The impact of MEIS1 TALE homeodomain transcription factor knockdown on glioma stem cell growth.

Myeloid ecotropic virus insertion site 1 (MEIS1) is a HOX co-factor necessary for organ development and normal hematopoiesis. Recently, MEIS1 has been linked to the development and progression of various cancers. However, its role in gliomagenesis particularly on glioma stem cells (GSCs) remains unclear. Here, we demonstrate that MEIS1 is highly upregulated in GSCs compared to normal, and glioma cells and to its differentiated counterparts. Inhibition of MEIS1 expression by shRNA significantly reduced GSC growth in both in vitro and in vivo experiments. On the other hand, integrated transcriptomics analyses of glioma datasets revealed that MEIS1 expression is correlated to cell cycle-related genes. Clinical data analysis revealed that MEIS1 expression is elevated in high-grade gliomas, and patients with high MEIS1 levels have poorer overall survival outcomes. The findings suggest that MEIS1 is a prognostic biomarker for glioma patients and a possible target for developing novel therapeutic strategies against GBM.

The CoREST repressor complex mediates phenotype switching and therapy resistance in melanoma.

Virtually all patients with BRAF-mutant melanoma develop resistance to MAPK inhibitors largely through nonmutational events. Although the epigenetic landscape is shown to be altered in therapy-resistant melanomas and other cancers, a specific targetable epigenetic mechanism has not been validated. Here, we evaluated the corepressor for element 1-silencing transcription factor (CoREST) epigenetic repressor complex and the recently developed bivalent inhibitor corin within the context of melanoma phenotype plasticity and therapeutic resistance. We found that CoREST was a critical mediator of the major distinct melanoma phenotypes and that corin treatment of melanoma cells led to phenotype reprogramming. Global assessment of transcript and chromatin changes conferred by corin revealed specific effects on histone marks connected to epithelial-mesenchymal transition-associated (EMT-associated) transcription factors and the dual-specificity phosphatases (DUSPs). Remarkably, treatment of BRAF inhibitor-resistant (BRAFi-R) melanomas with corin promoted resensitization to BRAFi therapy. DUSP1 was consistently downregulated in BRAFi-R melanomas, which was reversed by corin treatment and associated with inhibition of p38 MAPK activity and resensitization to BRAFi therapies. Moreover, this activity was recapitulated by the p38 MAPK inhibitor BIRB 796. These findings identify the CoREST repressor complex as a central mediator of melanoma phenotype plasticity and resistance to targeted therapy and suggest that CoREST inhibitors may prove beneficial for patients with BRAFi-resistant melanoma.

Suspected Primary Intracranial Melanoma with Widespread Distant Metastases in a Cat.

An 8-year-old female Domestic Shorthair presented with signs of intracranial disease. Magnetic resonance imaging (MRI) of the head showed an extra-axial space-occupying mass within the cranial vault with a similar intensity lesion within the overlying temporalis muscle. Postmortem examination found masses within the head, lung, liver, spleen, and kidney consistent with malignant melanoma. Intracranial melanoma is rarely reported in cats and is typically only seen as a metastatic lesion associated with an ocular mass. Melanomas can be readily recognised on MRI as they are one of the few lesions which are hyperintense on T1-weighted images.

Fecal microbiota transplanted from old mice promotes more colonic inflammation, proliferation, and tumor formation in azoxymethane-treated A/J mice than microbiota originating from young mice.

