RESUMO
BACKGROUND: The optimal treatment approach for low-risk prostate cancer (LRPC) remains controversial. While active surveillance is an increasingly popular option, definitive local treatments, including radical prostatectomy (RP), external beam radiotherapy (EBRT), and prostate seed implantation (PSI), are also commonly used. This study aimed to evaluate the survival outcomes of patients with LRPC using a large patient population from the National Cancer Database (NCDB). METHODS: We analyzed data from 195,452 patients diagnosed with LRPC between 2004 and 2015 using the NCDB. Patients were classified based on their treatment modalities, including RP, EBRT, PSI, or no local treatment (NLT). Only patients with Charlson-Deyo comorbidity scores of 0 or 1 were included to ensure comparability. Propensity score analysis was used to balance the treatment groups, and the accelerated failure time model was used to analyze the survival rates of the treatment groups. RESULTS: After a median follow-up of 70.8 months, 24,545 deaths occurred, resulting in an all-cause mortality rate of 13%. RP demonstrated a survival benefit compared with NLT, particularly in patients younger than 74 years of age. In contrast, radiation treatments (EBRT and PSI) did not improve survival in the younger age groups, except for patients older than 70 years for EBRT and older than 65 years for PSI. Notably, EBRT in patients younger than 65 years was associated with inferior outcomes. CONCLUSION: This study highlights the differences in survival outcomes among LRPC treatment modalities. RP was associated with improved survival compared to NLT, especially in younger patients. In contrast, EBRT and PSI showed survival benefits primarily in the older age groups. NLT is a reasonable choice, particularly in younger patients when RP is not chosen. These findings emphasize the importance of individualized treatment decisions for LRPC management.
Assuntos
Prostatectomia , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/terapia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Idoso , Pessoa de Meia-Idade , Bases de Dados Factuais , Taxa de Sobrevida , Resultado do Tratamento , Braquiterapia , Fatores Etários , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: Desmoplastic small round-cell tumor (DSCRT) in adults is an extremely rare (age-adjusted incidence 0.3 per million) and aggressive sarcoma with limited data for optimal management. PATIENTS AND METHODS: Retrospective analysis of patients with DSCRT diagnosis (2010-2020) was performed following Institutional Review Board approval. The follow-up period was from pathological diagnosis to the last patient contact. Endpoints were type of response and duration of response. RESULTS: In the current analysis, first-line treatment in all cases was vincristine, anthracycline, and cyclophosphamide alternating with ifosfamide and etoposide (VAC-IE) with 100% response for a mean duration of 9.8 (range=5-12) months. Patients received 1-4 subsequent lines of therapy. All patients received temozolomide with irinotecan (50% partial response, duration 8-9 months). Two patients that underwent consolidative cytoreductive surgery with hyperthermic intraperitoneal chemotherapy had a longer survival (30.6 vs. 11.2 months). Patients suffered 100% mortality with a median survival was 17.8 (range=11.2-30.6) months. CONCLUSION: While aggressive multimodality treatment is always warranted for DSCRT, the options are limited by the multicentric presentation, short-lived initial response and lack of established subsequent therapy portending a poor prognosis. Consolidative cytoreductive surgery following first-line therapy may improve survival.
Assuntos
Tumor Desmoplásico de Pequenas Células Redondas/terapia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Procedimentos Cirúrgicos de Citorredução , Tumor Desmoplásico de Pequenas Células Redondas/mortalidade , Tumor Desmoplásico de Pequenas Células Redondas/patologia , Humanos , Quimioterapia Intraperitoneal Hipertérmica/métodos , Masculino , Terapia de Alvo Molecular/métodosRESUMO
The zoophytophagous predator Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is capable of inducing plant defenses in tomato due to its phytophagous behavior. These induced defenses, which include the release of herbivore-induced plant volatiles (HIPVs), have been proven to affect the oviposition behavior and reduce the subsequent performance of some tomato pests. However, the effect of induction of plant defenses by N. tenuis on the preference, development, and reproduction of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) remains unknown. In this research, T. urticae did not show preference for the odor source emitted by intact tomato plants when compared with N. tenuis-punctured plants and jasmonic acid (JA) deficient mutant tomato plants. Furthermore, the number of eggs laid by T. urticae on intact tomato plants or on N. tenuis-punctured plants was similar. However, in a greenhouse experiment conducted to evaluate whether the defense induction mediated by N. tenuis had an effect on T. urticae the infestation of T. urticae was significantly reduced by 35% on those plants previously activated by N. tenuis when compared to the control. The expression of a JA-responsive gene that was upregulated and the transcription of the plant protein inhibitor II was higher on activated plants relative to the control. These results can serve as a basis for the development of new management strategies for T. urticae based on plant defense mechanisms induced from the phytophagous behavior of N. tenuis.
