RESUMO
Hyperactivation of phosphatidylinositol 3-kinase (PI3K) pathway occurs frequently in head and neck squamous cell carcinoma (HNSCC). However, clinical outcomes of targeting the PI3K pathway have been underwhelming. In present study, we investigated the resistant mechanisms and potential combination therapeutic strategy to overcome adaptive resistance to PI3K inhibitor in HNSCC. Treatment of NVP-BKM120, a pan-PI3K inhibitor, led to upregulation of interleukin-6 (IL-6) and subsequent activation of either extracellular signal-regulated kinase (ERK) or signal transducers and activators of transcription 3 (STAT3), causing modest antitumor effects on the growth of HNSCC cells. Blockade of autocrine IL-6 signaling with siRNA or neutralizing antibody for IL-6 receptor (IL-6R) completely abolished NVP-BKM120-induced activation of ERK and STAT3 as well as expression of c-Myc oncogene, which resulted in enhanced sensitivity to NVP-BKM120. Moreover, when compared with a pharmacologic inhibitor or silencing of STAT3, trametinib, a MEK inhibitor, in combination with NVP-BKM120 yielded more potent anti-proliferative effects by inhibiting S phase transition, arresting cells at G0/G1 phase, and downregulating IL-6 and c-Myc expression. Furthermore, as compared with either agent alone, combination of NVP-BKM120 with trametinib or tocilizumab, a humanized anti-IL-6R antibody, significantly suppressed tumor growth in NVP-BKM120-resistant patient-derived tumor xenograft (PDTX) models, which was also confirmed in PDTX-derived cell lines. Collectively, these results suggested that IL-6/ERK signaling is closely involved in adaptive resistance of NVP-BKM120 in HNSCC cells, providing a rationale for a novel combination therapy to overcome resistance to PI3K inhibitors.
Assuntos
Aminopiridinas/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma de Células Escamosas/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Interleucina-6/metabolismo , Morfolinas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Aminopiridinas/uso terapêutico , Animais , Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Comunicação Autócrina/efeitos dos fármacos , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Interleucina-6/genética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos NOD , Morfolinas/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Piridonas/farmacologia , Piridonas/uso terapêutico , Pirimidinonas/farmacologia , Pirimidinonas/uso terapêutico , RNA Interferente Pequeno/metabolismo , Receptores de Interleucina-6/antagonistas & inibidores , Receptores de Interleucina-6/metabolismo , Fator de Transcrição STAT3/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Changes in chromosome number and structure are important contributors to adaptation, speciation and macroevolution. In flowering plants, polyploidy and subsequent reductions in chromosome number by fusion are major sources of chromosomal evolution, but chromosome number increase by fission has been relatively unexplored. Here, we use comparative linkage mapping with gene-based markers to reconstruct chromosomal synteny within the model flowering plant genus Mimulus (monkeyflowers). Two sections of the genus with haploid numbers ≥ 14 have been inferred to be relatively recent polyploids because they are phylogenetically nested within numerous taxa with low base numbers (n=8-10). We combined multiple data sets to build integrated genetic maps of the M. guttatus species complex (section Simiolus, n=14) and the M. lewisii group (section Erythranthe; n=8), and then aligned the two integrated maps using >100 shared markers. We observed strong segmental synteny between M. lewisii and M. guttatus maps, with essentially 1-to-1 correspondence across each of 16 chromosomal blocks. Assuming that the M. lewisii (and widespread) base number of 8 is ancestral, reconstruction of 14 M. guttatus chromosomes requires at least eight fission events (likely shared by Simiolus and sister section Paradanthus (n=16)), plus two fusion events. This apparent burst of fission in the yellow monkeyflower lineages raises new questions about mechanisms and consequences of chromosomal fission in plants. Our comparative maps also provide insight into the origins of a chromosome exhibiting centromere-associated female meiotic drive and create a framework for transferring M. guttatus genome resources across the entire genus.
