Medical Cell Biology Commons^™

Renal Cell Carcinoma Unclassified With Medullary Phenotype In A Patient With Neurofibromatosis Type 2, Sanila Sarkar, Whitney Throckmorton, Racheal Bingham, Pavlos Msaouel, Giannicola Genovese, John Slopis, Priya Rao, Zsila Sadighi, Cynthia E Herzog

Faculty, Staff and Student Publications

We present, to our knowledge, the first reported case of germline neurofibromatosis Type 2 (NF2) associated with renal cell carcinoma unclassified with medullary phenotype (RCCU-MP) with somatic loss by immunohistochemistry of the SMARCB1 tumor suppressor gene located centromeric to NF2 on chromosome 22q. Our patient is a 15-year-old with germline neurofibromatosis Type 2 (NF2) confirmed by pathogenic mutation of c.-854-??46+??deletion. Her NF2 history is positive for a right optic nerve sheath meningioma, CNIII schwannoma requiring radiation therapy and post gross total resection of right frontotemporal anaplastic meningioma followed by radiation. At age 15 she developed new onset weight loss and …

Differential Spatial Gene And Protein Expression Associated With Recurrence Following Chemoradiation For Localized Anal Squamous Cell Cancer, Sharia Hernandez, Prajnan Das, Emma B Holliday, Li Shen, Wei Lu, Benny Johnson, Craig A Messick, Cullen M Taniguchi, John Skibber, Ethan B Ludmir, Y Nancy You, Grace Li Smith, Brian Bednarski, Larisa Kostousov, Eugene J Koay, Bruce D Minsky, Matthew Tillman, Shaelynn Portier, Cathy Eng, Albert C Koong, George J Chang, Wai Chin Foo, Jing Wang, Luisa Solis Soto, Van K Morris

Faculty, Staff and Student Publications

The identification of transcriptomic and protein biomarkers prognosticating recurrence risk after chemoradiation of localized squamous cell carcinoma of the anus (SCCA) has been limited by a lack of available fresh tissue at initial presentation. We analyzed archival FFPE SCCA specimens from pretreatment biopsies prior to chemoradiation for protein and RNA biomarkers from patients with localized SCCA who recurred (N = 23) and who did not recur (N = 25). Tumor cells and the tumor microenvironment (TME) were analyzed separately to identify biomarkers with significantly different expression between the recurrent and non-recurrent groups. Recurrent patients had higher mean protein expression of …

Hla Factors Versus Non-Hla Factors For Haploidentical Donor Selection, Rohtesh S Mehta, Kai Cao, Rima M Saliba, Gheath Al-Atrash, Amin M Alousi, Konstantinos Lontos, Curtis Marcoux, Yudith Carmazzi, Gabriela Rondon, Qaiser Bashir, Chitra M Hosing, Partow Kebriaei, Issa Khouri, David Marin, Yago Nieto, Betul Oran, Uday R Popat, Muzaffar H Qazilbash, Jeremy Ramdial, Katayoun Rezvani, Richard E Champlin, Elizabeth J Shpall

Faculty, Staff and Student Publications

When multiple haploidentical donors are available for transplantation, those of younger generations are generally selected over those of older generations. However, it is unclear who is the optimal donor when selecting candidates from within a generation, such as father versus mother, son versus daughter, or brother versus sister. Although traditionally male donors are favored over female donors, particularly for male recipients, and significant associations of individual HLA mis(matches) on outcomes are being increasingly recognized, the hierarchy of factors for donor selection is indeterminate. To assess whether HLA factors take precedence over non-HLA factors and to isolate the influence of specific …

Actin Cytoskeleton Vulnerability To Disulfide Stress Mediates Disulfidptosi, Xiaoguang Liu, Litong Nie, Yilei Zhang, Yuelong Yan, Chao Wang, Medina Colic, Kellen Olszewski, Amber Horbath, Xiong Chen, Guang Lei, Chao Mao, Shiqi Wu, Li Zhuang, Masha V Poyurovsky, M James You, Traver Hart, Daniel D Billadeau, Junjie Chen, Boyi Gan