RESUMO
Pulmonary arterial hypertension (PAH) is a progressive disease that culminates in right heart failure and death. Prostacyclin (PGI2) and its derivatives are effective treatments for PAH when administered as continuous parenteral infusions. This treatment paradigm requires medical sophistication, and patients are at risk for complications from an indewelling catheter; drug interruptions may result in rebound pulmonary hypertension and death. We hypothesized that the salivary gland can be repurposed into an endogenous production site for circulating PGI2 through the expression of a fusion protein embodying cyclooxygenase-1 (Cox1) and prostacyclin synthase (PGIS) domains. We utilized ultrasound-assisted gene transfer, a nonviral gene transfer strategy that achieves robust gene transfer to the salivary gland. We initially found that Cox1-PGIS expression in livers of mice using an adenoviral vector dramatically increased circulating PGI2 relative to untreated rats or rats treated with PGIS alone. We then utilized ultrasound-assisted gene transfer to express Cox1-PGIS in the submandibular glands of rats and showed a significant elevation of circulating PGI2 that corresponded to approximately 30% of that seen in humans undergoing intravenous infusion therapy for PAH. These results suggest the feasibility of gene therapy to drive endogenous biosynthesis of PGI2 as a therapeutic strategy for the treatment of PAH.
Assuntos
Ciclo-Oxigenase 1/genética , Epoprostenol/genética , Expressão Gênica , Técnicas de Transferência de Genes , Proteínas Recombinantes de Fusão/genética , Glândulas Salivares/metabolismo , Adenoviridae/genética , Animais , DNA Complementar/genética , DNA Complementar/metabolismo , Terapia Genética , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Humanos , Fígado/metabolismo , Masculino , Camundongos , Ratos , Proteínas Recombinantes de Fusão/sangue , Proteínas Recombinantes de Fusão/metabolismo , Glândula Submandibular/metabolismo , Fatores de Tempo , Transcrição GênicaRESUMO
This investigation describes the clinical significance of phosphorylated focal adhesion kinase (FAK) at the major activating tyrosine site (Y397) in epithelial ovarian cancer (EOC) cells and tumor-associated endothelial cells. FAK gene amplification as a mechanism for FAK overexpression and the effects of FAK tyrosine kinase inhibitor VS-6062 on tumor growth, metastasis, and angiogenesis were examined. FAK and phospho-FAK(Y397) were quantified in tumor (FAK-T; pFAK-T) and tumor-associated endothelial (FAK-endo; pFAK-endo) cell compartments of EOCs using immunostaining and qRT-PCR. Associations between expression levels and clinical variables were evaluated. Data from The Cancer Genome Atlas were used to correlate FAK gene copy number and expression levels in EOC specimens. The in vitro and in vivo effects of VS-6062 were assayed in preclinical models. FAK-T and pFAK-T overexpression was significantly associated with advanced stage disease and increased microvessel density (MVD). High MVD was observed in tumors with elevated endothelial cell FAK (59%) and pFAK (44%). Survival was adversely affected by FAK-T overexpression (3.03 vs 2.06 y, P = 0.004), pFAK-T (2.83 vs 1.78 y, P<0.001), and pFAK-endo (2.33 vs 2.17 y, P = 0.005). FAK gene copy number was increased in 34% of tumors and correlated with expression levels (P<0.001). VS-6062 significantly blocked EOC and endothelial cell migration as well as endothelial cell tube formation in vitro. VS-6062 reduced mean tumor weight by 56% (P = 0.005), tumor MVD by 40% (P = 0.0001), and extraovarian metastasis (P<0.01) in orthotopic EOC mouse models. FAK may be a unique therapeutic target in EOC given the dual anti-angiogenic and anti-metastatic potential of FAK inhibitors.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Indóis/uso terapêutico , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Sulfonamidas/uso terapêutico , Inibidores da Angiogênese/farmacologia , Animais , Carcinoma Epitelial do Ovário , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Proteína-Tirosina Quinases de Adesão Focal/antagonistas & inibidores , Proteína-Tirosina Quinases de Adesão Focal/genética , Dosagem de Genes , Humanos , Indóis/farmacologia , Camundongos Nus , Metástase Neoplásica , Neoplasias Epiteliais e Glandulares/irrigação sanguínea , Neoplasias Epiteliais e Glandulares/patologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Neoplasias Ovarianas/irrigação sanguínea , Neoplasias Ovarianas/patologia , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Sulfonamidas/farmacologia , Tirosina/metabolismoRESUMO
