Medicine and Health Sciences Commons^™

Single-Cell Gene Expression Analysis Identifies Chronic Alcohol-Mediated Shift In Hepatocyte Molecular States After Partial Hepatectomy., Sirisha Achanta, Aalap Verma, Ankita Srivastava, Harshavardhan Nilakantan, Jan B. Hoek, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The analysis of molecular states of individual cells, as defined by their mRNA expression profiles and protein composition, has gained widespread interest in studying biological phenomena ranging from embryonic development to homeostatic tissue function and genesis and evolution of cancers. Although the molecular content of individual cells in a tissue can vary widely, their molecular states tend to be constrained within a transcriptional landscape partly described by the canonical archetypes of a population of cells. In this study, we sought to characterize the effects of an acute (partial hepatectomy) and chronic (alcohol consumption) perturbation on the molecular states of individual …

The Structure And Regulation Of Cullin 2 Based E3 Ubiquitin Ligases And Their Biological Functions., Weijia Cai, Haifeng Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Cullin-RING E3 ubiquitin ligase complexes play a central role in targeting cellular proteins for ubiquitination-dependent protein turnover through 26S proteasome. Cullin-2 is a member of the Cullin family, and it serves as a scaffold protein for Elongin B and C, Rbx1 and various substrate recognition receptors to form E3 ubiquitin ligases.

MAIN BODY OF THE ABSTRACT: First, the composition, structure and the regulation of Cullin-2 based E3 ubiquitin ligases were introduced. Then the targets, the biological functions of complexes that use VHL, Lrr-1, Fem1b, Prame, Zyg-11, BAF250, Rack1 as substrate targeting subunits were described, and their involvement in diseases …

Cells Activated For Wound Repair Have The Potential To Direct Collective Invasion Of An Epithelium., Brigid M Bleaken, A Sue Menko, Janice Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mechanisms regulating how groups of cells are signaled to move collectively from their original site and invade surrounding matrix are poorly understood. Here we develop a clinically relevant ex vivo injury invasion model to determine whether cells involved in directing wound healing have invasive function and whether they can act as leader cells to direct movement of a wounded epithelium through a three-dimensional (3D) extracellular matrix (ECM) environment. Similar to cancer invasion, we found that the injured cells invade into the ECM as cords, involving heterotypical cell-cell interactions. Mesenchymal cells with properties of activated repair cells that typically locate to …

Hormone-Induced Calcium Oscillations Depend On Cross-Coupling With Inositol 1,4,5-Trisphosphate Oscillations., Lawrence D Gaspers, Paula J Bartlett, Antonio Politi, Paul Burnett, Walson Metzger, Jane Johnston, Suresh K Joseph, Thomas Höfer, Andrew P Thomas

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Receptor-mediated oscillations in cytosolic Ca(2+) concentration ([Ca(2+)]i) could originate either directly from an autonomous Ca(2+) feedback oscillator at the inositol 1,4,5-trisphosphate (IP3) receptor or as a secondary consequence of IP3 oscillations driven by Ca(2+) feedback on IP3 metabolism. It is challenging to discriminate these alternatives, because IP3 fluctuations could drive Ca(2+) oscillations or could just be a secondary response to the [Ca(2+)]i spikes. To investigate this problem, we constructed a recombinant IP3 buffer using type-I IP3 receptor ligand-binding domain fused to GFP (GFP-LBD), which buffers IP3 in the physiological range. This IP3 buffer slows hormone-induced [IP3] dynamics without changing steady-state …

Loss Of Miro1-Directed Mitochondrial Movement Results In A Novel Murine Model For Neuron Disease., Tammy T Nguyen, Sang S Oh, David Weaver, Agnieszka Lewandowska, Dane Maxfield, Max-Hinderk Schuler, Nathan K Smith, Jane Macfarlane, Gerald Saunders, Cheryl A Palmer, Valentina Debattisti, Takumi Koshiba, Stefan Pulst, Eva L Feldman, György Hajnóczky, Janet M Shaw

