Empirical inference of circuitry and plasticity in a kinase signaling network

Our understanding of physiology and disease is hampered by the difficulty of measuring the circuitry and plasticity of signaling networks that regulate cell biology, and how these relate to phenotypes. Here, using mass spectrometry-based phosphoproteomics, we systematically characterized the topology of a network comprising the PI3K/Akt/mTOR and MEK/ERK signaling axes and confirmed its biological relevance by assessing its dynamics upon EGF and IGF1 stimulation. Measuring the activity of this network in models of acquired drug resistance revealed that cells chronically treated with PI3K or mTORC1/2 inhibitors differed in the way their networks were remodeled. Unexpectedly, we also observed a degree of heterogeneity in the network state between cells resistant to the same inhibitor, indicating that even identical and carefully controlled experimental conditions can give rise to the evolution of distinct kinase network statuses. These data suggest that the initial conditions of the system do not necessarily determine the mechanism by which cancer cells become resistant to PI3K/mTOR targeted therapies. The patterns of signaling network activity observed in the resistant cells mirrored the patterns of response to several drug combination treatments, suggesting that the activity of the defined signaling network truly reflected the evolved phenotypic diversity.Cell signaling pathways form complex networks of biochemical reactions that integrate and decode extracellular signals into appropriate responses (1). The reconstruction of these networks, and systematic analyses of their properties, is important in the advancement of our molecular understanding of disease at the systems level (2). The topology and plasticity of cell signaling networks play major roles in fundamental (3–5) and disease physiology (6, 7). Attempts to characterize such molecular organization have relied on inference algorithms that obtain information on protein interactions and posttranslational modification (PTMs) from the literature (8–10). The accuracy of network reconstruction using such models is limited by the availability of data (10) and by the fact that signaling events are often cell-type specific. As a result, although they can provide insightful data, models that derive network topologies from studies that have used different cell types and organisms result in composite or averaged networks, which, critically, do not always reflect network structure in specific cell types, at specific stages of cell development, or under defined physiological conditions (10).Reconstruction of signaling networks through the use of a single set of well-defined experimental data is appealing, because this approach does not commit to a preconception of how such networks may be wired in a given cell type under defined conditions (3). The maturation of phosphoproteomics techniques based on mass spectrometry (MS) is now allowing the simultaneous quantification of several thousands of phosphorylation sites per experiment, and approaches to derive kinase activity from these large-scale phosphoproteomics datasets have been reported (11–14). One such approach, named kinase substrate enrichment analysis (KSEA), is based on the premise that, because each phosphorylation site is the result of a kinase’s catalytic activity, phosphoproteomic profiling provides a means by which to capture and measure the activities of all kinases expressed in the system under investigation (14).Here, we first used MS-based phosphoproteomics to define a kinase signaling network by systematically identifying phosphorylation sites downstream of kinases targeted by small-molecule kinase inhibitors of the PI3K/Akt/mTOR and MEK-ERK signaling axes. These two ubiquitous pathways form a network that regulates growth factor, antigen, and insulin signaling while also being deregulated in most cancers (15–17). We then measured the activity and plasticity of different routes within this experimentally defined kinase signaling network in cells chronically treated with small-molecule inhibitors of PI3K and mTORC1/2. We found that remodeling of kinase networks in resistant cells produced patterns of signaling activity linked to their evolved phenotypes.     

Reading salt activates gustatory brain regions: FMRI evidence for semantic grounding in a novel sensory modality

Because many words are typically used in the context of their referent objects and actions, distributed cortical circuits for these words may bind information about their form with perceptual and motor aspects of their meaning. Previous work has demonstrated such semantic grounding for sensorimotor, visual, auditory, and olfactory knowledge linked to words, which is manifest in activation of the corresponding areas of the cortex. Here, we explore the brain basis of gustatory semantic links of words whose meaning is primarily related to taste. In a blocked functional magnetic resonance imaging design, Spanish taste words and control words matched for a range of factors (including valence, arousal, imageability, frequency of use, number of letters and syllables) were presented to 59 right-handed participants in a passive reading task. Whereas all the words activated the left inferior frontal (BA44/45) and the posterior middle and superior temporal gyri (BA21/22), taste-related words produced a significantly stronger activation in these same areas and also in the anterior insula, frontal operculum, lateral orbitofrontal gyrus, and thalamus among others. As these areas comprise primary and secondary gustatory cortices, we conclude that the meaning of taste words is grounded in distributed cortical circuits reaching into areas that process taste sensations.     

