RESUMO
BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a particularly vascularized solid tumor where the Raf/MEK/ERK pathway is activated; suggesting that inhibition of this pathway may have therapeutic potential. METHODS: We treated patient-derived HCC xenografts with (i) sorafenib, (ii) AZD6244 (ARRY-142886), and (iii) sorafenib plus AZD6244. Western blotting was employed to determine pharmacodynamic changes in biomarkers relevant to both angiogenesis and MEK signaling. Apoptosis, microvessel density, and cell proliferation were analyzed by immunohistochemistry. RESULTS: We report here that sorafenib treatment resulted in suppression of tumor growth, reduction in cell proliferation, induction of apoptosis and inhibition of mTOR targets. Sorafenib-induced elevation of the insulin-like growth factor receptor 1 (IGF-1R), phospho-c-Raf Ser338, phospho-MEK Ser217/221 and phospho-ERK Thr202/Tyr204 was attenuated by co-treating cells with anti-human IGF-1R antibody or over-expression of activated mutant p70S6K. Pharmacological inhibition of the MEK/ERK pathway by AZD6244 enhanced the anti-tumor effect of sorafenib in both orthotopic and ectopic models of HCC. Such inhibition led to a further increase in pro-apoptotic Bim, apoptosis and a profound inhibition of cell proliferation. CONCLUSION: Our findings underscore the potential of a combined therapeutic approach with sorafenib and MEK inhibitors in the treatment of HCC.
Assuntos
Antineoplásicos/uso terapêutico , Benzenossulfonatos/uso terapêutico , Benzimidazóis/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Piridinas/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzenossulfonatos/farmacologia , Benzimidazóis/farmacologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Sinergismo Farmacológico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos SCID , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neovascularização Patológica/tratamento farmacológico , Niacinamida/análogos & derivados , Compostos de Fenilureia , Piridinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sorafenibe , Quinases raf/metabolismoRESUMO
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Current therapeutic options include surgery and targeted molecular approaches such as imatinib and sunitinib. Our aim was to establish patient-derived GIST xenografts for the use of screening new drugs and improving current treatment regimens used in GIST. In this present study, we investigate the antitumor activity of sorafenib against patient-derived GIST xenografts. Murine xenograft models were given two oral doses of sorafenib daily for 30 days and growth of established tumor xenografts was monitored at least twice weekly by vernier caliper measurements. Western blotting was then used to determine changes in proteins in these xenografts before and after sorafenib therapy. Apoptotic and cell proliferation were analyzed by immunohistochemisty. Our data found that oral administration of sorafenib to mice, bearing patient-derived GIST xenografts, resulted in dose-dependent inhibition of tumor growth. Sorafenib-induced growth inhibition was associated with decreased cell proliferation, increased apoptosis, and reduction in tumor angiogenesis. Western blot analysis revealed that sorafenib inhibited C-Raf, phospho-extracellular signal-regulated kinase 1/2, and phospho-MEK1 (Thr286) slightly as well as phospho-c-Kit (Tyr568/Tyr570), phospho- platelet-derived growth factor receptor beta (Tyr1021), and phospho-Flk1 (Tyr951), suggesting that sorafenib inhibited GIST growth by blocking the Raf/MEK/extracellular signal-regulated kinase pathway and angiogenesis. Sorafenib also induced cell cycle arrest, evident through increased levels of p15 and p27 and decreased levels of p21, cyclin A, cyclin B1, and cdc-2. Our study provides a strong rationale for the clinical investigation of sorafenib in patients with GIST as well as an established platform for further drug evaluation studies using GIST xenograft models.