Aging is a strong risk factor for colorectal cancer (CRC). It is well established that gut microbial dysbiosis can play a role in the etiology of CRC. Although the composition of the gut microbial community changes with age and is reported to become more pro-inflammatory, it is unclear whether such changes are also pro-tumorigenic for the colon. To address this gap, we conducted fecal microbiota transplants (FMT) from young (DY, ~6 wk) and old (DO, ~72 wk) donor mice into young (8 wk) recipient mice that were pre-treated with antibiotics. After initiating tumorigenesis with azoxymethane, recipients were maintained for 19 wk during which time they received monthly FMT boosters. Compared to recipients of young donors (RY), recipients of old donors (RO) had an approximately 3-fold higher prevalence of histologically confirmed colon tumors (15.8 vs 50%, Chi2 P = .03), approximately 2-fold higher proliferating colonocytes as well as significantly elevated colonic IL-6, IL-1ß and Tnf-α. Transcriptomics analysis of the colonic mucosa revealed a striking upregulation of mitochondria-related genes in the RO mice, a finding corroborated by increased mitochondrial abundance. Amongst the differences in fecal microbiome observed between DY and DO mice, the genera Ruminoclostridium, Lachnoclostridium and Marvinbryantia were more abundant in DY mice while the genera Bacteroides and Akkermansia were more abundant in DO mice. Amongst recipients, Ruminoclostridium and Lachnoclostridium were higher in RY mice while Bacteroides was higher in RO mice. Differences in fecal microbiota were observed between young and old mice, some of which persisted upon transplant into recipient mice. Recipients of old donors displayed significantly higher colonic proliferation, inflammation and tumor abundance compared to recipients of young donors. These findings support an etiological role for altered gut microbial communities in the increased risk for CRC with increasing age and establishes that such risk can be transmitted between individuals.

Characterization of canine intestinal microRNA expression in inflammatory bowel disease and T-cell lymphoma.

Differentiating between canine inflammatory bowel disease (IBD) and intestinal T-cell lymphoma by histopathological examination of endoscopically-derived intestinal biopsies can be challenging and involves an invasive procedure requiring specialized equipment and training. A rapid, non-invasive method of diagnosis, such as blood or faecal analysis for a conserved and stable biomarker, would be a useful adjunct or replacement. Studies on dogs and humans with various types of lymphoma have shown altered microRNA (miRNA) expression patterns in blood, faeces and tissues indicating their potential use as biomarkers of disease. The present study used residual archived endoscopically-derived, formalin-fixed, paraffin-embedded (FFPE) duodenal tissue taken from pet dogs undergoing routine investigation of gastrointestinal disease. The dogs had previously been diagnosed with either normal/minimal intestinal inflammation, severe IBD or intestinal T-cell lymphoma. Next generation sequencing with qPCR validation was used to elucidate differentially expressed miRNAs between groups. Our results show that miRNA can be extracted from archived endoscopically-derived FFPE tissues from the canine duodenum and used to differentiate normal/minimally inflamed canine duodenal tissue from severe lymphoplasmacytic IBD and T-cell lymphoma.

Misexpression of genes lacking CpG islands drives degenerative changes during aging.

Cellular aging is characterized by disruption of the nuclear lamina and its associated heterochromatin. How these structural changes within the nucleus contribute to age-related degeneration of the organism is unclear. Genes lacking CpG islands (CGI− genes) generally associate with heterochromatin when they are inactive. Here, we show that the expression of these genes is globally activated in aged cells and tissues. This CGI− gene misexpression is a common feature of normal and pathological aging in mice and humans. We report evidence that CGI− gene up-regulation is directly responsible for age-related physiological deterioration, notably for increased secretion of inflammatory mediators.

A text-mining based analysis of 100,000 tumours affecting dogs and cats in the United Kingdom.

Cancer is a major reason for veterinary consultation, especially in companion animals. Cancer surveillance plays a key role in prevention but opportunities for such surveillance in companion animals are limited by the lack of suitable veterinary population health infrastructures. In this paper we describe a pathology-based animal tumour registry (PTR) developed within the Small Animal Veterinary Surveillance Network (SAVSNET) built from electronic pathology records (EPR) submitted to this network. From an original collection of 180232 free text (non-structured) EPRs reported between April 2018 and June 2019, we used specific text-mining methodologies to identify 109895 neoplasias. These data were normalized to describe both the tumour (type and location) and the animal (breed, neutering status and veterinary practice postcode). The resulting PTR, the largest of its kind for companion animals to date, is an important research resource being able to facilitate a wide array of research in areas including surveillance, clinical decision making and comparative cancer biology.

Spinal ectopic choroid plexus papilloma in a cat.

