RESUMO
The molecular diversity of receptors in human blood vessels remains largely unexplored. We developed a selection method in which peptides that home to specific vascular beds are identified after administration of a peptide library. Here we report the first in vivo screening of a peptide library in a patient. We surveyed 47,160 motifs that localized to different organs. This large-scale screening indicates that the tissue distribution of circulating peptides is nonrandom. High-throughput analysis of the motifs revealed similarities to ligands for differentially expressed cell-surface proteins, and a candidate ligand-receptor pair was validated. These data represent a step toward the construction of a molecular map of human vasculature and may have broad implications for the development of targeted therapies.
Assuntos
Vasos Sanguíneos/fisiologia , Biblioteca de Peptídeos , Variação Genética , Humanos , Oligopeptídeos/química , Especificidade de Órgãos , Reprodutibilidade dos Testes , SoftwareRESUMO
PURPOSE: To further assess preclinical and early clinical evidence that imatinib mesylate, a platelet-derived growth factor receptor (PDGFR) inhibitor, modulates taxane activity in prostate cancer and bone metastases, a randomized study was conducted. EXPERIMENTAL DESIGN: Men with progressive castration-resistant prostate cancer with bone metastases (n = 144) were planned for equal randomization to i.v. 30 mg/m(2) docetaxel on days 1, 8, 15, and 22 every 42 days with 600 mg imatinib daily or placebo, for an improvement in median progression-free survival from 4.5 to 7.5 months (two-sided alpha = 0.05 and beta = 0.20). Secondary end points included differential toxicity and bone turnover markers, tumor phosphorylated PDGFR (p-PDGFR) expression, and modulation of p-PDGFR in peripheral blood leukocytes. RESULTS: Accrual was halted early because of adverse gastrointestinal events. Among 116 evaluable men (57 docetaxel + imatinib; 59 docetaxel + placebo), respective median times to progression were 4.2 months (95% confidence interval, 3.1-7.5) and 4.2 months (95% confidence interval, 3.0-6.8; P = 0.58, log-rank test). Excess grade 3 toxicities (n = 23) in the docetaxel + imatinib group were principally fatigue and gastrointestinal. Tumor p-PDGFR expression was observed in 12 of 14 (86%) evaluable bone specimens. In peripheral blood leukocytes, p-PDGFR reduction was more likely in docetaxel + imatinib-treated patients compared with docetaxel + placebo (P < 0.0001), as were reductions in urine N-telopeptides (P = 0.004) but not serum bone-specific alkaline phosphatase (P = 0.099). CONCLUSIONS: These clinical and translational results question the value of PDGFR inhibition with taxane chemotherapy in prostate cancer bone metastases and are at variance with the preclinical studies. This discordance requires explanation.
Assuntos
Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/cirurgia , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Benzamidas , Neoplasias Ósseas/terapia , Castração , Estudos de Coortes , Intervalo Livre de Doença , Docetaxel , Humanos , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Piperazinas/administração & dosagem , Placebos , Pirimidinas/administração & dosagem , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Taxoides/administração & dosagemRESUMO
PURPOSE: Clinical trials of antiangiogenic agents used alone for advanced malignancy have been disappointing but preclinical studies suggest that the addition of radiation therapy could improve antitumor efficacy. To test the hypothesis that antiangiogenic therapy combined with radiation therapy can overcome the limitations of antiangiogenic monotherapy, we studied the effects of endostatin combined with radiation on the growth and vascularization of A431 human epidermoid carcinomas growing intramuscularly in the legs of mice. METHODS AND MATERIALS: Mice with established A431 human epidermoid leg tumors were treated with radiation, endostatin, both radiation and endostatin, or vehicle control. The experiment was repeated and mice from each group were killed at 2, 7, and 10 days after irradiation so that tumor tissue could be obtained to further analyze the kinetics of the antitumor, antivascular, and antiangiogenic response to therapy. RESULTS: Endostatin enhanced the antitumor effects of radiation, and prolonged disease-free survival was observed in the combined treatment group. Endothelial cell proliferation was increased in tumors after irradiation but was blocked by the concurrent administration of endostatin, and the combination of endostatin with radiation enhanced endothelial cell apoptosis within 48 h after irradiation. Expression of vascular endothelial growth factor, interleukin-8, and matrix metalloproteinase-2 were increased in tumors after irradiation, and this increase was blocked by concurrent administration of endostatin. CONCLUSION: These data indicate that endostatin can block tumor revascularization after radiation therapy and thereby augment radioresponse.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/radioterapia , Endostatinas/uso terapêutico , Neovascularização Patológica/prevenção & controle , Proteínas Angiogênicas/metabolismo , Animais , Apoptose , Carcinoma de Células Escamosas/patologia , Proliferação de Células/efeitos dos fármacos , Terapia Combinada , Masculino , Camundongos , Camundongos Nus , Tolerância a Radiação , Transplante HeterólogoRESUMO
PURPOSE: The insulin-like growth factor-I receptor (IGF-IR) and its ligands have been implicated in the pathogenesis and progression of various cancers, including those arising in the thyroid gland. We therefore evaluated whether the IGF-IR could serve as a potential target for therapy of anaplastic thyroid carcinoma (ATC). EXPERIMENTAL DESIGN: The expression and activation of the IGF-IR and some of its downstream signaling pathway components were evaluated in both human thyroid cancer specimens and thyroid cancer cell lines. The therapeutic potential of a humanized monoclonal antibody (A12) directed against IGF-IR was assessed in vitro and in vivo in an orthotopic model of ATC. Tumor volume and overall survival time were analyzed to evaluate the efficacy of A12 in vivo. RESULTS: IGF-IR was overexpressed in 94% of the thyroid cancers. Blockade of IGF-IR with A12 was effective in attenuating IGF-IR signaling both in vitro and in vivo. However, the inhibitory effects of A12 on cell proliferation were cell line dependent, as those ATC cell lines that had detectable levels of pIGF-IR were more sensitive to A12 treatment. A12 was equally effective in vivo, where it brought approximately 57% (P = 0.041) inhibition in tumor volume. The concomitant use of A12 and irinotecan produced additive effects and resulted in a 93% (P < 0.001) reduction in tumor volume. Blocking IGF-IR blocked Akt phosphorylation and decreased proliferation and microvessel density but increased apoptosis within the tumor xenografts. Our results also highlighted a previously undefined IGF-IR-mediated antiangiogenic effect on tumor-associated endothelium in thyroid cancers. CONCLUSION: Blocking the IGF-IR with A12 seems to be a potential avenue for treating patients with ATC by its direct antitumor effects and its effects on the tumor vasculature.