Faculty, Staff and Student Publications

SLC7A11-mediated cystine uptake suppresses ferroptosis yet promotes cell death under glucose starvation; the nature of the latter cell death remains unknown. Here, we show that aberrant accumulation of intracellular disulfides in SLC7A11high cells under glucose starvation induces a previously uncharacterized form of cell death distinct from apoptosis or ferroptosis. We term this cell death disulfidptosis. Chemical proteomics and cell biological analyses showed that glucose starvation in SLC7A11high cells induces aberrant disulfide bonds in actin cytoskeleton proteins and F-actin collapse in a SLC7A11-dependent manner. CRISPR screens and functional studies revealed that inactivation of the WAVE regulatory complex (WRC, which promotes actin …

Ferroptosis In Life: To Be Or Not To Be, Ling Xu, Yu'e Liu, Xi Chen, Hua Zhong, Yi Wang

Faculty, Staff and Students Publications

Ferroptosis is a novel type of programmed cell death, characterized by a dysregulated iron metabolism and accumulation of lipid peroxides. It features the alteration of mitochondria and aberrant accumulation of excessive iron as well as loss of the cysteine-glutathione-GPX4 axis. Eventually, the accumulated lipid peroxides result in lethal damage to the cells. Ferroptosis is induced by the overloading of iron and the accumulation of ROS and can be inhibited by the activation of the GPX4 pathway, FS1-CoQ10 pathway, GCH1-BH4 pathway, and the DHODH pathway, it is also regulated by the oncogenes and tumor suppressors. Ferroptosis involves various physiological and pathological …

Deep Learning-Based Pathology Image Analysis Predicts Cancer Progression Risk In Patients With Oral Leukoplakia, Xinyi Zhang, Frederico O Gleber-Netto, Shidan Wang, Roberta Rayra Martins-Chaves, Ricardo Santiago Gomez, Nadarajah Vigneswaran, Arunangshu Sarkar, William N William, Vassiliki Papadimitrakopoulou, Michelle Williams, Diana Bell, Doreen Palsgrove, Justin Bishop, John V Heymach, Ann M Gillenwater, Jeffrey N Myers, Renata Ferrarotto, Scott M Lippman, Curtis Rg Pickering, Guanghua Xiao

Faculty, Staff and Student Publications

BACKGROUND: Oral leukoplakia (OL) is associated with an increased risk for oral cancer (OC) development. Prediction of OL cancer progression may contribute to decreased OC morbidity and mortality by favoring early intervention. Current OL progression risk assessment approaches face large interobserver variability and is weakly prognostic. We hypothesized that convolutional neural networks (CNN)-based histology image analyses could accelerate the discovery of better OC progression risk models.

METHODS: Our CNN-based oral mucosa risk stratification model (OMRS) was trained to classify a set of nondysplastic oral mucosa (OM) and a set of OC H&E slides. As a result, the OMRS model could …

The Tumor-Immune Ecosystem In Shaping Metastasis, Yang Gao, Jeffrey M Rosen, Xiang H-F Zhang

Faculty, Staff and Students Publications

A better understanding of the mechanisms regulating cancer metastasis is critical to develop new therapies and decrease mortality. Emerging evidence suggests that the interactions between tumor cells and the host immune system play important roles in establishing metastasis. Tumor cells are able to recruit immune cells, which in turn promotes tumor cell invasion, intravasation, survival in circulation, extravasation, and colonization in different organs. The tumor-host immunological interactions also generate a premetastatic niche in distant organs which facilitates metastasis. In this review, we summarize the recent findings on how tumor cells and immune cells regulate each other to coevolve and promote …

Excess Folic Acid Intake Increases Dna De Novo Point Mutations, Xuanye Cao, Jianfeng Xu, Ying L Lin, Robert M Cabrera, Qiuying Chen, Chaofan Zhang, John W Steele, Xiao Han, Steven S Gross, Bogdan J Wlodarczyk, James R Lupski, Wei Li, Hongyan Wang, Richard H Finnell, Yunping Lei

Faculty, Staff and Students Publications

No abstract provided.

