Medical Genetics Commons^™

The Srg Rat, A Sprague-Dawley Rag2/Il2rg Double-Knockout Validated For Human Tumor Oncology Studies, Fallon K. Noto, Jaya Sangodkar, Bisoye Towobola Adedeji, Sam Moody, Christopher B. Mcclain, Ming Tong, Eric Ostertag, Jack Crawford, Xiaohua Gao, Lauren Hurst, Caitlin M. O'Connor, Erika N. Hanson, Sudeh Izadmehr, Rita Tohmé, Jyothsna Narla, Kristin Lesueur, Kajari Bhattacharya, Amit Rupani, Marwan K. Tayeh, Jeffrey W. Innis, Matthew D. Galsky, B. Mark Evers, Analisa Difeo, Goutham Narla, Tseten Y. Jamling

Markey Cancer Center Faculty Publications

We have created the immunodeficient SRG rat, a Sprague-Dawley Rag2/Il2rg double knockout that lacks mature B cells, T cells, and circulating NK cells. This model has been tested and validated for use in oncology (SRG OncoRat®). The SRG rat demonstrates efficient tumor take rates and growth kinetics with different human cancer cell lines and PDXs. Although multiple immunodeficient rodent strains are available, some important human cancer cell lines exhibit poor tumor growth and high variability in those models. The VCaP prostate cancer model is one such cell line that engrafts unreliably and grows irregularly in …

Identification Of Functional Regulatory Elements In The Human Genome Using Pooled Crispr Screens., Samantha M. Borys, Scott T. Younger

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Genome-scale pooled CRISPR screens are powerful tools for identifying genetic dependencies across varied cellular processes. The vast majority of CRISPR screens reported to date have focused exclusively on the perturbation of protein-coding gene function. However, protein-coding genes comprise < 2% of the sequence space in the human genome leaving a substantial portion of the genome uninterrogated. Noncoding regions of the genome harbor important regulatory elements (e.g. promoters, enhancers, silencers) that influence cellular processes but high-throughput methods for evaluating their essentiality have yet to be established.

RESULTS: Here, we describe a CRISPR-based screening approach that facilitates the functional profiling of thousands of noncoding regulatory elements in parallel. We selected the tumor suppressor p53 as a model system and designed a pooled CRISPR library targeting thousands of p53 binding sites throughout the genome. Following transduction into dCas9-KRAB-expressing cells we identified several regulatory elements that influence cell proliferation. Moreover, …

Deficient Histone H3 Propionylation By Brpf1-Kat6 Complexes In Neurodevelopmental Disorders And Cancer., Kezhi Yan, Justine Rousseau, Keren Machol, Laura A. Cross, Katherine E. Agre, Cynthia Forster Gibson, Anne Goverde, Kendra Engleman, Hannah Verdin, Elfride De Baere, Lorraine Potocki, Dihong Zhou, Maxime Cadieux-Dion, Gary A. Bellus, Monisa D. Wagner, Rebecca J. Hale, Natacha Esber, Alan F. Riley, Benjamin D. Solomon, Megan T. Cho, Kirsty Mcwalter, Roy Eyal, Meagan K. Hainlen, Bryce A. Mendelsohn, Hillary M. Porter, Brendan C. Lanpher, Andrea M. Lewis, Juliann Savatt, Isabelle Thiffault, Bert Callewaert, Philippe M. Campeau, Xiang-Jiao Yang

Manuscripts, Articles, Book Chapters and Other Papers

Lysine acetyltransferase 6A (KAT6A) and its paralog KAT6B form stoichiometric complexes with bromodomain- and PHD finger-containing protein 1 (BRPF1) for acetylation of histone H3 at lysine 23 (H3K23). We report that these complexes also catalyze H3K23 propionylation in vitro and in vivo. Immunofluorescence microscopy and ATAC-See revealed the association of this modification with active chromatin. Brpf1 deletion obliterates the acylation in mouse embryos and fibroblasts. Moreover, we identify BRPF1 variants in 12 previously unidentified cases of syndromic intellectual disability and demonstrate that these cases and known BRPF1 variants impair H3K23 propionylation. Cardiac anomalies are present in a subset of the …

Precision Medicine In Pediatric Cancer: Current Applications And Future Prospects., Atif Ahmed, Divya S. Vundamati, Midhat S. Farooqi, Erin M. Guest

Manuscripts, Articles, Book Chapters and Other Papers

Precision oncologic medicine is an emerging approach for cancer treatment that has recently taken giant steps in solid clinical practice. Recent advances in molecular diagnostics that can analyze the individual tumor's variability in genes have provided greater understanding and additional strategies to treat cancers. Although tumors can be tested by several molecular methods, the use of next-generation sequencing (NGS) has greatly facilitated our understanding of pediatric cancer and identified additional therapeutic opportunities. Pediatric tumors have a different genetic make-up, with a fewer number of actionable targets than adult tumors. Nevertheless, precision oncology in the pediatric population has greatly improved the …