PURPOSE: Mucinous ovarian carcinomas have a distinct clinical pattern compared with other subtypes of ovarian carcinoma. Here, we evaluated (i) stage-specific clinical significance of mucinous ovarian carcinomas in a large cohort and (ii) the functional role of Src kinase in preclinical models of mucinous ovarian carcinoma. EXPERIMENTAL DESIGN: A total of 1,302 ovarian cancer patients including 122 (9.4%) cases of mucinous carcinoma were evaluated for survival analyses. Biological effects of Src kinase inhibition were tested using dasatinib-based therapy in a novel orthotopic mucinous ovarian cancer model (RMUG-S-ip2). RESULTS: Patients with advanced-stage mucinous ovarian cancer had significantly worse survival than those with serous histology: median overall survival, 1.67 versus 3.41 years, P = 0.002; median survival time after recurrence of 0.53 versus 1.66 years, P < 0.0001. Among multiple ovarian cancer cell lines, RMUG-S-ip2 mucinous ovarian cancer cells showed the highest Src kinase activity. Moreover, oxaliplatin treatment induced phosphorylation of Src kinase. This induced activity by oxaliplatin therapy was inhibited by concurrent administration of dasatinib. Targeting Src with dasatinib in vivo showed significant antitumor effects in the RMUG-S-ip2 model but not in the serous ovarian carcinoma (SKOV3-TR) model. Combination therapy of oxaliplatin with dasatinib further showed significant effects on reducing cell viability, increasing apoptosis, and in vivo antitumor effects in the RMUG-S-ip2 model. CONCLUSIONS: Our results suggest that poor survival of women with mucinous ovarian carcinoma is associated with resistance to cytotoxic therapy. Targeting Src kinase with a combination of dasatinib and oxaliplatin may be an attractive approach for this disease.
Assuntos
Adenocarcinoma Mucinoso/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Pirimidinas/farmacologia , Tiazóis/farmacologia , Quinases da Família src/antagonistas & inibidores , Adenocarcinoma Mucinoso/genética , Adenocarcinoma Mucinoso/patologia , Adulto , Idoso , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular , Dasatinibe , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/farmacologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Oxaliplatina , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/administração & dosagem , Tiazóis/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases da Família src/genética , Quinases da Família src/metabolismoRESUMO
BACKGROUND: Intramural delivery of lipids into the coronaries of pigs fed high-cholesterol diet results in the formation of localized atherosclerotic-like lesions within 12 weeks. These lesions are located in positively remodeled vessels and are associated to the development of abundant adventitial vasa vasorum and mononuclear cell infiltrate. In this study, we aimed to analyze the degree of expression of various inflammatory chemokines within the developed lesions compared with control segments injected with saline. METHODS: Balloon injury was performed in 15 coronary arteries of pigs fed high-cholesterol diet for 12 weeks. Two weeks after procedure, 60 coronary segments were randomized to either intramural injections of complex lipids (n=30) or normal saline (n=30). Neovessel density in the lesions was analyzed by lectin stain. Segments were processed for RNA expression of inflammatory chemokines such as monocyte chemoattractant protein-1 and vascular endothelial growth factor. RESULTS: At 12 weeks, the percentage area of stenosis seen in histological sections was modest in both groups (lipids: 17.3±15 vs. saline: 32.4±22.8, P=.017). The lipid group showed higher vasa vasorum (VV) quantity (saline: 18.2±14.9 VV/section vs. lipids: 30.6±21.6 VV/section, P<.05) and vasa vasorum density (saline: 7.3±4.6 VV/mm(2) vs. lipids: 16.5±9 VV/mm(2), P<.001). In addition, monocyte chemoattractant protein-1 expression was higher in the lipid group (1.5±1.12) compared with saline control group (0.83±0.34, P<.01). Vascular endothelial growth factor expression was also higher in the lipid group (1.36±0.9) compared with saline group (0.87±0.33, P<.05). CONCLUSION: The intramural injection of complex lipids into the coronary arteries of pigs maintained in a high-cholesterol diet results in focal lesions located in positively remodeled vessels that have a high neovessel count and express proinflammatory chemokines.
