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Full-Text Articles in Life Sciences

The Phenomenon Of Multidrug Resistance In Glioblastomas, Alexandr N. Chernov, Diana A. Alaverdian, Elvira S. Galimova, Alessandra Renieri, Elisa Frullanti, Ilaria Meloni, Olga V. Shamova Jun 2022

The Phenomenon Of Multidrug Resistance In Glioblastomas, Alexandr N. Chernov, Diana A. Alaverdian, Elvira S. Galimova, Alessandra Renieri, Elisa Frullanti, Ilaria Meloni, Olga V. Shamova

Hematology/Oncology and Stem Cell Therapy

The most common and aggressive brain tumor in the adult population is glioblastoma (GBM). The lifespan of patients does not exceed 22 months. One of the reasons for the low effectiveness of GBM treatment is its radioresistance and chemoresistance. In the current review, we discuss the phenomenon of multidrug resistance of GBM in the context of the expression of ABC family transporter proteins and the mechanisms of proliferation, angiogenesis, and recurrence. We focused on the search of molecular targets among growth factors, receptors, signal transduction proteins, microRNAs, transcription factors, proto-oncogenes, tumor suppressor genes, and their single-nucleotide polymorphisms.


Differential Expression Of Cellular And Exosomal Microrna Isolated From Oral Cancer Cells And Their Resistance To Chemotherapy, Brady Petersen May 2022

Differential Expression Of Cellular And Exosomal Microrna Isolated From Oral Cancer Cells And Their Resistance To Chemotherapy, Brady Petersen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: MicroRNAs are abundant small non-coding RNA with a variety of known functions, including transcriptional activation and inhibition. Recent evidence has suggested that microRNA expression may influence the responsiveness of some cancers to chemotherapy, including liver and lung cancers. Some evidence has now suggested that specific microRNAs, such as miR-21, miR-155, and miR-375, may influence oral cancer responsiveness to chemotherapy – although much remains to be discovered.

Objective: Based upon the lack of evidence in this area, the primary objective of this study was to evaluate microRNA expression and responsiveness among oral cancers.

Methods: Five commercially available oral cancer cell …


Mutant Kras Alters Extracellular Vesicle Microrna Sorting In Pancreatic Cystic Neoplasms, Rachel L. Dittmar Dec 2021

Mutant Kras Alters Extracellular Vesicle Microrna Sorting In Pancreatic Cystic Neoplasms, Rachel L. Dittmar

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest cancers by organ site with a 5-year survival rate of just 10.8%. This is largely because most patients do not experience symptoms until the disease has already metastasized. The best hope to cure PDAC is surgery, which can only be done with a curative intent at an early stage when the disease is localized. There are no reliable circulating, body-fluid-based biomarkers to detect early stage PDAC or its precursor lesions in a timely manner for effective surgical intervention. When potential PDAC precursor lesions, such as mucinous pancreatic cysts are found, there are …


Targeting Epigenetic Mechanisms In Endometriosis, Sarah Elizabeth Brunty Jan 2021

Targeting Epigenetic Mechanisms In Endometriosis, Sarah Elizabeth Brunty

Theses, Dissertations and Capstones

Endometriosis is a complex and elusive gynecological disease in which the inner lining of the uterus grows in locations outside of the uterus and forms lesions. It is known to affect 1 in 9 women of reproductive age worldwide. Symptoms of endometriosis include severe pain, heavy periods, and infertility. While multiple theories of origin exist, none fully encompass all aspects of the disease, although all theories agree that this is an inflammation-driven disease. Due to this, many researchers are turning towards epigenetics to explain the initiation and progression of endometriosis. However, what is causing these epigenetic changes is still a …


Microrna In The Mammalian Growth Plate: Matrix Vesicles And 1Α,25-Dihydroxyvitamin D3, Niels C. Asmussen Jan 2021

Microrna In The Mammalian Growth Plate: Matrix Vesicles And 1Α,25-Dihydroxyvitamin D3, Niels C. Asmussen

Theses and Dissertations

Growth plate chondrocytes are the driving force of long bone elongation and they accomplish this vital task, in part, by producing, remodeling, and finally mineralizing the cartilage tissue that makes up the growth plate. This mineralized tissue is turned over again as bone forming cells invade and began the process of turning mineralized cartilage into bone. Chondrocytes undergo a distinct series of observable phases as they move through this process transitioning from a stage of proliferation to one of hypertrophy and finally capillary invasion. Chondrocytes produce matrix vesicles (MVs) that they release into the growth plate and that attach to …