Assuntos
Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Carcinoma/tratamento farmacológico , Receptor IGF Tipo 1/antagonistas & inibidores , Neoplasias da Glândula Tireoide/tratamento farmacológico , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Reações Antígeno-Anticorpo , Antineoplásicos/imunologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Fator de Crescimento Insulin-Like I/farmacologia , Fator de Crescimento Insulin-Like II/farmacologia , Masculino , Metilação , Camundongos , Camundongos Nus , Neovascularização Patológica/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Receptor IGF Tipo 1/biossíntese , Receptor IGF Tipo 1/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Relação Estrutura-Atividade , Neoplasias da Glândula Tireoide/patologia , Transplante Heterólogo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Although gemcitabine has been approved as the first-line chemotherapeutic reagent for pancreatic cancer, its response rate is low and average survival duration is still only marginal. Because epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR), and platelet-derived growth factor receptor (PDGFR) modulate tumor progression, we hypothesized that inhibition of phosphorylation of all three on tumor cells, tumor-associated endothelial cells, and stroma cells would improve the treatment efficacy of gemcitabine in an orthotopic pancreatic tumor model in nude mice and prolong survival. We implanted L3.6pl, a human pancreatic cancer cell, in the pancreas of nude mice. We found that tumor-associated endothelial cells in this model highly expressed phosphorylated EGFR, VEGFR, and PDGFR. Oral administration of AEE788, a dual tyrosine kinase inhibitor against EGFR and VEGFR, decreased phosphorylation of EGFR and VEGFR. PDGFR phosphorylation was inhibited by STI571. Although i.p. injection of gemcitabine did not inhibit tumor growth, its combination with AEE788 and STI571 produced >80% inhibition of tumor growth and prolonged survival in parallel with increases in number of tumor cells and tumor-associated endothelial cell apoptosis, decreased microvascular density, decreased proliferation rate, and prolonged survival. STI571 treatment also decreased pericyte coverage on tumor-associated endothelial cells. Thus, inhibiting phosphorylation of EGFR, VEGFR, and PDGFR in combination with gemcitabine enhanced the efficacy of gemcitabine, resulting in inhibition of experimental human pancreatic cancer growth and significant prolongation of survival.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Animais , Benzamidas , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Sinergismo Farmacológico , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , Mesilato de Imatinib , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Camundongos Nus , Neoplasias Pancreáticas/irrigação sanguínea , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/patologia , Fosforilação/efeitos dos fármacos , Piperazinas/administração & dosagem , Piperazinas/farmacologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Purinas/administração & dosagem , Purinas/farmacologia , Pirimidinas/administração & dosagem , Pirimidinas/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , GencitabinaRESUMO
Patients suffering from bone metastases of follicular thyroid carcinoma (FTC) have a poor prognosis because of the lack of effective treatment strategies. The overexpression of epidermal growth factor receptor (EGFR) associated with increased vascularity has been implicated in the pathogenesis of FTC and subsequent bone metastases. We hypothesized that inhibiting the phosphorylation of the EGFR and vascular endothelial growth factor receptor (VEGFR) by AEE788, a dual tyrosine kinase inhibitor of EGFR and VEGFR, in combination with paclitaxel would inhibit experimental FTC bone lesions and preserve bone structure. We tested this hypothesis using the human WRO FTC cell line. In culture, AEE788 inhibited the EGF-mediated phosphorylation of EGFR, VEGFR2, mitogen-activated protein kinase, and Akt in culture. AEE788, alone and in combination with paclitaxel, inhibited cell growth and induced apoptosis. When WRO cells were injected into the tibia of nude mice, tumor and endothelial cells within the lesions expressed phosphorylated EGFR, VEGFR, Akt, and mitogen-activated protein kinase that were inhibited by the oral administration of AEE788. Therapy consisting of orally given AEE788 and i.p. injected paclitaxel induced a high level of apoptosis in tumor-associated endothelial cells and tumor cells with the inhibition of tumor growth in the bone and the preservation of bone structure. Collectively, these data show that blocking the phosphorylation of EGFR and VEGFR with AEE788 combined with paclitaxel can significantly inhibit experimental human FTC in the bone of nude mice.