Assuntos
Antineoplásicos/uso terapêutico , Benzenossulfonatos/uso terapêutico , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/patologia , Piridinas/uso terapêutico , Animais , Sequência de Bases , Peso Corporal/efeitos dos fármacos , Modelos Animais de Doenças , Progressão da Doença , Éxons/genética , Tumores do Estroma Gastrointestinal/genética , Tumores do Estroma Gastrointestinal/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos SCID , Mutação/genética , Niacinamida/análogos & derivados , Compostos de Fenilureia , Fosforilação , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Sorafenibe , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. Vascular endothelial growth factor, platelet derived growth factor and the Raf/mitogen-activated protein kinase/extracellular signal regulated kinase (Raf/MEK/ERK) signalling pathway regulates the growth, neovascularization, invasiveness and metastatic potential of HCC. In this study, we investigated the in vivo antitumour activity and mechanisms of action of sorafenib tosylate on four patient-derived HCC xenografts. Sorafenib dosed at 50 mg/kg and 100 mg/kg inhibited tumour growth by 85% and 96%, respectively. Sorafenib-induced growth suppression and apoptosis were associated with inhibition of angiogenesis, down-regulation of phospho-platelet-derived growth factor receptor beta Tyr1021, phospho-eIF4E Ser209, phospho-c-Raf Ser259, c-Raf, Mcl-1, Bcl-2, Bcl-x and positive cell cycle regulators, up-regulation of apoptosis signalling kinase-1, p27 and p21. Expression of IGF-1Rbeta and phosphorylation of c-Raf Ser338, MEK1/2 Ser217/221 and ERK1/2 Thr202/Tyr204 were increased by sorafenib treatment. Phosphorylation of mammalian target-of-rapamycin (mTOR) targets (p70S6K, S6R and 4EBP1) was reduced by sorafenib in sorafenib-sensitive lines but activated in sorafenib-less-sensitive 10-0505 xenograft. Sorafenib-induced phosphorylation of c-met, p70S6K and 4EBP1 was significantly reduced when 10-0505 cells were co-treated with anti-human anti-HGF antibody, suggesting that treatment with sorafenib leads to increased HGF secretion and activation of c-met and mTOR targets. Treatment of 10-0505 tumours with sorafenib plus rapamycin resulted in growth inhibition, inhibition of vascular endothelial growth factor receptor-2 phosphorylation, increased apoptosis and completely blocked sorafenib-induced phosphorylation of mTOR targets and cyclin B1 expression. These data also provide a strong rationale for clinical investigation of sorafenib in combination with mTOR inhibitors in patients with HCC.
Assuntos
Antineoplásicos/farmacologia , Benzenossulfonatos/farmacologia , Divisão Celular/efeitos dos fármacos , Neoplasias Hepáticas Experimentais/patologia , Piridinas/farmacologia , Sirolimo/farmacologia , Animais , Linhagem Celular Tumoral , Camundongos , Niacinamida/análogos & derivados , Compostos de Fenilureia , Fosforilação , SorafenibeRESUMO
Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide and highly resistant to available chemotherapies. Mammalian target of rapamycin (mTOR) functions to regulate protein translation, angiogenesis and cell cycle progression in many cancers including HCC. In the present study, subcutaneous patient-derived HCC xenografts were used to study the effects of an mTOR inhibitor, RAD001 (everolimus), on tumour growth, apoptosis and angiogenesis. We report that oral administration of RAD001 to mice bearing patient-derived HCC xenografts resulted in a dose-dependent inhibition of tumour growth. RAD001-induced growth suppression was associated with inactivation of downstream targets of mTOR, reduction in VEGF expression and microvessel density, inhibition of cell proliferation, up-regulation of p27(Kip1) and down-regulation of p21(Cip1/Waf1), Cdk-6, Cdk-2, Cdk-4, cdc-25C, cyclin B1 and c-Myc. Our data indicate that the mTOR pathway plays an important role in angiogenesis, cell cycle progression and proliferation of liver cancer cells. Our study provides a strong rationale for clinical investigation of mTOR inhibitor RAD001 in patients with HCC.
Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Sirolimo/análogos & derivados , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Apoptose , Peso Corporal , Carcinoma Hepatocelular/sangue , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Everolimo , Humanos , Neoplasias Hepáticas/sangue , Masculino , Camundongos , Camundongos SCID , Microvasos/patologia , Fosforilação , Proteínas Quinases/metabolismo , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR , Fator A de Crescimento do Endotélio Vascular/sangueRESUMO
PURPOSE: Hepatocellular carcinoma (HCC) is the fifth most common primary neoplasm; surgery is the only curative option but 5-year survival rates are only 25% to 50%. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) are known to be involved in growth and neovascularization of HCC. Therefore, agents that target these pathways may be effective in the treatment of HCC. The aim of this study was to determine the antineoplastic activity of brivanib alaninate, a dual inhibitor of VEGF receptor (VEGFR) and FGF receptor (FGFR) signaling pathways. EXPERIMENTAL DESIGN: Six different s.c. patient-derived HCC xenografts were implanted into mice. Tumor growth was evaluated in mice treated with brivanib compared with control. The effects of brivanib on apoptosis and cell proliferation were evaluated by immunohistochemistry. The SK-HEP1 and HepG2 cells were used to investigate the effects of brivanib on the VEGFR-2 and FGFR-1 signaling pathways in vitro. Western blotting was used to determine changes in proteins in these xenografts and cell lines. RESULTS: Brivanib significantly suppressed tumor growth in five of six xenograft lines. Furthermore, brivanib-induced growth inhibition was associated with a decrease in phosphorylated VEGFR-2 at Tyr(1054/1059), increased apoptosis, reduced microvessel density, inhibition of cell proliferation, and down-regulation of cell cycle regulators. The levels of FGFR-1 and FGFR-2 expression in these xenograft lines were positively correlated with its sensitivity to brivanib-induced growth inhibition. In VEGF-stimulated and basic FGF stimulated SK-HEP1 cells, brivanib significantly inhibited VEGFR-2, FGFR-1, extracellular signal-regulated kinase 1/2, and Akt phosphorylation. CONCLUSION: This study provides a strong rationale for clinical investigation of brivanib in patients with HCC.