The Tfiis N-Terminal Domain (Tnd): A Transcription Assembly Module At The Interface Of Order And Disorder, Katerina Cermakova, Vaclav Veverka, H Courtney Hodges

Faculty, Staff and Students Publications

Interaction scaffolds that selectively recognize disordered protein strongly shape protein interactomes. An important scaffold of this type that contributes to transcription is the TFIIS N-terminal domain (TND). The TND is a five-helical bundle that has no known enzymatic activity, but instead selectively reads intrinsically disordered sequences of other proteins. Here, we review the structural and functional properties of TNDs and their cognate disordered ligands known as TND-interacting motifs (TIMs). TNDs or TIMs are found in prominent members of the transcription machinery, including TFIIS, super elongation complex, SWI/SNF, Mediator, IWS1, SPT6, PP1-PNUTS phosphatase, elongin, H3K36me3 readers, the transcription factor MYC, and …

Uncovering Novel Regulators Of Memory Using C Elegans Genetic And Genomic Analysis, Katie L Brandel-Ankrapp, Rachel N Arey

Faculty, Staff and Students Publications

How organisms learn and encode memory is an outstanding question in neuroscience research. Specifically, how memories are acquired and consolidated at the level of molecular and gene pathways remains unclear. In addition, memory is disrupted in a wide variety of neurological disorders; therefore, discovering molecular regulators of memory may reveal therapeutic targets for these disorders. C. elegans are an excellent model to uncover molecular and genetic regulators of memory. Indeed, the nematode's invariant neuronal lineage, fully mapped genome, and conserved associative behaviors have allowed the development of a breadth of genetic and genomic tools to examine learning and memory. In …

Emerging Treatments For Myelodysplastic Syndromes: Biological Rationales And Clinical Translation, Juan Jose Rodriguez-Sevilla, Vera Adema, Guillermo Garcia-Manero, Simona Colla

Faculty, Staff and Student Publications

Myelodysplastic syndromes (MDSs) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized by myeloid dysplasia, peripheral blood cytopenias, and increased risk of progression to acute myeloid leukemia (AML). The standard of care for patients with MDS is hypomethylating agent (HMA)-based therapy; however, nearly 50% of patients have no response to the treatment. Patients with MDS in whom HMA therapy has failed have a dismal prognosis and no approved second-line therapy options, so enrollment in clinical trials of experimental agents represents these patients' only chance for improved outcomes. A better understanding of the molecular and biological mechanisms underpinning MDS …

Differential Regulation Of H3k9/H3k14 Acetylation By Small Molecules Drives Neuron-Fate-Induction Of Glioma Cell, Xincheng Liu, Cui Guo, Tiandong Leng, Zhen Fan, Jialuo Mai, Jiehong Chen, Jinhai Xu, Qianyi Li, Bin Jiang, Ke Sai, Wenzhuo Yang, Jiayu Gu, Jingyi Wang, Shuxin Sun, Zhijie Chen, Yingqian Zhong, Xuanming Liang, Chaoxin Chen, Jing Cai, Yuan Lin, Jiankai Liang, Jun Hu, Guangmei Yan, Wenbo Zhu, Wei Yin

Faculty, Staff and Student Publications

Differentiation therapy using small molecules is a promising strategy for improving the prognosis of glioblastoma (GBM). Histone acetylation plays an important role in cell fate determination. Nevertheless, whether histone acetylation in specific sites determines GBM cells fate remains to be explored. Through screening from a 349 small molecule-library, we identified that histone deacetylase inhibitor (HDACi) MS-275 synergized with 8-CPT-cAMP was able to transdifferentiate U87MG GBM cells into neuron-like cells, which were characterized by cell cycle arrest, rich neuron biomarkers, and typical neuron electrophysiology. Intriguingly, acetylation tags of histone 3 at lysine 9 (H3K9ac) were decreased in the promoter of multiple …

Endothelial-To-Osteoblast Transition In Normal Mouse Bone Development, Song-Chang Lin, Guoyu Yu, Yu-Chen Lee, Jian H Song, Xingzhi Song, Jianhua Zhang, Theocharis Panaretakis, Christopher J Logothetis, Yoshihiro Komatsu, Li-Yuan Yu-Lee, Guocan Wang, Sue-Hwa Lin

