The Histone Methyltransferase SUV39H1 Suppresses Embryonal Rhabdomyosarcoma Formation in Zebrafish

Epigenetics, or the reversible and heritable marks of gene regulation not including DNA sequence, encompasses chromatin modifications on both the DNA and histones and is as important as the DNA sequence itself. Chromatin-modifying factors are playing an increasingly important role in tumorigenesis, particularly among pediatric rhabdomyosarcomas (RMS), revealing potential novel therapeutic targets. We performed an overexpression screen of chromatin-modifying factors in a KRASG12D-driven zebrafish model for RMS. Here, we describe the identification of a histone H3 lysine 9 histone methyltransferase, SUV39H1, as a suppressor of embryonal RMS formation in zebrafish. This suppression is specific to the histone methyltransferase activity of SUV39H1, as point mutations in the SET domain lacked the effect. SUV39H1-overexpressing and control tumors have a similar proliferation rate, muscle differentiation state, and tumor growth rate. Strikingly, SUV39H1-overexpressing fish initiate fewer tumors, which results in the observed suppressive phenotype. We demonstrate that the delayed tumor onset occurs between 5 and 7 days post fertilization. Gene expression profiling at these stages revealed that in the context of KRASG12D overexpression, SUV39H1 may suppress cell cycle progression. Our studies provide evidence for the role of SUV39H1 as a tumor suppressor

Bureaucracy and Wildlife: A Historical Overview

This paper provides a framework for understanding the Government\u27s position on many wildlife topics, including humane ethics. The Government\u27s historical role in wildlife conservation is traced to pertinent theories of bureaucracy. It is shown that Government involvement in wildlife conservation increased through successive stages of change because of interest group activity

Relationships between high-stakes clinical skills exam scores and program director global competency ratings of first-year pediatric residents

Responding to mandates from the Accreditation Council for Graduate Medical Education (ACGME) and American Osteopathic Association (AOA), residency programs have developed competency-based assessment tools. One such tool is the American College of Osteopathic Pediatricians (ACOP) program directors’ annual report. High-stakes clinical skills licensing examinations, such as the Comprehensive Osteopathic Medical Licensing Examination Level 2-Performance Evaluation (COMLEX-USA Level 2-PE), also assess competency in several clinical domains.The purpose of this study is to investigate the relationships between program director competency ratings of first-year osteopathic residents in pediatrics and COMLEX-USA Level 2-PE scores from 2005 to 2009.The sample included all 94 pediatric first-year residents who took COMLEX-USA Level 2-PE and whose training was reviewed by the ACOP for approval of training between 2005 and 2009. Program director competency ratings and COMLEX-USA Level 2-PE scores (domain and component) were merged and analyzed for relationships.Biomedical/biomechanical domain scores were positively correlated with overall program director competency ratings. Humanistic domain scores were not significantly correlated with overall program director competency ratings, but did show moderate correlation with ratings for interpersonal and communication skills. The six ACGME or seven AOA competencies assessed empirically by the ACOP program directors’ annual report could not be recovered by principal component analysis; instead, three factors were identified, accounting for 86% of the variance between competency ratings.A few significant correlations were noted between COMLEX-USA Level 2-PE scores and program director competency ratings. Exploring relationships between different clinical skills assessments is inherently difficult because of the heterogeneity of tools used and overlap of constructs within the AOA and ACGME core competencies

Introducing Blended Learning to Medical Students in a Clinical Training Environment

Third year medical students typically learn through supervised patient interaction in a clinical setting, often based in academic or hospital-based training sites. As one of the five medical schools in the Philadelphia area, PCOM strives to find the best training sties for its students in a number of specialties. Due to the increasing number of students in the region as well as a decreasing number of available training sites (as a result of reduced hospitalization rates and lengths of stay), finding suitable training sites for students has been a challenge. In order to better meet the academic needs of our students, new educational models are required. These models need to address a number of key challenges. 1.Inconsistent clinical exposure to patients whose demographics and presenting problems vary by site. 2.Inconsistent training and quality of clinical preceptors at each of the clinical sites. 3.Insufficient clinic training sites to accommodate expanding class size.https://digitalcommons.pcom.edu/posters/1014/thumbnail.jp