Assuntos
Aneuploidia , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Mimulus/genética , Poliploidia , Centrômero/genética , Evolução Molecular , Haploidia , Mimulus/classificação , Especificidade da Espécie , SinteniaRESUMO
We developed a video-assisted gliding test to evaluate the gliding force and the flexion angle with unrestricted joint motion. Tendon adhesion was induced in a chicken model of flexor digitorum profundus (FDP) injury at the annular pulley region of the long toe. The chicken feet were harvested immediately after injury, and 2 weeks and 6 weeks after injury. During the gliding test, the injured FDP was pulled for 15 mm then returned to its initial position. The test was recorded using a video camera and registered to the gliding test mechanical data. The maximum flexion angle and gliding resistance were calculated. The maximum flexion angle was significantly decreased from 78 (SD 10) in controls to 42 (SD 22) in tendons with injury, while gliding resistance was significantly increased in week 2 (0.06, SD 0.05) and week 6 (0.07, SD 0.01) after injury.
Assuntos
Modelos Animais de Doenças , Amplitude de Movimento Articular/fisiologia , Traumatismos dos Tendões/fisiopatologia , Tendões/fisiopatologia , Gravação em Vídeo/métodos , Animais , Fenômenos Biomecânicos , Galinhas , Fibrose , Traumatismos dos Tendões/patologia , Tendões/patologia , Cicatrização/fisiologiaRESUMO
BACKGROUND: Stathmin1 is a microtubule-regulating protein that has an important role in the assembly and disassembly of the mitotic spindle. The roles of stathmin1 in carcinogenesis of various cancers, including prostate and breast cancer, have been explored. However, its expression and roles in gastric cancer have not yet been described. METHODS: Stathmin1 expression in paraffin-embedded tissue sections from 226 patients was analysed by immunohistochemistry. Roles of stathmin1 were studied using a specific small interfering RNA (siRNA). RESULTS: The expression of stathmin1 was positively correlated with lymph node metastasis, TNM stages and vascular invasion, and negatively with recurrence-free survival, in the diffuse type of gastric cancer. The median recurrence-free survival in patients with a negative and positive expression of stathmin1 was 17.0 and 7.0 months, respectively (P=0.009). When the expression of stathmin1 was knocked down using siRNA, the proliferation, migration and invasion of poorly differentiated gastric cancer cells in vitro were significantly inhibited. Moreover, stathmin1 siRNA transfection significantly slowed the growth of xenografts in nude mice. CONCLUSION: These results suggest that stathmin1 can be a good prognostic factor for recurrence-free survival rate and is a therapeutic target in diffuse-type gastric cancer.
Assuntos
Carcinoma/genética , Movimento Celular/genética , Proliferação de Células , Estatmina/genética , Neoplasias Gástricas/genética , Idoso , Animais , Carcinoma/metabolismo , Carcinoma/mortalidade , Carcinoma/patologia , Estudos de Casos e Controles , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , RNA Interferente Pequeno/farmacologia , Estatmina/antagonistas & inibidores , Estatmina/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Although fine-needle aspiration (FNA) is currently used for the diagnosis of lymphoma, its diagnostic utility in patients with head and neck (HN) lymphoma is unclear. We therefore assessed the utility of initial clinical and FNA diagnoses for HN lymphoma in a clinician's perspective. METHODS: We conducted a retrospective study of total 109 patients with HN lymphoma underwent both FNA and tissue diagnoses from January 2000 through December 2005. The diagnostic sensitivity of FNA was compared with that of histopathology. FNA diagnosis was based on cytomorphology alone in 69 patients and on immunophenotyping plus morphology in 40. RESULTS: On clinical diagnosis, lymphoma was suspected in 54 patients, nonlymphoma/metastatic malignancy in 31, and benign disease in 24. FNA diagnosed lymphoma in 41 patients; suspicious of lymphoma in 23; atypical lymphoma in 20; benign disease in 19; and was nondiagnostic in 6 patients. Diagnostic accuracy of FNA was not significantly improved by repeat core needle biopsy and immunophenotyping. Delay from FNA to tissue diagnosis was significant in the benign FNA-diagnostic group, with a mean 49 days. CONCLUSIONS: The clinical and FNA diagnoses of HN lymphoma may be incomplete and include the potential pitfall of significant diagnostic delay.
