Faculty Bibliography

Pancreatic cancer is one of the most lethal cancers worldwide. No effective screening methods exist, and available treatment modalities do not effectively treat the disease. Inflammatory conditions such as pancreatitis represent a well-known risk factor for pancreatic cancer development. Yet only in the past 2 decades has pancreatic cancer been recognized as an inflammation-driven cancer, and the precise mechanisms underlying the pathogenic role of inflammation are beginning to be explored in detail. A substantial amount of preclinical and clinical evidence suggests that bacteria are likely to influence this process by activating immune receptors and perpetuating cancer-associated inflammation. The recent explosion of investigations of the human microbiome have highlighted how perturbations of commensal bacterial populations can promote inflammation and promote disease processes, including carcinogenesis. The elucidation of the interplay between inflammation and microbiome in the context of pancreatic carcinogenesis will provide novel targets for intervention to prevent and treat pancreatic cancer more efficiently. Further studies toward this direction are urgently needed.

Promoters and enhancers establish precise gene transcription patterns. The development of functional approaches for their identification in mammalian cells has been complicated by the size of these genomes. Here we report a high-throughput functional assay for directly identifying active promoter and enhancer elements called FIREWACh (Functional Identification of Regulatory Elements Within Accessible Chromatin), which we used to simultaneously assess over 80,000 DNA fragments derived from nucleosome-free regions within the chromatin of embryonic stem cells (ESCs) and identify 6,364 active regulatory elements. Many of these represent newly discovered ESC-specific enhancers, showing enriched binding-site motifs for ESC-specific transcription factors including SOX2, POU5F1 (OCT4) and KLF4. The application of FIREWACh to additional cultured cell types will facilitate functional annotation of the genome and expand our view of transcriptional network dynamics.

The phosphoinositide-3 kinase (PI3K) pathway is deregulated in a significant proportion of melanomas, and PI3K pathway activation in combination with constitutively active mitogen-activated protein kinase signaling shows synergistic effects in the process of melanoma tumorigenesis. Recently, a tumor suppressor function for the lipid phosphatase inositol polyphosphate 4-phosphatase type II (INPP4B) has been described in breast and prostate cancers, with impact on PI3K signaling output. Given the importance of PI3K pathway activity for melanoma formation and growth, we aimed to assess the role of INPP4B in melanocytic tumors. Our studies in native tumors suggest that decreased INPP4B expression is an event correlating with tumor progression in melanocytic neoplasms. We further demonstrate that INPP4B regulates PI3K/Akt signaling and exerts a tumor suppressor effect, impacting the proliferative, invasive, and tumorigenic capacity of melanoma cells. INPP4B expression in melanocytic neoplasms may therefore have potential as a biomarker for disease progression and as a modulator for the prediction of treatment outcome.

Noncoding RNAs (ncRNAs) represent a class of RNA molecules that typically do not code for proteins. Emerging data suggest that ncRNAs play an important role in several physiological and pathological conditions such as cancer and cardiovascular diseases, including atherosclerosis. The best-characterized ncRNAs are the microRNAs which are small, approximately 22-nucleotide sequences of RNA that regulate gene expression at the posttranscriptional level through transcript degradation or translational repression. MicroRNAs control several aspects of atherosclerosis, including endothelial cell, vascular smooth cell, and macrophage functions as well as lipoprotein metabolism. Apart from microRNAs, recently ncRNAs, especially long ncRNAs, have emerged as important potential regulators of the progression of atherosclerosis. However, the molecular mechanism of their regulation and function as well as the significance of other ncRNAs such as small nucleolar RNAs during atherogenesis is largely unknown. In this review, we summarize the recent findings in the field, highlighting the importance of ncRNAs in atherosclerosis and discuss their potential use as therapeutic targets in cardiovascular diseases.

The major risks of pacemaker and implantable cardioverter defibrillator extraction are attributable to the fibrotic tissue that encases them in situ, yet little is known about the cellular and functional properties of this response. In the present research, we performed a histological and mechanical analysis of human tissue collected from the lead-tissue interface to better understand this process and provide insights for the improvement of lead design and extraction. The lead-tissue interface consisted of a thin cellular layer underlying a smooth, acellular surface, followed by a circumferentially organized collagen-rich matrix. 51.8+/-4.9% of cells were myofibroblasts via immunohistochemistry, with these cells displaying a similar circumferential organization. Upon mechanical testing, samples exhibited a triphasic force-displacement response consisting of a toe region during initial tensioning, a linear elastic region and a yield and failure region. Mean fracture load was 5.6+/-2.1N, and mean circumferential stress at failure was 9.5+/-4.1MPa. While the low cellularity and fibrotic composition of tissue observed herein is consistent with a foreign body reaction to an implanted material, the significant myofibroblast response provides a mechanical explanation for the contractile forces complicating extractions. Moreover, the tensile properties of this tissue suggest the feasibility of circumferential mechanical tissue disruption, similar to balloon angioplasty devices, as a novel approach to assist with lead extraction.

