Life Sciences Commons^™

Identification Of The Phosphatase Nudt5 As A Target For The Treatment Of Triple Negative Breast Cancer, Jing Qian

Dissertations & Theses (Open Access)

Abstract

Background: Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer, characterized by the absence of estrogen receptor (ER) and progesterone receptor (PR) expression, as well as the lack of overexpression of the human epidermal growth factor receptor 2 (HER2). Unlike ER-positive and HER2-positive tumors that can be treated with hormone therapy or HER2-targeted treatment, respectively, triple-negative breast cancer (TNBC) poses a challenge with limited treatment alternatives for affected women. The currently FDA-approved systemic regimens for TNBC patients remain as conventional chemotherapy and PARP inhibitors (only applicable for a subset of BRCA-mutated TNBC patients). Consequently, our …

Dna Damage Response-Related Proteins Are Prognostic For Outcome In Both Adult And Pediatric Acute Myelogenous Leukemia Patients: Samples From Adults And From Children Enrolled In A Children's Oncology Group Study, Stefan E Hubner, Eduardo S De Camargo Magalhães, Fieke W Hoff, Brandon D Brown, Yihua Qiu, Terzah M Horton, Steven M Kornblau

Student and Faculty Publications

The survival of malignant leukemic cells is dependent on DNA damage repair (DDR) signaling. Reverse Phase Protein Array (RPPA) data sets were assembled using diagnostic samples from 810 adult and 500 pediatric acute myelogenous leukemia (AML) patients and were probed with 412 and 296 strictly validated antibodies, respectively, including those detecting the expression of proteins directly involved in DDR. Unbiased hierarchical clustering identified strong recurrent DDR protein expression patterns in both adult and pediatric AML. Globally, DDR expression was associated with gene mutational statuses and was prognostic for outcomes including overall survival (OS), relapse rate, and remission duration (RD). In …

Reverse Phase Protein Array Profiling Identifies Recurrent Protein Expression Patterns Of Dna Damage-Related Proteins Across Acute And Chronic Leukemia: Samples From Adults And The Children's Oncology Group, Fieke W Hoff, Ti'ara L Griffen, Brandon D Brown, Terzah M Horton, Jan Burger, William Wierda, Stefan E Hubner, Yihua Qiu, Steven M Kornblau

Student and Faculty Publications

DNA damage response (DNADR) recognition and repair (DDR) pathways affect carcinogenesis and therapy responsiveness in cancers, including leukemia. We measured protein expression levels of 16 DNADR and DDR proteins using the Reverse Phase Protein Array methodology in acute myeloid (AML) (n = 1310), T-cell acute lymphoblastic leukemia (T-ALL) (n = 361) and chronic lymphocytic leukemia (CLL) (n = 795) cases. Clustering analysis identified five protein expression clusters; three were unique compared to normal CD34+ cells. Individual protein expression differed by disease for 14/16 proteins, with five highest in CLL and nine in T-ALL, and by age in …

Cytosolic Dna Sensing Protein Pathway Is Activated In Human Hearts With Dilated Cardiomyopathy, Leila Rouhi, Sirisha M Cheedipudi, Benjamin Cathcart, Priyatansh Gurha, Ali J Marian

Student and Faculty Publications

INTRODUCTION: The genome is constantly exposed to numerous stressors, which induce DNA lesions, including double-stranded DNA breaks (DSBs). DSBs are the most dangerous, as they induce genomic instability. In response to DNA damage, the cell activates nuclear DNA damage response (DDR) and the cytosolic DNA sensing protein (CDSP) pathways, the latter upon release of the DSBs to the cytosol. The CDSP pathway activates NFκB and IRF3, which induce the expression of the pro-inflammatory genes. There is scant data on the activation of the CDSP pathway in human hearts with dilated cardiomyopathy (DCM).