Metabolic And Molecular Insights Into An Essential Role Of Nicotinamide Phosphoribosyltransferase., Li Q. Zhang, Leon Van Haandel, Min Xiong, Peixin Huang, Daniel P. Heruth, Chengpeng Bi, R Gaedigk, Xun Jiang, Ding-You Li, Gerald Wyckoff, Dmitry N. Grigoryev, Li Gao, Linheng Li, Min Wu, J Steven Leeder, Shui Qing Ye

Manuscripts, Articles, Book Chapters and Other Papers

Nicotinamide phosphoribosyltransferase (NAMPT) is a pleiotropic protein implicated in the pathogenesis of acute respiratory distress syndrome, aging, cancer, coronary heart diseases, diabetes, nonalcoholic fatty liver disease, obesity, rheumatoid arthritis, and sepsis. However, the underlying molecular mechanisms of NAMPT in these physiological and pathological processes are not fully understood. Here, we provide experimental evidence that a Nampt gene homozygous knockout (Nampt-/-) resulted in lethality at an early stage of mouse embryonic development and death within 5-10 days in adult mice accompanied by a 25.24±2.22% body weight loss, after the tamoxifen induction of NamptF/F × Cre mice. These results substantiate that Nampt …

Predicting Targeted Drug Combinations Based On Pareto Optimal Patterns Of Coexpression Network Connectivity, Nadia M. Penrod, Casey S. Greene, Jason H. Moore

Dartmouth Scholarship

Molecularly targeted drugs promise a safer and more effective treatment modality than conventional chemotherapy for cancer patients. However, tumors are dynamic systems that readily adapt to these agents activating alternative survival pathways as they evolve resistant phenotypes. Combination therapies can overcome resistance but finding the optimal combinations efficiently presents a formidable challenge. Here we introduce a new paradigm for the design of combination therapy treatment strategies that exploits the tumor adaptive process to identify context-dependent essential genes as druggable targets. We have developed a framework to mine high-throughput transcriptomic data, based on differential coexpression and Pareto optimization, to investigate drug-induced …

Discovery Of Molecular Associations Among Aging, Stem Cells, And Cancer Based On Gene Expression Profiling., Xiaosheng Wang

Journal Articles: Genetics, Cell Biology & Anatomy

The emergence of a huge volume of "omics" data enables a computational approach to the investigation of the biology of cancer. The cancer informatics approach is a useful supplement to the traditional experimental approach. I reviewed several reports that used a bioinformatics approach to analyze the associations among aging, stem cells, and cancer by microarray gene expression profiling. The high expression of aging- or human embryonic stem cell-related molecules in cancer suggests that certain important mechanisms are commonly underlying aging, stem cells, and cancer. These mechanisms are involved in cell cycle regulation, metabolic process, DNA damage response, apoptosis, p53 signaling …

Microarray-Based Cancer Prediction Using Single Genes., Xiaosheng Wang, Richard Simon

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Although numerous methods of using microarray data analysis for cancer classification have been proposed, most utilize many genes to achieve accurate classification. This can hamper interpretability of the models and ease of translation to other assay platforms. We explored the use of single genes to construct classification models. We first identified the genes with the most powerful univariate class discrimination ability and then constructed simple classification rules for class prediction using the single genes.

RESULTS: We applied our model development algorithm to eleven cancer gene expression datasets and compared classification accuracy to that for standard methods including Diagonal Linear …