Assuntos
Quimiocinas/metabolismo , Ésteres do Colesterol , Doença da Artéria Coronariana/imunologia , Mediadores da Inflamação/metabolismo , Lipoproteínas LDL , Placa Aterosclerótica/imunologia , Animais , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Quimiocinas/genética , Colesterol na Dieta , Doença da Artéria Coronariana/induzido quimicamente , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/patologia , Modelos Animais de Doenças , Injeções Intra-Arteriais , Neovascularização Patológica/imunologia , Neovascularização Patológica/patologia , Placa Aterosclerótica/induzido quimicamente , Placa Aterosclerótica/genética , Placa Aterosclerótica/patologia , RNA Mensageiro/metabolismo , Sus scrofa , Fatores de Tempo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Liposomes have been used as imaging and therapeutic agents in various tissues but only infrequently in the cardiovascular system. We prepared a liposome to target atheromas in a Watanabe heritable hyperlipidemic (WHHL) rabbit model. Liposomes labeled with rhodamine and nanogold were injected intra-arterially into the descending thoracic aortas of WHHL rabbits. The arterial segments of interest were perfusion-fixed and evaluated with immunohistochemistry, light microscopy, and electron microscopy. Deconvolution microscopy showed that rhodamine label was concentrated in the plaque shoulder regions of advanced-stage atheromas; however, rhodamine label was not found in adjacent, non-atherosclerotic aorta. Transmission electron microscopy revealed liposome remnants and the highest concentration of nanogold label in lipid-laden areas of atheromas. Liposomes were concentrated in areas of lipoprotein-associated phospholipase A(2) expression. We conclude that modified liposomes can be delivered to the shoulder regions of advanced atheromas in WHHL rabbits and may be useful therapeutically for targeting metabolically active plaque.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Hiperlipidemias/tratamento farmacológico , Lipossomos/farmacocinética , Placa Aterosclerótica/tratamento farmacológico , 1-Alquil-2-acetilglicerofosfocolina Esterase/metabolismo , Animais , Aorta Torácica/metabolismo , Aorta Torácica/ultraestrutura , Modelos Animais de Doenças , Técnica de Fratura por Congelamento , Ouro/farmacocinética , Hiperlipidemias/genética , Injeções Intra-Arteriais , Lipossomos/química , Nanopartículas Metálicas , Microscopia Eletrônica , Placa Aterosclerótica/genética , Coelhos , Rodaminas/farmacocinéticaRESUMO
AIMS: There is little in vivo data in regards to the impact of adventitial neovascularisation on vascular remodelling and plaque composition. Using a porcine model of coronary atherosclerosis, we aimed to determine the impact of adventitial neovascularisation on plaque composition and vascular remodelling evaluated by IVUS. METHODS AND RESULTS: Coronary atherosclerosis was induced by adventitial delivery of lipids and a high cholesterol diet. At termination all vessels were analysed using IVUS to determine the degree of remodelling of each individual segment containing atherosclerotic lesions. Then, each segment was correlated with its correspondent histological frame for plaque composition and neovessel density. A total of 57 atherosclerotic lesions at different stages of development were analysed. The total neovessel count (TNC) correlated to the degree of plaque burden (15.6+/-7.2 TNC in <40% stenosis versus 35.7+/-14.0 TNC in >60% stenosis, p<0.01) and to the amount of intra-plaque collagen (32.4+/-14.1%, lower TNC tertile versus 47.5+/-8.9% upper TNC tertile, p< 0.01). The amount of intra-plaque SMC content inversely correlated with the TNC (49.7+/-18.9% versus 36.4+/-14.4%, lower versus upper tertiles, p<0.05). Plaques with the highest TNC showed higher remodelling indexes by IVUS (0.89+/-0.32 in lower TNC tertile versus 1.36+/-0.73 in upper TNC tertile, p<0.05) and higher macrophage cell content (161.42+/-157.6 in lower TNC tertile versus 340.6+/-127.2 in upper TNC tertile, p<0.05) compared to non-remodelled segments. CONCLUSIONS: Adventitial neovascularisation is more prominent in positively remodelled segments and appears to be associated to SMC loss, increase collagen deposition and localised macrophage infiltration.