Assuntos
Neoplasias Ósseas/prevenção & controle , Neoplasias Ósseas/secundário , Receptores ErbB/antagonistas & inibidores , Purinas/farmacologia , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Neoplasias da Glândula Tireoide/irrigação sanguínea , Adenocarcinoma Folicular/irrigação sanguínea , Adenocarcinoma Folicular/patologia , Adenocarcinoma Folicular/prevenção & controle , Adenocarcinoma Folicular/secundário , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Ósseas/irrigação sanguínea , Neoplasias Ósseas/patologia , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Receptores ErbB/biossíntese , Receptores ErbB/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/biossíntese , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Paclitaxel/administração & dosagem , Paclitaxel/farmacologia , Fosforilação/efeitos dos fármacos , Reação em Cadeia da Polimerase , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Purinas/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Pancreatic carcinomas express high levels of urokinase-type plasminogen activator (uPA) and its receptor (uPAR), both of which mediate cell migration and invasion. We investigated the hypotheses that (a) insulin-like growth factor-I (IGF-I)- and hepatocyte growth factor (HGF)-mediated migration and invasion of human pancreatic carcinoma cells require uPA and uPAR function and (b) inhibition of uPAR inhibits tumor growth, retroperitoneal invasion, and hepatic metastasis of human pancreatic carcinomas in mice. Using transwell assays, we investigated the effect of IGF-I and HGF on L3.6pl migration and invasion. We measured the induction of uPA and uPAR following treatment of cells with IGF-I and HGF using immunoprecipitation and Western blot analysis. The importance of uPA and uPAR on L3.6pl cell migration and invasion was studied by inhibiting their activities with amiloride and antibodies before cytokine treatment. In an orthotopic mouse model of human pancreatic carcinoma, we evaluated the effect of anti-uPAR monoclonal antibodies with and without gemcitabine on primary tumor growth, retroperitoneal invasion, and hepatic metastasis. IGF-I and HGF mediated cell migration and invasion in L3.6pl cells. In addition, IGF-I and HGF induced uPA and uPAR expression in L3.6pl cells. In vitro, blockade of uPA and uPAR activity inhibited IGF-I- and HGF-mediated cell migration and invasion. Treatment of mice with anti-uPAR monoclonal antibody significantly decreased pancreatic tumor growth and hepatic metastasis and completely inhibited retroperitoneal invasion. Our study shows the importance of the uPA/uPAR system in pancreatic carcinoma cell migration and invasion. These findings suggest that uPAR is a potential target for therapy in patients with pancreatic cancer.
Assuntos
Movimento Celular/fisiologia , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Receptor IGF Tipo 1/antagonistas & inibidores , Receptores de Superfície Celular/antagonistas & inibidores , Amilorida/farmacologia , Animais , Anticorpos Monoclonais/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Fator de Crescimento de Hepatócito/farmacologia , Humanos , Fator de Crescimento Insulin-Like I/farmacologia , Neoplasias Hepáticas Experimentais/secundário , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Neovascularização Patológica , Neoplasias Pancreáticas/irrigação sanguínea , Proteínas Proto-Oncogênicas c-met/fisiologia , Receptor IGF Tipo 1/fisiologia , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/imunologia , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Ativador de Plasminogênio Tipo Uroquinase/biossínteseRESUMO
PURPOSE: We investigated whether concomitant blockade of the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) signaling pathways by AEE788, a dual inhibitor of EGFR and VEGFR tyrosine kinases, would inhibit the growth of cutaneous squamous cell carcinoma (SCC) cells and human cutaneous cancer xenografts in nude mice. EXPERIMENTAL DESIGN: We examined the effects of AEE788 on the phosphorylation of EGFR and VEGFR-2 in cutaneous SCC cells expressing EGFR and VEGFR-2 and cutaneous SCC cell growth and apoptosis. We assessed the in vivo antitumor effects of AEE788 in a xenograft model in nude mice. AEE788 (50 mg/kg) was given orally thrice weekly to mice that had been s.c. injected with Colo16 tumor cells. Mechanisms of in vivo AEE788 activity were determined by immunohistochemical analysis. RESULTS: Treatment of cutaneous SCC cells with AEE788 led to dose-dependent inhibition of EGFR and VEGFR-2 phosphorylation, growth inhibition, and induction of apoptosis. In mice treated with AEE788, tumor growth was inhibited by 54% at 21 days after the start of treatment compared with control mice (P < 0.01). Immunohistochemical analysis revealed that AEE788 inhibited phosphorylation of EGFR and VEGFR and induced apoptosis of tumor cells and tumor-associated endothelial cells. CONCLUSIONS: In addition to inhibiting cutaneous cancer cell growth by blocking EGFR and VEGFR signaling pathways in vitro, AEE788 inhibited in vivo tumor growth by inducing tumor and endothelial cell apoptosis.