The Risks And Benefits Of Long-Term Use Of Hydroxyurea In Sickle Cell Anemia: A 17.5 Year Follow-Up., M. H. Steinberg, W. F. Mccarthy, O. Castro, S. K. Ballas, F. D. Armstrong, W. Smith, K. Ataga, P. Swerdlow, A. Kutlar, L. Decastro, M. A. Waclawiw, E. Orringer, S. Jones, D. Strayhorn, W. Rosse, G. Phillips, D. Pearce, A. Johnson-Telfair, L. Daitch, P. Milner, A. Tracy, S. Valdez, G. E. Allen, J. Moshang, B. Scott, C. Bigelow, A. Anderson, V. Sabahi, T. Harrington, W. Labrousse, C. Pegelow, D. Temple, E. Case, R. Harrell, S. Childerie, S. Embury, B. Schmidt, D. Davies, Y. Saunthararajah, M. Koshy, N. Talischy-Zahed, L. Dorn, G. Pendarvis, M. Mcgee, M. Telfer, A. Davis, O. C. Onyekwere, C. Nwokolo, H. Finke, E. Perlin, J. Siteman, M. Bryan, T. Saunders, Y. Barber, P. Gascon, P. Di Paolo, S. Gargiulo, J. Eckman, E. Carter-Randall, J. H. Bailey, A. Platt, L. Waller, G. Ramirez, V. Knors, S. Hernandez, E. M. Rodriguez, E. Wilkes, E. Vichinsky, W. Hagar, C. Hoehner, E. Hackney-Stevens, S. Claster, A. Earles, K. Kleman, K. Mclaughlin, L. White, B. Maddox, L. Usry, A. Brenner, K. Williams, R. O'Brien, K. Genther, S. Shurin, B. Berman, K. Chiarucci, L. Keverline, N. Olivieri, J. Chow, M. Hui, D. Shaw, N. Lewis, M. Okam, E. Mandell, A. Palmer, K. Bridges, B. Tynan, C. Winograd, R. Bellevue, H. Dosik, M. Sheikhai, P. Ryans, H. Souffrant, B. Adler, A. Johnson-Telfair, L. Eskridge, J. Prchal, J. Braddock, T. Mcardle, T. Carlos, A. Roundtree-Schmotzer, D. Gardner

Department of Medicine Faculty Papers

A randomized, controlled clinical trial established the efficacy and safety of short-term use of hydroxyurea in adult sickle cell anemia. To examine the risks and benefits of long-term hydroxyurea usage, patients in this trial were followed for 17.5 years during which they could start or stop hydroxyurea. The purpose of this follow-up was to search for adverse outcomes and estimate mortality. For each outcome and for mortality, exact 95% confidence intervals were calculated, or tests were conducted at alpha = 0.05 level (P-value <0.05 for statistical significance). Although the death rate in the overall study cohort was high (43.1%; 4.4 per 100 person-years), mortality was reduced in individuals with long-term exposure to hydroxyurea. Survival curves demonstrated a significant reduction in deaths with long-term exposure. Twenty-four percent of deaths were due to pulmonary complications; 87.1% occurred in patients who never took hydroxyurea or took it for <5 years. Stroke, organ dysfunction, infection, and malignancy were similar in all groups. Our results, while no longer the product of a randomized study because of the ethical concerns of withholding an efficacious treatment, suggest that long-term use of hydroxyurea is safe and might decrease mortality.

Proliferation Of Aneuploid Human Cells Is Limited By A P53-Dependent Mechanism, Sarah L. Thompson, Duane A. Compton

Dartmouth Scholarship

Most solid tumors are aneuploid, and it has been proposed that aneuploidy is the consequence of an elevated rate of chromosome missegregation in a process called chromosomal instability (CIN). However, the relationship of aneuploidy and CIN is unclear because the proliferation of cultured diploid cells is compromised by chromosome missegregation. The mechanism for this intolerance of nondiploid genomes is unknown. In this study, we show that in otherwise diploid human cells, chromosome missegregation causes a cell cycle delay with nuclear accumulation of the tumor suppressor p53 and the cyclin kinase inhibitor p21. Deletion of the p53 gene permits the accumulation …

Accurate Molecular Classification Of Cancer Using Simple Rules., Xiaosheng Wang, Osamu Gotoh

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: One intractable problem with using microarray data analysis for cancer classification is how to reduce the extremely high-dimensionality gene feature data to remove the effects of noise. Feature selection is often used to address this problem by selecting informative genes from among thousands or tens of thousands of genes. However, most of the existing methods of microarray-based cancer classification utilize too many genes to achieve accurate classification, which often hampers the interpretability of the models. For a better understanding of the classification results, it is desirable to develop simpler rule-based models with as few marker genes as possible.

METHODS: …

Hiv-1 Tat And Aids-Associated Cancer: Targeting The Cellular Anti-Cancer Barrier?, Giuseppe Nunnari, Johanna A Smith, René Daniel

Department of Medicine Faculty Papers

The acquired immunodeficiency syndrome (AIDS) is accompanied by a significant increase in the incidence of neoplasms. Several causative agents have been proposed for this phenomenon. These include immunodeficiency and oncogenic DNA viruses and the HIV-1 protein Tat. Cancer in general is closely linked to genomic instability and DNA repair mechanisms. The latter maintains genomic stability and serves as a cellular anti-cancer barrier. Defects in DNA repair pathway are associated with carcinogenesis. This review focuses on newly discovered connections of the HIV-1 protein Tat, as well as cellular co-factors of Tat, to double-strand break DNA repair. We propose that the Tat-induced …