanoma has suggested that FAK could be a promising target for therapeutic intervention. To further investigate the function of FAK in melanoma, FAK expression was down-regulated by stable transfection of plasmid harboring FAK small interfering RNA (siRNA) into melanoma cell line. Two stable cell lines, F10-siFAK and F10-control, have been constructed and screened. Compared with the F10-control, both the mRNA and protein levels of FAK decreased significantly, and the cell cycle of F10-siFAK was arrested at G1 phase. Furthermore, the tumor growth rate of F10-siFAK cells was notably slower than that of F10-control in in vivo tumor models. These results show that FAK is an important regulatory gene in melanoma. The stable FAK-knockdown melanoma cell line is an useful tool for further investigation of FAK's function in the progression of melanoma, and also an effective means of drug screening for anti-melanoma therapeutics.
Animals ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Focal Adhesion Protein-Tyrosine Kinases ; genetics ; metabolism ; G1 Phase ; Gene Knockdown Techniques ; Melanoma, Experimental ; enzymology ; pathology ; Mice ; Mice, Inbred C57BL ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Plasmids ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Transfection

OBJECTIVETo establish a syngeneic mouse model of liver tumor stably expressing hepatitis B virus (HBV) antigens.

METHODSMelanoma cell line B16 cells were transfected with pLXSN-2HBV. Cells (named B16/HBV) stably and persistently expressing HBV surface (HBsAg) and core (HBcAg) antigens were identified. The cells were injected into the hepatic subcapsular space of fifteen C57BL/6J mice. The mice were divided into 3 groups, receiving 100, 1000 or 5000 cells in a total volume of 5 µl per mouse, respectively, five mice in each group. Two weeks after the tumor cell inoculation, serum samples from the mice were collected weekly and the serum concentration of HBsAg and anti-HBs was quantified by ELISA. The tumor growth in the mouse liver was monitored by a high-resolution ultrasound system. Expression of HBsAg and HBcAg in the tumor tissues was determined by immunohistochemistry.

RESULTSLiver tumors were formed in all the mice receiving 1000 and 5000 B16/HBV cells per mouse, and in 80% of the mice receiving 100 B16/HBV cells. HBsAg and anti-HBs were detectable in their sera from 2 weeks after tumor cell inoculation. The mice receiving 100 cells per mouse began to die 4 weeks, those receiving 1000 cells per mouse began to die 3 - 4 weeks and those receiving 5000 cells began to die 2 - 3 weeks after the cell inoculation. All the tumor cells expressed HBsAg and HBcAg.

CONCLUSIONSThe B16/HBV cells stably and persistently express HBV antigens both in vitro and in vivo. A mouse model of transplanted liver tumor stably expressing HBV antigens has been successfully established by inoculation of those cells into the hepatic subcapsular space.

Animals ; Cell Line, Tumor ; Disease Models, Animal ; Female ; Hepatitis B Core Antigens ; metabolism ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B e Antigens ; metabolism ; Hepatitis B virus ; genetics ; metabolism ; Liver Neoplasms, Experimental ; immunology ; virology ; Melanoma, Experimental ; metabolism ; pathology ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Plasmids ; Recombinant Proteins ; genetics ; metabolism ; Transfection

OBJECTIVEThis paper aims to investigate the anti-tumor mechanism of inactivated Sendai virus (Hemagglutinating virus of Japan envelope, HVJ-E) for murine melanoma (B16F10).

METHODSThe murine dendritic cells (DCs) were treated with HVJ-E, and then the cytokines secreted from DCs and costimulation-related molecules on DCs were measured. Meanwhile, the expression of β-catenin in HVJ-E treated murine melanoma cells was detected. In addition, HVJ-E was intratumorally injected into the melanoma on C57BL/6 mice, and the immune cells, CTL response and tumor volume were analyzed.