Assuntos
Apoptose , Carcinoma de Células Escamosas/patologia , Purinas/farmacologia , Neoplasias Cutâneas/patologia , Administração Oral , Animais , Proliferação de Células , Células Endoteliais , Receptores ErbB/antagonistas & inibidores , Humanos , Camundongos , Camundongos Nus , Purinas/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Transdução de Sinais , Transplante HeterólogoRESUMO
Expression of the epidermal growth factor (EGF) and activation of its receptor (EGFR), a tyrosine kinase, are associated with progressive growth of head and neck cancer. Expression of the vascular endothelial growth factor (VEGF) is associated with angiogenesis and progressive growth of tumor. The tyrosine kinase inhibitor NVP-AEE788 (AEE788) blocks the EGF and VEGF signaling pathways. We examined the effects of AEE788 administered alone, or with paclitaxel (Taxol), on the progression of human head and neck cancer implanted orthotopically into nude mice. Cells of two different human oral cancer lines, JMAR and MDA1986, were injected into the tongues of nude mice. Mice with established tumors were randomized to receive three times per week oral AEE788, once weekly injected paclitaxel, AEE788 plus paclitaxel, or placebo. Oral tumors were resected at necropsy. Kinase activity, cell proliferation, apoptosis, and mean vessel density were determined by immunohistochemical immunofluorescent staining. AEE788 inhibited cell growth, induced apoptosis, and reduced the phosphorylation of EGFR, VEGFR-2, AKT, and mitogen-activated protein kinase in both cell lines. Mice treated with AEE788 and AEE788 plus paclitaxel had decreased microvessel density, decreased proliferative index, and increased apoptosis. Hence, AEE788 inhibited tumor vascularization and growth and prolonged survival. Inhibition of EGFR and VEGFR phosphorylation by AEE788 effectively inhibits cellular proliferation of squamous cell carcinoma of the head and neck, induces apoptosis of tumor endothelial cells and tumor cells, and is well tolerated in mice. These data recommend the consideration of patients with head and neck cancer for inclusion in clinical trials of AEE788.
Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Receptores ErbB/antagonistas & inibidores , Neoplasias Bucais/tratamento farmacológico , Purinas/uso terapêutico , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/uso terapêutico , Animais , Linhagem Celular Tumoral , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Nus , Paclitaxel/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologiaRESUMO
We determined whether lyophilized High Five (H5) insect cells engineered to produce IFN-beta (H5BVIFN-beta) could induce systemic immunity against occult brain metastases. C3H/HeN mice were injected s.c. with syngeneic UV-2237M fibrosarcoma or K-1735M2 melanoma cells. Intralesional injection of 2 x 10(6) lyophilized H5BVIFN-beta cells produced complete regression of the s.c. tumors. Six weeks later, UV-2237M fibrosarcoma cells or K-1735M2 melanoma cells were injected into the internal carotid artery of naive or treated mice. UV-2237M brain metastases developed in naive mice or mice cured of K-1735M2 tumors but not in mice cured of UV-2237M tumors. Similarly, K-1735M2 brain metastases developed in naive mice or mice cured of UV-2237M fibrosarcomas but not in mice cured of K-1735M2 melanoma. In the next set of studies, mice were injected s.c. with UV-2237M fibrosarcoma cells. On day 7, UV-2237M fibrosarcoma cells or K-1735M2 cells were implanted into the internal carotid artery, and on day 10, the s.c. tumors were injected with lyophilized H5BVIFN-beta. Both the s.c. tumors and the occult brain metastases produced from carotid injections were eradicated in a tumor-specific manner. The regression of the brain metastases was abrogated by depletion of CD4(+) or CD8(+) cells from immunized mice. These results demonstrate that specific systemic immunity can be induced by lyophilized H5BVIFN-beta and that the resultant immune response can eliminate established brain metastasis.
Assuntos
Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/terapia , Imunoterapia Ativa/métodos , Interferon beta/uso terapêutico , Animais , Baculoviridae/genética , Neoplasias Encefálicas/imunologia , Linfócitos T CD8-Positivos/imunologia , Fibrossarcoma/imunologia , Fibrossarcoma/secundário , Fibrossarcoma/terapia , Vetores Genéticos/genética , Insetos/virologia , Interferon beta/biossíntese , Interferon beta/genética , Interferon beta/imunologia , Melanoma Experimental/imunologia , Melanoma Experimental/secundário , Melanoma Experimental/terapia , Camundongos , Camundongos Endogâmicos C3H , Linfócitos T/imunologiaRESUMO
Angiopoietin (Ang)-1 and -2 are critical regulators of embryonic and postnatal neovascularization. Ang-1 activates the endothelial cell-specific tyrosine kinase receptor Tie-2, which in turn leads to enhanced endothelial cell survival and stabilization. The effects of Ang-1 on tumor angiogenesis remain controversial; although we have previously demonstrated that Ang-1 overexpression in colon cancer cells leads to a decrease in s.c. tumor growth, others have shown that Ang-1 may be proangiogenic. Few studies have addressed the role of the Angs in tumors growing in the organ of metastatic growth. We hypothesized that overexpression of Ang-1 may inhibit the growth of colon cancers growing in the liver by inhibition of angiogenesis. We also wanted to investigate the mechanisms by which Ang-1 affects angiogenesis in vivo. Human colon cancer cells (HT29) were stably transfected with an Ang-1 construct or an empty vector (pcDNA) and injected directly into the livers of nude mice. After 37 days, livers were harvested and weighed, and tumor sizes were measured. In an additional experiment, to validate the paracrine effect of Ang-1, various mixtures of control cells and Ang-1-transfected cells were injected into livers, and tumor growth was assessed. Direct effects of recombinant Ang-1 on angiogenesis were studied with an in vivo Gelfoam angiogenesis assay. The impact of Ang-1 on vascular permeability was investigated using an intradermal Miles assay with conditioned media from transfected cells. Liver weights (P < 0.05), tumor volumes (P < 0.05), vessel counts (P < 0.01), and tumor cell proliferation (P < 0.01) in the Ang-1 group were significantly lower than those in the control (pcDNA) group. Tumor vessels in the Ang-1 group developed a significantly higher degree of pericyte coverage (P < 0.02) than vessels in pcDNA tumors. In the cell mixture experiment, even as few as a 1:10 mixture of Ang-1-transfected cells/control cells resulted in a significant reduction of hepatic tumor volumes (P < 0.04). In the angiogenesis assay, vessel counts in Gelfoam implants were significantly decreased by the addition of Ang-1 (P < 0.01). Finally, conditioned medium from Ang-1-transfected cells decreased vascular permeability more than that from control cells (P < 0.05). Our results suggest that Ang-1 is an important regulator of angiogenesis and vascular permeability and that this effect may be secondary to increasing periendothelial support and vessel stabilization. Thus, Ang-1 could potentially serve as an antineoplastic or anti-permeability agent for patients with metastatic colorectal cancer.