Faculty, Staff and Student Publications

Metastatic prostate cancer (PCa) in bone induces bone-forming lesions. We have previously shown that PCa-induced bone originates from endothelial cells (ECs) that have undergone EC-to-osteoblast (OSB) transition. Here, we investigated whether EC-to-OSB transition also occurs during normal bone formation. We developed an EC and OSB dual-color reporter mouse (DRM) model that marks EC-OSB hybrid cells with red and green fluorescent proteins. We observed EC-to-OSB transition (RFP and GFP co-expression) in both endochondral and intramembranous bone formation during embryonic development and in adults. Co-expression was confirmed in cells isolated from DRM. Bone marrow– and lung-derived ECs underwent transition to OSBs and …

Transcriptome, Proteome, And Protein Synthesis Within The Intracellular Cytomatrix, Tattym E Shaiken, Sandra L Grimm, Mohamad Siam, Amanda Williams, Abdol-Hossein Rezaeian, Daniel Kraushaar, Emily Ricco, Matthew J Robertson, Cristian Coarfa, Antrix Jain, Anna Malovannaya, Fabio Stossi, Antone R Opekun, Alyssa P Price, Julien Dubrulle

Faculty, Staff and Students Publications

Despite the knowledge that protein translation and various metabolic reactions that create and sustain cellular life occur in the cytoplasm, the structural organization within the cytoplasm remains unclear. Recent models indicate that cytoplasm contains viscous fluid and elastic solid phases. We separated these viscous fluid and solid elastic compartments, which we call the cytosol and cytomatrix, respectively. The distinctive composition of the cytomatrix included structural proteins, ribosomes, and metabolome enzymes. High-throughput analysis revealed unique biosynthetic pathways within the cytomatrix. Enrichment of biosynthetic pathways in the cytomatrix indicated the presence of immobilized biocatalysis. Enzymatic immobilization and segregation can surmount spatial impediments, …

Visualization Of Preimplantation Uterine Fluid Absorption In Mice Using Alexa Fluor™ 488 Hydrazide†, Yuehuan Li, Taylor Elijah Martin, Jonathan Matthew Hancock, Rong Li, Suvitha Viswanathan, John P Lydon, Yi Zheng, Xiaoqin Ye

Faculty, Staff and Students Publications

Uterine fluid plays important roles in supporting early pregnancy events and its timely absorption is critical for embryo implantation. In mice, its volume is maximum on day 0.5 post-coitum (D0.5) and approaches minimum upon embryo attachment ~D4.0. Its secretion and absorption in ovariectomized rodents were shown to be promoted by estrogen and progesterone (P4), respectively. The temporal mechanisms in preimplantation uterine fluid absorption remain to be elucidated. We have established an approach using intraluminally injected Alexa Fluor™ 488 Hydrazide (AH) in preimplantation control (RhoAf/f) and P4-deficient RhoAf/fPgrCre/+ mice. In control mice, bulk entry (seen as smeared cellular staining) via uterine …

In Vivo Gene Delivery Into Mouse Mammary Epithelial Cells Through Mammary Intraductal Injection, Wen Bu, Yi Li

Faculty, Staff and Students Publications

Mouse mammary glands comprise ductal trees, which are lined by epithelial cells and have one opening at the tip of each nipple. The epithelial cells play a major role in mammary gland function and are the origin of most mammary tumors. Introducing genes of interest into mouse mammary epithelial cells is a critical step in evaluating gene function in epithelial cells and generating mouse mammary tumor models. This goal can be accomplished through the intraductal injection of a viral vector carrying the genes of interest into the mouse mammary ductal tree. The injected virus subsequently infects mammary epithelial cells, bringing …

Post-Transcriptional Regulation In Cranial Neural Crest Cells Expands Developmental Potential, Rachel A Keuls, Young Sun Oh, Ivanshi Patel, Ronald J Parchem