Micrornas Associated With Melanoma Inflammation And Response To Pd-1 Inhibition, Robert Szczepaniak Sloane Dec 2020

Micrornas Associated With Melanoma Inflammation And Response To Pd-1 Inhibition, Robert Szczepaniak Sloane

Dissertations & Theses (Open Access)

Melanoma is an aggressive malignancy of melanocytes with historically poor outcomes. Melanoma therapy has improved markedly over the past decade with advances in molecularly targeted agents and immunotherapies. Immune checkpoint inhibitors achieve T-cell mediated anti-tumor efficacy by blocking engagement of inhibitory checkpoints on T-cells to overcome immunosuppressive signals from tumor cells and the broader microenvironment. Despite these advances, there are a significant proportion of patients who do not benefit from existing immunotherapy strategies making it a priority to identify and target the mechanisms that confer resistance to therapy. We demonstrate that microRNAs are accurate markers of microenvironment composition with prognostic …


Evaluating Biogenesis Of 5’-Tailed Mirtrons, Jonathan D. Hoover May 2020

Evaluating Biogenesis Of 5’-Tailed Mirtrons, Jonathan D. Hoover

Honors Theses

MicroRNAs are 22 nucleotide, non-coding RNAs that serve as substrates for Argonaute proteins to induce RNA interference pathways. Intron-derived miRNA precursors called “mirtrons” have been identified and classified primarily through deep sequencing methods. Unlike most miRNAs, mirtrons are derived from splicing events and also exhibit high levels of post-transcriptional nucleotide addition to hairpin precursors. Most relevant among these modifications is 3’ uridylation as it inhibits mirtron biogenesis in multiple model systems. Mirtrons may also possess additional nucleotides adjacent to the pre-miRNA hairpin at the 3’ and/or 5’ ends. These nucleotide “tails” are removed prior to Dicer cleaving the hairpin. In …


Profiling Of Small Non-Coding Rna In Bovine Somatic Cell Nuclear Transfer Embryos During Early Development Through The Maternal-To-Embryonic Transition, Abby D. Benninghoff, Jocelyn Cuthbert Apr 2020

Profiling Of Small Non-Coding Rna In Bovine Somatic Cell Nuclear Transfer Embryos During Early Development Through The Maternal-To-Embryonic Transition, Abby D. Benninghoff, Jocelyn Cuthbert

Browse all Datasets

Supplementary File 1. Read lengths and annotation summaries of sncRNA: Microsoft Excel document with information from small RNA sequencing on the aligned, annotated reads.

Supplementary File 2. Normalized and variance-stabilized values for annotated sncRNAs: Microsoft Excel document with normalized and variance-stabilized reads generated by RNA sequencing of small non-coding RNA from cattle embryos.

Supplementary File 3. Results of DESeq2 analyses for miRNAs, tRNA fragments and piRNAs: Microsoft Excel document with results of DESeq2 differential expression analysis comparing scNT vs IVF embryos at each developmental stage and sequential comparisons of developmental stage for both IVF and scNT embryos.

Supplementary File 4. …


Mapping Transcriptional Changes Associated With The Maternal-To-Embryonic Transition In Bovine Embryos To Small Non-Coding Rna Profiles In Both In Vitro-Fertilized And Scnt Cattle Embryos, Abby D. Benninghoff, Jocelyn Cuthbert Apr 2020

Mapping Transcriptional Changes Associated With The Maternal-To-Embryonic Transition In Bovine Embryos To Small Non-Coding Rna Profiles In Both In Vitro-Fertilized And Scnt Cattle Embryos, Abby D. Benninghoff, Jocelyn Cuthbert

Browse all Datasets

Supplementary File 1. Normalized reads for annotated mRNA transcripts. Microsoft Excel document providing normalized sequencing reads per sample.

Supplementary File 2. Results of DESeq2 analyses for annotated mRNAs. Microsoft Excel document with results of DESeq2 differential expression analysis comparing scNT vs IVF embryos at each developmental stage and sequential comparisons of developmental stage for both IVF and scNT embryos.