Assuntos
Alanina/análogos & derivados , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Triazinas/farmacologia , Alanina/farmacologia , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Masculino , Camundongos , Modelos Químicos , Transplante de Neoplasias , Neovascularização Patológica , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidoresRESUMO
Gastric cancer is a deadly disease for which current therapeutic options are extremely limited. Vascular endothelial growth factor receptors and platelet-derived growth factor receptors regulate gastric cancer cell proliferation, invasion, and tumor angiogenesis. In the present study, we report that sorafenib therapy effectively inhibited tumor growth and angiogenesis in tumor xenografts. These were associated with reduction in the phosphorylation of vascular endothelial growth factor receptor-2 Tyr951, c-Kit Tyr568/570, platelet-derived growth factor receptor-beta Tyr1021, and Akt Ser473 and Thr308, down-regulation of positive cell cycle regulators, increased apoptosis, and up-regulation of p27. Sorafenib treatment also caused up-regulation of p-c-Raf Ser338 and p-extracellular signal-regulated kinase (ERK) Thr202/Tyr204 in gastric cancer xenografts. The combination of sorafenib and MAP/ERK kinase inhibitor AZD6244 enhances the effectiveness of each compound alone. Potential effect of sorafenib/AZD6244 included increase in proapoptotic Bim. Our data show that MAP/ERK kinase inhibition enhances the antitumor activity of sorafenib in vivo, supporting a rationale for multitargeted suppression of the angiogenesis and ERK signaling network in gastric cancer therapy.
Assuntos
Antineoplásicos/uso terapêutico , Benzenossulfonatos/uso terapêutico , Benzimidazóis/uso terapêutico , Modelos Animais de Doenças , Piridinas/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Animais , Western Blotting , Sinergismo Farmacológico , Humanos , Camundongos , Camundongos SCID , Niacinamida/análogos & derivados , Compostos de Fenilureia , Sorafenibe , Neoplasias Gástricas/patologiaRESUMO
The purpose of this study was to confirm our hypothesis that the development of functional intestinal obstruction in carcinomatosis peritonei [CP] is related to cytokine-mediated inhibition of the Akt pathway and to investigate the phenomenon of relative adrenal insufficiency in CP. Human adrenocortical cells [NCI-H295R] were treated with serum derived from eight cancer patients who had intestinal obstruction and functional adrenal insufficiency. Serum from three normal healthy subjects and three who had CP but without intestinal obstruction or adrenal insufficiency were used as controls. The differential effects of serum on the treated cells were studied using Western blot analysis. Cortisol production of these treated cells was assayed with cortisol ELISA kits. Phosphorylation of Akt at Ser473 and Ser308 in cells was significantly reduced when treated with serum from patients with intestinal obstruction but not controls. Phosphorylation of PDK1 at Ser241, mTOR downstream targets like p70S6 at Thr421/Ser424 and Thr389, and lastly 4EBP-1 at Ser70 a downstream target of p70S6 was reduced by approximately 50%, 40%, and 70%, respectively. There was enhanced phosphorylation of elF4E an initiating factor in protein translation in cells treated with patient serum compared to controls. Cortisol synthesis was stimulated upon treatment with patient serum but not with control serum. Inhibition of Akt phosphorylation is a mechanism that could play a major role in the development of intestinal obstruction in carcinomatosis peritonei. The identification of the mediating cytokines will lead to the development of cogent targeted therapeutic strategies