CASE SUMMARY: A 10-year-old male neutered Russian Blue cat was presented with a 2-month history of progressive non-ambulatory paraparesis. Spinal MRI revealed a well-demarcated, compressive intradural extramedullary mass at the level of T1 vertebra. The mass had subtle hyperintensity on T2-weighted images, was isointense on T1-weighted images and had diffuse, marked enhancement following gadolinium administration. Neuroaxis MRI, including limited brain sequences, excluded other visible lesions. Thoracic and abdominal radiographs were unremarkable. The mass was resected via a dorsal C7-T2 laminectomy and durotomy. Histopathology revealed a neoplasm composed of columnar-to-polygonal cells forming bilayered palisading patterns with a few apical cilia. Three mitoses were noted in 10 high-power fields. This was consistent with an epithelial neoplasm and initially a metastatic adenocarcinoma was considered most likely. Full-body CT with contrast and including the brain found rhinitis but did not identify any additional neoplastic foci. Biopsies of the nasal cavity and fine-needle aspiration of the spleen and liver were unremarkable. On immunohistochemical evaluation, pan-cytokeratin and E-cadherin immunolabelling was observed; however, synaptophysin, thyroglobulin, chromogranin A and glial fibrillary acidic protein was not detected. This, along with the histological morphology and absence of a primary tumour, was compatible with an ectopic choroid plexus neoplasm. Follow-up performed at 3, 14 and 24 months postoperatively revealed neurological improvement without recurrence. RELEVANCE AND NOVEL INFORMATION: We describe the presentation, histopathological and immunohistochemical features and outcome of a case of a rare ectopic choroid plexus neoplasm in the spinal cord of a cat.

Cytoplasmic expression of a model antigen with M Cell-Targeting moiety in lactic acid bacteria and implication of the mechanism as a mucosal vaccine via oral route.

Lactic acid bacteria (LAB) have been widely studied as mucosal vaccine delivery carriers against many infectious diseases for heterologous expression of protein antigens. There are three antigen expression strategies for LAB: cytoplasmic expression (CE), cell surface display (SD), and extracellular secretion (ES). Despite the generally higher protein expression level and many observations of antigen-specific immunogenicity in CE, its application as a mucosal vaccine has been overlooked relative to SD and ES because of the antigens enclosed by the LAB cell wall. We hypothesized that the antigens in CE could be released from the LAB into the intestinal lumen before host bacterial access to gut-associated lymphoid tissue (GALT), which could contribute to antigen-specific immune responses after oral administration. To elucidate this hypothesis, three recombinant Lactobacillus plantarum (LP) strains were constructed to produce a model antigen, BmpB, with or without an M cell-targeting moiety, and their immunogenicities were analyzed comparatively as oral vaccines in mouse model. The data indicated that the recombinant LPs producing BmpBs with different conformations could induce mucosal immunity differentially. This suggests that the cytoplasmic antigens in LAB could be released into the intestinal lumen, subsequently translocated through M cells, and stimulate the GALT to generate antigen-specific immune responses. Therefore, the CE strategy has great potential, especially in the application of oral LAB vaccines as well as SD and ES strategies. This research provides a better understanding of the mechanism for recombinant oral LAB vaccines and gives insight to the future design of LAB vaccines and oral delivery applications for useful therapeutic proteins.

Conserved dual-mode gene regulation programs in higher eukaryotes.

Recent genomic data analyses have revealed important underlying logics in eukaryotic gene regulation, such as CpG islands (CGIs)-dependent dual-mode gene regulation. In mammals, genes lacking CGIs at their promoters are generally regulated by interconversion between euchromatin and heterochromatin, while genes associated with CGIs constitutively remain as euchromatin. Whether a similar mode of gene regulation exists in non-mammalian species has been unknown. Here, through comparative epigenomic analyses, we demonstrate that the dual-mode gene regulation program is common in various eukaryotes, even in the species lacking CGIs. In cases of vertebrates or plants, we find that genes associated with high methylation level promoters are inactivated by forming heterochromatin and expressed in a context-dependent manner. In contrast, the genes with low methylation level promoters are broadly expressed and remain as euchromatin even when repressed by Polycomb proteins. Furthermore, we show that invertebrate animals lacking DNA methylation, such as fruit flies and nematodes, also have divergence in gene types: some genes are regulated by Polycomb proteins, while others are regulated by heterochromatin formation. Altogether, our study establishes gene type divergence and the resulting dual-mode gene regulation as fundamental features shared in a broad range of higher eukaryotic species.