Objective. To determine the actions of lithium chloride (LiCl) on catabolic events in articular chondrocytes and cartilage degradation after interleukin (IL)-1beta(beta) treatment and after surgically induced osteoarthritis (OA) in mice. Methods. The expression levels of catabolic genes in human articular chondrocytes treated with LiCl followed by IL-1beta were determined by real time PCR. To understand the mechanism of how LiCl affects catabolic events in articular chondrocytes after IL-1beta treatment, the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB) was determined using luciferase reporter assays, and the activities of mitogen-activated protein kinases (MAPK) and signal transducer and activator of transcription 3 (Stat3) signaling pathway were determined by immunoblot analysis of total cell lysates. Mouse femoral head explant cultures treated with IL-1beta and a surgically induced OA mouse model were used to determine the effect of LiCl on proteoglycan loss and cartilage degradation. Results. LiCl treatment resulted in decreased catabolic marker mRNA levels and activation of NF-kappaB, p38 MAPK, and Stat3 signaling in IL-1beta -treated chondrocytes. Furthermore, LiCl directly inhibited IL-6-stimulated activation of Stat3 signaling. Consequently, loss of proteoglycan and cartilage destruction in LiCl-treated knee joints 8 weeks after OA-induced surgery or in LiCl-treated femoral head explants after IL-1beta treatment were markedly reduced compared to vehicle-treated joints or explants. Conclusion. LiCl reduced catabolic events in IL-1beta -treated human articular chondrocytes and cartilage destruction in IL-1beta -treated mouse femoral head explants and in surgically induced OA mouse models via the inhibition of NF-kappaB, p38 and Stat3 signaling pathway activities. (c) 2014 American College of Rheumatology.

Voluntary medical male circumcision (VMMC) is capable of reducing the risk of sexual transmission of HIV from females to males by approximately 60%. In 2007, the WHO and the Joint United Nations Programme on HIV/AIDS (UNAIDS) recommended making VMMC part of a comprehensive HIV prevention package in countries with a generalized HIV epidemic and low rates of male circumcision. Modeling studies undertaken in 2009-2011 estimated that circumcising 80% of adult males in 14 priority countries in Eastern and Southern Africa within five years, and sustaining coverage levels thereafter, could avert 3.4 million HIV infections within 15 years and save US$16.5 billion in treatment costs. In response, WHO/UNAIDS launched the Joint Strategic Action Framework for accelerating the scale-up of VMMC for HIV prevention in Southern and Eastern Africa, calling for 80% coverage of adult male circumcision by 2016. While VMMC programs have grown dramatically since inception, they appear unlikely to reach this goal. This review provides an overview of findings from the PLOS Collection "Voluntary Medical Male Circumcision for HIV Prevention: Improving Quality, Efficiency, Cost Effectiveness, and Demand for Services during an Accelerated Scale-up." The use of devices for VMMC is also explored. We propose emphasizing management solutions to help VMMC programs in the priority countries achieve the desired impact of averting the greatest possible number of HIV infections. Our recommendations include advocating for prioritization and funding of VMMC, increasing strategic targeting to achieve the goal of reducing HIV incidence, focusing on programmatic efficiency, exploring the role of new technologies, rethinking demand creation, strengthening data use for decision-making, improving governments' program management capacity, strategizing for sustainability, and maintaining a flexible scale-up strategy informed by a strong monitoring, learning, and evaluation platform.

Pancreatic ductal adenocarcinoma (PDAC) is strikingly resistant to conventional therapeutic approaches. We previously demonstrated that the histone deacetylase-associated protein SIN3B is essential for oncogene-induced senescence in cultured cells. Here, using a mouse model of pancreatic cancer, we have demonstrated that SIN3B is required for activated KRAS-induced senescence in vivo. Surprisingly, impaired senescence as the result of genetic inactivation of Sin3B was associated with delayed PDAC progression and correlated with an impaired inflammatory response. In murine and human pancreatic cells and tissues, levels of SIN3B correlated with KRAS-induced production of IL-1alpha. Furthermore, evaluation of human pancreatic tissue and cancer cells revealed that Sin3B was decreased in control and PDAC samples, compared with samples from patients with pancreatic inflammation. These results indicate that senescence-associated inflammation positively correlates with PDAC progression and suggest that SIN3B has potential as a therapeutic target for inhibiting inflammation-driven tumorigenesis.

