Medicine and Health Sciences Commons^™

Impact Of Kras/Nras Mutational Heterogeneity On Clinical Outcomes In Colorectal Cancer, Jonathan M. Loree

Dissertations & Theses (Open Access)

Introduction: Mutations in KRAS/NRAS (RAS) predict a lack of benefit from anti-EGFR agents in metastatic colorectal cancer (mCRC). As next generation sequencing (NGS) has advanced, we are discovering atypical and low allele frequency mutations. We aimed to evaluate how NGS can optimally define RAS mutant CRC and the role of relative mutant allele frequency (rMAF) as a biomarker.

Methods: Using institutional and public cohorts of mCRC patients with NGS results, we described the prevalence and clinical impact of atypical (not in current guidelines) and low rMAF RAS mutations (RAS MAF by the MAF of the mutated gene with …

Hypotonia And Intellectual Disability Without Dysmorphic Features In A Patient With Pign-Related Disease., Isabelle Thiffault, Britton Zuccarelli, Holly Welsh, Xuan Yuan, Emily Farrow, Lee Zellmer, Neil Miller, Sarah Soden, Ahmed Abdelmoity, Robert A Brodsky, Carol Saunders

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Defects in the human glycosylphosphatidylinositol anchor biosynthetic pathway are associated with inherited glycosylphosphatidylinositol (GPI)-deficiencies characterized by a broad range of clinical phenotypes including multiple congenital anomalies, dysmorphic faces, developmental delay, hypotonia, and epilepsy. Biallelic variants in PIGN, encoding phosphatidylinositol-glycan biosynthesis class N have been recently associated with multiple congenital anomalies hypotonia seizure syndrome.

CASE PRESENTATION: Our patient is a 2 year old male with hypotonia, global developmental delay, and focal epilepsy. Trio whole-exome sequencing revealed heterozygous variants in PIGN, c.181G > T (p.Glu61*) and c.284G > A (p.Arg95Gln). Analysis of FLAER and anti-CD59 by flow-cytometry demonstrated a shift in this patient's …

Abl Kinase Regulation By Braf/Erk And Cooperation With Akt In Melanoma, Aditi Jain, Rakshamani Tripathi, Courtney P. Turpin, Chi Wang, Rina Plattner

Pharmacology and Nutritional Sciences Faculty Publications

The melanoma incidence continues to increase, and the disease remains incurable for many due to its metastatic nature and high rate of therapeutic resistance. In particular, melanomas harboring BRAF^V600E and PTEN mutations often are resistant to current therapies, including BRAF inhibitors (BRAFi) and immune checkpoint inhibitors. Abl kinases (Abl/Arg) are activated in melanomas and drive progression; however, their mechanism of activation has not been established. Here we elucidate a novel link between BRAF^V600E/ERK signaling and Abl kinases. We demonstrate that BRAF^V600E/ERK play a critical role in binding, phosphorylating and regulating Abl localization and Abl/Arg activation …

Zinc Transporters Ybtx And Znuabc Are Required For The Virulence Of Yersinia Pestis In Bubonic And Pneumonic Plague In Mice, Alexander G. Bobrov, Olga Kirillina, Marina Y. Fosso, Jacqueline D. Fetherston, M. Clarke Miller, Tiva T. Vancleave, Joseph A. Burlison, William K. Arnold, Matthew B. Lawrenz, Sylvie Garneau-Tsodikova, Robert D. Perry

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A number of bacterial pathogens require the ZnuABC Zinc (Zn²⁺) transporter and/or a second Zn²⁺ transport system to overcome Zn²⁺ sequestration by mammalian hosts. Previously we have shown that in addition to ZnuABC, Yersinia pestis possesses a second Zn²⁺ transporter that involves components of the yersiniabactin (Ybt), siderophore-dependent iron transport system. Synthesis of the Ybt siderophore and YbtX, a member of the major facilitator superfamily, are both critical components of the second Zn²⁺ transport system. Here we demonstrate that a ybtX znu double mutant is essentially avirulent in mouse models of bubonic and pneumonic …

Dysregulated Gpcr Signaling And Therapeutic Options In Uveal Melanoma., Vivian Chua, Dominic Lapadula, Clinita Randolph, Jeffrey L. Benovic, Philip B. Wedegaertner, Andrew E. Aplin

Department of Biochemistry and Molecular Biology Faculty Papers

Uveal melanoma is the most common primary intraocular malignant tumor in adults and arises from the transformation of melanocytes in the uveal tract. Even after treatment of the primary tumor, up to 50% of patients succumb to metastatic disease. The liver is the predominant organ of metastasis. There is an important need to provide effective treatment options for advanced stage uveal melanoma. To provide the preclinical basis for new treatments, it is important to understand the molecular underpinnings of the disease. Recent genomic studies have shown that mutations within components of G protein-coupled receptor (GPCR) signaling are early events associated …