Comparison between the Real-Time PCR and Crystal Diagnostic Xpress Immunoassay Methods for Detecting Salmonella and Shiga Toxin-Producing Escherichia coli in the Air of Beef Slaughter Establishments.

ABSTRACT: The aim of this study was to compare the effectiveness of a quantitative real-time PCR (qPCR) molecular method and the Crystal Diagnostic Xpress (CDx) immunoassay for detecting Salmonella and Shiga toxin-producing Escherichia coli (STEC) in air samples collected from abattoirs in Texas. The 70 air samples were collected from two small and two large meat processing plants in the spring and summer with a wetted wall cyclone air sampler. The samples were divided equally into two parts: one part was used for the qPCR assay, and the other part was enriched for 18 and 36 h and evaluated with the CDx immunoassay. All samples for which positive results were obtained were confirmed by plating and by biochemical and serological tests as recommended by AOAC International to verify results of rapid methods. With the qPCR and CDx assays and 36 h of enrichment, 37.5 and 57.1% of the samples, respectively, were positive for Salmonella (P < 0.05) and 65.0 and 60.7%, respectively, were positive for STEC (P > 0.05). Air samples required longer enrichment for the CDx immunoassay than recommended by the manufacturer for food samples. Recovery of Salmonella and STEC increased 16 and 47%, respectively, when enrichment was extended from 18 to 36 h. The prevalence of Salmonella and STEC obtained with both methods was affected by the size of the processing plant and the processing stage. Detection rates for samples from larger plants were higher for both pathogens. Significantly higher prevalence was obtained for samples from the stunning and dehiding areas than for those from the fabrication rooms and chillers. Salmonella detection was higher with the CDx assay than with the qPCR assay, but no differences were found for the detection of STEC by the qPCR and CDx assays. These results highlight the importance of method adjustments when testing matrices other than foods. More research is needed to understand the dynamics of pathogen dispersal in aerosols and how this affects the effectiveness of current rapid detection methods.

Spontaneous Regression of a Mandibular Plasmacytoma in a Juvenile Dog: A Case Report.

A 4 mo old female Finnish lapphund presented for further investigation of a swelling of the right rostral mandible. A computed tomography scan showed the swelling to be an expansile and osteolytic mandibular lesion. Histopathology revealed a poorly differentiated, moderately well-demarcated, unencapsulated, highly infiltrative round cell neoplasm, and immunohistochemistry was supportive of a plasmacytoma. Performance of a rostral partial mandibulectomy was initially discussed with the owners, but the lesion improved spontaneously both clinically and on repeated computed tomography scanning before surgery could be performed. It subsequently almost completely resolved 6 mo after diagnosis. Hypotheses for spontaneous regression of the lesion are discussed and the human literature is briefly reviewed.

Super-enhancer-guided mapping of regulatory networks controlling mouse trophoblast stem cells.

Trophectoderm (TE) lineage development is pivotal for proper implantation, placentation, and healthy pregnancy. However, only a few TE-specific transcription factors (TFs) have been systematically characterized, hindering our understanding of the process. To elucidate regulatory mechanisms underlying TE development, here we map super-enhancers (SEs) in trophoblast stem cells (TSCs) as a model. We find both prominent TE-specific master TFs (Cdx2, Gata3, and Tead4), and >150 TFs that had not been previously implicated in TE lineage, that are SE-associated. Mapping targets of 27 SE-predicted TFs reveals a highly intertwined transcriptional regulatory circuitry. Intriguingly, SE-predicted TFs show 4 distinct expression patterns with dynamic alterations of their targets during TSC differentiation. Furthermore, depletion of a subset of TFs results in dysregulation of the markers for specialized cell types in placenta, suggesting a role during TE differentiation. Collectively, we characterize an expanded TE-specific regulatory network, providing a framework for understanding TE lineage development and placentation.

Author Correction: ZSCAN10 expression corrects the genomic instability of iPSCs from aged donors.