Supplementary File 3. Results of Metascape ontology analyses for differentially expressed mRNAs. Microsoft Excel document with results of Metascape ontology analyses for biological processes associated with predicted mRNA targets of differentially expressed miRNAs.

Supplementary File 4. Cytoscape networks for differentially expressed …


Microrna Expression Profiling Of Normal And Malignant Human Colonic Stem Cells Identifies, Vignesh Viswanathan, Lynn Opdenaker, Shirin Modarai, Jeremy Z Fields, Gregory Gonye, Bruce M Boman Apr 2020

Microrna Expression Profiling Of Normal And Malignant Human Colonic Stem Cells Identifies, Vignesh Viswanathan, Lynn Opdenaker, Shirin Modarai, Jeremy Z Fields, Gregory Gonye, Bruce M Boman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

MicroRNAs (miRNAs) have a critical role in regulating stem cells (SCs) during development, and because aberrant expression of miRNAs occurs in various cancers, our goal was to determine if dysregulation of miRNAs is involved in the SC origin of colorectal cancer (CRC). We previously reported that aldehyde dehydrogenase (ALDH) is a marker for normal and malignant human colonic SCs and tracks SC overpopulation during colon tumorigenesis. MicroRNA expression was studied in ALDH-positive SCs from normal and malignant human colon tissues by Nanostring miRNA profiling. Our findings show that: (1) A unique miRNA signature distinguishes ALDH-positive CRC cells from ALDH-positive normal …


Novel Roles Of Tobacco-Associated Genes Underlying Disparate Survival In Appalachian Head And Neck Squamous Cell Carcinoma, Brenen William Papenberg Jan 2020

Novel Roles Of Tobacco-Associated Genes Underlying Disparate Survival In Appalachian Head And Neck Squamous Cell Carcinoma, Brenen William Papenberg

Graduate Theses, Dissertations, and Problem Reports

Head and neck squamous cell carcinoma (HNSCC) is an aggressive neoplasm primarily caused by tobacco consumption or human papillomavirus (HPV) infection. Incidence and mortality rates for HNSCC vary geographically. Appalachian residents consume tobacco products to a greater extent than national averages, a risk factor known to promote HPV-negative HNSCC through increased genomic instability. Male Appalachian patients display significantly worse relative survival than Appalachian females or non-Appalachian residents of either sex. Secondary analysis of available cancer registry outcome data from 2007-2013 indicates that white males with stage IV oral cavity/pharyngeal (OC/P) HNSCC are responsible for the decreased male survival observed within …


The Influence Of Mir-322 On Skeletal Muscle Differentiation, Miles Alexander Soyer Aug 2019

The Influence Of Mir-322 On Skeletal Muscle Differentiation, Miles Alexander Soyer

Legacy Theses & Dissertations (2009 - 2024)

Skeletal muscle plays a crucial role in coordinating voluntary movement and accounts for nearly 50% of total body mass. Dysregulation in skeletal muscle development is known to cause muscle degenerative diseases including the devastating Duchenne Muscular Dystrophy (DMD). The majority of the biological studies investigating muscle development were based on myogenic transcription factors and signaling molecules including: Pax7, Myf5, MyoD, WNT, TGF-β and BMP. After the discovery of non-coding RNAs including microRNAs, it was postulated that these molecules could regulate gene expression and thus affect differentiation and development. MicroRNAs are small non-coding RNAs (~17-25 nucleotides) that regulate gene expression negatively …


Microrna Profiling And Engineering Of Cho Cell Lines Stably Expressing Difficult-To-Express Lysosomal Protein, Ifeanyi Amadi May 2019

Microrna Profiling And Engineering Of Cho Cell Lines Stably Expressing Difficult-To-Express Lysosomal Protein, Ifeanyi Amadi

KGI Theses and Dissertations

Difficult-to-express (DTE) recombinant proteins like multi-specific proteins, DTE monoclonal antibodies and lysosomal enzymes, have seen difficulties in manufacturability using Chinese hamster ovary (CHO) cells and other mammalian cells as production platforms. CHO cells are preferably used for protein production because of their innate ability to secrete human-like recombinant proteins with post-translational modification, resistance to viral infection and familiarity with drug regulators. However, despite huge progress made in engineering CHO cells for high volumetric productivity, expression of DTE proteins like recombinant lysosomal sulfatase represent one of the poorly understood proteins. Furthermore, there are growing interest in the use of microRNAs (miRNAs) …


