Chemicals and Drugs Commons^™

Alanyl-Trna Synthetase Quality Control Prevents Global Dysregulation Of The Escherichia Coli Proteome, Paul Kelly, Nicholas Backes, Kyle Mohler, Christopher Buser, Arundhati Kavoor, Jesse Rinehart, Gregory Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mechanisms have evolved to prevent errors in replication, transcription, and translation of genetic material, with translational errors occurring most frequently. Errors in protein synthesis can occur at two steps, during tRNA aminoacylation and ribosome decoding. Recent advances in protein mass spectrometry have indicated that previous reports of translational errors have potentially underestimated the frequency of these events, but also that the majority of translational errors occur during ribosomal decoding, suggesting that aminoacylation errors are evolutionarily less tolerated. Despite that interpretation, there is evidence that some aminoacylation errors may be regulated, and thus provide a benefit to the cell, while others …

A Systematic Comparison Of Lipopolymers For Sirna Delivery To Multiple Breast Cancer Cell Lines: In Vitro Studies, Hamidreza Montazeri Aliabadi, Remant Bahadur Kc, Emira Bousoik, Ashley Barbarino, Bindu Thapa, Melissa Coyle, Parvin Mahdipoor, Hasan Uludağ

Pharmacy Faculty Articles and Research

Small interfering RNA (siRNA) therapy is a promising approach for treatment of a wide range of cancers, including breast cancers that display variable phenotypic features. To explore the general utility of siRNA therapy to control aberrant expression of genes in breast cancer, we conducted a detailed analysis of siRNA delivery and silencing response in vitro in 6 separate breast cancer cell models (MDA-MB-231, MDA-MB-231-KRas-CRM, MCF-7, AU565, MDA-MB-435 and MDA-MB-468 cells). Using lipopolymers for siRNA complexation and delivery, we found a large variation in siRNA delivery efficiency depending on the specific lipopolymer used for siRNA complexation and delivery. Some lipopolymers were …

The Fitness Landscape Of The African Salmonella Typhimurium St313 Strain D23580 Reveals Unique Properties Of The Pbt1 Plasmid, Rocío Canals, Roy R. Chaudhuri, Rebecca E. Steiner, Siân V. Owen, Natalia Quinones-Olvera, Melita A. Gordon, Michael Baym, Michael Ibba, Jay C. D. Hinton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have used a transposon insertion sequencing (TIS) approach to establish the fitness landscape of the African Salmonella enterica serovar Typhimurium ST313 strain D23580, to complement our previous comparative genomic and functional transcriptomic studies. We used a genome-wide transposon library with insertions every 10 nucleotides to identify genes required for survival and growth in vitro and during infection of murine macrophages. The analysis revealed genomic regions important for fitness under two in vitro growth conditions. Overall, 724 coding genes were required for optimal growth in LB medium, and 851 coding genes were required for growth in SPI-2-inducing minimal medium. These …

Predicting Premature Birth Risk With Cfrna, Jason Lin, Jonathan Marin, John Santerre

SMU Data Science Review

Identifying which genes are early indicators for preterm births using cell-free ribonucleic acid (cfRNA) from non-invasive blood tests provided by pregnant women can improve prenatal care. Currently, there are no medical tests for early detection of preterm birth risk in routine checkups for pregnant women. Recent studies have shown potential genes that can predict preterm birth. Machine learning techniques are utilized to see if the Area Under the Curve (AUC) can be improved upon when evaluating the prediction accuracy for chosen genes sequences and concentrations. Using cell-free RNA data from non-invasive blood tests in conjunction with machine learning, we improve …

Evaluating The Therapeutic Efficacy Of Grb2 Inhibition In Ovarian Malignancies, Olivia Lara

Dissertations & Theses (Open Access)

Purpose: Adaptor proteins such as growth factor receptor-bound protein-2 (Grb2) play important roles in cancer cell signaling. In the present study, we examined the biological effects of liposomal antisense oligodeoxynucleotide that blocks Grb2 expression (L-Grb2) in ovarian cancer models.

Experimental Design: Murine orthotopic models of ovarian cancer (OVCAR5 and SKOV3ip1) were used to study the biological effects of L-Grb2 on tumor growth. In vitro experiments (cell viability assay, Western blot analysis, siRNA transfection, and reverse phase protein array) were carried out to elucidate the mechanism and potential predictors of tumor response to L-Grb2.

Results: Treatment with L-Grb2 decreased tumor growth …

Translational Control Of Antibiotic Resistance, Anne Witzky, Rodney Tollerson Ii, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Many antibiotics available in the clinic today directly inhibit bacterial translation. Despite the past success of such drugs, their efficacy is diminishing with the spread of antibiotic resistance. Through the use of ribosomal modifications, ribosomal protection proteins, translation elongation factors and mistranslation, many pathogens are able to establish resistance to common therapeutics. However, current efforts in drug discovery are focused on overcoming these obstacles through the modification or discovery of new treatment options. Here, we provide an overview for common mechanisms of resistance to translation-targeting drugs and summarize several important breakthroughs in recent drug development.