In the version of this Article originally published, Supplementary Fig. 6j showed incorrect values for the LS and AG4 glutathione samples, and Fig. 5c and Supplementary Fig. 6j did not include all n = 6 samples for the hESC, Y-hiPSC and AG4-ZSCAN10 groups as was stated in the legend. In addition, the bars for hESC, Y-hiPSC, AG4-ZCNAN10, AG4 and LS in Supplementary Fig. 6i and j have been reproduced from Fig. 5b and c, respectively. Fig. 6e was also reproduced in the lower panel of Supplementary Fig. 6h, to enable direct comparison of the data, however this was not explained in the original figure legends. The correct versions of these figures and their legends are shown below, and Supplementary Table 5 has been updated with the source data for all numerical data in the manuscript.

Tumor penetrating peptides inhibiting MYC as a potent targeted therapeutic strategy for triple-negative breast cancers.

Overexpression of MYC oncogene is highly prevalent in many malignancies such as aggressive triple-negative breast cancers (TNBCs) and it is associated with very poor outcome. Despite decades of research, attempts to effectively inhibit MYC, particularly with small molecules, still remain challenging due to the featureless nature of its protein structure. Herein, we describe the engineering of the dominant-negative MYC peptide (OmoMYC) linked to a functional penetrating 'Phylomer' peptide (FPPa) as a therapeutic strategy to inhibit MYC in TNBC. We found FPPa-OmoMYC to be a potent inducer of apoptosis (with IC50 from 1-2 µM) in TNBC cells with negligible effects in non-tumorigenic cells. Transcriptome analysis of FPPa-OmoMYC-treated cells indicated that the fusion protein inhibited MYC-dependent networks, inducing dynamic changes in transcriptional, metabolic, and apoptotic processes. We demonstrated the efficacy of FPPa-OmoMYC in inhibiting breast cancer growth when injected orthotopically in TNBC allografts. Lastly, we identified strong pharmacological synergisms between FPPa-OmoMYC and chemotherapeutic agents. This study highlights a novel therapeutic approach to target highly aggressive and chemoresistant MYC-activated cancers.

Aldosterone-producing adrenocortical carcinoma with myxoid differentiation in a cat.

A 10-year-old male neutered Persian cat was presented with an abdominal mass and history of weakness. Blood smear examination found marked elliptocytosis, and serum biochemical analysis revealed hypokalemia, hypochloremia, increased creatine kinase activity, and a high aldosterone concentration. Cytologic examination of the mass revealed neoplastic endocrine cells with moderate criteria of malignancy, favoring adrenocortical neoplasia. The adrenal mass was surgically excised and histologically characterized by lobules of mildly pleomorphic, polygonal neoplastic cells with moderate to abundant, occasionally granular, eosinophilic cytoplasm. Lobules were separated by fine fibrovascular trabeculae, and numerous cystic cavities containing amorphous eosinophilic material that stained positive with Alcian blue and periodic acid-Schiff were seen. Neoplastic cells were multifocally positive for cytochrome P450 aldosterone synthase. Based on clinicopathologic and immunohistochemical findings the present case was diagnosed as an aldosterone-producing adrenocortical carcinoma with myxoid differentiation. While this entity has not been reported in cats, myxoid differentiation of adrenocortical carcinomas has been found in other species and can pose a major diagnostic challenge on microscopic examination.

Differences in Rate of Complete Excision of Basal Cell Carcinoma by Dermatologists, Plastic Surgeons and General Practitioners: A Large Cross-Sectional Study.

BACKGROUND: Due to the increasing incidence of basal cell carcinoma (BCC) and rising health care costs, health care insurance companies seek ways to shift skin surgery for BCC from secondary to primary care. OBJECTIVES: To study the differences in complete excision of BCC by general practitioners (GPs), dermatologists, and plastic surgeons. METHODS: A retrospective cross-sectional study of pathology records of 2,986 standard excisions of primary BCCs performed by a GP, dermatologist, or plastic surgeon in the area of Southwest Netherlands between 2008 and 2014. To compare the risk of an incomplete BCC excision between the specialties, the odds ratio (OR) was used adjusted for patient age, sex, tumor site, size, and histological subtype. RESULTS: BCCs were completely excised by GPs in 70%, which was lower than the 93% by dermatologists and 83% by plastic surgeons (p < 0.001). Compared to the dermatologist, BCCs which were excised by a GP were 6 times higher at risk of an incomplete excision (adjusted OR 6, 95% CI 5-8) and 2 times higher at risk when excised by a plastic surgeon (adjusted OR 2, 95% CI 2-3). CONCLUSION: BCCs were more often completely excised by dermatologists than by GPs and plastic surgeons. Dermatologists probably perform better because of their extensive training and high experience in BCC care. To minimize incomplete BCC excision, GPs should receive specific training before the shift of BCC care from secondary to primary care is justifiable.