The Molecular Mechanisms Underlying The Cancer Killing Effect Of Interleukin-24, Leah Eshanie Persaud May 2019

The Molecular Mechanisms Underlying The Cancer Killing Effect Of Interleukin-24, Leah Eshanie Persaud

Dissertations, Theses, and Capstone Projects

Interleukin-24 (IL-24) is an immunomodulatory cytokine that also displays specific anti-tumor effects across many cancer cell types. The tumor suppressor activities of IL-24 include inhibition of angiogenesis, metastasis, toxic autophagy, cancer-specific apoptosis, and sensitization to traditional cancer treatments like chemotherapy and radiation. Overexpression of IL-24 can selectively induce apoptosis in various cancer cells while having no adverse effects on normal cells. Due to this favorable killing effect, IL-24 is currently in phase II clinical trials. There is accumulating evidence that IL-24’s anti-cancer activity is primarily through the endoplasmic reticulum (ER) stress pathway but other pathways leading to cell death are …


The Role Of Ppal In The Moss Physcomitrella Patens., Noela M. Botaka May 2019

The Role Of Ppal In The Moss Physcomitrella Patens., Noela M. Botaka

College of Arts & Sciences Senior Honors Theses

Protein prenylation is a post-translational modification that involves the addition of lipid groups to the carboxy end of a target protein and is necessary for protein activity. Prenylation has important roles in the cell: targeting and localizing proteins to subcellular compartments and promoting protein-protein interactions. As a highly conserved process in eukaryotes, prenylation is especially important for plant development. In contrast to other eukaryotes, in which loss of prenylation components can be lethal, in the flowering plant Arabidopsis thaliana and the moss Physcomitrella patens, most are viable. Prior studies have shown that prenylation is involved in ABA hormone responses, …


Circular Rna Circhipk3 Promotes The Proliferation And Differentiation Of Chicken Myoblast Cells By Sponging Mir-30a-3p, Biao Chen, Jiao Yu, Lijin Guo, Mary Shannon Byers, Zhijun Wang, Xiaolan Chen, Haiping Xu, Qinghua Nie Feb 2019

Circular Rna Circhipk3 Promotes The Proliferation And Differentiation Of Chicken Myoblast Cells By Sponging Mir-30a-3p, Biao Chen, Jiao Yu, Lijin Guo, Mary Shannon Byers, Zhijun Wang, Xiaolan Chen, Haiping Xu, Qinghua Nie

Biology Student Research

Circular RNAs and microRNAs widely exist in various species and play crucial roles in multiple biological processes. It is essential to study their roles in myogenesis. In our previous sequencing data, both miR-30a-3p and circular HIPK3 (circHIPK3) RNA, which are produced by the third exon of the HIPK3 gene, were differentially expressed among chicken skeletal muscles at 11 embryo age (E11), 16 embryo age (E16), and 1-day post-hatch (P1). Here, we investigated their potential roles in myogenesis. Proliferation experiment showed that miR-30a-3p could inhibit the proliferation of myoblast. Through dual-luciferase assay and Myosin heavy chain (MYHC) immunofluorescence, we found that …


Microrna-4719 And Microrna-6756-5p Correlate With Castration-Resistant Prostate Cancer Progression Through Interleukin-24 Regulation, Dibash K. Das, Leah Persaud, Moira Sauane Jan 2019

Microrna-4719 And Microrna-6756-5p Correlate With Castration-Resistant Prostate Cancer Progression Through Interleukin-24 Regulation, Dibash K. Das, Leah Persaud, Moira Sauane

Publications and Research

Prostate cancer (PCa) is the second leading cause of cancer death in the United States. The five-year survival rate for men diagnosed with localized PCa is nearly 100%, yet for those diagnosed with aggressive PCa, it is less than 30%. The pleiotropic cytokine Interleukin-24 (IL-24) has been shown to specifically kill PCa cells compared to normal cells when overexpressed in both in vitro and in vivo studies. Despite this, the mechanisms regulating IL-24 in PCa are not well understood. Since specific microRNAs (miRNAs) are dysregulated in PCa, we used miRNA target prediction algorithm tools to identify miR-4719 and miR-6556-5p as …


Computational Analysis Of Genomic Variants Affecting Predicted Microrna:Target Interactions In Prostate Cancer., Angélica Paola Hernández Pérez Jul 2018

