An integrated cellular and molecular model of gastric neuroendocrine cancer evolution highlights therapeutic targets.

Gastric neuroendocrine carcinomas (G-NEC) are aggressive malignancies with poorly understood biology and a lack of disease models. Here, we use genome sequencing to characterize the genomic landscapes of human G-NEC and its histologic variants. We identify global and subtype-specific alterations and expose hitherto unappreciated gains of MYC family members in a large part of cases. Genetic engineering and lineage tracing in mice delineate a model of G-NEC evolution, which defines MYC as a critical driver and positions the cancer cell of origin to the neuroendocrine compartment. MYC-driven tumors have pronounced metastatic competence and display defined signaling addictions, as revealed by large-scale genetic and pharmacologic screening of cell lines and organoid resources. We create global maps of G-NEC dependencies, highlight critical vulnerabilities, and validate therapeutic targets, including candidates for clinical drug repurposing. Our study gives comprehensive insights into G-NEC biology.

In vivo interrogation of regulatory genomes reveals extensive quasi-insufficiency in cancer evolution.

In contrast to mono- or biallelic loss of tumor-suppressor function, effects of discrete gene dysregulations, as caused by non-coding (epi)genome alterations, are poorly understood. Here, by perturbing the regulatory genome in mice, we uncover pervasive roles of subtle gene expression variation in cancer evolution. Genome-wide screens characterizing 1,450 tumors revealed that such quasi-insufficiency is extensive across entities and displays diverse context dependencies, such as distinct cell-of-origin associations in T-ALL subtypes. We compile catalogs of non-coding regions linked to quasi-insufficiency, show their enrichment with human cancer risk variants, and provide functional insights by engineering regulatory alterations in mice. As such, kilo-/megabase deletions in a Bcl11b-linked non-coding region triggered aggressive malignancies, with allele-specific tumor spectra reflecting gradual gene dysregulations through modular and cell-type-specific enhancer activities. Our study constitutes a first survey toward a systems-level understanding of quasi-insufficiency in cancer and gives multifaceted insights into tumor evolution and the tissue-specific effects of non-coding mutations.

Adipocyte-derived extracellular vesicles increase insulin secretion through transport of insulinotropic protein cargo.

Adipocyte-derived extracellular vesicles (AdEVs) are membranous nanoparticles that convey communication from adipose tissue to other organs. Here, to delineate their role as messengers with glucoregulatory nature, we paired fluorescence AdEV-tracing and SILAC-labeling with (phospho)proteomics, and revealed that AdEVs transfer functional insulinotropic protein cargo into pancreatic ß-cells. Upon transfer, AdEV proteins were subjects for phosphorylation, augmented insulinotropic GPCR/cAMP/PKA signaling by increasing total protein abundances and phosphosite dynamics, and ultimately enhanced 1st-phase glucose-stimulated insulin secretion (GSIS) in murine islets. Notably, insulinotropic effects were restricted to AdEVs isolated from obese and insulin resistant, but not lean mice, which was consistent with differential protein loads and AdEV luminal morphologies. Likewise, in vivo pre-treatment with AdEVs from obese but not lean mice amplified insulin secretion and glucose tolerance in mice. This data suggests that secreted AdEVs can inform pancreatic ß-cells about insulin resistance in adipose tissue in order to amplify GSIS in times of increased insulin demand.

Virtual Journal Club Beyond the Pandemic: An Enduring and Fluid Educational Forum.

OBJECTIVE: Since its inception, journal club has been a cornerstone to the life-long process of medical education. The virtual journal club (VJC), initiated as a robust solution to many educational challenges encountered during COVID-19 pandemic-related distance learning, provides an enduring and fluid forum for multilevel teaching and learning. MATERIALS AND METHODS: In this manuscript we share our institutions' reasoning and methods to implement a VJC for multi-level learners. A standardized format applicable to all VJC sessions was adopted to ensure reproducibility from presenter to presenter. Sessions were held via video conference platforms. Pedagogy regularly emphasized in undergraduate medical education was adopted. Informal assessment of each session's strengths and areas for improvement was performed. RESULTS: A total of 30 sessions were held prior to manuscript submission, including discussion of 36 refereed journal articles from March 26, 2020, to April 20, 2021. The virtual journal club was very well received by all participants. The medical students and residents found the information current and engaging. The fellows stated that the journal club strengthened their knowledge base and enhanced communication and teaching skills. The attendings learned from its encouraged frank discussion of differing practice patterns. The format of these sessions offers an ideal setting to teach medical students and residents how to evaluate and employ evidence-based medicine and meets multiple LCME and ACGME requirements. CONCLUSIONS: This VJC forum allows for development of essential nonclinical skills including lifelong active learning and analysis, peer collaboration, and technology adaptation and usage.

Blobbing injury patterns.