Implications of CpG islands on chromosomal architectures and modes of global gene regulation.

CpG islands (CGIs) have long been implicated in the regulation of vertebrate gene expression. However, the involvement of CGIs in chromosomal architectures and associated gene expression regulations has not yet been thoroughly explored. By combining large-scale integrative data analyses and experimental validations, we show that CGIs clearly reconcile two competing models explaining nuclear gene localizations. We first identify CGI-containing (CGI+) and CGI-less (CGI-) genes are non-randomly clustered within the genome, which reflects CGI-dependent spatial gene segregation in the nucleus and corresponding gene regulatory modes. Regardless of their transcriptional activities, CGI+ genes are mainly located at the nuclear center and encounter frequent long-range chromosomal interactions. Meanwhile, nuclear peripheral CGI- genes forming heterochromatin are activated and internalized into the nuclear center by local enhancer-promoter interactions. Our findings demonstrate the crucial implications of CGIs on chromosomal architectures and gene positioning, linking the critical importance of CGIs in determining distinct mechanisms of global gene regulation in three-dimensional space in the nucleus.

How the Start into the Clinical Elective Year Could be Improved: Qualitative Results and Recommendations from Student Interviews.

Background: Entering the Clinical Elective Year (CEY) is a challenging transition phase for undergraduate medical students. Students become members of a professional team, thereby taking over certain tasks, which are executed more or less independently. Factors which facilitate (or impede) this transition in the perception of students are not well described. We therefore wanted to explore, what students perceived to be helpful during the first phase of the CEY and possibly derive respective recommendations. Methods: We conducted semi-structured interviews with 5th year medical students after they had completed the first two months of their CEY. Students were asked which problems they had faced and how they felt prepared for the CEY. Interviews were audio-recorded, transcribed, and analysed by qualitative content analysis. Results: From 34 interviews, we included 28 into analysis. Overall, 24 students were satisfied or very satisfied with their start into the CEY. Satisfaction was expressed with respect to workplace experiences, learning progress, responsibilities and team integration. Especially, students appreciated if they were integrated as active members of the team, were given responsibility for certain units of work, and received well-structured formal teaching and supervision. Students had divergent opinions about the quality of teaching and supervision, about their own achievements, and the recognition they received. Students recommended improvements in respect to formal teaching and supervision by clinical supervisors, preparation of the CEY by university, and supporting structures in the hosting institution. Conclusion: Students in this study were generally satisfied with the first two months of their CEY. Facilitating factors were active and responsible involvement into routine patient care, and high quality formal teaching and supervision. Findings may inform universities, teaching hospitals, and students how to better shape the first phase of the CEY.

Fosl1 overexpression directly activates trophoblast-specific gene expression programs in embryonic stem cells.

During early development in placental mammals, proper trophoblast lineage development is essential for implantation and placentation. Defects in this lineage can cause early pregnancy failures and other pregnancy disorders. However, transcription factors controlling trophoblast development remain poorly understood. Here, we utilize Fosl1, previously implicated in trophoblast giant cell development as a member of the AP-1 complex, to trans-differentiate embryonic stem (ES) cells to trophoblast lineage-like cells. We first show that the ectopic expression of Fosl1 is sufficient to induce trophoblast-specific gene expression programs in ES cells. Surprisingly, we find that this transcriptional reprogramming occurs independently of changes in levels of ES cell core factors during the cell fate change. This suggests that Fosl1 acts in a novel way to orchestrate the ES to trophoblast cell fate conversion compared to previously known reprogramming factors. Mapping of Fosl1 targets reveals that Fosl1 directly activates TE lineage-specific genes as a pioneer factor. Our work suggests Fosl1 may be used to reprogram ES cells into differentiated cell types in trophoblast lineage, which not only enhances our knowledge of global trophoblast gene regulation but also may provide a future therapeutic tool for generating induced trophoblast cells from patient-derived pluripotent stem cells.