Computational Analysis Of Genomic Variants Affecting Predicted Microrna:Target Interactions In Prostate Cancer., Angélica Paola Hernández Pérez

KGI Theses and Dissertations

Prostate cancer (PCa) is the most common cancer of men in the United States and is third only to lung and colon as a cause of cancer death. Clinical behavior of the disease is variable and the combination of prostate-specific antigen (PSA) screening and Gleason score staging are currently the best available molecular and pathology tools to predict outcomes. Cancer biology research establishes microRNAs (miRNAs) as key molecular components in both normal and pathological states. Thus, elucidating miRNAs perturbed by genomic alterations will expand our understanding of the molecular taxonomy of PCa with the aim to complement current practices in …


Identification Of Regulatory Mirnas Associated With Ethanol-Induced Microglial Activation Using Integrated Proteomic And Transcriptomic Approaches, Brandi Jo Cook Mar 2018

Identification Of Regulatory Mirnas Associated With Ethanol-Induced Microglial Activation Using Integrated Proteomic And Transcriptomic Approaches, Brandi Jo Cook

USF Tampa Graduate Theses and Dissertations

Chronic consumption of, and acute intoxication from, alcohol can have profound effects on the functional integrity of the central nervous system (CNS). The resident immunomodulatory cells of the CNS, microglia, provide signaling factors with both pro- and anti-inflammatory effects for protection. Microglial activation ranges through a multiplex of phases, of which have yet to be defined when induced by exposure to alcohol, and how the activation impacts surrounding cells. Exposure of alcohol has been revealed to induce an immune response in microglia, which can exhibit characteristics unique to a pro-inflammatory response depending on dose and time of alcohol exposure. To …


Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell Dec 2017

Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell

Arts & Sciences Electronic Theses and Dissertations

Regulation of gene expression is essential to life. Post-transcriptional regulation of gene expression is a complex process with many inputs that lead to changes in localization, translation and stability of mRNAs. The translation and stability of many mRNAs is regulated by cis-elements, such as mRNA-structure or codon optimality; and by trans-acting factors such as RBPs and miRNAs. Here I report on the complex interactions between RBPs, miRNAs and characteristics of their target mRNAs in respect to effects on translation and RNA stability.

Using a reporter based approach we studied modulation of microRNA-mediated repression by various mRNA characteristics. We observed the …


Deletion Of Cardiac Mir-17-92 Cluster Increases Ischemia/ Reperfusion Injury Via Pten Upregulation, Meeta B. Prakash Jan 2017

Deletion Of Cardiac Mir-17-92 Cluster Increases Ischemia/ Reperfusion Injury Via Pten Upregulation, Meeta B. Prakash

Theses and Dissertations

The miR-17- 92 cluster is necessary for cell proliferation and development of the cardiovascular system. Deletion of this cluster leads to death in neonatal mice. The role of this cluster still needs to be defined following ischemia and reperfusion. Methods and Results: Adult male mice were injected with Tamoxifen- was to induce inducible cardiac-specific miR-17- 92-deficient (miR-17- 92-def: MCM:TG:miR-17- 92 flox/flox ) and wild type (WT: MCM:NTG:miR-17-92 flox/flox ) mice were subjected to 30 minutes of myocardial ischemia via left anterior descending coronary artery ligation followed by reperfusion for 24 hours. Post I/R survival (48%) and ejection fraction were reduced, …


Identifying The Effects Of Unprocessed Let-7a-1 And Let-7a-3 In Non-Small Cell Lung Cancer, Hana Kubo, Phillip J. Mccown, Andrea L. Kasinski Aug 2016

Identifying The Effects Of Unprocessed Let-7a-1 And Let-7a-3 In Non-Small Cell Lung Cancer, Hana Kubo, Phillip J. Mccown, Andrea L. Kasinski

The Summer Undergraduate Research Fellowship (SURF) Symposium

MicroRNAs (miRNAs) are small, noncoding RNAs that regulate protein levels typically by interacting with the 3′ untranslated region (3′-UTR) of target messenger RNA (mRNAs) and are often aberrantly expressed in cancer. The let-7 miRNA family members are commonly regarded as cancer suppressors, by down-regulating the expression of oncoproteins such as RAS, HMGA2, and MYC. However, prior work indicates that unprocessed let-7 RNAs may be positively correlated with cancer phenotypes in lung cancer cell lines. Our study aims to identify the effects of unprocessed let-7a-1 and let-7a-3 in non-small cell lung cancer, by transfecting plasmids that express unprocessed let-7a-1 and let-7a-3 …