Faculty, Staff and Students Publications

Developmental potential is progressively restricted after germ layer specification during gastrulation. However, cranial neural crest cells challenge this paradigm, as they develop from anterior ectoderm, yet give rise to both ectodermal derivatives of the peripheral nervous system and ectomesenchymal bone and cartilage. How cranial neural crest cells differentiate into multiple lineages is poorly understood. Here, we demonstrate that cranial neural crest cells possess a transient state of increased chromatin accessibility. We profile the spatiotemporal emergence of premigratory neural crest and find evidence of lineage bias toward either a neuronal or ectomesenchymal fate, with each expressing distinct factors from earlier stages …

Bone Metastasis Initiation Is Coupled With Bone Remodeling Through Osteogenic Differentiation Of Ng2+ Cells, Weijie Zhang, Zhan Xu, Xiaoxin Hao, Tiancheng He, Jiasong Li, Yichao Shen, Kai Liu, Yang Gao, Jun Liu, David G Edwards, Aaron M Muscarella, Ling Wu, Liqun Yu, Longyong Xu, Xi Chen, Yi-Hsuan Wu, Igor L Bado, Yunfeng Ding, Sergio Aguirre, Hai Wang, Zbigniew Gugala, Robert L Satcher, Stephen T C Wong, Xiang H-F Zhang

Faculty, Staff and Students Publications

The bone microenvironment is dynamic and undergoes remodeling in normal and pathologic conditions. Whether such remodeling affects disseminated tumor cells (DTC) and bone metastasis remains poorly understood. Here, we demonstrated that pathologic fractures increase metastatic colonization around the injury. NG2+ cells are a common participant in bone metastasis initiation and bone remodeling in both homeostatic and fractured conditions. NG2+ bone mesenchymal stem/stromal cells (BMSC) often colocalize with DTCs in the perivascular niche. Both DTCs and NG2+ BMSCs are recruited to remodeling sites. Ablation of NG2+ lineage impaired bone remodeling and concurrently diminished metastatic colonization. In cocultures, NG2+ BMSCs, especially when …

Short-Term Pi3k Inhibition Prevents Breast Cancer In Preclinical Models, Amy T Ku, Adelaide I J Young, Ahmed Atef Ibrahim, Wen Bu, Weiyu Jiang, Meng Lin, Laterrica C Williams, Bryant Lee Mccue, George Miles, Chandandeep Nagi, Fariba Behbod, Yi Li

Faculty, Staff and Students Publications

Antiestrogen medication is the only chemoprevention currently available for women at a high risk of developing breast cancer; however, antiestrogen therapy requires years to achieve efficacy and has adverse side effects. Therefore, it is important to develop an efficacious chemoprevention strategy that requires only a short course of treatment. PIK3CA is commonly activated in breast atypical hyperplasia, the known precancerous precursor of breast cancer. Targeting PI3K signaling in these precancerous lesions may offer a new strategy for chemoprevention. Here, we first established a mouse model that mimics the progression from precancerous lesions to breast cancer. Next, we demonstrated that a …

Lef1 Drives A Central Memory Program And Supports Antitumor Activity Of Natural Killer T Cells, Ho Ngai, Gabriel A Barragan, Gengwen Tian, Julien C Balzeau, Chunchao Zhang, Amy N Courtney, Linjie Guo, Xin Xu, Michael S Wood, Janice M Drabek, Thorsten Demberg, Caroline M Sands, Cynthia N Chauvin-Fleurence, Erica J Di Pierro, Jeffrey M Rosen, Leonid S Metelitsa

Faculty, Staff and Students Publications

Vα24-invariant natural killer T cells (NKT) possess innate antitumor properties that can be exploited for cancer immunotherapy. We have shown previously that the CD62L+ central memory-like subset of these cells drives the in vivo antitumor activity of NKTs, but molecular mediators of NKT central memory differentiation remain unknown. Here, we demonstrate that relative to CD62L- cells, CD62L+ NKTs express a higher level of the gene encoding the Wnt/β-catenin transcription factor lymphoid enhancer binding factor 1 (LEF1) and maintain active Wnt/β-catenin signaling. CRISPR/Cas9-mediated LEF1 knockout reduced CD62L+ frequency after antigenic stimulation, whereas Wnt/β-catenin activator Wnt3a ligand increased CD62L+ frequency. LEF1 overexpression …