Cross-Species Array Comparative Genomic Hybridization Identifies Novel Oncogenic Events in Zebrafish and Human Embryonal Rhabdomyosarcoma

Human cancer genomes are highly complex, making it challenging to identify specific drivers of cancer growth, progression, and tumor maintenance. To bypass this obstacle, we have applied array comparative genomic hybridization (array CGH) to zebrafish embryonal rhabdomyosaroma (ERMS) and utilized cross-species comparison to rapidly identify genomic copy number aberrations and novel candidate oncogenes in human disease. Zebrafish ERMS contain small, focal regions of low-copy amplification. These same regions were commonly amplified in human disease. For example, 16 of 19 chromosomal gains identified in zebrafish ERMS also exhibited focal, low-copy gains in human disease. Genes found in amplified genomic regions were assessed for functional roles in promoting continued tumor growth in human and zebrafish ERMS – identifying critical genes associated with tumor maintenance. Knockdown studies identified important roles for Cyclin D2 (CCND2), Homeobox Protein C6 (HOXC6) and PlexinA1 (PLXNA1) in human ERMS cell proliferation. PLXNA1 knockdown also enhanced differentiation, reduced migration, and altered anchorage-independent growth. By contrast, chemical inhibition of vascular endothelial growth factor (VEGF) signaling reduced angiogenesis and tumor size in ERMS-bearing zebrafish. Importantly, VEGFA expression correlated with poor clinical outcome in patients with ERMS, implicating inhibitors of the VEGF pathway as a promising therapy for improving patient survival. Our results demonstrate the utility of array CGH and cross-species comparisons to identify candidate oncogenes essential for the pathogenesis of human cancer

Blended Learning Format for Pediatrics Clinical Rotation, Student Perspective

Introduction. Traditional medical educational models are shifting to incorporate learning technologies and online educational activities. Combining online and blended learning with the more traditional face-to-face clinical instruction appears to provide opportunity to engage leaners at remote clinical training sites. Objective. The purpose of this research study is to describe and evaluate the effectiveness of the blended-learning format for 3rd year medical students who participated in the pediatric blended learning supplement by investigating post-exercise survey responses, end-of-rotation examination (COMAT) scores and final course grades. Methods. Of the 264 third year students who completed the four-week clerkship in the 2014/15 academic year, 78 (29.5%) participated in the blended learning supplement and 186 (70.5%) participated in the traditional face-to-face course. Students in the study group were provided opportunity to complete a post-exercise survey regarding their experience with the blended learning format. The survey instrument included items specifically related to the online components of the course: 38 Likert-type items arranged in 10 sections with opportunity to provide open-ended comments for each section, as well as a 15-item adjective checklist. In addition, end-of-rotation examination (COMAT) scores and final course grades were compared between groups. Results. Overall students valued the blended learning experience. Of the 78 students in the study group, 53 completed the post-exercise survey (67.9% response rate). Of respondents, 88% agreed or strongly agreed with the statement “This was a practical learning experience,” and 85% agreed or strongly agreed with “The integration of eLearning and face-to-face learning helped me learn pediatrics.” Of respondents, 50% agreed or strongly agreed with the statement “I prefer this hybrid learning format to traditional face-to-face clinical rotations,” and 73% reported “The amount of work required for this course was appropriate.” Overall, 85% reported “I was satisfied with the overall learning experience.” A large number of comments (7/19 regarding “course format,” 8/19 regarding “overall experience,” and 3/14 regarding “open comments”) addressed desire to increase the amount of clinical exposure and face-to-face time with patients. Using a two-tailed t-test for analysis, no statistical differences were seen between control (traditional) and sample (blended learning) groups with regard to COMAT scores (p=0.321). Using a test for independence (using a chi squared distribution), final grades between groups were significantly different (p=0.015). Compared to the control group, more students in the blended learning group received a final grade of Honors. Conclusion. Results of this study support the use of blended learning in a clinical training environment. Students valued the blended learning approach, and while their end-of-rotation examination scores were not improved, they may have benefited from the blended learning supplement by receiving higher course grades. As more medical educators utilize blended learning, it is important to investigate the best balance between learning with technology and learning in a face-to-face setting. Online activities may enhance but should never fully replace face-to-face learning with real patients

