Substrate stiffness modulates lung cancer cell migration but not epithelial to mesenchymal transition.

Biomechanical properties of the tumor microenvironment, including matrix/substrate stiffness, play a significant role in tumor evolution and metastasis. Epithelial to Mesenchymal Transition (EMT) is a fundamental biological process that is associated with increased cancer cell migration and invasion. The goal of this study was to investigate (1) how substrate stiffness modulates the migration behaviors of lung adenocarcinoma cells (A549) and (2) if stiffness-induced changes in cell migration correlate with biochemical markers of EMT. Collagen-coated polydimethylsiloxane (PDMS) substrates and an Ibidi migration assay were used to investigate how substrate stiffness alters the migration patterns of A549 cells. RT-PCR, western blotting and immunofluorescence were used to investigate how substrate stiffness alters biochemical markers of EMT, that is, E-cadherin and N-cadherin, and the phosphorylation of focal adhesion proteins. Increases in substrate stiffness led to slower, more directional migration but did not alter the biochemical markers of EMT. Interestingly, growth factor (i.e., Transforming Growth Factor-ß) stimulation resulted in similar levels of EMT regardless of substrate stiffness. We also observed decreased levels of phosphorylated focal adhesion kinase (FAK) and paxillin on stiffer substrates which correlated with slower cell migration. These results indicate that substrate stiffness modulates lung cancer cell migration via focal adhesion signaling as opposed to EMT signaling.

Lung cancer risk test trial: study design, participant baseline characteristics, bronchoscopy safety, and establishment of a biospecimen repository.

BACKGROUND: The Lung Cancer Risk Test (LCRT) trial is a prospective cohort study comparing lung cancer incidence among persons with a positive or negative value for the LCRT, a 15 gene test measured in normal bronchial epithelial cells (NBEC). The purpose of this article is to describe the study design, primary endpoint, and safety; baseline characteristics of enrolled individuals; and establishment of a bio-specimen repository. METHODS/DESIGN: Eligible participants were aged 50-90 years, current or former smokers with 20 pack-years or more cigarette smoking history, free of lung cancer, and willing to undergo bronchoscopic brush biopsy for NBEC sample collection. NBEC, peripheral blood samples, baseline CT, and medical and demographic data were collected from each subject. DISCUSSION: Over a two-year span (2010-2012), 403 subjects were enrolled at 12 sites. At baseline 384 subjects remained in study and mean age and smoking history were 62.9 years and 50.4 pack-years respectively, with 34% current smokers. Obstructive lung disease (FEV1/FVC <0.7) was present in 157 (54%). No severe adverse events were associated with bronchoscopic brushing. An NBEC and matched peripheral blood bio-specimen repository was established. The demographic composition of the enrolled group is representative of the population for which the LCRT is intended. Specifically, based on baseline population characteristics we expect lung cancer incidence in this cohort to be representative of the population eligible for low-dose Computed Tomography (LDCT) lung cancer screening. Collection of NBEC by bronchial brush biopsy/bronchoscopy was safe and well-tolerated in this population. These findings support the feasibility of testing LCRT clinical utility in this prospective study. If validated, the LCRT has the potential to significantly narrow the population of individuals requiring annual low-dose helical CT screening for early detection of lung cancer and delay the onset of screening for individuals with results indicating low lung cancer risk. For these individuals, the small risk incurred by undergoing once in a lifetime bronchoscopic sample collection for LCRT may be offset by a reduction in their CT-related risks. The LCRT biospecimen repository will enable additional studies of genetic basis for COPD and/or lung cancer risk. TRIAL REGISTRATION: The LCRT Study, NCT 01130285, was registered with Clinicaltrials.gov on May 24, 2010.

Leukotriene B4 augments neutrophil phagocytosis of Klebsiella pneumoniae.

Neutrophils play a critical role in the clearance of bacteria from the lung and other organs by their capacity for phagocytosis and killing. Previously, we identified an important role for the leukotrienes in rat alveolar macrophage phagocytosis of Klebsiella pneumoniae. In this report, we explored the possibility that the leukotrienes play an important role in phagocytosis by neutrophils as well. Inhibition of endogenous leukotriene synthesis by 5-lipoxygenase knockout in mice or by pharmacologic means in human peripheral blood neutrophils attenuated phagocytosis of opsonized K. pneumoniae. Reduced phagocytosis was also observed in human neutrophils pretreated with a leukotriene B4 receptor but not a cysteinyl-leukotriene receptor antagonist. While leukotriene B4 reconstituted defective phagocytosis in leukotriene-deficient neutrophils and enhanced phagocytosis in neutrophils capable of leukotriene synthesis, leukotriene C4, leukotriene D4, 5-hydroperoxyeicosatetraenoic acid, and 5-oxo-eicosatetraenoic acid were ineffective. To determine the opsonin dependence of the leukotriene B4 augmentation of phagocytosis, we assessed the ability of leukotriene B4 to modulate neutrophil phagocytosis and the adherence of sheep erythrocytes opsonized with immunoglobulin G or the complement fragment C3bi. While leukotriene B4 augmented both Fc receptor- and complement receptor-mediated phagocytosis, increased adherence to leukotriene B4-treated neutrophils was limited to complement opsonized targets. In conclusion, we have identified a novel role for leukotriene B4 in the augmentation of neutrophil phagocytosis mediated by either the Fc or complement receptor.

Outcome analysis of goal directed therapy for impotence.

PURPOSE: We assessed patient preference, satisfaction and overall outcome of goal directed management of erectile dysfunction. MATERIALS AND METHODS: The results of goal directed therapy of impotence were assessed by an independent telephone survey of 377 consecutive men who had not received prior therapy and who were followed for a minimum of 2 years. RESULTS: Patients preferred medical to surgical therapies despite significantly higher satisfaction rates achieved with surgery. Average number of treatment modalities chosen by each patient was 2 (range 0 to 5). Ultimately, only 40% of the patients achieved a long-term satisfactory result with goal directed therapy. The remainder were not satisfied with the last treatment but chose no further therapy, were lost to followup or refused therapy from the outset. CONCLUSIONS: Our results clearly demonstrate a patient preference for the least invasive forms of therapy. Patients avoid significantly more effective but also more invasive treatment options despite unsatisfactory results with less invasive methods. Future research efforts should be concentrated on the development of new medical therapies to enhance overall patient satisfaction.