PURPOSE AND METHODS: Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) method is being played an important role for the inspection of clinical microorganism as a rapid and the price reduction. Mass spectra obtained by measuring become points of identification whether the peak pattern match any species mass spectral pattern. We currently use MALDI-TOF MS for rapid and accurate diagnosis of inactivated reference and clinical isolates of Mycobacterium because of the improved pretreatment techniques compared with former inspection methods that pose a higher risk of infection to the operator. The identification matching rate of score value (SV) peak pattern spectra was compared with that of conventional methods such as strain diffusion/amplification. Also, cultures were examined after a fixed number of days. Compared with the initial inspection technique, the pretreatment stage of current MALDI-TOF MS inspection techniques can improve the analysis of inactivated acid-fast bacteria that are often used as inspection criteria strains of clinical isolates. Next, we compared the concordance rate for identification between MALDI-TOF MS and conventional methods such as diffusion/amplification by comparison of peak pattern spectra and evaluated SV spectra to identify differences in the culture media after the retention period. RESULTS AND DISCUSSION: In examination of 158 strains of clinical isolated Mycobacterium tuberculosis complex (MTC), the identification coincidence rate in the genus level in a matching pattern was 99.4%, when the species level was included 94.9%. About 37 strains of nontuberculous mycobacteria (NTM), the identification coincidence rate in the genus level was 94.6%. M. bovis BCG (Tokyo strain) in the reference strain was judged by the matching pattern to be MTC, and it suggested that they are M. tuberculosis and affinity species with high DNA homology. Nontuberculous mycobacterial M. gordonae strain JATA 33-01 shared peak pattern spectra, excluding the isolates, with each clinically isolated strain. However, the mass spectra of six M. gordonae clinical isolates suggested polymorphisms with similar mass-to-charge ratios compared with those of the reference strains. The peak pattern spectra of the clinical isolates and reference strains, excluding the NTM M. gordonae strain JATA33-01, were consistent with the peak pattern characteristics of each isolate. However, a comparison between the peak patterns of the reference strains and those of the six clinically isolated M. gordonae strains revealed a similar mass-to-charge ratio, which may indicate few polymorphisms. The SV spectrum of the improved inspection technique showed no fidelity, but it was acceptable after days of culture as indicated by the decrease in SV (0.3 degree). Also, the reproducibility of this method was good, but no difference was observed from the SV of the improved inspection technique, which decreased by approximately 0.3 because of the number of days of culture storage. In addition, expansion of the database and dissemination of regional specificity by genotype analysis of clinical isolates was relevant to the accumulated data, as expected. In future studies, the relevance and regional specificity of clinical isolates by genotype analysis can be determined by stacking the solid media and database penetration.

Introduction: The main function of connexins is to form gap junctions; yet, recent studies show that Cx43 is not only a gap junction protein. In fact, Cx43 is a part of a protein interacting network (the connexome), likely to regulate other functions in a gap junction-independent manner. Recently, it was reported that loss of the last five amino acids of Cx43 (Cx43D378stop) leads to lethal ventricular arrhythmias in mice. Localization of Cx43 at the membrane and electrical coupling between cells was normal. Interestingly, there was a significant loss of sodium current amplitude. These observations linked two fundamental steps in action potential propagation, excitability and electrical coupling, through a common molecular mechanism. Here, we explore the hypothesis that the microtubular network at the cell end is part of the common link. Methods: N/A Results: Functional assays: Macropatch, and super-resolution scanning patch clamp in ventricular myocytes isolated from Cx43D378stop and Cre-negative (control) mice revealed a reduction in the amplitude of sodium current exclusively at the intercalated disc (ID), without a change in channel unitary conductance. Super-resolution fluorescence microscopy: direct stochastic optical reconstruction microscopy (20 nm resolution) showed Nav1.5 clusters in close proximity (or overlapping) with N-cadherin plaques. The distance between NaV1.5 clusters and the cell end increased from 57.2+12nm, n=365 in control to 111.7+11nm, n=446 in Cx43D378stop myocytes (p<0.001), indicating that mutation Cx43D378stop reduced NaV1.5 surface expression. This coincided with separation of the microtubule plus-end protein EB1 from N-cadherin-rich cell ends, from 23.7+31.9nm, n=665 in control, to 123.5+13.5nm, n=502 in Cx43D378stop cells (p<0.05). Conclusions: Functional surface expression of NaV1.5 at the ID depends on preservation of the Cx43 C-end. Cx43 is part of a molecular complex that anchors the microtubule plus-end to the cell end, thus allowing proper delivery of its ca!