This paper describes a dielectrophoretic method for selection of circulating melanoma cells (CMCs), which lack reliable identifying surface antigens and are extremely rare in blood. This platform captures CMCs individually by dielectrophoresis (DEP) at an array of wireless bipolar electrodes (BPEs) aligned to overlying nanoliter-scale chambers, which isolate each cell for subsequent on-chip single-cell analysis. To determine the best conditions to employ for CMC isolation in this DEP-BPE platform, the static and dynamic dielectrophoretic response of established melanoma cell lines, melanoma cells from patient-derived xenografts (PDX) and peripheral blood mononuclear cells (PBMCs) were evaluated as a function of frequency using two established DEP platforms.
View Article and Find Full Text PDFDuring metastasis, cancer cells from solid tissues, including epithelia, gain access to the lymphatic and hematogenous circulation where they are exposed to mechanical stress due to hemodynamic flow. One of these stresses that circulating tumor cells (CTCs) experience is fluid shear stress (FSS). While cancer cells may experience low levels of FSS within the tumor due to interstitial flow, CTCs are exposed, without extracellular matrix attachment, to much greater levels of FSS.
View Article and Find Full Text PDFPancreatic neuroendocrine neoplasms (pNENs) are slow growing cancers of increasing incidence that lack effective treatments once they become metastatic. Unfortunately, nearly half of pNEN patients present with metastatic liver tumors at diagnosis and current therapies fail to improve overall survival. Pre-clinical models of pNEN metastasis are needed to advance our understanding of the mechanisms driving the metastatic process and for the development of novel, targeted therapeutic interventions.
View Article and Find Full Text PDFPharmacological ascorbate (P-AscH, high-dose, intravenous vitamin C) is cytotoxic to tumor cells in doses achievable in humans. Phase I studies in pancreatic cancer (PDAC) utilizing P-AscH have demonstrated increases in progression free survival, suggesting a reduction in metastatic disease burden. The purpose of this study was to determine the effects of P-AscH on metastatic PDAC.
View Article and Find Full Text PDFHere we have improved an existing mouse model of prostate cancer based on prostate-specific deletion of Pten and Trp53 by incorporating a Cre-activatable luciferase reporter. By coupling the deletion of those genes to the activation of a luciferase reporter, we were able to monitor tumor burden non-invasively over time. We show that, consistent with previous reports, deletion of both Pten and Trp53 on a C57BL/6 background accelerates tumor growth and results in both the loss of androgen receptor expression and castrate resistant tumors as compared with loss of Pten alone.
View Article and Find Full Text PDFDuring metastasis, cancer cells traverse the circulation to reach distant organs. Conventionally, this journey has been regarded as mechanically destructive to circulating tumor cells from solid tissues. We have recently shown that cancer cells from diverse tissues actively resist destruction by fluid shear stress through a mechano-adaptive RhoA-actomyosin mechanism.
View Article and Find Full Text PDFDuring metastasis, cancer cells are exposed to potentially destructive hemodynamic forces including fluid shear stress (FSS) while en route to distant sites. However, prior work indicates that cancer cells are more resistant to brief pulses of high-level FSS in vitro relative to non-transformed epithelial cells. Herein, we identify a mechano-adaptive mechanism of FSS resistance in cancer cells.
View Article and Find Full Text PDFMetastatic disease is the leading cause of pancreatic ductal adenocarcinoma (PDAC) associated death. PDAC cells invade and enter the bloodstream early, before frank malignancy can be detected. Our objective was to develop an assay enabling the identification and quantification of circulating tumor cells (CTCs) from primary orthotopic PDAC tumors.
View Article and Find Full Text PDFEpithelial-to-mesenchymal transition (EMT) is implicated in cancer metastasis and drug resistance. Specifically targeting cancer cells in an EMT-like state may have therapeutic value. In this study, we developed a cell imaging-based high-content screening protocol to identify EMT-selective cytotoxic compounds.
View Article and Find Full Text PDFGenetic mouse models of soft tissue sarcoma provide critical insights into disease pathophysiology, which are oftentimes unable to be extracted from human tumor samples or xenograft models. In this study we describe a mouse model of soft tissue sarcoma mediated by adenoviral-Cre recombinase injection into Trp53fl/fl/Ptenfl/fl lox-stop-lox luciferase mice. Injection of adenovirus expressing Cre recombinase, either subcutaneously or intramuscularly in two experimental groups, results in viral infection and gene recombination with 100% penetrance within the first 24 hours following injection.
View Article and Find Full Text PDFThe sodium leak channel NARROW ABDOMEN (NA)/ NALCN is an important component of circadian pacemaker neuronal output. In , rhythmic expression of the NA channel regulator in a subset of adult pacemaker neurons has been proposed to contribute to circadian regulation of channel localization or activity. Here we have restricted expression of NA channel subunits or the regulator to either development or adulthood using the temperature-inducible -GAL80 system.
View Article and Find Full Text PDFCircadian clocks regulate membrane excitability in master pacemaker neurons to control daily rhythms of sleep and wake. Here, we find that two distinctly timed electrical drives collaborate to impose rhythmicity on Drosophila clock neurons. In the morning, a voltage-independent sodium conductance via the NA/NALCN ion channel depolarizes these neurons.
View Article and Find Full Text PDFPurpose: Hot flashes occur in approximately 80% of androgen-deprived men. Few intervention studies have been conducted to relieve hot flashes in men.
Patients And Methods: Eligible androgen-deprived men were randomly assigned to one of four daily regimens (2 × 2 factorial design) for 12 weeks: milk protein powder and placebo pill, venlafaxine and milk protein powder, soy protein powder and placebo pill, or venlafaxine and soy protein powder.
Roux-en-Y gastric bypass (RYGB) operation has become a popular choice for weight-reduction surgery. We report an outcome analysis of our early results with laparoscopic Roux-en-Y gastric bypass for superobese (BMI >50) patients. Between January 2000 and October 2001, we operated on 71 superobese patients.
View Article and Find Full Text PDFPurpose: The purpose of this study was to measure the effect of megestrol acetate (MA) on weight loss and quality of life (QOL) in patients with cancer of the lung or head and neck undergoing curative radiation therapy.
Methods And Materials: This was a Phase III, placebo-controlled, double-blind randomized study. Patients received either 800 mg/day of MA (20 milliliters po qAM) or placebo over a 12-week period.