Medical Biochemistry Commons^™

Kras Inhibitor That Simultaneously Inhibits Nucleotide Exchange Activity And Effector Engagement, Cynthia V Pagba, Amit K Gupta, Ali K Naji, Dharini Van Der Hoeven, Kelly Churion, Xiaowen Liang, Jacob Jakubec, Magnus Hook, Yan Zuo, Marisela Martinez De Kraatz, Jeffrey A Frost, Alemayehu A Gorfe

Faculty, Staff and Student Publications

We describe a small molecule ligand ACA-14 (2-hydroxy-5-{[(2-phenylcyclopropyl) carbonyl] amino} benzoic acid) as an initial lead for the development of direct inhibitors of KRAS, a notoriously difficult anticancer drug target. We show that the compound binds to KRAS near the switch regions with affinities in the low micromolar range and exerts different effects on KRAS interactions with binding partners. Specifically, ACA-14 impedes the interaction of KRAS with its effector Raf and reduces both intrinsic and SOS-mediated nucleotide exchange rates. Likely as a result of these effects, ACA-14 inhibits signal transduction through the MAPK pathway in cells expressing mutant KRAS and …

Unilateral ‘Crazy-Paving’ Pattern: An Exceptional Presentation Of Squamous Cell Carcinoma Of The Lung, Sumeera Banday, Shamim U Khan, Sabina Khan, Surinderpal S Anand, Ashok Shah

Faculty, Staff and Student Publications

The 'crazy-paving' pattern on high resolution computed tomography (HRCT) is a distinct imaging appearance that is still considered to be a radiological hallmark of pulmonary alveolar proteinosis. However, since its first description about three decades ago, more than 40 different clinical entities presenting as 'crazy-paving' patterns have been documented. This rather remarkable but uncommon imaging appearance is now considered to be a non-specific manifestation. A 62-year-old male referred for evaluation of productive cough, breathlessness and fever presented with 'crazy-paving' pattern on HRCT. Endobronchial biopsy done on presentation was consistent with the diagnosis of squamous cell carcinoma. This report highlights this …

Right Ventricular Energetic Biomarkers From 4d Flow Cmr Are Associated With Exertional Capacity In Pulmonary Arterial Hypertension, Xiaodan Zhao, Shuang Leng, Ru-San Tan, Ping Chai, Tee Joo Yeo, Jennifer Ann Bryant, Lynette L S Teo, Marielle V Fortier, Wen Ruan, Ting Ting Low, Ching Ching Ong, Shuo Zhang, Rob J Van Der Geest, John C Allen, Marina Hughes, Pankaj Garg, Teng Hong Tan, James W Yip, Ju Le Tan, Liang Zhong

Faculty, Staff and Student Publications

BACKGROUND: Cardiovascular magnetic resonance (CMR) offers comprehensive right ventricular (RV) evaluation in pulmonary arterial hypertension (PAH). Emerging four-dimensional (4D) flow CMR allows visualization and quantification of intracardiac flow components and calculation of phasic blood kinetic energy (KE) parameters but it is unknown whether these parameters are associated with cardiopulmonary exercise test (CPET)-assessed exercise capacity, which is a surrogate measure of survival in PAH. We compared 4D flow CMR parameters in PAH with healthy controls, and investigated the association of these parameters with RV remodelling, RV functional and CPET outcomes.

METHODS: PAH patients and healthy controls from two centers were prospectively …

Oral Nanomedicines For Sirna Delivery To Treat Inflammatory Bowel Disease, Jongyoon Shinn, Juyeon Lee, Seon Ah Lee, Seon Ju Lee, Ah Hyun Choi, Jung Seo Kim, Su Jin Kim, Hyo Jin Kim, Cherin Lee, Yejin Kim, Joohyeon Kim, Jonghee Choi, Byungchae Jung, Taeho Kim, Hyeontaek Nam, Hyungjun Kim, Yonghyun Lee

Faculty, Staff and Student Publications

RNA interference (RNAi) therapies have significant potential for the treatment of inflammatory bowel diseases (IBD). Although administering small interfering RNA (siRNA) via an oral route is desirable, various hurdles including physicochemical, mucus, and cellular uptake barriers of the gastrointestinal tract (GIT) impede both the delivery of siRNA to the target site and the action of siRNA drugs at the target site. In this review, we first discuss various physicochemical and biological barriers in the GI tract. Furthermore, we present recent strategies and the progress of oral siRNA delivery strategies to treat IBD. Finally, we consider the challenges faced in the …

Turning Nonselective Inhibitors Of Type I Protein Arginine Methyltransferases Into Potent And Selective Inhibitors Of Protein Arginine Methyltransferase 4 Through A Deconstruction-Reconstruction And Fragment-Growing Approach, Giulia Iannelli, Ciro Milite, Nils Marechal, Vincent Cura, Luc Bonnefond, Nathalie Troffer-Charlier, Alessandra Feoli, Donatella Rescigno, Yalong Wang, Alessandra Cipriano, Monica Viviano, Mark T Bedford, Jean Cavarelli, Sabrina Castellano, Gianluca Sbardella