Notch signaling expands a pre-malignant pool of T-cell acute lymphoblastic leukemia clones without affecting leukemia-propagating cell frequency

NOTCH1 pathway activation contributes to the pathogenesis of over 60% of T-cell acute lymphoblastic leukemia (T-ALL). While Notch is thought to exert the majority of its effects through transcriptional activation of Myc, it also likely has independent roles in T-ALL malignancy. Here, we utilized a zebrafish transgenic model of T-ALL, where Notch does not induce Myc transcription, to identify a novel Notch gene expression signature that is also found in human T-ALL and is regulated independently of Myc. Cross-species microarray comparisons between zebrafish and mammalian disease identified a common T-ALL gene signature, suggesting that conserved genetic pathways underlie T-ALL development. Functionally, Notch expression induced a significant expansion of pre-leukemic clones; however, a majority of these clones were not fully transformed and could not induce leukemia when transplanted into recipient animals. Limiting-dilution cell transplantation revealed that Notch signaling does not increase the overall frequency of leukemia-propagating cells (LPCs), either alone or in collaboration with Myc. Taken together, these data indicate that a primary role of Notch signaling in T-ALL is to expand a population of pre-malignant thymocytes, of which a subset acquire the necessary mutations to become fully transformed LPCs

Web-Based Objective Structured Clinical Examination with Remote Standardized Patients and Skype: Resident Experience

OBJECTIVE: Using Skype and remote standardized patients (RSPs), investigators sought to evaluate user acceptance of a web-based objective structured clinical examination (OSCE) among resident physicians. METHODS: After participating in four web-based clinical encounters addressing pain with RSPs, 59 residents from different training programs, disciplines and geographic locations completed a 52-item questionnaire regarding their experience with Skype and RSPs. Open-ended responses were solicited as well. RESULTS: The majority of participants (97%) agreed or strongly agreed the web-based format was convenient and a practical learning exercise, and 90% agreed or strongly agreed the format was effective in teaching communication skills. Although 93% agreed or strongly agreed they could communicate easily with RSPs using Skype, 80% preferred traditional face-to-face clinical encounters, and 58% reported technical difficulties during the encounters. Open-ended written responses supported survey results. CONCLUSION: Findings from this study expose challenges with technology and human factors, but positive experiences support the continued investigation of web-based OSCEs as a synchronous e-learning initiative for teaching and assessing doctor-patient communication. Such educational programs are valuable but unlikely to replace face-to-face encounters with patients. PRACTICE IMPLICATIONS: This web-based OSCE program provides physician learners with additional opportunity to improve doctor-patient communication

T-Lymphoblastic Lymphoma Cells Express High Levels of BCL2, S1P1, and ICAM1, Leading to a Blockade of Tumor Cell Intravasation

The molecular events underlying the progression of T-lymphoblastic lymphoma (T-LBL) to acute T-lymphoblastic leukemia (T-ALL) remain elusive. In our zebrafish model, concomitant overexpression of bcl-2 with Myc accelerated T-LBL onset while inhibiting progression to T-ALL. The T-LBL cells failed to invade the vasculature and showed evidence of increased homotypic cell-cell adhesion and autophagy. Further analysis using clinical biopsy specimens revealed autophagy and increased levels of BCL2, S1P1, and ICAM1 in human T-LBL compared with T-ALL. Inhibition of S1P1 signaling in T-LBL cells led to decreased homotypic adhesion in vitro and increased tumor cell intravasation in vivo. Thus, blockade of intravasation and hematologic dissemination in T-LBL is due to elevated S1P1 signaling, increased expression of ICAM1, and augmented homotypic cell-cell adhesion.Stem Cell and Regenerative Biolog