Nucleoside Analogues For Positron Emission Tomography Imaging And To Study Radiation Mediated Generation Of Radicals From Azides, Maria E. De Cabrera

FIU Electronic Theses and Dissertations

Gemcitabine is a potent anticancer cytidine analogue used to treat solid tumors. Its efficacy is diminished by rapid deamination to a toxic uridine derivative by cytidine deaminase. To overcome this limitation and add radioactive nuclei (¹⁸F or ⁶⁸Ga) for PET imaging, I synthesized two 4-N­-alkylgemcitabine analogues i) bearing β-keto tosylate moiety for subsequent ¹⁸F-fluorination and ii) having SCN-Bn-NOTA chelator to complex ⁶⁸Ga. The first was synthesized by replacement of tosylamide in 4-N­-tosylgemcitabine with 1-amino-10-undecene, followed by elaboration of terminal alkene through dihydroxylation, regioselective tosylation and oxidation. Subsequent fluorination using KF in …

Integration Of Random Forest Classifiers And Deep Convolutional Neural Networks For Classification And Biomolecular Modeling Of Cancer Driver Mutations, Steve Agajanian, Odeyemi Oluyemi, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Development of machine learning solutions for prediction of functional and clinical significance of cancer driver genes and mutations are paramount in modern biomedical research and have gained a significant momentum in a recent decade. In this work, we integrate different machine learning approaches, including tree based methods, random forest and gradient boosted tree (GBT) classifiers along with deep convolutional neural networks (CNN) for prediction of cancer driver mutations in the genomic datasets. The feasibility of CNN in using raw nucleotide sequences for classification of cancer driver mutations was initially explored by employing label encoding, one hot encoding, and embedding to …

A Robust Delivery System For Rna Therapeutics, Suleyman Bozal

University Scholar Projects

The field of RNA therapeutics is currently undergoing both transformation and expansion. Specifically, research in lipid nanoparticle (LNP) based RNA therapeutics is gaining significant traction. Other research into mechanisms of gene regulation and manipulation, including siRNA and the CRISPR/Cas9 system have demonstrated the potential of RNA-based disease treatment. This work identifies a delivery system which can regulate expression of green fluorescent protein (GFP) in human embryonic kidney cells (HEK293) stably expressing GFP.

Analysis of siRNA-induced gene knockdown demonstrates that the current siRNA-LNP formulation is equally as effective as a commercially available transfection reagent, Lipofectamine RNAiMAX (RNAiMAX), which is designed specifically …

A Robust Delivery System For Rna Therapeutics, Suleyman Bozal

Honors Scholar Theses

The field of RNA therapeutics is currently undergoing both transformation and expansion. Specifically, research in lipid nanoparticle (LNP) based RNA therapeutics is gaining significant traction. Other research into mechanisms of gene regulation and manipulation, including siRNA and the CRISPR/Cas9 system have demonstrated the potential of RNA-based disease treatment. This work identifies a delivery system which can regulate expression of green fluorescent protein (GFP) in human embryonic kidney cells (HEK293) stably expressing GFP.

Analysis of siRNA-induced gene knockdown demonstrates that the current siRNA-LNP formulation is equally as effective as a commercially available transfection reagent, Lipofectamine RNAiMAX (RNAiMAX), which is designed specifically …

Overcoming Degradation: A Novel Synthetic Strategy For Antisense Oligonucleotide Analogs, Annie Lin

Senior Honors Projects, 2010-2019

Antisense oligonucleotides (ASO) are single-stranded deoxyribonucleic acids that bind to mRNA to inhibit the synthesis of proteins that have been associated with the central mechanisms of disease development. Due to their gene silencing capabilities, the potential for ASOs as therapeutic agents is wide, but many toxicological challenges such as poor membrane permeability, low solubility, and rapid degradation by exonucleases must be overcome before ASO medications can be reliably utilized. In order to negate these challenges, the natural sugar- phosphate backbone of ASO’s, which is responsible for its rapid degradation, will be replaced by one that is hydrolytically stable. To do …

Effect Of Salt Concentration On Electrochemical Detection Of Dna, Ziming Dong, Eddie Madrigal, Ryan West Dr.