Faculty, Staff and Student Publications

Protein arginine methyltransferases (PRMTs) are important therapeutic targets, playing a crucial role in the regulation of many cellular processes and being linked to many diseases. Yet, there is still much to be understood regarding their functions and the biological pathways in which they are involved, as well as on the structural requirements that could drive the development of selective modulators of PRMT activity. Here we report a deconstruction-reconstruction approach that, starting from a series of type I PRMT inhibitors previously identified by us, allowed for the identification of potent and selective inhibitors of PRMT4, which regardless of the low cell …

The Intricate Interplay Between Cancer Stem Cells And Cell-Of-Origin Of Cancer: Implications For Therapeutic Strategies, Luis Alberto Vega, Misu A Sanson, María Belén Cubria, Shrijana Regmi, Brittany J Shah, Samuel A Shelburne, Anthony R Flores

Faculty, Staff and Student Publications

Antimicrobial resistance-encoding mobile genetic elements (MGEs) may contribute to the disease potential of bacterial pathogens. We previously described the association of Group A Streptococcus (GAS) derived from invasive disease with increasingly frequent antimicrobial resistance (AMR). We hypothesized that a 65-kb AMR-encoding MGE (ICESpyM92), highly conserved among closely related emergent invasive emm92 GAS, contributes to GAS disease potential. Here, we provide evidence that a combination of ICESpyM92- and core genome-dependent differential gene expression (DGE) contributes to invasive disease phenotypes of emergent emm92 GAS. Using isogenic ICESpyM92 mutants generated in distinct emm92 genomic backgrounds, we determined the presence of ICESpyM92 enhances GAS …

Mettl14-Mediated Epitranscriptome Modification Of Mn1 Mrna Promote Tumorigenicity And All-Trans-Retinoic Acid Resistance In Osteosarcoma, Hong-Bo Li, Gang Huang, Jian Tu, Dong-Ming Lv, Qing-Lin Jin, Jun-Kai Chen, Yu-Tong Zou, Dung-Fang Lee, Jing-Nan Shen, Xian-Biao Xie

Faculty, Staff and Student Publications

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents. The molecular mechanism behind OS progression and metastasis remains poorly understood, which limits the effectiveness of current therapies. RNA N

METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS), dot blotting, and colorimetric ELISA were used to detect m

FINDINGS: We observed the abundance of m

INTERPRETATION: Our study revealed that METTL14 contributes to OS progression and ATRA resistance as an m

FUNDING: This work was supported by the National Natural Science Foundation of China (Grants 81972510 and 81772864).

Kalium Channelrhodopsins Are Natural Light-Gated Potassium Channels That Mediate Optogenetic Inhibition, Elena G Govorunova, Yueyang Gou, Oleg A Sineshchekov, Hai Li, Xiaoyu Lu, Yumei Wang, Leonid S Brown, François St-Pierre, Mingshan Xue, John L Spudich

Faculty, Staff and Student Publications

Channelrhodopsins are used widely for optical control of neurons, in which they generate photoinduced proton, sodium or chloride influx. Potassium (K+) is central to neuron electrophysiology, yet no natural K+-selective light-gated channel has been identified. Here, we report kalium channelrhodopsins (KCRs) from Hyphochytrium catenoides. Previously known gated potassium channels are mainly ligand- or voltage-gated and share a conserved K+-selectivity filter. KCRs differ in that they are light-gated and have independently evolved an alternative K+ selectivity mechanism. The KCRs are potent, highly selective of K+ over Na+, and open in less than 1 ms following photoactivation. The permeability ratio PK/PNa of …

Phosphatidylserine And Phosphatidylethanolamine Asymmetry Have A Negligible Effect On The Global Structure, Dynamics, And Interactions Of The Kras Lipid Anchor, Mussie K Araya, Alemayehu A Gorfe

Faculty, Staff and Student Publications

The intrinsically disordered C-terminus of the prominent oncogenic protein KRAS-4B (KRAS) selectively interacts and clusters with phosphatidylserine (PS) lipids in the plasma membrane (PM). This 11-residue segment, called tK, contains a polybasic domain (PBD) of six contiguous lysine residues and a farnesylated cysteine. Previous molecular dynamics (MD) simulation studies of tK in phosphatidylcholine (PC)/PS bilayers have suggested that backbone conformational dynamics modulate tK-PS interactions. These simulations have been conducted in symmetric membranes whereas the PM is compositionally asymmetric, with the inner leaflet, where KRAS is localized, being enriched with PS and phosphatidylethanolamine (PE) lipids. To examine if bilayer asymmetry affects …