Assuntos
Tecido Conjuntivo/irrigação sanguínea , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Neovascularização Patológica/fisiopatologia , Animais , Colágeno/metabolismo , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/metabolismo , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Imuno-Histoquímica , Macrófagos/patologia , Miócitos de Músculo Liso/patologia , Neovascularização Patológica/diagnóstico por imagem , Neovascularização Patológica/metabolismo , Índice de Gravidade de Doença , Suínos , Ultrassonografia de IntervençãoRESUMO
PURPOSE: To show the functional, clinical, and biological significance of c-Jun-NH(2)-kinase (JNK)-1 in ovarian carcinoma. EXPERIMENTAL DESIGN: Analysis of the impact of JNK on 116 epithelial ovarian cancers was conducted. The role of JNK in vitro and in experimental models of ovarian cancer was assessed. We studied the role of N-5-[4-(4-methyl piperazine methyl)-benzoylamido]-2-methylphenyl-4-[3-(4-methyl)-pyridyl]-2-pyrimidine amine (WBZ_4), a novel JNK inhibitor redesigned from imatinib based on targeting wrapping defects, in cell lines and in experimental models of ovarian cancer. RESULTS: We found a significant association of pJNK with progression-free survival in the 116 epithelial ovarian cancers obtained at primary debulking therapy. WBZ_4 led to cell growth inhibition and increased apoptosis in a dose-dependent fashion in four ovarian cancer cell lines. In vivo, whereas imatinib had no effect on tumor growth, WBZ_4 inhibited tumor growth in orthotopic murine models of ovarian cancer. The antitumor effect was further increased in combination with docetaxel. Silencing of JNK-1 with systemically administered siRNA led to significantly reduced tumor weights compared with nonsilencing siRNA controls, indicating that indeed the antitumor effects observed were due to JNK-1 inhibition. CONCLUSIONS: These studies identify JNK-1 as an attractive therapeutic target in ovarian carcinoma and that the redesigned WBZ_4 compound should be considered for further clinical development.
Assuntos
Proteína Quinase 8 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 8 Ativada por Mitógeno/fisiologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/enzimologia , Piperazinas/farmacologia , Pirimidinas/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Indutores da Angiogênese , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Neovascularização Patológica/tratamento farmacológico , RNA Interferente Pequeno/farmacologiaRESUMO
A relatively new view of colorectal cancer is that its development/progression reflects the contribution of a large set of altered gene products in varying combinations, each providing a "fitness advantage." In searching for novel contributing gene products using Unigene cluster data mining, we found overrepresentation of expressed sequence tags corresponding to a previously uncharacterized gene (ZKSCAN3) in colorectal tumors. ZKSCAN3 was pursued for several reasons: (a) its sequence similarity with bowl required for Drosophila hindgut development; (b) it lies in a chromosomal region (6p22.1) amplified in colorectal cancer; and (c) its coding sequence predicts tandem C(2)H(2) zinc finger domains present in a class of proteins gaining attention for their role in oncogenesis/tumor progression. Reverse transcription-PCR confirmed overexpression in colorectal tumor tissue compared with adjacent nonmalignant mucosa due in part to gene amplification determined by Southern blotting. Further, immunohistochemistry with an antibody generated to the predicted protein sequence revealed higher ZKSCAN3 expression in invasive compared with noninvasive tumors. Intriguingly, the ZKSCAN3 protein was also expressed in tumors wild-type for genes (APC, p53, K-Ras) commonly targeted in colorectal cancer. ZKSCAN3 knockdown in two independent colon cancer cell lines impaired anchorage-independent growth and orthotopic tumor growth, whereas overexpression in a third cell line had the opposite effect and increased 5-fluorouracil resistance. Liposomal delivery of a ZKSCAN3-targeting small interfering RNA reduced tumorigenicity of orthotopic colon cancer. Thus, the hitherto uncharacterized ZKSCAN3 adds to an expanding set of encoded products contributing to the progression of colorectal cancer.