Assuntos
Indutores da Angiogênese/fisiologia , Permeabilidade Capilar/fisiologia , Neoplasias do Colo/patologia , Terapia Genética , Neoplasias Hepáticas Experimentais/secundário , Glicoproteínas de Membrana/fisiologia , Neovascularização Patológica/terapia , Indutores da Angiogênese/genética , Indutores da Angiogênese/uso terapêutico , Angiopoietina-1 , Animais , Técnicas de Cocultura , Meios de Cultivo Condicionados/farmacologia , Humanos , Neoplasias Hepáticas Experimentais/irrigação sanguínea , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Comunicação Parácrina , Pericitos/patologia , Fosforilação , Processamento de Proteína Pós-Traducional , Receptores Proteína Tirosina Quinases/metabolismo , Receptor TIE-2 , Proteínas Recombinantes de Fusão/fisiologia , Transfecção , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/transplante , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Members of the integrin family influence several aspects of tumor progression and metastasis, including cell survival, proliferation, and angiogenesis. Specific integrins such as alpha(v)beta(3) and alpha(v)beta(5) are involved in regulating endothelial cell function, and thus angiogenesis. We evaluated the effect of the alpha(v)beta(3)/alpha(v)beta(5) integrin antagonist S247 on the growth and angiogenesis of colon cancer liver metastases in an orthotopic murine model. Murine colon cancer cells were injected into the spleens of BALB/c mice to produce liver metastases. On day 7, miniature osmotic pumps were implanted into the subcutis to continuously infuse either saline or 70 mg/kg/day S247. All mice were sacrificed when control mice became moribund. Mice that received S247 developed significantly fewer liver metastases than did controls (P < 0.05). Using the same model, a subsequent survival study was performed. Mice were sacrificed when moribund as determined by an observer blinded to the treatment given. Treatment with S247 significantly prolonged overall survival (P < 0.05). Interestingly, primary tumors in the spleen were the cause of death in the S247-treated group as S247 appeared to have little effect on these tumors. Immunohistochemical staining demonstrated a significant reduction of vessels in liver metastases of S247-treated mice (P < 0.001), a significant increase in endothelial cell apoptosis (P < 0.05), and a significant decrease in pericyte coverage (P < 0.0001). To determine the role of S247 on angiogenesis, we examined the effect of S247 in vitro on human umbilical vein endothelial cells (HUVECs) and human vascular smooth muscle cells (hVSMCs). The addition of S247 to HUVECs and hVSMCs growing on vitronectin-coated flasks and in Matrigel significantly impaired cell growth and colony formation, respectively (P < 0.05). Furthermore, S247 completely inhibited the attachment of HUVECs and hVSMCs and increased apoptosis by six- to 9fold compared with controls. In in vitro invasion assays, S247-treated cells demonstrated decreased migration (P < 0.05). In conclusion, S247 demonstrated significant antimetastatic and antiangiogenic activity and impaired both endothelial and hVSMC/pericyte function in vitro and in vivo. The use of agents such as integrin antagonists that target multiple cell types involved in angiogenesis may be a more effective method of inhibiting angiogenesis than agents targeting only the endothelial cells.
