RESUMO
Leiomyosarcoma (LMS) represents a highly malignant, rare soft tissue sarcoma with high rates of morbidity and mortality. Previously, we demonstrated that tissue-isolated human LMS xenografts perfused in situ are highly sensitive to the direct anticancer effects of physiological nocturnal blood levels of melatonin which inhibited tumour cell proliferative activity, linoleic acid (LA) uptake and metabolism to 13-hydroxyoctadecadienoic acid (13-HODE). Here, we show the effects of low pharmacological blood concentrations of melatonin following oral ingestion of a melatonin supplement by healthy adult human female subjects on tumour proliferative activity, aerobic glycolysis (Warburg effect) and LA metabolic signalling in tissue-isolated LMS xenografts perfused in situ with this blood. Melatonin markedly suppressed aerobic glycolysis and induced a complete inhibition of tumour LA uptake, 13-HODE release, as well as significant reductions in tumour cAMP levels, DNA content and [(3) H]-thymidine incorporation into DNA. Furthermore, melatonin completely suppressed the phospho-activation of ERK 1/2, AKT, GSK3ß and NF-kB (p65). The addition of S20928, a nonselective melatonin antagonist, reversed these melatonin inhibitory effects. Moreover, in in vitro cell culture studies, physiological concentrations of melatonin repressed cell proliferation and cell invasion. These results demonstrate that nocturnal melatonin directly inhibited tumour growth and invasion of human LMS via suppression of the Warburg effect, LA uptake and other related signalling mechanisms. An understanding of these novel signalling pathway(s) and their association with aerobic glycolysis and LA metabolism in human LMS may lead to new circadian-based therapies for the prevention and treatment of LMS and potentially other mesenchymally derived solid tumours.
Assuntos
Glicólise/efeitos dos fármacos , Leiomiossarcoma/tratamento farmacológico , Melatonina/metabolismo , Animais , Sobrevivência Celular , Feminino , Humanos , Leiomiossarcoma/metabolismo , Leiomiossarcoma/patologia , Metástase Neoplásica , Ratos , Ratos Nus , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Traditional pancreaticoduodenectomy dissection techniques are tedious and time-consuming. The LigaSure(®) Vessel Sealing System is an alternative to standard dissection methods. LigaSure(®) can be used in replace of ligatures, clips, and sutures in most of the pancreaticoduodenectomy procedure. The objective of this study was to examine our experience with LigaSure(®) in pancreaticoduodenectomies and to show the safety and time-effectiveness. Forty-three pancreaticoduodenectomies were performed by a single surgeon using the LigaSure(®) device in place of traditional dissection techniques. A retrospective chart review was conducted to evaluate patient management and outcome. Demographics, preoperative, intraoperative, and postoperative data were analyzed. The average patient age was 61 years. Primary pathologic diagnoses were: periampullary carcinoma (56%), chronic pancreatitis (5%), cystic lesion (26%), neuroendocrine tumor (7%), and other (5%). Our patient population demonstrated American Society of Anesthesiologists Class I (2%), Class II (14%), III (75%), and IV (9%). Average operative time was 4:11 hours. The study group required an average of 0.49 ± 1.35 units of blood. Eight patients (19%) received blood transfusion, receiving an average of 2.63 ± 2.13 units. Patients had a median hospital stay of 10 days (range, 5 to 41 days). An oral diet was ordered for most patients by Day 4. Fourteen patients (32.5%) had a complication, including two patients requiring additional surgery for drainage of abscess. There were no postoperative deaths. The use of LigaSure(®) is a practical and safe alternative to standard dissection techniques. Operative time, blood loss, and complication rate are favorable compared with published series.
Assuntos
Adenocarcinoma/cirurgia , Dissecação/métodos , Laparoscopia/métodos , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia , Técnicas de Sutura/instrumentação , Procedimentos Cirúrgicos Vasculares/métodos , Adenocarcinoma/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Perda Sanguínea Cirúrgica/mortalidade , Perda Sanguínea Cirúrgica/prevenção & controle , Feminino , Humanos , Tempo de Internação/tendências , Ligadura/métodos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Hemorragia Pós-Operatória/mortalidade , Hemorragia Pós-Operatória/prevenção & controle , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento , Estados Unidos/epidemiologiaRESUMO
Disturbed sleep-wake cycle and circadian rhythmicity are associated with cancer, but the underlying mechanisms are unknown. Employing a tissue-isolated human breast xenograft tumor nude rat model, we observed that glycogen synthase kinase 3ß (GSK3ß), an enzyme critical in metabolism and cell proliferation/survival, exhibits a circadian rhythm of phosphorylation in human breast tumors. Exposure to light-at-night suppresses the nocturnal pineal melatonin synthesis, disrupting the circadian rhythm of GSK3ß phosphorylation. Melatonin activates GSK3ß by inhibiting the serine-threonine kinase Akt phosphorylation, inducing ß-catenin degradation and inhibiting epithelial-to-mesenchymal transition, a fundamental process underlying cancer metastasis. Thus, chronic circadian disruption by light-at-night via occupational exposure or age-related sleep disturbances may contribute to cancer incidence and the metastatic spread of breast cancer by inhibiting GSK3ß activity and driving epithelial-to-mesenchymal transition in breast cancer patients.
Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Ritmo Circadiano , Transição Epitelial-Mesenquimal , Quinase 3 da Glicogênio Sintase/metabolismo , Melatonina/metabolismo , Animais , Neoplasias da Mama/fisiopatologia , Linhagem Celular Tumoral , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/efeitos da radiação , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/efeitos da radiação , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos da radiação , Feminino , Glicogênio Sintase Quinase 3 beta , Humanos , Luz , Masculino , Melatonina/farmacologia , Modelos Biológicos , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Fosfosserina/metabolismo , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/fisiopatologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Fatores de Transcrição da Família Snail , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto Jovem , beta Catenina/metabolismoRESUMO
Appropriate laboratory animal facility lighting and lighting protocols are essential for maintaining the health and wellbeing of laboratory animals and ensuring the credible outcome of scientific investigations. Our recent experience in relocating to a new laboratory facility illustrates the importance of these considerations. Previous studies in our laboratory demonstrated that animal room contamination with light-at-night (LAN) of as little as 0.2 lx at rodent eye level during an otherwise normal dark-phase disrupted host circadian rhythms and stimulated the metabolism and proliferation of human cancer xenografts in rats. Here we examined how simple improvements in facility design at our new location completely eliminated dark-phase LAN contamination and restored normal circadian rhythms in nontumor-bearing rats and normal tumor metabolism and growth in host rats bearing tissue-isolated MCF7(SR(-)) human breast tumor xenografts or 7288CTC rodent hepatomas. Reducing LAN contamination in the animal quarters from 24.5 ± 2.5 lx to nondetectable levels (complete darkness) restored normal circadian regulation of rodent arterial blood melatonin, glucose, total fatty and linoleic acid concentrations, tumor uptake of O(2), glucose, total fatty acid and CO(2) production and tumor levels of cAMP, triglycerides, free fatty acids, phospholipids, and cholesterol esters, as well as extracellular-signal-regulated kinase, mitogen-activated protein kinase, serine-threonine protein kinase, glycogen synthase kinase 3ß, γ-histone 2AX, and proliferating cell nuclear antigen.
Assuntos
Academias e Institutos/normas , Ritmo Circadiano/fisiologia , Laboratórios/normas , Iluminação/normas , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Ratos Endogâmicos BUF/fisiologia , Ratos Nus/fisiologia , Animais , Animais de Laboratório/fisiologia , Glicemia/metabolismo , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Proliferação de Células , Feminino , Humanos , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Melatonina/sangue , Neoplasias Experimentais/irrigação sanguínea , Ratos , Transplante Heterólogo , Local de TrabalhoRESUMO
INTRODUCTION: The pineal gland hormone, melatonin, has been shown by numerous studies to inhibit the proliferation of estrogen receptor α (ERα)-positive breast cancer cell lines. Here, we investigated the role of melatonin in the regulation of breast cancer cell invasion. METHODS: Three invasive MCF-7 breast cancer cell clones - MCF-7/6, MCF-7/Her2.1, and MCF-7/CXCR4 cells - were employed in these studies. All three cell lines exhibited elevated phosphorylation of the ERK1/2 and p38 mitogen-activated protein kinase (MAPK) as determined by Western blot analysis. The effect of melatonin on the invasive potential of these human breast cancer cells was examined by matrigel invasion chamber assays. The expression and proteinase activity of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, were analyzed by Western blot analysis and gelatin zymography, respectively. RESULTS: Melatonin (10-9 M) significantly suppressed the invasive potential of MCF-7/6 and MCF-7/Her2.1 cells as measured by matrigel invasion chamber assays, and significantly repressed the proteinase activity of MMP-2 and MMP-9. In MCF-7/CXCR4 cells, melatonin significantly inhibited stromal-derived factor-1 (SDF-1/CXCL12) induced cell invasion and activity of MMP-9. Elevated expression of the MT1 melatonin receptor further enhanced, while luzindole, an MT1/MT2 antagonist, abrogated melatonin's anti-invasive effect, suggesting that melatonin's effect on invasion is mediated, principally, through the MT1 receptor. Furthermore, melatonin repressed the phosphorylation of p38 MAPK in MCF-7/Her2.1 cells and blocked stromal-derived factor-1 (SDF-1) induced p38 phosphorylation in MCF-7/CXCR4 cells. SB230580, a p38 inhibitor, was able to mimic, while transfection of the cells with a constitutively-active MKK6b construct blocked melatonin's effect on cell invasion, suggesting that the anti-invasive action of melatonin is mediated through the p38 pathway. CONCLUSIONS: Melatonin exerts an inhibitory effect on breast cancer cell invasion through down-regulation of the p38 pathway, and inhibition of MMP-2 and MMP-9 expression and activity.