12 research outputs found
The Use of PRS in Introductory Microeconomics: Some Evidence on Performance and Attendance
This paper uses a sample of 425 students from 4 large sections of Introductory Microeconomics during the period 2005 – 2007 to examine the impact of using the Personal Response System (PRS or Clickers) on class attendance and exam performance. The evidence suggests that the use of PRS has led to improved attendance. The exam scores are similar to classes that used online quizzes instead of the PRS. A survey of student attitudes towards the PRS indicates that the use of PRS helps with student learning and reinforcing important concepts. Based on the results of this study the authors believe that the PRS is a useful tool for all instructors, particularly those faced with large sections.
The Use of PRS in Introductory Microeconomics: Some Evidence on Performance and Attendance
This paper uses a sample of 425 students from 4 large sections of Introductory Microeconomics during the period 2005 – 2007 to examine the impact of using the Personal Response System (PRS or Clickers) on class attendance and exam performance. The evidence suggests that the use of PRS has led to improved attendance. The exam scores are similar to classes that used online quizzes instead of the PRS. A survey of student attitudes towards the PRS indicates that the use of PRS helps with student learning and reinforcing important concepts. Based on the results of this study the authors believe that the PRS is a useful tool for all instructors, particularly those faced with large sections
The 5-Hydroxymethylcytosine Landscape of Prostate Cancer
Analysis of DNA methylation is a valuable tool to understand disease progression and is increasingly being used to create diagnostic and prognostic clinical biomarkers. While conversion of cytosine to 5-methylcytosine (5mC) commonly results in transcriptional repression, further conversion to 5-hydroxymethylcytosine (5hmC) is associated with transcriptional activation. Here we perform the first study integrating whole-genome 5hmC with DNA, 5mC, and transcriptome sequencing in clinical samples of benign, localized, and advanced prostate cancer. 5hmC is shown to mark activation of cancer drivers and downstream targets. Furthermore, 5hmC sequencing revealed profoundly altered cell states throughout the disease course, characterized by increased proliferation, oncogenic signaling, dedifferentiation, and lineage plasticity to neuroendocrine and gastrointestinal lineages. Finally, 5hmC sequencing of cell-free DNA from patients with metastatic disease proved useful as a prognostic biomarker able to identify an aggressive subtype of prostate cancer using the genes TOP2A and EZH2, previously only detectable by transcriptomic analysis of solid tumor biopsies. Overall, these findings reveal that 5hmC marks epigenomic activation in prostate cancer and identify hallmarks of prostate cancer progression with potential as biomarkers of aggressive disease. SIGNIFICANCE: In prostate cancer, 5-hydroxymethylcytosine delineates oncogene activation and stage-specific cell states and can be analyzed in liquid biopsies to detect cancer phenotypes. See related article by Wu and Attard, p. 3880.publishedVersionPeer reviewe
The evolutionary history of lethal metastatic prostate cancer
Cancers emerge from an ongoing Darwinian evolutionary process, often leading to multiple competing subclones within a single primary tumour. This evolutionary process culminates in the formation of metastases, which is the cause of 90% of cancer-related deaths. However, despite its clinical importance, little is known about the principles governing the dissemination of cancer cells to distant organs. Although the hypothesis that each metastasis originates from a single tumour cell is generally supported, recent studies using mouse models of cancer demonstrated the existence of polyclonal seeding from and interclonal cooperation between multiple subclones. Here we sought definitive evidence for the existence of polyclonal seeding in human malignancy and to establish the clonal relationship among different metastases in the context of androgen-deprived metastatic prostate cancer. Using whole-genome sequencing, we characterized multiple metastases arising from prostate tumours in ten patients. Integrated analyses of subclonal architecture revealed the patterns of metastatic spread in unprecedented detail. Metastasis-to-metastasis spread was found to be common, either through de novo monoclonal seeding of daughter metastases or, in five cases, through the transfer of multiple tumour clones between metastatic sites. Lesions affecting tumour suppressor genes usually occur as single events, whereas mutations in genes involved in androgen receptor signalling commonly involve multiple, convergent events in different metastases. Our results elucidate in detail the complex patterns of metastatic spread and further our understanding of the development of resistance to androgen-deprivation therapy in prostate cancer.This is an ICGC Prostate Cancer study funded by: Cancer Research UK (2011-present); NIH NCI Intramural Program (2013-2014); Academy of Finland (2011-present); Cancer Society of Finland (2013-present); PELICAN Autopsy Study family members and friends (1998-2004); John and Kathe Dyson (2000); US National Cancer Institute CA92234 (2000-2005); American Cancer Society (1998-2000); Johns Hopkins University Department of Pathology (1997-2011); Women's Board of Johns Hopkins Hospital (1998); The Grove Foundation (1998); Association for the Cure of Cancer of the Prostate (1994-1998); American Foundation for Urologic Disease (1991-1994); Bob Champion Cancer Trust (2013-present); Research Foundation – Flanders (FWO) [FWO-G.0687.12] (2012-present). E.P. is a European Hematology Association Research Fellow
The Somatic Genomic Landscape of Glioblastoma
We describe the landscape of somatic genomic alterations based on multi-dimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer
Salary distribution and team performance in Major League Baseball
This paper presents evidence that payroll inequality within a team is negatively related to on field performance, in terms of team winning percentages in Major League Baseball. This relationship is increasing over time during the sample period and robust to changes in the relationship between payroll and winning. We find strong evidence that, in levels, total team payroll and team specific Gini coefficients are nonstationary. The results also indicate that there exists a structural break in the relationship between payroll, inequality, and winning percent following the strike of 1994-1995.Major League Baseball Gini coefficients Payroll inequality
Concordance of Circulating Tumor DNA and Matched Metastatic Tissue Biopsy in Prostate Cancer.