Assuntos
Neoplasias Colorretais/patologia , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Análise por Conglomerados , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Primers do DNA , Progressão da Doença , Humanos , Imuno-Histoquímica , Camundongos , RNA Interferente Pequeno/administração & dosagem , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genéticaRESUMO
Apoptosis (programmed cell death type I) and autophagy (type II) are crucial mechanisms regulating cell death and homeostasis. The Bcl-2 proto-oncogene is overexpressed in 50-70% of breast cancers, potentially leading to resistance to chemotherapy, radiation and hormone therapy-induced apoptosis. Here, we investigated the role of Bcl-2 in autophagy in breast cancer cells. Silencing of Bcl-2 by siRNA in MCF-7 breast cancer cells downregulated Bcl-2 protein levels (>85%) and led to inhibition of cell growth (71%) colony formation (79%), and cell death (up to 55%) by autophagy but not apoptosis. Induction of autophagy was demonstrated by acridine orange staining, electron microscopy and an accumulation of GFP-LC3-II in autophagosomal membranes in MCF-7 cells transfected with GFP-LC-3(GFP-ATG8). Silencing of Bcl-2 by siRNA also led to induction of LC-3-II, a hallmark of autophagy, ATG5 and Beclin-1 autophagy promoting proteins. Knockdown of ATG5 significantly inhibited Bcl-2 siRNA-induced LC3-II expression, the number of GFP-LC3-II-labeled autophagosome positive cells and autophagic cell death (p < 0.05). Furthermore, doxorubicin at a high dose (IC(95), 1 microM) induced apoptosis but at a low dose (IC(50), 0.07 microM) induced only autophagy and Beclin-1 expression. When combined with Bcl-2 siRNA, doxorubicin (IC(50)) enhanced autophagy as indicated by the increased number cells with GFP-LC3-II-stained autophagosomes (punctuated pattern positive). These results provided the first evidence that targeted silencing of Bcl-2 induces autophagic cell death in MCF-7 breast cancer cells and that Bcl-2 siRNA may be used as a therapeutic strategy alone or in combination with chemotherapy in breast cancer cells that overexpress Bcl-2.
Assuntos
Autofagia/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica/genética , Inativação Gênica/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Interferência de RNA/fisiologia , RNA Interferente Pequeno/fisiologia , Autofagia/fisiologia , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Feminino , Inibidores do Crescimento/fisiologia , Humanos , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-bcl-2/biossínteseRESUMO
PURPOSE: Tissue transglutaminase (TG2) is a multifunctional protein that is implicated in development of drug resistance and metastasis. Therefore, we examined therapeutic targeting of TG2 for inhibiting growth and metastasis of in vivo growing pancreatic ductal adenocarcinoma (PDAC) in nude mice. EXPERIMENTAL DESIGN: We implanted Panc-28 pancreatic cancer cells to induce orthotopic PDAC tumors in nude mice and determined the efficacy of liposomal TG2 small interfering RNA (siRNA) either alone or in combination with gemcitabine. RESULTS: We show that down-regulation of endogenous TG2 by siRNA could effectively block the growth of PDAC. Moreover, down-regulation of TG2 significantly enhanced the therapeutic efficacy of gemcitabine against PDAC and inhibited metastatic spread of the disease. The antitumor activity was related to inhibition of proliferation, angiogenesis, and Akt phosphorylation. CONCLUSION: siRNA-mediated down-regulation of TG2 represents a promising therapeutic approach for improved treatment of PDAC.