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Defective mitochondrial distribution in neurons is proposed to cause ATP depletion and calcium-buffering deficiencies that compromise cell function. However, it is unclear whether aberrant mitochondrial motility and distribution alone are sufficient to cause neurological disease. Calcium-binding mitochondrial Rho (Miro) GTPases attach mitochondria to motor proteins for anterograde and retrograde transport in neurons. Using two new KO mouse models, we demonstrate that Miro1 is essential for development of cranial motor nuclei required for respiratory control and maintenance of upper motor neurons required for ambulation. Neuron-specific loss of Miro1 causes depletion of mitochondria from corticospinal tract axons and progressive neurological deficits mirroring …

Chronic Arsenic Exposure And Angiogenesis In Human Bronchial Epithelial Cells Via The Ros/Mir-199a-5p/Hif-1Α/Cox-2 Pathway., Jun He, Min Wang, Yue Jiang, Qiudan Chen, Shaohua Xu, Qing Xu, Bing-Hua Jiang, Ling-Zhi Liu

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background: Environmental and occupational exposure to arsenic is a major public health concern. Although it has been identified as a human carcinogen, the molecular mechanism underlying the arsenic-induced carcinogenesis is not well understood.Objectives: We aimed to determine the role and mechanisms of miRNAs in arsenic-induced tumor angiogenesis and tumor growth.Methods: We utilized an in vitro model in which human lung epithelial BEAS-2B cells were transformed through long-term exposure to arsenic. A human xenograft tumor model was established to assess tumor angiogenesis and tumor growth in vivo. Tube formation assay and chorioallantoic membranes assay were used to assess tumor angiogenesis.Results: We …

Different Mechanisms Of Inflammation Induced In Virus And Autoimmune-Mediated Models Of Multiple Sclerosis In C57bl6 Mice., Abhinoy Kishore, Anurag Kanaujia, Soma Nag, A M Rostami, Lawrence C. Kenyon, Kenneth S Shindler, Jayasri Das Sarma

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the human central nervous system (CNS). Neurotropic demyelinating strain of MHV (MHV-A59 or its isogenic recombinant strain RSA59) induces MS-like disease in mice mediated by microglia, along with a small population of T cells. The mechanism of demyelination is at least in part due to microglia-mediated myelin stripping, with some direct axonal injury. Immunization with myelin oligodendrocyte glycoprotein (MOG) induces experimental autoimmune encephalomyelitis (EAE), a mainly CD4(+) T-cell-mediated disease, although CD8(+) T cells may play a significant role in demyelination. It is possible that both autoimmune and nonimmune mechanisms such as …

Proline-Rich Tyrosine Kinase 2 (Pyk2) Regulates Igf-I-Induced Cell Motility And Invasion Of Urothelial Carcinoma Cells, Marco Genua, Shi-Qiong Xu, Simone Buraschi, Stephen C. Peiper, Leonard G. Gomella, Antonio Belfiore, Renato V. Iozzo, Andrea Morrione

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The insulin-like growth factor receptor I (IGF-IR) plays an essential role in transformation by promoting cell growth and protecting cancer cells from apoptosis. We have recently demonstrated that the IGF-IR is overexpressed in invasive bladder cancer tissues and promotes motility and invasion of urothelial carcinoma cells. These effects require IGF-I-induced Akt- and MAPK-dependent activation of paxillin. The latter co-localizes with focal adhesion kinases (FAK) at dynamic focal adhesions and is critical for promoting motility of urothelial cancer cells. FAK and its homolog Proline-rich tyrosine kinase 2 (Pyk2) modulate paxillin activation; however, their role in regulating IGF-IR-dependent signaling and motility in …

P16/Rb Correlations In Oropharyngeal Squamous Cell Carcinoma (Oscc), Madalina Tuluc, Voichita Bar-Ad, David Cognetti

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The objective of this study is to explore the patterns of Rb expression in p16 positive and negative OSCC, in relation to patient's smoking history.

Aberrant Expression Of Cd56 On Granulocytes And Monocytes In Myeloproliferative Neoplasm And Myelodysplastic Syndrome, Ping Gong, Md, Fernanco Metrebian, Md, Alina Dulau-Florea, Md, Zi-Xuan Wang, Phd, Renu Bajaj, Phd, Stephen C Peiper, Jerald Z. Gong, Md

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Conclusions:

Aberrant CD56 expression on granulocytes is seen in all aubtypes MPN and high grade MDS. CD56 expression in MPN correlated with bone marrow morphology, BCR/ABL transcript, and bone marrow engraftment study following treatment. Identification of abnormal CD56+ granulocytes and monocytes is helpful in both the initial diagnosis and long-term follow up of patients with MPN and MDS.