Endothelial Hspa12b Is A Novel Protein For The Preservation Of Cardiovascular Function In Polymicrobial Sepsis Via Exosome Mir-126, Xia Zhang Aug 2016

Endothelial Hspa12b Is A Novel Protein For The Preservation Of Cardiovascular Function In Polymicrobial Sepsis Via Exosome Mir-126, Xia Zhang

Electronic Theses and Dissertations

Sepsis is the most frequent cause of mortality in most intensive care units. Cardiovascular dysfunction is a major complication associated with sepsis, with high mortality rates up to 70%. Currently, there is no effective treatment approach for sepsis.

The integrity of the endothelium is fundamental for the homeostasis of the cardiovascular system. Sepsis induces endothelial cell injury which is the key factor for multiple organ failure. The increased expression of adhesion molecules and chemokines in endothelial cell promotes leukocytes infiltration into the tissue. The loss of tight junction proteins and increased permeability of the endothelial cells will provoke tissue hypoxia …


The Uas-Gal4 System In D. Melanogaster: An Insight Into The Influence Of Micrornas On The Developmental Pathways Of The Wing, Emily R. Wilson May 2016

The Uas-Gal4 System In D. Melanogaster: An Insight Into The Influence Of Micrornas On The Developmental Pathways Of The Wing, Emily R. Wilson

Honors Theses

By examining genetic pathways in D. melanogaster, a better understanding of the homologous regulatory mechanisms in humans can be utilized to further enhance knowledge of the roles of microRNA within development. This study utilizes the UAS-Gal4 system in order to produce a mutant phenotype capable of being visually studied and analyzed, focusing on the developmental pathway of the wing in D. melanogaster. Dissections of the wandering third instar larvae yielded wing disc tissue expressing the downregulation of loquacious and CG17386.


Microrna-186 And Metastatic Prostate Cancer., Dominique Zilpha Jones May 2016

Microrna-186 And Metastatic Prostate Cancer., Dominique Zilpha Jones

Electronic Theses and Dissertations

MicroRNA (miR) dysregulation alters cancer-associated gene expression, which contributes to cancer pathogenesis. For example, miR-186 over expression lead to enhanced proliferation and migration in pancreatic cancer cell models. However, the role of miR-186 in prostate cancer (PCa) remains controversial. Previously, miR-186-5p was up-regulated in PCa patient serum (stage III/IV) compared to controls. Furthermore, miR-186-5p was up-regulated in metastatic PCa (PC-3, MDA PCa 2b, LNCaP) relative to normal prostate epithelial cells (RWPE1). We hypothesized miR-186 inhibition will reduce aggressive PCa using metastatic cell models. To test this, we evaluated whether miR-186-5p inhibition would reduce aggressive PCa behavior and overexpression induce malignant …


Staufen Negatively Modulates Microrna Activity In Caenorhabditis Elegans, Zhiji Ren, Isana Veksler-Lublinsky, David Morrissey, Victor Ambros Mar 2016

Staufen Negatively Modulates Microrna Activity In Caenorhabditis Elegans, Zhiji Ren, Isana Veksler-Lublinsky, David Morrissey, Victor Ambros

Victor R. Ambros

The double-stranded RNA-binding protein Staufen has been implicated in various post-transcriptional gene regulatory processes. Here we demonstrate that the Caenorhabditis elegans homolog of Staufen, STAU-1, functionally interacts with microRNAs. Loss-of-function mutations of stau-1 significantly suppress phenotypes of let-7 family microRNA mutants, a hypomorphic allele of dicer and a lsy-6 microRNA partial loss-of-function mutant. Furthermore, STAU-1 modulates the activity of lin-14, a target of lin-4 and let-7 family microRNAs, and this modulation is abolished when the 3' untranslated region of lin-14 is removed. Deep sequencing of small RNA cDNA libraries reveals no dramatic change in the levels of microRNAs, or other …


Caenorhabditis Elegans Alg-1 Antimorphic Mutations Uncover Functions For Argonaute In Microrna Guide Strand Selection And Passenger Strand Disposal, Anna Y. Zinovyeva, Isana Veksler-Lublinsky, Ajay A. Vashisht, James A. Wohlschlegel, Victor R. Ambros Oct 2015

