Safety and Effectiveness of Vessel Sealing for Dissection during Pancreaticoduodenectomy

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.

Melatonin suppression of aerobic glycolysis (Warburg effect), survival signalling and metastasis in human leiomyosarcoma

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, GSK3β 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.

Safety and effectiveness of vessel sealing for dissection during pancreaticoduodenectomy

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.

Circadian gating of epithelial-to-mesenchymal transition in breast cancer cells via melatonin-regulation of GSK3β

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 3β (GSK3β), 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 GSK3β phosphorylation. Melatonin activates GSK3β by inhibiting the serine-threonine kinase Akt phosphorylation, inducing β-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 GSK3β activity and driving epithelial-to-mesenchymal transition in breast cancer patients.

Eliminating animal facility light-at-night contamination and its effect on circadian regulation of rodent physiology, tumor growth, and metabolism: a challenge in the relocation of a cancer research laboratory

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 3β, γ-histone 2AX, and proliferating cell nuclear antigen.

Abstract 1324: Melatonin-depleted blood from healthy adult men exposed to environmental light at night stimulates growth, signal transduction and metabolic activity of tissue-isolated human prostate cancer xenografts in nude rats

Light at night (LAN), via its ability to suppress nocturnal circadian pineal melatonin production, has been associated with an increased risk of prostate, breast, and endometrial cancers reported in rotating night shift workers. In previous studies, we determined that melatonin's tumor growth inhibitory mechanism occurs via an MT1 melatonin receptor-mediated suppression of tumor cAMP leading to an inhibition of tumor linoleic acid (LA) uptake and its metabolism to the mitogenic signaling molecule 13-hydroxyoctadecadienoic acid (13-HODE). These events culminate in down-regulation of the epidermal growth factor and insulin-like growth factor-1 pathways. Tissue-isolated, androgen-independent PC3 human prostate tumor xenografts (n=3/group; 57 perfusions) perfused for 60 minutes in situ in male nude rats with melatonin-rich blood (> 100 pg/ml) collected from healthy adult, male subjects (n = 3) during the night were compared to those perfused with melatonin-deficient blood (< 10 pg/ml) collected during the daytime or nighttime following 90 minutes of ocular exposure to bright, white fluorescent light (2800 lux). Perfusion of tissue-isolated PC3 human prostate xenografts with human donor nighttime-collected, melatonin-rich blood samples resulted in substantial reductions (60 – 99%) in tumor cAMP levels, LA uptake, 13-HODE production, glucose uptake, O2 consumption and CO2 production, and [3H]thymidine incorporation into tumor DNA, compared to tumors perfused with daytime-collected or nighttime/light exposure-collected, melatonin-diminished blood samples. The activation of MEK, ERK 1/2, Akt, and glycogen synthase kinase-3β (GSK3β), was also markedly diminished in tumors perfused with melatonin-rich, nighttime-collected blood and stimulated in tumors perfused with melatonin-deficient blood collected after exposure to light at night. Tumor inhibitions by melatonin-rich blood were completely prevented by a non-selective MT1/MT2 melatonin receptor antagonist, forskolin, pertussis toxin, or 8-Bromo-cAMP. These results are the first to demonstrate that the nocturnal melatonin signal in blood collected from male human volunteers during the night suppresses signal transduction, metabolic and growth activity in tissue-isolated PC3 human prostate cancer xenografts via an MT1 melatonin receptor-mediated mechanism. These findings are also the first to show that blood collected from human subjects exposed to light at night markedly stimulates human prostate cancer growth, signal transduction and metabolic activity via suppression of the nocturnal circadian melatonin signal.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1324. doi:10.1158/1538-7445.AM2011-1324

Inhibition of breast cancer cell invasion by melatonin is mediated through regulation of the p38 mitogen-activated protein kinase signaling pathway

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.