RESUMO
Human prostate tumor vaccine and gene therapy trials using ex vivo methods to prime dendritic cells (DCs) with prostate specific membrane antigen (PSMA) have been somewhat successful, but to date the lengthy ex vivo manipulation of DCs has limited the widespread clinical utility of this approach. Our goal was to improve upon cancer vaccination with tumor antigens by delivering PSMA via a CD40-targeted adenovirus vector directly to DCs as an efficient means for activation and antigen presentation to T-cells. To test this approach, we developed a mouse model of prostate cancer by generating clonal derivatives of the mouse RM-1 prostate cancer cell line expressing human PSMA (RM-1-PSMA cells). To maximize antigen presentation in target cells, both MHC class I and TAP protein expression was induced in RM-1 cells by transduction with an Ad vector expressing interferon-gamma (Ad5-IFNγ). Administering DCs infected ex vivo with CD40-targeted Ad5-huPSMA, as well as direct intraperitoneal injection of the vector, resulted in high levels of tumor-specific CTL responses against RM-1-PSMA cells pretreated with Ad5-IFNγ as target cells. CD40 targeting significantly improved the therapeutic antitumor efficacy of Ad5-huPSMA encoding PSMA when combined with Ad5-IFNγ in the RM-1-PSMA model. These results suggest that a CD-targeted adenovirus delivering PSMA may be effective clinically for prostate cancer immunotherapy.
Assuntos
Adenoviridae/genética , Antígenos de Superfície/genética , Antígenos CD40/metabolismo , Células Dendríticas/imunologia , Vetores Genéticos/genética , Glutamato Carboxipeptidase II/genética , Neoplasias da Próstata/prevenção & controle , Vacinação/métodos , Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Membro 3 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Adjuvantes Imunológicos/metabolismo , Animais , Apresentação de Antígeno/genética , Apresentação de Antígeno/imunologia , Antígenos de Superfície/metabolismo , Antígenos CD40/imunologia , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/virologia , Glutamato Carboxipeptidase II/metabolismo , Antígenos HLA-A/genética , Humanos , Interferon gama/genética , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/virologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Terapia de Alvo Molecular , Neoplasias da Próstata/genética , Neoplasias da Próstata/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Linfócitos T Citotóxicos/virologiaRESUMO
PURPOSE: Activation of the c-Met and epidermal growth factor receptors (EGFR) promotes the growth and survival of non-small cell lung cancer (NSCLC). Specific receptor antagonists have shown efficacy in the clinic, but tumors often become resistant to these therapies. We investigated the ability of (-)-epigallocatechin-3-gallate (EGCG) to inhibit cell proliferation, and c-Met receptor and EGFR kinase activation in several NSCLC cell lines. EXPERIMENTAL DESIGN: NSCLC cell lines with variable sensitivity to the EGFR antagonist erlotinib were studied. Cell growth was evaluated using proliferation and colony formation assays. Kinase activation was assessed via Western blot analysis. Experiments were conducted with EGCG, the EGFR antagonist erlotinib, and the c-Met inhibitor SU11274. The antagonists were also tested in a xenograft model using SCID mice. RESULTS: EGCG inhibited cell proliferation in erlotinib-sensitive and -resistant cell lines, including those with c-Met overexpression, and acquired resistance to erlotinib. The combination of erlotinib and EGCG resulted in greater inhibition of cell proliferation and colony formation than either agent alone. EGCG also completely inhibited ligand-induced c-Met phosphorylation and partially inhibited EGFR phosphorylation. The triple combination of EGCG/erlotinib/SU11274 resulted in a greater inhibition of proliferation than EGCG with erlotinib. Finally, the combination of EGCG and erlotinib significantly slowed the growth rate of H460 xenografts. CONCLUSION: EGCG is a potent inhibitor of cell proliferation, independent of EGFR inhibition, in several NSCLC cell lines, including those resistant to both EGFR kinase inhibitors and those overexpressing c-Met. Therefore, EGCG might be a useful agent to study as an adjunct to other anticancer agents.
Assuntos
Anticarcinógenos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Catequina/análogos & derivados , Proliferação de Células/efeitos dos fármacos , Receptores ErbB/antagonistas & inibidores , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Animais , Catequina/farmacologia , Linhagem Celular Tumoral , Cloridrato de Erlotinib , Humanos , Indóis/farmacologia , Masculino , Camundongos , Camundongos SCID , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Sulfonamidas/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We have shown previously that, in astrocytoma cells, synemin is present at the leading edge, an unusual localization for an intermediate filament (IF) protein. Here, we report that synemin down-regulation with specific small hairpin RNAs (shRNAs) sharply decreased the migration of astrocytoma cells. The presence of synemin at the leading edge also correlated with a high migratory potential, as shown by comparing astrocytoma cells to carcinoma cells without synemin at the leading edge. Synemin-silenced astrocytoma cells were smaller and spread more slowly than controls. In addition, synemin silencing reduced proliferation without increasing apoptosis. The adhesion to substratum and distribution of vinculin in focal contacts of synemin-silenced astrocytoma cells were similar to those of controls. Synemin-silenced cells, however, exhibited a reduction in the amount of filamentous (F) -actin and of alpha-actinin, but not of vinculin, associated with F-actin. Altogether, these results demonstrate that synemin is important for the malignant behavior of astrocytoma cells and that it contributes to the high motility of these cells by modulating the dynamics of alpha-actinin and actin.