Caenorhabditis Elegans Alg-1 Antimorphic Mutations Uncover Functions For Argonaute In Microrna Guide Strand Selection And Passenger Strand Disposal, Anna Y. Zinovyeva, Isana Veksler-Lublinsky, Ajay A. Vashisht, James A. Wohlschlegel, Victor R. Ambros

Victor R. Ambros

MicroRNAs are regulators of gene expression whose functions are critical for normal development and physiology. We have previously characterized mutations in a Caenorhabditis elegans microRNA-specific Argonaute ALG-1 (Argonaute-like gene) that are antimorphic [alg-1(anti)]. alg-1(anti) mutants have dramatically stronger microRNA-related phenotypes than animals with a complete loss of ALG-1. ALG-1(anti) miRISC (microRNA induced silencing complex) fails to undergo a functional transition from microRNA processing to target repression. To better understand this transition, we characterized the small RNA and protein populations associated with ALG-1(anti) complexes in vivo. We extensively characterized proteins associated with wild-type and mutant ALG-1 and found that the mutant …


Drosophila Let-7 Microrna Is Required For Remodeling Of The Neuromusculature During Metamorphosis, Nicholas S. Sokol, Peizhang Xu, Yuh-Nung Jan, Victor R. Ambros Oct 2015

Drosophila Let-7 Microrna Is Required For Remodeling Of The Neuromusculature During Metamorphosis, Nicholas S. Sokol, Peizhang Xu, Yuh-Nung Jan, Victor R. Ambros

Victor R. Ambros

The Drosophila let-7-Complex (let-7-C) is a polycistronic locus encoding three ancient microRNAs: let-7, miR-100, and fly lin-4 (miR-125). We find that the let-7-C locus is principally expressed in the pupal and adult neuromusculature. let-7-C knockout flies appear normal externally but display defects in adult behaviors (e.g., flight, motility, and fertility) as well as clear juvenile features in their neuromusculature. We find that the function of let-7-C to ensure the appropriate remodeling of the abdominal neuromusculature during the larval-to-adult transition is carried out predominantly by let-7 alone. This heterochronic role of let-7 is likely just one of the ways in which …


Effect Of Life History On Microrna Expression During C. Elegans Development, Xantha Karp, Molly Hammell, Maria C. Ow, Victor R. Ambros Oct 2015

Effect Of Life History On Microrna Expression During C. Elegans Development, Xantha Karp, Molly Hammell, Maria C. Ow, Victor R. Ambros

Victor R. Ambros

Animals have evolved mechanisms to ensure the robustness of developmental outcomes to changing environments. MicroRNA expression may contribute to developmental robustness because microRNAs are key post-transcriptional regulators of developmental gene expression and can affect the expression of multiple target genes. Caenorhabditis elegans provides an excellent model to study developmental responses to environmental conditions. In favorable environments, C. elegans larvae develop rapidly and continuously through four larval stages. In contrast, in unfavorable conditions, larval development may be interrupted at either of two diapause stages: The L1 diapause occurs when embryos hatch in the absence of food, and the dauer diapause occurs …


The Role Of Mir-526b In Cox-2 Mediated Human Breast Cancer Progression And Induction Of Stem-Like Phenotype Via Ep4 Receptor Signaling, Erin O. Landman Jun 2014

The Role Of Mir-526b In Cox-2 Mediated Human Breast Cancer Progression And Induction Of Stem-Like Phenotype Via Ep4 Receptor Signaling, Erin O. Landman

Electronic Thesis and Dissertation Repository

Our laboratory previously established that aberrant expression of cyclo-oxygenase (COX)-2 promotes breast cancer progression and metastasis via multiple mechanisms, including stem-like cell (SLC) induction, owing to activation of the prostaglandin E2 receptor EP4. COX-2 expression was linked to up-regulation of miRNA-526b. We hypothesized that miR-526b is regulated by EP4 activity, and that miR-526b supports breast cancer progression and induction of SLCs. Using stably miR-526b transfected MCF-7 and SKBR-3 cells in functional assays, including tumorsphere formation in vitro and lung colony formation in vivo, we observed enhanced migration, invasion, proliferation, tumorsphere formation, and in vivo tumorigenecity compared to controls. EP4 …