Assuntos
Biópsia por Agulha , Neoplasias de Cabeça e Pescoço/patologia , Linfoma/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Fatores de TempoAssuntos
Síndrome do Nevo Basocelular/genética , Carcinoma Basocelular/genética , Mutação em Linhagem Germinativa , Receptores de Superfície Celular/genética , Adolescente , Povo Asiático , Feminino , Humanos , Coreia (Geográfico) , Mutagênese Insercional/genética , Receptores Patched , Receptor Patched-1RESUMO
BACKGROUND AND OBJECTIVE: To evaluate and compare the effect of two clinically available central nervous system stimulants, namely doxapram and aminophylline on arousal from sevoflurane anaesthesia and bispectral index. METHODS: This randomized, double-blind, placebo-controlled, prospective study was conducted in 90 adult females, ASA I-II, scheduled for elective lower abdominal surgeries at Taipei Medical University Hospital. At 5 min before the completion of surgery, under sevoflurane anaesthesia, patients were divided into three groups to receive doxapram 1 mg kg(-1), aminophylline 2 mg kg(-1) or saline placebo intravenous. Standard vital signs, end-tidal CO(2), end-expiratory sevoflurane concentration, bispectral index and neuromuscular blockade were measured plus clinical parameters of recovery from general anaesthesia. RESULTS: Compared with the control group, patients receiving doxapram or aminophylline showed a similarly faster recovery from sevoflurane anaesthesia correlated with increase in bispectral index. CONCLUSION: Intravenous administration of doxapram 1 mg kg(-1) or aminophylline 2 mg kg(-1) hastened the early recovery from sevoflurane anaesthesia. The arousal effect of aminophylline and doxapram appears to be similar.
Assuntos
Aminofilina/uso terapêutico , Cardiotônicos/uso terapêutico , Estimulantes do Sistema Nervoso Central/uso terapêutico , Doxapram/uso terapêutico , Eletroencefalografia/efeitos dos fármacos , Adulto , Análise de Variância , Período de Recuperação da Anestesia , Anestesia Geral , Anestesia por Inalação , Anestésicos Inalatórios , Nível de Alerta/efeitos dos fármacos , Terapia Combinada , Método Duplo-Cego , Feminino , Humanos , Éteres Metílicos , Monitorização Intraoperatória/métodos , Estudos Prospectivos , Desempenho Psicomotor/efeitos dos fármacos , SevofluranoRESUMO
Tumor necrosis factor (TNF) is a proinflammatory cytokine involved in the pathogenesis of rheumatoid arthritis, and antagonism of TNF may reduce the activity of the disease. Among a number of techniques for gene transfer in vivo, the direct injection of plasmid DNA into muscle is simple, inexpensive, and safe. In this study, we attempted to treat collagen-induced arthritis (CIA) with anti-TNF gene therapy by transferring the plasmid encoding soluble p75 TNF receptor linked to the Fc portion of human IgG1 (sTNFR:Fc) using in vivo electroporation. DBA/1 mice were immunized with bovine type II collagen and boosted with the same antigen. At 2 days after boosting, the plasmid vector containing cDNA for the sTNFR:Fc was injected into one selected site in the gastrocnemius muscle followed by electroporation. Serum levels of sTNFR:Fc reached 2.3 ng/ml on day 5 when gene expression reached its peak. Macroscopic analysis of paws for redness, swelling and deformities showed that the onset of moderate-to-severe CIA in mice treated with sTNFR:Fc was prevented on a significant level compared with the control mice (P<0.05). The beneficial effect of sTNFR:Fc DNA transfer lasted for at least 18 days following treatment. In addition, both the synovitis and the erosion of cartilage in the knee joints were dramatically reduced in mice treated with sTNFR:Fc (P<0.05). The expression of IL-1beta and IL-12 in the paw was also decreased by sTNFR:Fc treatment (P<0.01) while there was little change in the levels of IL-17 and vWF. These data showed that sTNFR:Fc expression plasmid was effective in the prevention of CIA, and in vivo electroporation-mediated gene transfer may provide a new approach to cytokine therapy in autoimmune arthritis.