Real-time knowledge of the somatic genome can influence management of patients with metastatic castration-resistant prostate cancer (mCRPC). While routine metastatic tissue biopsy is challenging in mCRPC, plasma circulating tumor DNA (ctDNA) has emerged as a minimally invasive tool to sample the tumor genome. However, no systematic comparisons of matched "liquid" and "solid" biopsies have been performed that would enable ctDNA profiling to replace the need for direct tissue sampling. We performed targeted sequencing across 72 clinically relevant genes in 45 plasma cell-free DNA (cfDNA) samples collected at time of metastatic tissue biopsy. We compared ctDNA alterations with exome sequencing data generated from matched tissue and quantified the concordance of mutations and copy number alterations using the Fisher exact test and Pearson correlations. Seventy-five point six percent of cfDNA samples had a ctDNA proportion greater than 2% of total cfDNA. In these patients, all somatic mutations identified in matched metastatic tissue biopsies were concurrently present in ctDNA. Furthermore, the hierarchy of variant allele fractions for shared mutations was remarkably similar between ctDNA and tissue. Copy number profiles between matched liquid and solid biopsy were highly correlated, and individual copy number calls in clinically actionable genes were 88.9% concordant. Detected alterations included AR amplifications in 22 (64.7%) samples, SPOP mutations in three (8.8%) samples, and inactivating alterations in tumor suppressors TP53 , PTEN , RB1 , APC , CDKN1B , BRCA2 , and PIK3R1 . In several patients, ctDNA sequencing revealed robust changes not present in paired solid biopsy, including clinically relevant alterations in the AR, WNT, and PI3K pathways. Our study shows that, in the majority of patients, a ctDNA assay is sufficient to identify all driver DNA alterations present in matched metastatic tissue and supports development of DNA biomarkers to guide mCRPC patient management based on ctDNA alone
The Molecular Taxonomy of Primary Prostate Cancer
There is substantial heterogeneity among primary prostate cancers, evident in the spectrum of molecular abnormalities and its variable clinical course. As part of The Cancer Genome Atlas (TCGA), we present a comprehensive molecular analysis of 333 primary prostate carcinomas. Our results revealed a molecular taxonomy in which 74% of these tumors fell into one of seven subtypes defined by specific gene fusions (ERG, ETV1/4, and FLI1) or mutations (SPOP, FOXA1, and IDH1). Epigenetic profiles showed substantial heterogeneity, including an IDH1 mutant subset with a methylator phenotype. Androgen receptor (AR) activity varied widely and in a subtype-specific manner, with SPOP and FOXA1 mutant tumors having the highest levels of AR-induced transcripts. 25% of the prostate cancers had a presumed actionable lesion in the PI3K or MAPK signaling pathways, and DNA repair genes were inactivated in 19%. Our analysis reveals molecular heterogeneity among primary prostate cancers, as well as potentially actionable molecular defectsclose
Integrated genomic characterization of endometrial carcinoma
We performed an integrated genomic, transcriptomic and proteomic characterization of 373 endometrial carcinomas using array- and sequencing-based technologies. Uterine serous tumours and ~25% of high-grade endometrioid tumours had extensive copy number alterations, few DNA methylation changes, low oestrogen receptor/progesterone receptor levels, and frequent TP53 mutations. Most endometrioid tumours had few copy number alterations or TP53 mutations, but frequent mutations in PTEN, CTNNB1, PIK3CA, ARID1A and KRAS and novel mutations in the SWI/SNF chromatin remodelling complex gene ARID5B. A subset of endometrioid tumours that we identified had a markedly increased transversion mutation frequency and newly identified hotspot mutations in POLE. Our results classified endometrial cancers into four categories: POLE ultramutated, microsatellite instability hypermutated, copy-number low, and copy-number high. Uterine serous carcinomas share genomic features with ovarian serous and basal-like breast carcinomas. We demonstrated that the genomic features of endometrial carcinomas permit a reclassification that may affect post-surgical adjuvant treatment for women with aggressive tumours.National Institutes of Health (U.S.) (Grant 5U24CA143799-04)National Institutes of Health (U.S.) (Grant 5U24CA143835-04)National Institutes of Health (U.S.) (Grant 5U24CA143840-04)National Institutes of Health (U.S.) (Grant 5U24CA143843-04)National Institutes of Health (U.S.) (Grant 5U24CA143845-04)National Institutes of Health (U.S.) (Grant 5U24CA143848-04)National Institutes of Health (U.S.) (Grant 5U24CA143858-04)National Institutes of Health (U.S.) (Grant 5U24CA143866-04)National Institutes of Health (U.S.) (Grant 5U24CA143867-04)National Institutes of Health (U.S.) (Grant 5U24CA143882-04)National Institutes of Health (U.S.) (Grant 5U24CA143883-04)National Institutes of Health (U.S.) (Grant 5U24CA144025-04)National Institutes of Health (U.S.) (Grant U54HG003067-11)National Institutes of Health (U.S.) (Grant U54HG003079-10)National Institutes of Health (U.S.) (Grant U54HG003273-10