Assuntos
Inibidores da Angiogênese/farmacologia , Neoplasias do Colo/tratamento farmacológico , Integrina alfaVbeta3/antagonistas & inibidores , Neoplasias Hepáticas/prevenção & controle , Neoplasias Hepáticas/secundário , Neovascularização Patológica/tratamento farmacológico , Compostos Orgânicos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Transdução de Sinais/efeitos dos fármacosRESUMO
Stat1 is deficient or inactive in many types of human tumors whereas some tumors have activated Stat1. Whether Stat1 affects tumor growth and metastasis is unclear. In the present study, we used Stat1 knockout tumor cells to determine (1) whether Stat1 can regulate angiogenesis, growth, and metastasis of tumor cells; and (2) whether Stat1 is required for the inhibitory effect of IFN-beta on the expression of angiogenic factor bFGF. Highly tumorigenic and metastatic RAD-105 tumor cells derived from a fibrosarcoma of a Stat1 knockout mouse were reconstituted with a Stat1 expression vector. The reconstitution of Stat1 suppressed the tumorigenicity and metastasis of RAD-105 cells in nude mice which correlated with a decreased microvessel density and decreased expression of proangiogenic molecules bFGF, MMP-2, and MMP-9 in vivo. Moreover, noncytotoxic concentrations of IFN-beta significantly inhibited the in vitro expression of bFGF in the Stat1-reconstituted cells but not in the Stat1-deficient cells, which was consistent with decreased bFGF expression of Stat1-reconstituted tumors in vivo. Therefore, Stat1 is essential for IFN-mediated inhibition of bFGF production, suggesting that tumor-intrinsic Stat1 is an important mediator for antiangiogenic signals, such as IFN. Collectively, these data demonstrate that Stat1 expressed by tumor cells is a negative regulator of tumor angiogenesis and, hence, tumor growth and metastasis.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Neoplasias Experimentais , Neovascularização Patológica , Transativadores/fisiologia , Animais , Divisão Celular , Proteínas de Ligação a DNA/genética , Fatores de Crescimento Endotelial/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fibrossarcoma/sangue , Fibrossarcoma/etiologia , Fibrossarcoma/metabolismo , Fibrossarcoma/patologia , Interferon beta/farmacologia , Cinética , Linfocinas/metabolismo , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos Nus , Metástase Neoplásica , Neoplasias Experimentais/sangue , Neoplasias Experimentais/etiologia , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Fator de Transcrição STAT1 , Transativadores/genética , Transfecção , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
PURPOSE AND EXPERIMENTAL DESIGN: Insulin-like growth factors (IGFs) I and II and their principle receptor, IGF-I receptor (IGF-IR), are frequently expressed in human colon cancers and play a role in preventing apoptosis, enhancing cell proliferation, and inducing expression of vascular endothelial growth factor (VEGF). To elucidate the in vitro and in vivo effects of IGF-IR in human colon cancer growth and angiogenesis, HT29 cells were transfected with a truncated dominant-negative (DN) form of IGF-IR or vector alone. RESULTS: IGF-I increased VEGF expression in parental and vector-transfected cells, whereas IGF-I induction of VEGF mRNA and protein was abrogated in IGF-IR DN cells. The IGF-IR DN cells demonstrated inhibited growth in both monolayer culture and soft agar (P < 0.05). s.c. injections of IGF-IR DN cells in nude mice led to significantly decreased tumor growth (P < 0.05). Immunohistochemical analyses revealed that IGF-I DN tumors demonstrated decreased tumor cell proliferation, VEGF expression, and vessel count and increased tumor cell apoptosis (P < 0.05 for all parameters compared with controls). Furthermore, IGF-IR DN-transfected cells yielded significantly decreased tumorigenicity and growth in the liver. CONCLUSIONS: These studies demonstrate that the IGF ligand-receptor system plays an important role in multiple mechanisms that mediate human colon cancer growth including regulation of VEGF and angiogenesis.
Assuntos
Neoplasias do Colo/patologia , Neovascularização Patológica/patologia , Receptor IGF Tipo 1/fisiologia , Animais , Apoptose , Divisão Celular , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/metabolismo , Fatores de Crescimento Endotelial/genética , Fatores de Crescimento Endotelial/metabolismo , Genes Dominantes , Humanos , Técnicas Imunoenzimáticas , Marcação In Situ das Extremidades Cortadas , Técnicas In Vitro , Injeções Subcutâneas , Fator de Crescimento Insulin-Like I/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias Hepáticas/prevenção & controle , Linfocinas/genética , Linfocinas/metabolismo , Masculino , Camundongos , Camundongos Nus , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , RNA Mensageiro/metabolismo , Transfecção , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
PURPOSE: The purpose of this study was to determine the effects of adenoviral transgene expression of MMAC/PTEN on the in vitro and in vivo growth and survival of PC3 human prostate cancer cells. EXPERIMENTAL DESIGN: Adenoviruses expressing MMAC/PTEN or green fluorescent protein as a control were introduced into PC3 cells, and effects on signal transduction pathways and growth of tumors in an orthotopic nude mouse model were determined. RESULTS: MMAC/PTEN expression in PC3 cells decreased the level of phospho Akt but not that of phospho Mapk or FAK. Expression of MMAC/PTEN inhibited the in vitro growth of PC3 cells primarily by blocking cell cycle progression. Ex vivo introduction of MMAC/PTEN expression did not inhibit the tumorigenicity of orthotopically implanted PC3 cells, but it did significantly reduce tumor size and completely inhibited the formation of metastases. In vivo treatment of pre-established orthotopic PC3 tumors with adenoviral MMAC/PTEN did not significantly reduce local tumor size, but it did diminish metastasis formation. CONCLUSIONS: MMAC/PTEN functionally regulates prostate cancer cell metastatic potential in an in vivo model system and may be an important biological marker and therapeutic target for human prostate cancer.