Loss Of Retinoblastoma (Rb) Tumor Suppressor Expression In Breast Cancer Correlates With Better Response To Neoadjuvant Chemotherapy, Jeanne Mcfalls, Md, Jessica Kline, Ba, Gordon Schwartz, Md, Mba, Facs, Angieszka Witkiewicz, Md

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Conclusions:

Loss of RB tumor suppressor staining in pre-treatment breast cancer biopsies can be used prior to initiation of neoadjuvant chemotherapy to predict good tumor response. This association between RB loss and good neoadjuvant response holds regardless of ER status and across various chemotherapy regimens. Assessment of RB status in the pre-treatment biopsy could be useful clinical tool to define patients who are most likely to benefit from neoadjuvant chemotherapy.

Expression Of Stem Cell Marker Aldh1 In Cervical Intraepithelial Neoplasia, Ping Gong, Juan Palazzo, Md

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Conclusions:

Cervical dysplasia show positive staining for ALDH1 compared to normal cervical mucosa.

ALDH1 positive cells distribution parallels the dysplastic cells in cervical dysplasia.

CSC, as detected by ALDH1 expression, may play a role in the progression of cervical intraepithelial neoplasia and carcinogenesis.

P53 Expression In Oropharyngeal Squamous Cell Carcinoma In Increased In Hpv Positive Smokers, Madalina Tuluc, Voichita Bar-Ad, Zi-Xuan Wang, Joseph Curry

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background and Objectives

High risk HPV is associated with oropharyngeal SCC (OSCC) and is responsible for the increasing incidence of this cancer type among younger patients.

Patients with HPV positive oropharyngeal SCC have a better prognosis when compared with HPV negative, tobacco induced SCC.

HPV E6 inactivates p53 leading to low expression of p53; tobacco induced oropharyngeal SCC is characterized by p53 overexpression, resistance to treatment and poor prognosis. However, in many cases of HPV OSCC, there is a history of current or remote smoking, making this disease a multifactorial process. We expect that smoking will influence the level of …

Decorin Antagonizes The Angiogenic Network: Concurrent Inhibition Of Met, Hypoxia Inducible Factor 1Α, Vascular Endothelial Growth Factor A, And Induction Of Thrombospondin-1 And Timp3, Thomas Neill, Hannah Painter, Simone Buraschi, Rick T. Owens, Michael P. Lisanti, Liliana Schaefer, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Decorin, a small leucine-rich proteoglycan, inhibits tumor growth by antagonizing multiple receptor tyrosine kinases including EGFR and Met. Here, we investigated decorin during normoxic angiogenic signaling. An angiogenic PCR array revealed a profound decorin-evoked transcriptional inhibition of pro-angiogenic genes, such as HIF1A. Decorin evoked a reduction of hypoxia inducible factor (HIF)-1α and vascular endothelial growth factor A (VEGFA) in MDA-231 breast carcinoma cells expressing constitutively-active HIF-1α. Suppression of Met with decorin or siRNA evoked a similar reduction of VEGFA by attenuating downstream β-catenin signaling. These data establish a noncanonical role for β-catenin in regulating VEGFA expression. We found that exogenous …

Uterine Dysfunction In Biglycan And Decorin Deficient Mice Leads To Dystocia During Parturition., Zhiping Wu, Abraham W Aron, Elyse E Macksoud, Renato V Iozzo, Chi-Ming Hai, Beatrice E Lechner

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cesarean birth rates are rising. Uterine dysfunction, the exact mechanism of which is unknown, is a common indication for Cesarean delivery. Biglycan and decorin are two small leucine-rich proteoglycans expressed in the extracellular matrix of reproductive tissues and muscle. Mice deficient in biglycan display a mild muscular dystrophy, and, along with mice deficient in decorin, are models of Ehlers-Danlos Syndrome, a connective tissue anomaly associated with uterine rupture. As a variant of Ehlers-Danlos Syndrome is caused by a genetic mutation resulting in abnormal biglycan and decorin secretion, we hypothesized that biglycan and decorin play a role in uterine function. Thus, …

Graft Versus Host Disease Of The Brain Following Allogeneic Stem Cell Transplant For Myelodysplastic Syndrome, Janet Yoo, Lindsay Simon, Zi-Xuan Wang, Phd, Lawrence C. Kenyon