INTRODUCTION: "Blobbing" is a modern outdoor activity where a participant sits on the end of a partially inflated air bag ("blobber") and is launched into the water when another participant jumps onto the air bag from a platform on the opposite side ("jumper"). This is the first study to evaluate the injury patterns associated with blobbing. PATIENTS AND METHODS: A retrospective data analysis was conducted based on 86 patients who sustained blobbing injuries between January 2011 and December 2016. The date of birth, gender, day of injury, diagnosis, body region of trauma, and treatment were recorded for the patients. Treatment was subclassified into conservative or surgical treatment. The position of the participant was recorded as either a jumper or a blobber. RESULTS: One-third of the patients sustained a spine injury, which was the most common body part injured. The most frequent type of injury was cervical spine distortion. All shoulder (n = 9), elbow (n = 3), hand (n = 2), knee (n = 3), and foot (n = 12) injuries occurred in jumpers, whereas all ear (n = 6) and lung (n = 5) injuries occurred in blobbers. Head (n = 5) and spine (n = 33) injuries were distributed in jumpers and blobbers. Sixty-nine patients were treated with conservative treatment. Three ankle fractures and two spine fractures were treated with immediate surgical treatment. Twelve patients were treated with conservative treatment but were referred for potential surgery at their hospital at home. CONCLUSION: Both jumpers and blobbers were prone to injuries. More severe injuries with the potential for surgical treatment occurred in jumpers, presumably because of bad landings. This analysis of the injury patterns in blobbers might lead to the introduction of protective gear and changes in the behavior of participants in order to reduce the risk of injury.

Schwann cell-derived periostin promotes autoimmune peripheral polyneuropathy via macrophage recruitment.

Chronic inflammatory demyelinating polyneuropathy (CIDP) and Guillain-Barre syndrome (GBS) are inflammatory neuropathies that affect humans and are characterized by peripheral nerve myelin destruction and macrophage-containing immune infiltrates. In contrast to the traditional view that the peripheral nerve is simply the target of autoimmunity, we report here that peripheral nerve Schwann cells exacerbate the autoimmune process through extracellular matrix (ECM) protein induction. In a spontaneous autoimmune peripheral polyneuropathy (SAPP) mouse model of inflammatory neuropathy and CIDP nerve biopsies, the ECM protein periostin (POSTN) was upregulated in affected sciatic nerves and was primarily expressed by Schwann cells. Postn deficiency delayed the onset and reduced the extent of neuropathy, as well as decreased the number of macrophages infiltrating the sciatic nerve. In an in vitro assay, POSTN promoted macrophage chemotaxis in an integrin-AM (ITGAM) and ITGAV-dependent manner. The PNS-infiltrating macrophages in SAPP-affected nerves were pathogenic, since depletion of macrophages protected against the development of neuropathy. Our findings show that Schwann cells promote macrophage infiltration by upregulating Postn and suggest that POSTN is a novel target for the treatment of macrophage-associated inflammatory neuropathies.

Extending antigen release from particulate vaccines results in enhanced antitumor immune response.

Tumor-specific CD8+ cytotoxic T lymphocytes (CTLs) play a critical role in an anti-tumor immune response. However, vaccination intended to elicit a potent CD8+ T cell responses employing tumor-associated peptide antigens, are typically ineffective due to poor immunogenicity. Previously, we engineered a polyethylene glycol (PEG) hydrogel-based subunit vaccine for the delivery of an antigenic peptide and CpG (adjuvant) to elicit potent CTLs. In this study, we further examined the effect of antigen release kinetics on their induced immune responses. A CD8+ T cell epitope peptide from OVA (CSIINFEKL) and CpG were co-conjugated to nanoparticles utilizing either a disulfide or a thioether linkage. Subsequent studies comparing peptide release rates as a function of linker, determined that the thioether linkage provided sustained release of peptide over 72h. Ability to control the release of peptide resulted in both higher and prolonged antigen presentation when compared to disulfide-linked peptide. Both NP vaccine formulations resulted in activation and maturation of bone marrow derived dendritic cells (BMDCs) and induced potent CD8+ T cell responses when compared to soluble antigen and soluble CpG. Immunization with either disulfide or thioether linked vaccine constructs effectively inhibited EG7-OVA tumor growth in mice, however only treatment with the thioether linked vaccine construct resulted in enhanced survival.

Combination central tolerance and peripheral checkpoint blockade unleashes antimelanoma immunity.

Blockade of immune checkpoint proteins (e.g., CTLA-4, PD-1) improves overall survival in advanced melanoma; however, therapeutic benefit is limited to only a subset of patients. Because checkpoint blockade acts by "removing the brakes" on effector T cells, the efficacy of checkpoint blockade may be constrained by the limited pool of melanoma-reactive T cells in the periphery. In the thymus, autoimmune regulator (Aire) promotes deletion of T cells reactive against self-antigens that are also expressed by tumors. Thus, while protecting against autoimmunity, Aire also limits the generation of melanoma-reactive T cells. Here, we show that Aire deficiency in mice expands the pool of CD4+ T cells capable of melanoma cell eradication and has additive effects with anti-CTLA-4 antibody in slowing melanoma tumor growth and increasing survival. Moreover, pharmacologic blockade of central T cell tolerance and peripheral checkpoint blockade in combination enhanced antimelanoma immunity in a synergistic manner. In melanoma patients treated with anti-CTLA-4 antibody, clinical response to therapy was associated with a human Aire polymorphism. Together, these findings suggest that Aire-mediated central tolerance constrains the efficacy of peripheral checkpoint inhibition and point to simultaneous blockade of Aire and checkpoint inhibitors as a novel strategy to enhance antimelanoma immunity.