Assuntos
Adenocarcinoma/prevenção & controle , Adenoviridae/genética , Metástase Linfática/prevenção & controle , Monoéster Fosfórico Hidrolases/genética , Neoplasias da Próstata/prevenção & controle , Transfecção , Proteínas Supressoras de Tumor/genética , Adenocarcinoma/genética , Adenocarcinoma/secundário , Animais , Apoptose , Bromodesoxiuridina , Ciclo Celular/fisiologia , Divisão Celular , Genes Supressores de Tumor , Terapia Genética , Humanos , Marcação In Situ das Extremidades Cortadas , Metástase Linfática/genética , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , PTEN Fosfo-Hidrolase , Monoéster Fosfórico Hidrolases/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
PURPOSE: We evaluated the expression of platelet-derived growth factor (PDGF) ligands and receptors in clinical specimens of human pancreatic adenocarcinomas and determined the therapeutic effect of STI571 (Gleevec), a protein tyrosine kinase inhibitor of PDGF receptor (PDGFR), on human pancreatic carcinoma cells growing in the pancreas and liver of nude mice. EXPERIMENTAL DESIGN: Immunohistochemical staining for PDGF-AA and -BB ligands, PDGFR-alpha and -beta, and phosphorylated PDGFR-alpha and -beta was performed on 31 specimens of human pancreatic cancer and L3.6pl human pancreatic adenocarcinoma cell line. To determine the in vivo effects of STI571, nude mice with L3.6pl cells injected into the pancreas were randomized 7 days later to receive one of the following treatments: sterile water p.o. (control), STI571, gemcitabine, or a combination of STI571 and gemcitabine. RESULTS: In 29 of 31 clinical specimens of human pancreatic adenocarcinoma, both tumor cells and tumor-associated endothelial cells expressed phosphorylated PDGFR-alpha and -beta. L3.6pl cells growing in culture expressed moderate amounts of PDGF-AA and little to no PDGFR-alpha or -beta, whereas L3.6pl cells growing in the pancreas of nude mice expressed a high level of PDGF and receptors. Colocalization immunohistochemical analysis demonstrated expression of activated PDGFR-beta by tumor-associated endothelial cells in both the pancreas and in liver metastases. Tumors of mice treated for 4 weeks with STI571 (50 mg/kg or 100 mg/kg p.o. daily) were slightly smaller than controls. Tumors treated with gemcitabine and STI571 (50 mg/kg) were >70% smaller than tumors in control mice and 36% smaller than those in mice treated with gemcitabine only (P < 0.0002 and P < 0.04, respectively). Combination therapy also inhibited spontaneous metastasis to the liver. Tumors from mice treated with both STI571 and gemcitabine had decreased expression of activated (phosphorylated) PDGFR-alpha and -beta, decreased mean vessel density, decreased cell proliferation, and increased apoptosis of tumor cells. CONCLUSIONS: Collectively, these data show that activated PDGFR on tumor cells and tumor-endothelial cells can be a novel target for therapy of pancreatic carcinoma.
Assuntos
Carcinoma/patologia , Metástase Neoplásica , Neoplasias Pancreáticas/patologia , Piperazinas/farmacologia , Pirimidinas/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Adenocarcinoma/metabolismo , Animais , Antineoplásicos/farmacologia , Becaplermina , Benzamidas , Western Blotting , Divisão Celular , Linhagem Celular Tumoral , Humanos , Mesilato de Imatinib , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Ligantes , Camundongos , Camundongos Nus , Microscopia de Fluorescência , Fosforilação , Molécula-1 de Adesão Celular Endotelial a Plaquetas/biossíntese , Fator de Crescimento Derivado de Plaquetas/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-sis , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Fatores de TempoRESUMO
PURPOSE: We determined whether chronic administration of IFN-alpha at optimal biological dose inhibits angiogenesis of human pancreatic carcinoma growing in the pancreas of nude mice. EXPERIMENTAL DESIGN: Cells of the human pancreatic cancer cell line L3.6pl were implanted into the pancreas of nude mice. Seven days later, groups of mice received s.c. injection with IFN-alpha alone (50,000 units biweekly or 10,000 units daily), i.p. injection with gemcitabine alone (125 mg/kg biweekly), or injection with both daily IFN-alpha and biweekly gemcitabine for 35 days. In a survival study, the mice were treated until they became moribund. RESULTS: Biweekly treatments with 50,000 units of IFN-alpha alone were ineffective. In contrast, daily injections of IFN-alpha (10,000 units/day) alone, biweekly injections of gemcitabine alone, or the combination of IFN-alpha and gemcitabine reduced tumor volume by 53%, 70%, and 87%, respectively. Immunohistochemical analysis revealed that treatment with IFN-alpha alone or with IFN-alpha plus gemcitabine inhibited expression of the proangiogenic molecules basic fibroblast growth factor and matrix metalloproteinase 9 more than did treatment with gemcitabine alone. These treatments also decreased the staining of proliferating cell nuclear antigen within the tumor and induced apoptosis in tumor-associated mouse endothelial cells (staining with CD31/terminal deoxynucleotidyl transferase-mediated nick end labeling), leading to a decrease in microvessel density. CONCLUSIONS: These data show that administration of IFN-alpha at optimal biological dose and schedule in combination with gemcitabine induced apoptosis in tumor-associated endothelial cells and decreased growth of human pancreatic cancer cells in the pancreas, leading to a significant increase in survival.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Endotélio Vascular/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Animais , Divisão Celular/efeitos dos fármacos , Desoxicitidina/administração & dosagem , Relação Dose-Resposta a Droga , Endotélio Vascular/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Humanos , Implantes Experimentais , Interferon-alfa/administração & dosagem , Interleucina-8/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neoplasias Experimentais , Neoplasias Pancreáticas/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Taxa de Sobrevida , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular/metabolismo , GencitabinaRESUMO