Tissue-Resident Memory T Cells Trigger Rapid Exudation And Local Antibody Accumulation, Pamela C Rosato, Sahar Lotfi-Emran, Vineet Joag, Sathi Wijeyesinghe, Clare F Quarnstrom, Hanna N Degefu, Rebecca Nedellec, Jason M Schenkel, Lalit K Beura, Lars Hangartner, Dennis R Burton, David Masopust

Faculty, Staff and Student Publications

Adaptive immunity is didactically partitioned into humoral and cell-mediated effector mechanisms, which may imply that each arm is separate and does not function together. Here, we report that the activation of CD8+ resident memory T cells (TRM) in nonlymphoid tissues triggers vascular permeability, which facilitates rapid distribution of serum antibodies into local tissues. TRM reactivation was associated with transcriptional upregulation of antiviral signaling pathways as well as Fc receptors and components of the complement cascade. Effects were local, but evidence is presented that TRM in brain and reproductive mucosa are both competent to induce rapid antibody exudation. TRM reactivation in …

Fibrinogen-Like Protein 2: Its Biological Function Across Cell Types And The Potential To Serve As An Immunotherapy Target For Brain Tumors, Sheng Zhang, Ganesh Rao, Amy Heimberger, Shulin Li

Faculty, Staff and Student Publications

Brain tumors are among the 10 leading causes of cancer-related death and present unique treatment challenges due to their critical location, genetic heterogeneity, and the blood-brain barrier. Recent advances in targeted immunotherapy and immune checkpoint blocking therapy provide alternative therapeutic strategies for brain tumors. Fibrinogen-like protein 2 (FGL2), which induces transformation from low-grade glioma to high-grade glioblastoma, is a type II membrane protein that is highly expressed in both host immune cells and tumor cells. Studies have uncovered multiple forms of FGL2 proteins with a broad range of roles in inducing immune tolerance and avoiding immune surveillance in tumor cells. …

Sumoylation Regulates Functional Properties Of The Oocyte Transcription Factors Sohlh1 And Nobox, Bethany K Patton, Surabhi Madadi, Shawn M Briley, Avery A Ahmed, Stephanie A Pangas

Faculty, Staff and Students Publications

SOHLH1 and NOBOX are oocyte-expressed transcription factors with critical roles in ovary development and fertility. In mice, Sohlh1 and Nobox are essential for fertility through their regulation of the oocyte transcriptional network and cross-talk to somatic cells. Sumoylation is a posttranslational modification that regulates transcription factor function, and we previously showed that mouse oocytes deficient for sumoylation had an altered transcriptional landscape that included significant changes in NOBOX target genes. Here, we show that mouse SOHLH1 is modified by SUMO2/3 at lysine 345 and mutation of this residue alters SOHLH1 nuclear to cytoplasmic localization. In NOBOX, we identify a non-consensus …

Modeling Ewing Sarcoma Lung Metastasis, Atreyi Dasgupta, Lyazat Kurenbekova, Tajhal D Patel, Kimal Rajapakshe, Gargi Ghosal, Bikesh Nirala, Cristian Coarfa, Jason Yustein

Faculty, Staff and Students Publications

Ewing Sarcoma (EwS) is the second most common malignant bone tumor in adolescents and young adults. The single-most powerful predictor of outcome in EwS is presence of metastatic burden at the time of diagnosis. Patients with metastatic Ewing Sarcoma have an abysmal 5-year survival rate of 10–25%, which has not changed over the past 30–40 years. Thus, unraveling underlying mechanisms of EwS metastasis are imperative for developing effective therapeutic measures. Investigations towards this goal are limited by the lack of reliable genetically engineered mouse models and specialized metastatic models. Using two established cell lines, A673 and TC71, we generated lung …

Early Life Reprogramming-Based Treatment Promotes Longevity, Patrizia Pessina, Bruno Di Stefano

Faculty, Staff and Students Publications

Short-term expression of Yamanaka factors early in life promotes epigenetic reprogramming and an increased healthy lifespan in a mouse model of accelerated aging.