Assuntos
Neoplasias Pancreáticas/terapia , RNA Interferente Pequeno/administração & dosagem , Transglutaminases/antagonistas & inibidores , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Proteínas de Ligação ao GTP , Inativação Gênica , Humanos , Masculino , Camundongos , Neovascularização Patológica/terapia , Neoplasias Pancreáticas/enzimologia , Fosfatidilcolinas/administração & dosagem , Proteína 2 Glutamina gama-Glutamiltransferase , Transglutaminases/genéticaRESUMO
A better understanding of the mechanisms involved in small interference RNA (siRNA) gene silencing opens new horizons for the development of the targeted therapy of malignant and benign diseases. As a research tool, siRNA has proven to be highly effective in silencing specific genes and modulating intracellular signaling pathways. However, systemic delivery of siRNA has been more problematic due to degradation and poor cellular uptake. In order to overcome these limitations, a variety of strategies are being developed including new delivery vehicles and chemical modifications. Here, we review potential approaches for the systemic delivery of siRNA for cancer treatment.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Neoplasias/genética , Neoplasias/terapia , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Animais , Ácido Fólico/química , Humanos , Lipossomos/química , Polímeros/química , RNA Interferente Pequeno/químicaRESUMO
BACKGROUND: Interleukin-8 (IL-8) is a proangiogenic cytokine that is overexpressed in many human cancers. We investigated the clinical and biologic significance of IL-8 in ovarian carcinoma using human samples and orthotopic mouse models. METHODS: Tumor expression of IL-8 was assessed by immunohistochemistry among ovarian cancer patients (n = 102) with available clinical and survival data. We examined the effect of IL-8 gene silencing with small interfering RNAs incorporated into neutral liposomes (siRNA-DOPCs), alone and in combination with docetaxel, on in vivo tumor growth, angiogenesis (microvessel density), and tumor cell proliferation in mice (n = 10 per treatment group) bearing orthotopic taxane-sensitive (HeyA8 and SKOV3ip1) and taxane-resistant (SKOV3ip2.TR) ovarian tumors. All statistical tests were two-sided. RESULTS: Of the 102 cancer specimens, 43 (42%) had high IL-8 expression and 59 (58%) had low or no IL-8 expression; high IL-8 expression was associated with advanced tumor stage (P = .019), high tumor grade (P = .031), and worse survival (median survival for patients with high vs low IL-8 expression: 1.62 vs 3.79 years; P < .001). Compared with empty liposomes, IL-8 siRNA-DOPC reduced the mean tumor weight by 32% (95% confidence interval [CI] = 14% to 50%; P = .03) and 52% (95% CI = 27% to 78%; P = .03) in the HeyA8 and SKOV3ip1 mouse models, respectively. In all three mouse models, treatment with IL-8 siRNA-DOPC plus the taxane docetaxel reduced tumor growth the most compared with empty liposomes (77% to 98% reduction in tumor growth; P < .01 for all). In the HeyA8 and SKOV3ip1 models, tumors from mice treated with IL-8 siRNA-DOPC alone had lower microvessel density than tumors from mice treated with empty liposomes (HeyA8: 34% lower, 95% CI = 32% to 36% lower [P = .002]; SKOV3ip1: 39% lower, 95% CI = 34% to 44% lower [P = .007]). Compared with empty liposomes, IL-8 siRNA-DOPC plus docetaxel reduced tumor cell proliferation by 35% (95% CI = 25% to 44%; P < .001) and 38% (95% CI = 28% to 48%; P < .001) in the HeyA8 and SKOV3ip1 models, respectively. CONCLUSIONS: Increased IL-8 expression is associated with poor clinical outcome in human ovarian carcinoma, and IL-8 gene silencing decreases tumor growth through antiangiogenic mechanisms.
Assuntos
Antineoplásicos/administração & dosagem , Inativação Gênica , Interleucina-8/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , RNA Interferente Pequeno/administração & dosagem , Taxoides/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Animais , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Docetaxel , Células Endoteliais , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Immunoblotting , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Lipossomos , Camundongos , Camundongos Nus , Microcirculação , Pessoa de Meia-Idade , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neovascularização Patológica , Neoplasias Ovarianas/irrigação sanguínea , Fosforilação , Prognóstico , Modelos de Riscos Proporcionais , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para CimaRESUMO
Targeting kinases is central to drug-based cancer therapy but remains challenging because the drugs often lack specificity, which may cause toxic side effects. Modulating side effects is difficult because kinases are evolutionarily and hence structurally related. The lack of specificity of the anticancer drug imatinib enables it to be used to treat chronic myeloid leukemia, where its target is the Bcr-Abl kinase, as well as a proportion of gastrointestinal stromal tumors (GISTs), where its target is the C-Kit kinase. However, imatinib also has cardiotoxic effects traceable to its impact on the C-Abl kinase. Motivated by this finding, we made a modification to imatinib that hampers Bcr-Abl inhibition; refocuses the impact on the C-Kit kinase; and promotes inhibition of an additional target, JNK, a change that is required to reinforce prevention of cardiotoxicity. We established the molecular blueprint for target discrimination in vitro using spectrophotometric and colorimetric assays and through a phage-displayed kinase screening library. We demonstrated controlled inhibitory impact on C-Kit kinase in human cell lines and established the therapeutic impact of the engineered compound in a novel GIST mouse model, revealing a marked reduction of cardiotoxicity. These findings identify the reengineered imatinib as an agent to treat GISTs with curbed side effects and reveal a bottom-up approach to control drug specificity.