Preventive physiotherapy interventions for back care in children and adolescents: a meta-analysis

ABSTRACT: BACKGROUND: Preventive interventions improve healthy behaviours and they also increase knowledge regarding back care in children and adolescents, but studies exhibit great variability in their contents, duration and number of sessions, and in the assessment methods. The purpose of this study was to review the empirical evidence regarding preventive physiotherapy interventions for back care in children and adolescents, and to ascertain the most efficacious treatments, in what way and under which circumstances. METHODS: Studies were located from computerized databases (Cochrane Library, Medline, PEDro, Web of Science and IME) and other sources. The search period extended to May 2012. To be included in the meta-analysis, studies had to use physical therapy methodologies of preventive treatment on children and adolescents, and to compare a treatment and a control group. Treatment, participant, methodological, and extrinsic characteristics of the studies were coded. Two researchers independently coded all of the studies. As effect size indices, standardized mean differences were calculated for measures of behaviours and knowledge, both in the posttest and in the follow-up. The random and mixed-effects models were used for the statistical analyses and sensitivity analyses were carried out in order to check the robustness of the meta-analytic results. RESULTS: A total of 19 papers fulfilled the selection criteria, producing 23 independent studies. On average, the treatments reached a statistically significant effectiveness in the behaviours acquired, both in the posttest and in the follow-up (d+ = 1.33 and d+ = 1.80, respectively), as well as in measures of knowledge (posttest; d+ = 1.29; follow-up: d+ = 0.76). Depending on the outcome measure, the effect sizes were affected by different moderator variables, such as the type of treatment, the type of postural hygiene, the teaching method, or the use of paraprofessionals as cotherapists. CONCLUSIONS: The interventions were successful in significantly increasing the behaviours and knowledge acquired both in the posttest and in the follow-up. The combined treatment of postural hygiene with physiotherapy exercise exhibited the best results. The small number of studies limits the generalizability of the results.     

Serial assessment of lymphocytes and apoptosis in the prostate during coordinated intraprostatic dendritic cell injection and radiotherapy

Local radiotherapy plus intratumoral syngeneic dendritic cell injection can mediate apoptosis/cell death and immunological tumor eradication in murine models. A novel method of coordinated intraprostatic, autologous dendritic cell injection together with radiation therapy was prospectively evaluated in five HLA-A2(+) subjects with high-risk, localized prostate cancer, using androgen suppression, 45 Gy external beam radiation therapy in 25 fractions over 5 weeks, dendritic cell injections after fractions 5, 15 and 25 and then interstitial radioactive seed placement. Serial prostate biopsies before and during treatment showed increased apoptotic cells and parenchymal distribution of CD8(+) cells. CD8(+) T-cell responses to test peptides were assessed using an enzyme-linked immunosorbent spot IFN-γ production assay, demonstrating some prostate cancer-specific protein-derived peptides associated with increased titer. In conclusion, the technique was feasible and well-tolerated and specific immune responses were observable. Future trials could further test the utility of this approach and improve on temporal coordination of intratumoral dendritic cell introduction with particular timelines of therapy-induced apoptosis.     

Developing Strategies for Reducing Cancer Disparities via Cross-Institutional Collaboration: Outreach Efforts for the Partnership Between the Ponce School of Medicine and the Moffitt Cancer Center

The disproportionate burden of cancer among U.S. Hispanics is well documented. Historically, epidemiologic data on U.S. Hispanics and cancer have aggregated all Hispanics as one homogeneous group without appreciating the diversity of this population with regard to nativity (nationality/geographic origin). The authors report on the initial efforts of a collaborative academic institutional partnership between a minority-serving institution and a National Cancer Institute-designated cancer center to address cancer health disparities in two Hispanic communities in Puerto Rico and Florida. This article outlines the joint Outreach Program's initial collaborative strategies and activities in community outreach, cancer education, and research that mutually benefit both the Ponce (Puerto Rico) and Tampa (Florida) Hispanic communities. This partnership program used innovative multipronged community-engagement strategies in the two communities to reduce cancer health disparities. Specific projects and lessons learned from three outreach/cancer education projects and two pilot research projects are discussed. The challenges of balancing service and research agendas in communities with disparate levels of resources and infrastructure are summarized to inform future initiatives in this partnership, as well as serve as an example for similar minority-serving institution/cancer center partnerships to reduce cancer health disparities.     

Imaging in orbital trauma

Orbital trauma is one of the most common reasons for ophthalmology specialty consultation in the emergency department setting. We survey the literature from 1990 to present to describe the role of computed tomography (CT), magnetic resonance imaging (MRI) and their associated angiography in some of the most commonly encountered orbital trauma conditions. CT orbit can often detect certain types of foreign bodies, lens dislocation, ruptured globe, choroidal or retinal detachments, or cavernous sinus thrombosis and thus complement a bedside ophthalmic exam that can sometimes be limited in the setting of trauma. CT remains the workhorse for acute orbital trauma owing to its rapidity and ability to delineate bony abnormalities; however MRI remains an important modality in special circumstances such as soft tissue assessment or with organic foreign bodies.