The Nlrp3 Inflammasome Fires Up Heme-Induced Inflammation In Hemolytic Conditions, Suruchi Salgar, Beatriz E Bolívar, Jonathan M Flanagan, Shaniqua J Anum, Lisa Bouchier-Hayes

Faculty, Staff and Students Publications

Overactive inflammatory responses are central to the pathophysiology of many hemolytic conditions including sickle cell disease. Excessive hemolysis leads to elevated serum levels of heme due to saturation of heme scavenging mechanisms. Extracellular heme has been shown to activate the NLRP3 inflammasome, leading to activation of caspase-1 and release of pro-inflammatory cytokines IL-1β and IL-18. Heme also activates the non-canonical inflammasome pathway, which may contribute to NLRP3 inflammasome formation and leads to pyroptosis, a type of inflammatory cell death. Some clinical studies indicate there is a benefit to blocking the NLRP3 inflammasome pathway in patients with sickle cell disease and …

Enhancer-Promoter Entanglement Explains Their Transcriptional Interdependence, Anil K Panigrahi, David M Lonard, Bert W O'Malley

Faculty, Staff and Students Publications

Enhancers not only activate target promoters to stimulate messenger RNA (mRNA) synthesis, but they themselves also undergo transcription to produce enhancer RNAs (eRNAs), the significance of which is not well understood. Transcription at the participating enhancer-promoter pair appears coordinated, but it is unclear why and how. Here, we employ cell-free transcription assays using constructs derived from the human GREB1 locus to demonstrate that transcription at an enhancer and its target promoter is interdependent. This interdependence is observable under conditions where direct enhancer-promoter contact (EPC) takes place. We demonstrate that transcription activation at a participating enhancer-promoter pair is dependent on i) …

Mixcan: A Framework For Cell-Type-Aware Transcriptome-Wide Association Studies With An Application To Breast Cancer, Xiaoyu Song, Jiayi Ji, Joseph H Rothstein, Stacey E Alexeeff, Lori C Sakoda, Adriana Sistig, Ninah Achacoso, Eric Jorgenson, Alice S Whittemore, Robert J Klein, Laurel A Habel, Pei Wang, Weiva Sieh

Faculty, Staff and Student Publications

Human bulk tissue samples comprise multiple cell types with diverse roles in disease etiology. Conventional transcriptome-wide association study approaches predict genetically regulated gene expression at the tissue level, without considering cell-type heterogeneity, and test associations of predicted tissue-level expression with disease. Here we develop MiXcan, a cell-type-aware transcriptome-wide association study approach that predicts cell-type-level expression, identifies disease-associated genes via combination of cell-type-level association signals for multiple cell types, and provides insight into the disease-critical cell type. As a proof of concept, we conducted cell-type-aware analyses of breast cancer in 58,648 women and identified 12 transcriptome-wide significant genes using MiXcan compared …

Hypoxia Truncates And Constitutively Activates The Key Cholesterol Synthesis Enzyme Squalene Monooxygenase, Hudson W Coates, Isabelle M Capell-Hattam, Ellen M Olzomer, Ximing Du, Rhonda Farrell, Hongyuan Yang, Frances L Byrne, Andrew J Brown

Faculty, Staff and Student Publications

Cholesterol synthesis is both energy- and oxygen-intensive, yet relatively little is known of the regulatory effects of hypoxia on pathway enzymes. We previously showed that the rate-limiting and first oxygen-dependent enzyme of the committed cholesterol synthesis pathway, squalene monooxygenase (SM), can undergo partial proteasomal degradation that renders it constitutively active. Here, we show hypoxia is a physiological trigger for this truncation, which occurs through a two-part mechanism: (1) increased targeting of SM to the proteasome via stabilization of the E3 ubiquitin ligase MARCHF6 and (2) accumulation of the SM substrate, squalene, which impedes the complete degradation of SM and liberates …

Generation Of A Tree Shrew Breast Cancer Model Using Lentivirus Expressing Pik3ca-H1047r, Li Zeng, Hong-Yan Zhang, Chuan-Yu Yang, Zhuo Cheng, Qiu-Yun Jiang, Yao Luo, Yi Li, Fu-Bing Li, Ce-Shi Chen

Faculty, Staff and Students Publications

No abstract provided.