Exome Analysis Of Rare And Common Variants Within The Nod Signaling Pathway., Gaia Andreoletti, Valentina Shakhnovich, Kathy Christenson, Tracy Coelho, Rachel Haggarty, Nadeem A. Afzal, Akshay Batra, Britt-Sabina Petersen, Matthew Mort, R Mark Beattie, Sarah Ennis

Manuscripts, Articles, Book Chapters and Other Papers

Pediatric inflammatory bowel disease (pIBD) is a chronic heterogeneous disorder. This study looks at the burden of common and rare coding mutations within 41 genes comprising the NOD signaling pathway in pIBD patients. 136 pIBD and 106 control samples underwent whole-exome sequencing. We compared the burden of common, rare and private mutation between these two groups using the SKAT-O test. An independent replication cohort of 33 cases and 111 controls was used to validate significant findings. We observed variation in 40 of 41 genes comprising the NOD signaling pathway. Four genes were significantly associated with disease in the discovery cohort …

The Fatty Acid Regulator Fadr Influences The Expression Of The Virulence Cascade In The El Tor Biotype Of Vibrio Cholerae By Modulating The Levels Of Toxt Via Two Different Mechanisms, Gabriela Kovacikova, Wei Lin, Ronald K. Taylor, Karen Skorupski

Dartmouth Scholarship

FadR is a master regulator of fatty acid (FA) metabolism that coordinates the pathways of FA degradation and biosynthesis in enteric bacteria. We show here that a ΔfadR mutation in the El Tor biotype of Vibrio cholerae prevents the expression of the virulence cascade by influencing both the transcription and the posttranslational regulation of the master virulence regulator ToxT. FadR is a transcriptional regulator that represses the expression of genes involved in FA degradation, activates the expression of genes involved in unsaturated FA (UFA) biosynthesis, and also activates the expression of two operons involved in saturated FA (SFA) biosynthesis. …

A Novel Compound-Heterozygous Epithelial Cell Adhesion Molecule Mutation In Tufting Enteropathy., Valentina Shakhnovich, Darrell Dinwiddie, Amber Hildreth, Thomas M. Attard, Stephen Kingsmore

Manuscripts, Articles, Book Chapters and Other Papers

No abstract provided.

Pathogenic Determinants And Mechanisms Of Als/Ftd Linked To Hexanucleotide Repeat Expansions In The C9orf72 Gene., Xinmei Wen, Thomas Westergard, Piera Pasinelli, Davide Trotti

Department of Neuroscience Faculty Papers

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two apparently distinct neurodegenerative diseases, the former characterized by selective loss of motor neurons in the brain and spinal cord and the latter characterized by selective atrophy of frontal and temporal lobes. Over the years, however, growing evidence from clinical, pathological and genetic findings has suggested that ALS and FTD belong to the same clinic-pathological spectrum disorder. This concept has been further supported by the identification of the most common genetic cause for both diseases, an aberrantly expanded hexanucleotide repeat GGGGCC/ CCCCGG sequence located in a non-coding region of the gene …

Development Of A New Real-Time Pcr Screening Kit For Hbs And Common Beta-Thalassemia Mutations Observed In Turkey, Derya Kan Karaer, Mehmet Ali̇ Ergün, Hati̇ce Ilgin Ruhi̇, Jale Öztürk, Hali̇l Kara, Deni̇z Rei̇soğlu Çakmak, Tali̇hanur Aydoğmuş, Ferda Emri̇ye Perçi̇n

Turkish Journal of Medical Sciences

Background/aim: IVSI-110 (G>A), IVSI-6 (T>C), IVSII-1 (G>A), IVSII-745 (C>G), IVSI-1 (G>A), and HbS are mutations covering 76% of all the β-globin mutations in the Turkish population. In this study, our aim is to develop a reliable, fast, real-time kit for these mutations using the TaqMan probe method. Materials and methods: This study included 100 individuals with beta-thalassemia or sickle cell anemia who had unknown mutations, and 21 controls with known mutations. Results: We designed a kit containing the IVSI-110 (G>A), IVSI-6 (T>C), IVSII-1 (G>A), IVSII-745 (C>G), IVSI-1 (G>A), and HbS …

Egfr, Kras, And Braf Mutational Profiles Of Female Patients With Micropapillary Predominant Invasive Lung Adenocarcinoma, Funda Demi̇rağ, Aydin Yilmaz, Ni̇lgün Yilmaz Demi̇rci̇, Ülkü Yilmaz, Yurdanur Erdoğan

Turkish Journal of Medical Sciences

Background/aim: This study aimed to analyze EGFR, KRAS, and BRAF mutations in females with micropapillary predominant invasive lung adenocarcinoma and their relationships with immunohistochemical and clinicopathological patterns.Materials and methods: A total of 15 females with micropapillary lung adenocarcinoma were selected. Mutational analysis of the EGFR, KRAS, and BRAF genes was carried out. Information regarding the demographic data, tumor size, treatment, and survival time for each patient was collated, and the predominant cell type, secondary architectural growth patterns, psammoma bodies, necrosis, and visceral pleural and angiolymphatic invasions were evaluated.Results: We identified EGFR mutation in six cases, KRAS mutation in three cases, …