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Graft-versus-host disease (GVHD) is a frequent cause of morbidity and mortality following bone marrow transplantation (BMT). GVHD occurs when immune cells transplanted from a non-identical donor (the graft) recognize the transplant recipient (the host) as foreign, thereby initiating an immune reaction that causes disease in the transplant recipient. GVHD, which can present either acutely or chronically, typically involves the skin, gastrointestinal tract, and liver. In contrast, GVHD involving other organs such as the heart and kidney is highly uncommon and involvement of the central nervous system has only very rarely been described in the literature. We report an unusual case …

Blood-Brain Barrier Abnormalities Caused By Hiv-1 Gp120: Mechanistic And Therapeutic Implications., Jean-Pierre Louboutin, David S Strayer

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The blood-brain barrier (BBB) is compromised in many systemic and CNS diseases, including HIV-1 infection of the brain. We studied BBB disruption caused by HIV-1 envelope glycoprotein 120 (gp120) as a model. Exposure to gp120, whether acute [by direct intra-caudate-putamen (CP) injection] or chronic [using SV(gp120), an experimental model of ongoing production of gp120] disrupted the BBB, and led to leakage of vascular contents. Gp120 was directly toxic to brain endothelial cells. Abnormalities of the BBB reflect the activity of matrix metalloproteinases (MMPs). These target laminin and attack the tight junctions between endothelial cells and BBB basal laminae. MMP-2 and …

Mutant Tdp-43 In Motor Neurons Promotes The Onset And Progression Of Als In Rats, Cao Huang, Jianbin Tong, Fangfang Bi, Hongxia Zhou, Xu-Gang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Amyotrophic lateral sclerosis (ALS) is characterized by progressive motor neuron degeneration, which ultimately leads to paralysis and death. Mutation of TAR DNA binding protein 43 (TDP-43) has been linked to the development of an inherited form of ALS. Existing TDP-43 transgenic animals develop a limited loss of motor neurons and therefore do not faithfully reproduce the core phenotype of ALS. Here, we report the creation of multiple lines of transgenic rats in which expression of ALS-associated mutant human TDP-43 is restricted to either motor neurons or other types of neurons and skeletal muscle and can be switched on and off. …

Switches, Excitable Responses And Oscillations In The Ring1b/Bmi1 Ubiquitination System., Lan K Nguyen, Javier Muñoz-García, Helene Maccario, Aaron Ciechanover, Walter Kolch, Boris N Kholodenko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

In an active, self-ubiquitinated state, the Ring1B ligase monoubiquitinates histone H2A playing a critical role in Polycomb-mediated gene silencing. Following ubiquitination by external ligases, Ring1B is targeted for proteosomal degradation. Using biochemical data and computational modeling, we show that the Ring1B ligase can exhibit abrupt switches, overshoot transitions and self-perpetuating oscillations between its distinct ubiquitination and activity states. These different Ring1B states display canonical or multiply branched, atypical polyubiquitin chains and involve association with the Polycomb-group protein Bmi1. Bistable switches and oscillations may lead to all-or-none histone H2A monoubiquitination rates and result in discrete periods of gene (in)activity. Switches, overshoots …

Expression Of Cancer Stem Cell Biomarkers In Male Breast Cancer, Ping Gong, Md, Juan P. Palazzo, Md

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Male breast cancer is an uncommon disease, representing <1% of all breast cancer diagnoses. The prognostic factors and expression of molecular markers in male breast carcinomas are similar to female cancer. Cancer stem cell (CSC)s have been associated with tumor aggressiveness and drug resistance. CSCs are characterized by CD44 and/or ALDH1 expression. We investigated their expression in male breast cancer.

