RESUMO
Endostatin potentiates the antimitotic effects of paclitaxel (taxol) on endothelial cells (ECs). P125A-endostatin and taxol-treated ECs showed multipolar spindles and nuclear lobulation, leading to mitotic catastrophe and cell death. Induction of nuclear abnormalities was found to be dependent on ß-catenin levels as wnt-mediated overexpression of ß-catenin reversed the changes in nuclear morphology. These results prompted us to investigate whether antiangiogenic gene therapy and paclitaxel chemotherapy can synergistically inhibit angiogenesis and tumor growth. We first determined the effect of combination treatment in a transgenic mouse model of breast cancer. Intramuscular injection of recombinant adeno-associated virus type-2 virus induced sustained expression of P125A-endostatin. In vivo studies showed that combination therapy inhibited mammary cancer growth, delayed the onset of multifocal mammary adenocarcinomas, decreased tumor angiogenesis and increased survival in treated mice. In a second model, female athymic mice were orthotopically transplanted with a metastatic human breast cancer cell line. Antiangiogenic gene therapy in combination with paclitaxel inhibited tumor angiogenesis and lung/lymph-node metastasis in this model. These studies demonstrate cooperation between endostatin gene therapy and chemotherapy to inhibit tumor initiation, growth and metastasis.
Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias da Mama/terapia , Endostatinas/farmacologia , Endotélio Vascular/efeitos dos fármacos , Terapia Genética/métodos , Paclitaxel/uso terapêutico , Poliploidia , Proteínas Recombinantes/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Células Cultivadas , Endotélio Vascular/citologia , Feminino , Humanos , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Camundongos , Proteínas Mutantes/farmacologia , Metástase Neoplásica/prevenção & controle , Transplante de Neoplasias , Neovascularização Patológica/tratamento farmacológico , beta Catenina/metabolismoRESUMO
Kringle 5 (K5) of human plasminogen is a potent angiogenesis inhibitor. In this study, we investigated the effects of recombinant adeno-associated virus (AAV)-mediated delivery of K5 in mouse models of human ovarian cancer. A single intramuscular injection of AAV-K5 resulted in sustained expression of K5 reaching a maximum serum level of 800 ng ml(-1). Gene therapy inhibited both vascular endothelial growth factor (VEGF)-induced and tumor cell-induced angiogenesis in matrigel plug assays. Furthermore, a single injection of AAV-K5 significantly inhibited both subcutaneous and intraperitoneal growth of human ovarian cancer cells. Immunofluorescence studies of residual tumors surgically resected from the treated animals showed reduced tumor burden, which correlated with the inhibition of tumor neovascularization. In addition, AAV-K5 gene therapy differentially affected the nascent vessels more than mature vasculature and induced apoptotic death of tumor cells. These data show that AAV-K5 can be effectively used to inhibit ovarian cancer.
Assuntos
Terapia Genética , Neovascularização Patológica/terapia , Neoplasias Ovarianas/terapia , Fragmentos de Peptídeos/genética , Plasminogênio/genética , Animais , Apoptose , Dependovirus , Feminino , Vetores Genéticos , Humanos , Camundongos , Camundongos Nus , Neovascularização Fisiológica/genética , Neoplasias Ovarianas/irrigação sanguínea , Fatores de Crescimento do Endotélio Vascular/farmacologiaRESUMO
Ovarian physiology is intricately connected to hormonally regulated angiogenic response. Recent advances in the post genomic revolution have significantly impacted our understanding of ovarian function. In an angiogenesis perspective, the ovary offers a unique opportunity to unravel the molecular orchestration of blood vessel development and regression under normal conditions. A majority of ovarian cancers develop from the single layer of epithelium surrounding the ovaries. Angiogenesis is critical for the development of ovarian cancer and its peritoneal dissemination. The present review summarizes recent findings on the angiogenic response in neoplastic ovaries and discusses the prospects of using anti-angiogenic approaches to treat ovarian cancer.
Assuntos
Terapia Genética/métodos , Neovascularização Patológica/fisiopatologia , Neovascularização Fisiológica/fisiologia , Neoplasias Ovarianas/fisiopatologia , Ovário/irrigação sanguínea , Indutores da Angiogênese/metabolismo , Inibidores da Angiogênese/uso terapêutico , Feminino , Vetores Genéticos/uso terapêutico , Humanos , Neoplasias Ovarianas/terapia , Conformação ProteicaRESUMO
Earlier studies have shown that a point mutation in human endostatin at position 125 (human endostatin wherein proline 125 was substituted with alanine, P125A-endostatin) improves endothelial cell binding and antiangiogenic activity. In the present study, we investigated the effect of recombinant adeno-associated virus (rAAV)-mediated gene delivery of P125A-endostatin (rAAV-P125Aendo) in a mouse model of ovarian carcinoma. Intramuscular (i.m.) injection of rAAV-P125Aendo resulted in a dose-dependent increase in serum endostatin levels. Consequently, vascular endothelial growth factor- and basic fibroblast growth factor-mediated angiogenesis was significantly inhibited in mice injected with rAAV-P125Aendo as compared to control mice injected with rAAV-LacZ. Furthermore, gene therapy using rAAV-P125Aendo construct showed sustained secretion of P125A-endostatin for up to 9 weeks after a single i.m. administration. Recombinant AAV-P125Aendo injection significantly inhibited the growth of human ovarian cancer cells in athymic nude mice. Immunofluorescence studies of residual tumors surgically removed from the rAAV-P125Aendo-treated animals showed decreased number of vessel ends and vessel length, indicating inhibition of angiogenesis. These studies suggest that recombinant AAV-mediated antiangiogenic gene therapy methods can be used to inhibit ovarian cancer growth.