PURPOSE: Despite maximal therapy, surgically treated patients with stage I non-small cell lung cancer (NSCLC) are at risk for developing metastatic disease. Histopathologic findings cannot adequately predict disease progression, so there is a need to identify molecular factors that serve this purpose. Because the ErbB receptors play an important role in lung cancer progression, we analyzed the expression of epidermal growth factor receptor (EGFR), phosphorylated EGFR, transforming growth factor alpha (TGFalpha), and HER2-neu as potential prognostic factors in stage I NSCLC. EXPERIMENTAL DESIGN: Using immunohistochemical techniques, we retrospectively analyzed formalin-fixed, paraffin-embedded samples from 111 patients with resected pathological stage I NSCLC. Then we correlated these data with patient clinical outcome. RESULTS: Median follow-up was 69.3 months. EGFR overexpression (defined as >10% membranous staining) was found in 66 tumors (59.5%). It was significantly more common in T(2) tumors than in T(1) tumors (P = 0.001), and in more squamous cell carcinomas than in adenocarcinomas (P = 0.07). HER2-neu overexpression was found in 19 tumors (17.1%) and was significantly more common in adenocarcinomas than in squamous cell carcinomas (P = 0.035). Synchronous overexpression of EGFR and HER2-neu was found in 11 tumors (9.9%). Patients with these tumors had a significantly shorter time to recurrence (P = 0.006) and a trend toward shorter overall survival (P = 0.093). Phosphorylated EGFR and transforming growth factor alpha were detected but were not related to prognosis. CONCLUSIONS: Synchronous overexpression of EGFR and HER2-neu at the protein level predicts increased recurrence risk and may predict decreased survival in patients with stage I NSCLC. This suggests that important interactions take place among the different members of the ErbB family during tumor development and suggests a method for choosing targeted therapy. A prospective study is planned.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Receptores ErbB/metabolismo , Neoplasias Pulmonares/metabolismo , Recidiva Local de Neoplasia/metabolismo , Receptor ErbB-2/metabolismo , Adenocarcinoma/diagnóstico , Adenocarcinoma/metabolismo , Adenocarcinoma Bronquioloalveolar/diagnóstico , Adenocarcinoma Bronquioloalveolar/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Progressão da Doença , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Neoplasias Pulmonares/diagnóstico , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Estadiamento de Neoplasias , Fosforilação , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Fator de Crescimento Transformador alfa/metabolismoRESUMO
PURPOSE: Because survival for patients with oral cancer has not improved over the past 25 years, new approaches for treatment are needed. Targeted molecular therapy against epidermal growth factor receptor (EGFR) has shown promise as an adjuvant therapy in preliminary studies in several solid tumors, including head and neck cancer. The objective of this study was to determine the efficacy of paclitaxel and PKI166, a novel inhibitor of EGFR, against oral cavity cancer. EXPERIMENTAL DESIGN AND RESULTS: JMAR human oral cancer cells were pretreated for 1 h with PKI166 and then stimulated with epidermal growth factor. EGFR-specific tyrosine kinase autophosphorylation measured by Western immunoblotting was inhibited by PKI166 in a dose-dependent fashion at all doses tested (0.01-1 micro M). Next, the induction of apoptosis in JMAR cells treated with paclitaxel (0.001 to 0.1 micro M) with or without PKI166 (0, 1, or 2 micro M) was determined using a propidium iodide assay. The addition of 2.0 micro M PKI166 significantly increased tumor cell death, shifting the amount of paclitaxel needed to induce apoptosis in 50% of cells from 0.1 to 0.001 micro M. These in vitro findings were confirmed using an orthotopic model of oral cancer. JMAR oral cancer cells were implanted into the tongues of nude mice. After lingual tumors developed, mice were randomized into four groups (n = 10): (a) oral PKI166 (100 mg/kg); (b) i.p. paclitaxel (200 micro g/wk); (c) PKI166 and paclitaxel; or (d) placebo. Mice treated with PKI166/paclitaxel demonstrated a significant increase in survival (P = 0.028). After necropsy, all tongue tumors were evaluated for apoptosis by the terminal deoxynucleotidyl transferase-mediated nick end labeling assay. A greater apoptotic fraction of tumor cells was found in tumors of mice treated with paclitaxel and PKI166 as compared with the other treatment groups (136.4 versus 37.8; P = 0.016). CONCLUSIONS: Combination therapy with paclitaxel and PKI166 prolongs survival in an orthotopic preclinical model of tongue cancer by increasing programmed cell death of oral cancer.
Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Apoptose , Receptores ErbB/antagonistas & inibidores , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/mortalidade , Paclitaxel/uso terapêutico , Pirimidinas/uso terapêutico , Pirróis/uso terapêutico , Animais , Western Blotting , Morte Celular , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Marcação In Situ das Extremidades Cortadas , Ligantes , Masculino , Camundongos , Camundongos Nus , Microscopia de Fluorescência , Neoplasias Bucais/metabolismo , Neoplasias/patologia , Fosforilação , Propídio/uso terapêutico , Língua/patologia , Neoplasias da Língua/tratamento farmacológico , Tirosina/metabolismoRESUMO
We assessed vascular endothelial growth factor (VEGF) expression in four different human Ewing's sarcoma cell lines (TC71, SK-ES, RD, and A4573) and in tumors in nude mice induced following s.c. injection of TC71 cells. Three of the four cell lines (TC71, SK-ES, and A4573) expressed significantly higher levels of VEGF than did normal human osteoblasts. Transfection of the adenovirus type 5 early region 1A (E1A) gene into TC71 cells down-regulated VEGF expression in vitro. In the mice bearing TC71 cell tumors, intratumoral injections of an adenoviral vector containing the E1A gene (Ad-E1A) decreased VEGF expression, inhibited tumor growth, and increased the survival rates in comparison with the mice given injections of PBS or an adenoviral vector containing beta-galactosidase (Ad-beta-gal). E1A gene therapy also significantly reduced blood vessel density and induced cell apoptosis in the tumors. These results demonstrate that E1A gene therapy inhibits angiogenesis, most likely by suppression of VEGF expression. Thus, E1A gene therapy may be a new therapeutic approach for Ewing's sarcoma.