Assuntos
Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/enzimologia , MAP Quinase Quinase 4/antagonistas & inibidores , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-kit , Pirimidinas/farmacologia , Animais , Benzamidas , Cardiotoxinas/química , Cardiotoxinas/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Fusão bcr-abl , Cardiopatias/induzido quimicamente , Cardiopatias/enzimologia , Humanos , Mesilato de Imatinib , Células K562 , MAP Quinase Quinase 4/metabolismo , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/enzimologia , Piperazinas/efeitos adversos , Piperazinas/química , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/química , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Pirimidinas/efeitos adversos , Pirimidinas/química , Ratos , Ratos Sprague-DawleyRESUMO
There is growing evidence that chronic stress and other behavioral conditions are associated with cancer pathogenesis and progression, but the mechanisms involved in this association are poorly understood. We examined the effects of two mediators of stress, norepinephrine and epinephrine, on the activation of signal transducer and activator of transcription-3 (STAT3), a transcription factor that contributes to many promalignant pathways. Exposure of ovarian cancer cell lines to increasing concentrations of norepinephrine or epinephrine showed that both independently increased levels of phosphorylated STAT3 in a dose-dependent fashion. Immunolocalization and ELISA of nuclear extracts confirmed increased nuclear STAT3 in response to norepinephrine. Activation of STAT3 was inhibited by blockade of the beta1- and beta2-adrenergic receptors with propranolol, and by blocking protein kinase A with KT5720, but not with the alpha receptor blockers prazosin (alpha1) and/or yohimbine (alpha2). Catecholamine-mediated STAT3 activation was not inhibited by pretreatment with an anti-interleukin 6 (IL-6) antibody or with small interfering RNA (siRNA)-mediated decrease in IL-6 or gp130. Regarding the effects of STAT3 activation, exposure to norepinephrine resulted in an increase in invasion and matrix metalloproteinase (MMP-2 and MMP-9) production. These effects were completely blocked by STAT3-targeting siRNA. In mice, treatment with liposome-incorporated siRNA directed against STAT3 significantly reduced isoproterenol-stimulated tumor growth. These studies show IL-6-independent activation of STAT3 by norepinephrine and epinephrine, proceeding through the beta1/beta2-adrenergic receptors and protein kinase A, resulting in increased matrix metalloproteinase production, invasion, and in vivo tumor growth, which can be ameliorated by the down-regulation of STAT3.
Assuntos
Epinefrina/farmacologia , Norepinefrina/farmacologia , Neoplasias Ovarianas/patologia , Fator de Transcrição STAT3/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Linhagem Celular Tumoral , Proliferação de Células , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Feminino , Humanos , Interleucina-6/fisiologia , Metaloproteinases da Matriz/fisiologia , Camundongos , Invasividade NeoplásicaRESUMO
Recent studies have demonstrated that chronic stress promotes tumor growth, angiogenesis, and metastasis. In ovarian cancer, levels of the pro-angiogenic cytokine, interleukin 6 (IL-6), are known to be elevated in individuals experiencing chronic stress, but the mechanism(s) by which this cytokine is regulated and its role in tumor growth remain under investigation. Here we show that stress hormones such as norepinephrine lead to increased expression of IL-6 mRNA and protein levels in ovarian carcinoma cells. Furthermore, we demonstrate that norepinephrine stimulation activates Src tyrosine kinase and this activation is required for increased IL-6 expression. These results demonstrate that stress hormones activate signaling pathways known to be critical in ovarian tumor progression.