AIM: We aimed to determine expression levels of …

Development Of The Ark Assay For Quantitating Dna- Protein Crosslink Accumulation And Fanconi Anemia Pathway Involvement In The Repair Process, Naeh Klages-Mundt

Dissertations & Theses (Open Access)

DNA-protein crosslinks (DPCs) are a common DNA lesion naturally arising in cells, wherein protein becomes covalently and irreversibly bound to the DNA. Given their excessive size, these adducts present a significant challenge to replication and transcription, thus requiring timely and efficient repair. However, the precise mechanisms involved with processing DPC removal remain unclear. Moreover, current methodologies to quantitate DPC accumulation and removal are restrained by a range of limitations. Here, we describe and discuss a new DPC detection assay – the ARK assay – capable of overcoming the limitations incurred by prior assays. The design, which uses dual chaotropic lysis …

Npsd4: A New Player In Sumo-Dependent Dna Repair, Erin Atkinson

Dissertations & Theses (Open Access)

The human genome is under constant threat from sources of damage and stress. Improper resolution of DNA damage lesions can lead to mutations, oncogene activation, and genomic instability. Difficult-to-replicate-loci present barriers to DNA replication that, when not properly resolved, lead to replication fork stalling and collapse and genomic instability.

DNA damage and replication stress trigger signaling cascades potentiated by multiple types of post-translational modifications, including SUMOylation. Through proteomic analysis of proteins involved in SUMOylation following DNA damage, our lab identified an uncharacterized protein that we named New Player in SUMO-dependent DNA damage repair 4 (NPSD4). Through an additional proteomic screen, …

Disruption Of Dna Polymerase Zeta Promotes An Innate Immune Response, Sara Martin

Dissertations & Theses (Open Access)

DNA polymerase ζ (pol ζ) is a specialized polymerase that protects cells from the consequences of DNA damage and stress. Without pol ζ function mammalian cells and yeast are exquisitely sensitive to genotoxic stresses including ultraviolet irradiation and platinum compounds such as the chemotherapeutic agent cisplatin. This elevated sensitivity arises from the central role of pol ζ in lesion bypass. Pol ζ is also required to protect cells from endogenous genomic damage or stress. In primary mammalian cells, the function of pol ζ is required for genome protection and normal proliferation. Immortalized Rev3lknockout (KO) MEFs are under considerable constitutive …

Mechanism Of Incorporation And Repair Of Uracil At Highly Transcribed Genes In Saccharomyces Cerevisiae, Norah Auma Owiti

Dissertations & Theses (Open Access)

Recombination and mutagenesis are elevated by high levels of transcription. The correlation between transcription and genome instability is largely explained by the topological and structural changes in DNA and the associated physical obstacles generated by the transcription machinery. However, such explanation does not directly account for the unique types of mutations originating from the non-canonical residues such as uracil, which are also elevated at highly transcribed regions. Apurinic/Apyrimic or Abasic (AP) sites derived from uracil excision, accumulate at a higher rate in actively transcribed regions of the genome in S. cerevisiae and are primarily repaired by base excision repair (BER) …

Investigation Of The Roles Of Asf1 And Caf-1-Mediated Chromatin Assembly In The Human Dna Damage Response, Ting-Hsiang Huang

Dissertations & Theses (Open Access)

The access-repair-restore model for the role of chromatin in DNA repair infers that chromatin is a mere obstacle to DNA repair. However, here we show that blocking chromatin assembly of newly-synthesized histones, via knockdown of the histone chaperones ASF1A, CAF-1 or a mutation that specifically prevents ASF1 binding to histones, hinders loading of Rad51 onto ssDNA during homologous recombination, as a consequence of reduced recruitment of the Rad51 loader MMS22L/TONSL to ssDNA, resulting in persistent RPA foci, extensive DNA end-resection, and persistent activation of the ATR-Chk1 pathway. By contrast, ASF1 and CAF-1 render the rapid inactivation of ATM Chk2 pathway …