Role And Mechanism Of Arsenic In Regulating Angiogenesis., Ling-Zhi Liu, Yue Jiang, Richard L Carpenter, Yi Jing, Stephen C Peiper, Bing-Hua Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Arsenic is a wide spread carcinogen associated with several kinds of cancers including skin, lung, bladder, and liver cancers. Lung is one of the major targets of arsenic exposure. Angiogenesis is the pivotal process during carcinogenesis and chronic pulmonary diseases, but the role and mechanism of arsenic in regulating angiogenesis remain to be elucidated. In this study we show that short time exposure of arsenic induces angiogenesis in both human immortalized lung epithelial cells BEAS-2B and adenocarcinoma cells A549. To study the molecular mechanism of arsenic-inducing angiogenesis, we find that arsenic induces reactive oxygen species (ROS) generation, which activates AKT …

The Variable Presentations Of Anaplastic Spindle Cell Squamous Carcinoma Associated With Tall Cell Variant Of Papillary Thyroid Carcinoma., Pallavi P Gopal, Kathleen T Montone, Zubair Baloch, Madalina Tuluc, Virginia Livolsi

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: In 1976, Hawk and Hazard described the tall cell variant (TCV) of papillary thyroid carcinoma (PTC). While the lesions they described had cytologic features of papillary carcinoma, they showed more aggressive behavior with a greater propensity for extrathyroid extension and lymphovascular invasion than classic PTC. In 1991, Bronner and LiVolsi described a series of patients with TCV that progressed to spindle cell squamous carcinoma (SCSC), a unique form of anaplastic thyroid carcinoma. This study describes the variable clinical and pathologic presentations in 31 patients with anaplastic SCSC arising in association with TCV.

METHODS: The surgical pathology archives as well …

Mir-21 Induced Angiogenesis Through Akt And Erk Activation And Hif-1Α Expression., Ling-Zhi Liu, Chongyong Li, Qi Chen, Yi Jing, Richard Carpenter, Yue Jiang, Hsiang-Fu Kung, Lihui Lai, Bing-Hua Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

MicroRNAs (miRNAs) are endogenous, small noncoding RNAs that play important roles in various cellular functions and tumor development. Recent studies have indicated that miR-21 is one of the important miRNAs associated with tumor growth and metastasis, but the role and molecular mechanism of miR-21 in regulating tumor angiogenesis remain to be elucidated. In this study, miR-21 was overexpressed by transfecting pre-miR-21 into human prostate cancer cells and tumor angiogenesis was assayed using chicken chorioallantoic membrane (CAM). We found that overexpression of miR-21 in DU145 cells increased the expression of HIF-1α and VEGF, and induced tumor angiogenesis. AKT and extracellular regulated …

Fus Transgenic Rats Develop The Phenotypes Of Amyotrophic Lateral Sclerosis And Frontotemporal Lobar Degeneration., Cao Huang, Hongxia Zhou, Jianbin Tong, Han Chen, Yong-Jian Liu, Dian Wang, Xiaotao Wei, Xu-Gang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Fused in Sarcoma (FUS) proteinopathy is a feature of frontotemporal lobar dementia (FTLD), and mutation of the fus gene segregates with FTLD and amyotrophic lateral sclerosis (ALS). To study the consequences of mutation in the fus gene, we created transgenic rats expressing the human fus gene with or without mutation. Overexpression of a mutant (R521C substitution), but not normal, human FUS induced progressive paralysis resembling ALS. Mutant FUS transgenic rats developed progressive paralysis secondary to degeneration of motor axons and displayed a substantial loss of neurons in the cortex and hippocampus. This neuronal loss was accompanied by ubiquitin aggregation and …

Evidence-Based Genomic Diagnosis Characterized Chromosomal And Cryptic Imbalances In 30 Elderly Patients With Myelodysplastic Syndrome And Acute Myeloid Leukemia., Renu Bajaj, Fang Xu, Bixia Xiang, Katherine Wilcox, Autumn J Diadamo, Rachana Kumar, Alexandra Pietraszkiewicz, Stephanie Halene, Peining Li

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: To evaluate the clinical validity of genome-wide oligonucleotide array comparative genomic hybridization (aCGH) for detecting somatic abnormalities, we have applied this genomic analysis to 30 cases (13 MDS and 17 AML) with clonal chromosomal abnormalities detected in more than 50% of analyzed metaphase cells.