Creative Activity and Research Day - CARD

Electrochemical approaches for biological sensing offer the potential advantages of facile sample preparation, fast response times, ease of parallel and multiplexed measurements, and the possibility of miniaturization (of sample sizes, electrodes, and associated electronics). All of these factors contribute towards the feasibility of electrochemical methods in biological sensing and analysis. This potential has already been achieved with the commercialization of blood glucose meters, which often rely on an electrochemical transduction mechanism. We have previously demonstrated the ability to electrochemically detect and differentiate complementary and mismatched DNA using our method of melting DNA duplexes at electrified gold surfaces, i.e. e-melting. Recently, …

Saturated Fatty Acid Activates T Cell Inflammation Through A Nicotinamide Nucleotide Transhydrogenase (Nnt)-Dependent Mechanism, Grace Mccambridge, Madhur Agrawal, Alanna Keady, Philip A. Kern, Hatice Hasturk, Barbara S. Nikolajczyk, Leena P. Bharath

Honors Senior Capstone Projects

Circulating fatty acids (FAs) increase with obesity and can drive mitochondrial damage and inflammation. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial protein that positively regulates nicotinamide adenine dinucleotide phosphate (NADPH), a key mediator of energy transduction and redox homeostasis. The role that NNT-regulated bioenergetics play in the inflammatory response of immune cells in obesity is untested. Our objective was to determine how free fatty acids (FFAs) regulate inflammation through impacts on mitochondria and redox homeostasis of peripheral blood mononuclear cells (PBMCs). PBMCs from lean subjects were activated with a T cell-specific stimulus in the presence or absence of generally pro-inflammatory …

The Atpase Mechanism Of Uvra2 Reveals The Distinct Roles Of Proximal And Distal Atpase Sites In Nucleotide Excision Repair, Brandon C. Case, Silas Hartley, Memie Osuga, David Jeruzalmi, Manju M. Hingorani

Publications and Research

The UvrA2 dimer finds lesions in DNA and initiates nucleotide excision repair. Each UvrA monomer contains two essential ATPase sites: proximal (P) and distal (D). The manner whereby their activities enable UvrA2 damage sensing and response remains to be clarified. We report three key findings from the first pre-steady state kinetic analysis of each site. Absent DNA, a P2ATP-D2ADP species accumulates when the low-affinity proximal sites bind ATP and enable rapid ATP hydrolysis and phosphate release by the highaffinity distal sites, and ADP release limits catalytic turnover. Native DNA stimulates ATP hydrolysis by all four sites, causing UvrA2 to transition …

Itch Nuclear Translocation And H1.2 Polyubiquitination Negatively Regulate The Dna Damage Response, Lufen Chang, Lei Shen, Hu Zhou, Jing Gao, Hangyi Pan, Li Zheng, Brian Armstrong, Yang Peng, Guang Peng, Binhua P. Zhou, Steven T. Rosen, Binghui Shen

Molecular and Cellular Biochemistry Faculty Publications

The downregulation of the DNA damage response (DDR) enables aggressive tumors to achieve uncontrolled proliferation against replication stress, but the mechanisms underlying this process in tumors are relatively complex. Here, we demonstrate a mechanism through which a distinct E3 ubiquitin ligase, ITCH, modulates DDR machinery in triple-negative breast cancer (TNBC). We found that expression of a nuclear form of ITCH was significantly increased in human TNBC cell lines and tumor specimens. Phosphorylation of ITCH at Ser257 by AKT led to the nuclear localization of ITCH and ubiquitination of H1.2. The ITCH-mediated polyubiquitination of H1.2 suppressed RNF8/RNF168-dependent formation of 53BP1 foci, …

Toward An Enzyme-Coupled, Bioorthogonal Platform For Methyltransferases: Probing The Specificity Of Methionine Adenosyltransferases, Tyler D. Huber

Theses and Dissertations--Pharmacy

Methyl group transfer from S-adenosyl-l-methionine (AdoMet) to various substrates including DNA, proteins, and natural products (NPs), is accomplished by methyltransferases (MTs). Analogs of AdoMet, bearing an alternative S-alkyl group can be exploited, in the context of an array of wild-type MT-catalyzed reactions, to differentially alkylate DNA, proteins, and NPs. This technology provides a means to elucidate MT targets by the MT-mediated installation of chemoselective handles from AdoMet analogs to biologically relevant molecules and affords researchers a fresh route to diversify NP scaffolds by permitting the differential alkylation of chemical sites vulnerable to NP MTs that are unreactive to …

Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes, Kyle Rice

Theses and Dissertations (Comprehensive)

New strategies are urgently needed to combat infectious diseases in an era of rising antibiotic resistance. Furthermore, an emerging appreciation for the human microbiome’s role in maintaining health motivates discovery of species-specific antibiotics that minimally disrupt our native bacterial communities. Small molecule modifications to bacterial cell surfaces represent a potentially rich source of new targets for next generation antibiotics, as these molecules mediate virulence and evasion of the host immune response. Phosphocholine (PCho) is a rare cell surface modification that contributes to virulence, and modifications with phosphonates like 2-aminoethylphosphonate (AEP) are even more unusual and therefore provide opportunities for species- …