The Roles Of Malt1 In Nf-Κb Activation And Solid Tumor Progression, Deng Pan

Dissertations & Theses (Open Access)

The transcription factor NF-κB plays a central role in many aspects of biological processes and diseases, such as inflammation and cancer. Although it has been suggested thatNF-κB is critical in tumorigenesis and tumor progression, the molecular mechanism by which NF-κB is activated in solid tumor remains largely unknown. In the current work, we focus on growth factor receptor-induced NF-κB activation and tumor progression, including epidermal growth factor receptor (EGFR)-induced NF-κB in lung cancer and heregulin receptor (HER2)-induced NF-κB in breast cancer. We found that Mucosa-associated lymphoma translocation protein 1 (MALT1), also known as paracaspase, is required for EGFR-induced NF-κB activation …

Brit1/Mcph1 Mediates The Dna Damage Response By Inducing P53 Stability And Promoting Atr Signaling, Edward Wang

Dissertations & Theses (Open Access)

The BRCT-repeat inhibitor of hTERT (BRIT1)/MCPH1 protein promotes the process of homologous recombination (HR) to repair DNA double strand breaks (DSBs). In response to DSBs, BRIT1 foci form at damaged sites, and recruits downstream repair proteins including 53BP1, MDC1, NBS1, and the SWI/SNF complex to the DSB region to promote DNA repair. BRIT1 copy number deficiency correlates with increased genomic instability in ovarian cancer specimens and breast cancer cell lines. Here, we propose that additional functions of BRIT1 include a direct interaction with the p53 tumor suppressor protein to promote p53 stability, and binding and recruitment of TopBP1 to sites …

Fancm And Faap24 Maintain Genomic Stability Through Cooperative And Unique Functions, Yucai Wang

Dissertations & Theses (Open Access)

Fanconi anemia (FA) is a rare recessive genetic disease with an array of clinical manifestations including multiple congenital abnormalities, progressive bone marrow failure and profound cancer susceptibility. A hallmark of cells derived from FA patients is hypersensitivity to DNA interstrand crosslinking agents such as mitomycin C (MMC) and cisplatin, suggesting that FA- and FA-associated proteins play important roles in protecting cells from DNA interstrand crosslink (ICL) damage. Two genes involved in the FA pathway, FANCM and FAAP24, are of particular interest because they contain DNA interacting domains. However, there are no definitive patient mutations for these two genes, and the …

Atm Signaling To Tsc2: Mechanisms And Implications For Cancer Therapy, Angela Alexander

Dissertations & Theses (Open Access)

Ataxia telangiectasia mutated (ATM) is a critical component of the cellular response to DNA damage, where it acts as a damage sensor, and signals to a large network of proteins which execute the important tasks involved in responding to the damage, namely inducing cell cycle checkpoints, inducing DNA repair, modulating transcriptional responses, and regulating cell death pathways if the damage cannot be repaired faithfully. We have now discovered that an additional novel component of this ATM-dependent damage response involves induction of autophagy in response to oxidative stress. In contrast to DNA damage-induced ATM activation however, oxidative stress induced ATM, occurs …

E2f1 And Tumor Suppression: The Role Of P21, Mirnas, And The Dna Damage Response, Regina L. Weaks

Dissertations & Theses (Open Access)

E2F1 is a multi-faceted protein that has roles in a number of important cellular processes including cell cycle regulation, apoptosis, proliferation, and the DNA damage response (DDR). Moreover, E2F1 has opposing roles in tumor development, acting as either a tumor suppressor or an oncogene depending on the context. In human cancer, E2F1 is often deregulated through aberrations in the Rb-p16INK4a-cyclin D1 pathway. In these studies we examined three mechanisms by which E2F1 might mediate its tumor suppressive properties: p21-induced senescence, miRNAs, and the DNA damage response. We found that E2F1 acts as a tumor suppressor in response to ras activation …