RESULTSHVJ-E injected into B16F10 melanoma obviously inhibited the growth of the tumor and prolonged the survival time of the tumor-bearing mice. Profiles of cytokines secreted by dendritic cells (DCs) after HVJ-E stimulation showed that the number of cytokines released was significantly higher than that elicited by PBS (1P<0.05). The co-stimulation-related molecules on DCs were comparable to those stimulated by LPS. Immunohistochemical examinations demonstrated the repression of β-catenin in B16F10 melanoma cells after HVJ-E treatment. Meanwhile, real-time reverse transcription PCR revealed that HVJ-E induced a remarkable infiltration of CD11c positive cells, chemokine ligand 10 (CXCL10) molecules, interleukin-2 (IL-2) molecule, CD4(+) and CD8(+) T cells into HVJ-E injected tumors. Furthermore, the mRNA expression level of β-catenin in the HVJ-E injected tumors was also down-regulated. In addition, B16F10-specific CTLs were induced significantly after HVJ-E was injected into the tumor-bearing mice.

CONCLUSIONThis is the first report to show the effective inhibition of melanoma tumors by HVJ-E alone and the mechanism through which it induces antitumor immune responses and regulates important signal pathways for melanoma invasion. Therefore, HVJ-E shows its prospect as a novel therapeutic for melanoma therapy.

Animals ; Cell Line, Tumor ; Cytokines ; genetics ; metabolism ; Dendritic Cells ; immunology ; physiology ; virology ; Down-Regulation ; Gene Expression Regulation, Neoplastic ; Melanoma ; immunology ; pathology ; virology ; Mice ; Mice, Inbred C57BL ; Neoplasms, Experimental ; Real-Time Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; Sendai virus ; physiology ; Virus Inactivation ; Virus Replication ; beta Catenin ; genetics ; metabolism

OBJECTIVETo explore the anti-tumor mechanism of the combination of cisplatin with DC vaccine in tumor-bearing mice.

METHODSB16 melanoma cells were treated with cisplatin at the final concentration of 20 µg/ml in vitro for 24 h. The expression of HMGB1, Hsp70 and TGF-β were detected by Western blot. B16 tumor-bearing mouse models were generated. The therapeutic effect of the combination of cisplatin (100 µg/mouse i.p., for sequential 3 days) and intratumoral injection of DC cells (3×10(6)/mouse, twice with a 7-day interval) in the tumor-bearing mouse models was evaluated. Expression of MHC II, ICAM-1 and CD86 was analyzed by flow cytometry. The mice were sacrificed at 28 days after tumor cell inoculation. The tumors were removed and weighed, and tissue samples were taken for pathological examination. Tumor infiltrating lymphocytes (TIL) were isolated by discontinuous gradient centrifugation. The distribution of T-reg and CD8(+) T cells in the TIL was analyzed by flow cytometry, and the ratio of CD8(+) T/T-reg was determined. The activity of cytotoxic lymphocytes (CTL) was determined by microcytotoxicity assay.

RESULTSCisplatin enhanced both the B16 cell apoptosis and HMGB1 expression. After loading with cisplatin-treated cell lysate, the expression of MHC II, ICAM-1 and CD86 on DC cells were (47.5 ± 8.8)%, (35.5 ± 8.3)% and (36.2 ± 9.2)%, respectively. At 28 days after tumor cell inoculation, the tumor weight of the control group was (2.1 ± 0.6) g, that of the cisplatin group was (0.3 ± 0.2) g and that of cisplatin + DC vaccine group was (0.5 ± 0.2) g, showing a significant inhibition of tumor growth (P < 0.01). Furthermore, the CD8(+) T/T-reg ratio and CTL activity in TIL were also significantly enhanced in the tumor-bearing mice treated with cisplatin + DC vaccine. When the effector-to-target ratio was 20:1, 10:1 and 5:1, the CTL activity in the cisplatin + DC vaccine treated mice was (25.0 ± 5.0)%, (22.0 ± 6.0)% and (14.0 ± 4.0)%, respectively, significantly higher than (8.2 ± 3.6)%, (6.7 ± 1.8)% and (3.6 ± 1.9)%, respectively, in the control group (all P < 0.01).

CONCLUSIONCisplatin promotes the anti-tumor effect of DC vaccine by down-regulating T-reg cells and enhancing the CTL activity in tumors.

Animals ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; B7-2 Antigen ; metabolism ; CD8-Positive T-Lymphocytes ; pathology ; Cancer Vaccines ; pharmacology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Dendritic Cells ; immunology ; metabolism ; Female ; Genes, MHC Class II ; HMGB1 Protein ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Melanoma, Experimental ; pathology ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; T-Lymphocytes, Cytotoxic ; immunology ; T-Lymphocytes, Regulatory ; pathology ; Tumor Burden ; drug effects