RESULTS: The aCGH detected all numerical chromosomal gains and losses from the mainline clones and 113 copy number alterations (CNAs) ranging from 0.257 to 102.519 megabases (Mb). Clinically significant recurrent deletions of 5q (involving the RPS14 gene), 12p12.3 (ETV6 gene), 17p13 (TP53 gene), 17q11.2 (NF1 gene) and 20q, double minutes containing the MYC gene and …

Transgenic Rat Model Of Neurodegeneration Caused By Mutation In The Tdp Gene., Hongxia Zhou, Cao Huang, Han Chen, Dian Wang, Carlisle P Landel, Pedro Yuxing Xia, Robert Bowser, Yong-Jian Liu, Xu Gang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

TDP-43 proteinopathies have been observed in a wide range of neurodegenerative diseases. Mutations in the gene encoding TDP-43 (i.e., TDP) have been identified in amyotrophic lateral sclerosis (ALS) and in frontotemporal lobe degeneration associated with motor neuron disease. To study the consequences of TDP mutation in an intact system, we created transgenic rats expressing normal human TDP or a mutant form of human TDP with a M337V substitution. Overexpression of mutant, but not normal, TDP caused widespread neurodegeneration that predominantly affected the motor system. TDP mutation reproduced ALS phenotypes in transgenic rats, as seen by progressive degeneration of motor neurons …

N-Glycosylation Status Of E-Cadherin Controls Cytoskeletal Dynamics Through The Organization Of Distinct Β-Catenin- And Γ-Catenin-Containing Ajs., Basem T Jamal, Mihai Nita-Lazar, Zhennan Gao, Bakr Amin, Janice Walker, Maria A Kukuruzinska

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

N-glycosylation of E-cadherin has been shown to inhibit cell-cell adhesion. Specifically, our recent studies have provided evidence that the reduction of E-cadherin N-glycosylation promoted the recruitment of stabilizing components, vinculin and serine/threonine protein phosphatase 2A (PP2A), to adherens junctions (AJs) and enhanced the association of AJs with the actin cytoskeleton. Here, we examined the details of how N-glycosylation of E-cadherin affected the molecular organization of AJs and their cytoskeletal interactions. Using the hypoglycosylated E-cadherin variant, V13, we show that V13/β-catenin complexes preferentially interacted with PP2A and with the microtubule motor protein dynein. This correlated with dephosphorylation of the microtubule-associated protein …

Intra-Tumor Heterogeneity Of Mlh1 Promoter Methylation Revealed By Deep Single Molecule Bisulfite Sequencing., Katherine E Varley, David G Mutch, Tina B Edmonston, Paul J Goodfellow, Robi D Mitra

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

A single tumor may contain cells with different somatic mutations. By characterizing this genetic heterogeneity within tumors, advances have been made in the prognosis, treatment and understanding of tumorigenesis. In contrast, the extent of epigenetic intra-tumor heterogeneity and how it influences tumor biology is under-explored. We have characterized epigenetic heterogeneity within individual tumors using next-generation sequencing. We used deep single molecule bisulfite sequencing and sample-specific DNA barcodes to determine the spectrum of MLH1 promoter methylation across an average of 1000 molecules in each of 33 individual samples in parallel, including endometrial cancer, matched blood and normal endometrium. This first glimpse, …

Nerve Injection Of Viral Vectors Efficiently Transfers Transgenes Into Motor Neurons And Delivers Rnai Therapy Against Als., Rui Wu, Hongyan Wang, Xugang Xia, Hongxia Zhou, Chunyan Liu, Maria Castro, Zuoshang Xu

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

RNA interference (RNAi) mediates sequence-specific gene silencing, which can be harnessed to silencing disease-causing genes for therapy. Particularly suitable diseases are those caused by dominant, gain-of-function type of gene mutations. In these diseases, the mutant gene generates a mutant protein or RNA product, which possesses toxic properties that harm cells. By silencing the mutant gene, the toxicity can be lessened because the amount of the toxic product is lowered in cells. In this report, we tested RNAi therapy in a mouse model for amyotrophic lateral sclerosis (ALS), which causes motor neuron degeneration, paralysis, and death. We used a transgenic model …

Positional Information Generated By Spatially Distributed Signaling Cascades., Javier Muñoz-García, Zoltan Neufeld, Boris N Kholodenko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The temporal and stationary behavior of protein modification cascades has been extensively studied, yet little is known about the spatial aspects of signal propagation. We have previously shown that the spatial separation of opposing enzymes, such as a kinase and a phosphatase, creates signaling activity gradients. Here we show under what conditions signals stall in the space or robustly propagate through spatially distributed signaling cascades. Robust signal propagation results in activity gradients with long plateaus, which abruptly decay at successive spatial locations. We derive an approximate analytical solution that relates the maximal amplitude and propagation length of each activation profile …