Publications by authors named "Victoria Yan"

Article Synopsis
  • * Recent studies indicate that human enolase 2 (ENO2) inhibitors, particularly a compound called HEX, show significant potential in targeting N. fowleri by blocking its glucose metabolism, making it toxic to these pathogens.
  • * While HEX treatment extended the survival of infected rodents significantly compared to untreated controls, it did not fully eradicate the amoebae in their brains, indicating a need for further research to optimize its use as a treatment for primary amoebic meningoencephalitis (PAM).
View Article and Find Full Text PDF

The relationship (or lack thereof) between the clinical activity of remdesivir and its ability to reduce viral titers in patients with COVID-19 has not been fully delineated. There is a misconception that remdesivir was FDA-approved for COVID-19 due to its ability to reduce viral titers. Here, we analyze all clinical studies of remedesivir in COVID-19 that quantifed SARS-CoV-2 titers.

View Article and Find Full Text PDF

Infections with the pathogenic free-living amoebae can lead to life-threatening illnesses including catastrophic primary amebic meningoencephalitis (PAM). Efficacious treatment options for these infections are lacking and the mortality rate remains >95% in the US. Glycolysis is very important for the infectious trophozoite lifecycle stage and inhibitors of glucose metabolism have been found to be toxic to the pathogen.

View Article and Find Full Text PDF

Glucose metabolism is critical for the African trypanosome, , serving as the lone source of ATP production for the bloodstream form (BSF) parasite in the glucose-rich environment of the host blood. Recently, phosphonate inhibitors of human enolase (ENO), the enzyme responsible for the interconversion of 2-phosphoglycerate (2-PG) to phosphoenolpyruvate (PEP) in glycolysis or PEP to 2-PG in gluconeogenesis, have been developed for the treatment of glioblastoma multiforme (GBM). Here, we have tested these agents against ENO (ENO) and found the compounds to be potent enzyme inhibitors and trypanocides.

View Article and Find Full Text PDF

Tumor angiogenesis is a cancer hallmark, and its therapeutic inhibition has provided meaningful, albeit limited, clinical benefit. While anti-angiogenesis inhibitors deprive the tumor of oxygen and essential nutrients, cancer cells activate metabolic adaptations to diminish therapeutic response. Despite these adaptations, angiogenesis inhibition incurs extensive metabolic stress, prompting us to consider such metabolic stress as an to therapies targeting cancer metabolism.

View Article and Find Full Text PDF

Metabolically labile prodrugs can experience stark differences in catabolism incurred by the chosen route of administration. This is especially true for phosph(on)ate prodrugs, in which successive promoiety removal transforms a lipophilic molecule into increasingly polar compounds. We previously described a phosphonate inhibitor of enolase (HEX) and its bis-pivaloyloxymethyl ester prodrug (POMHEX) capable of eliciting strong tumor regression in a murine model of enolase 1 ()-deleted glioblastoma following parenteral administration.

View Article and Find Full Text PDF

Feline infectious peritonitis (FIP) is a fatal disease of cats that currently lacks licensed and affordable vaccines or antiviral therapeutics. The disease has a spectrum of clinical presentations including an effusive ("wet") form and non-effusive ("dry") form, both of which may be complicated by neurologic or ocular involvement. The feline coronavirus (FCoV) biotype, termed feline infectious peritonitis virus (FIPV), is the etiologic agent of FIP.

View Article and Find Full Text PDF
Article Synopsis
  • Cancers with a specific enzyme deletion (ENO1) are sensitive to treatment targeting a related enzyme (ENO2).
  • Previous studies showed promise with a specific inhibitor (HEX) that can shrink tumors in certain models of glioblastoma.
  • This research aimed to find better prodrug options (forms that release the active drug) for ENO2 inhibition, assessing different types that could be more effective and stable in the bloodstream.
View Article and Find Full Text PDF

Biomolecular condensation has emerged as a key organizing principle governing the formation of membraneless cellular assemblies. Revealing the mechanism of formation of biomolecular condensates requires the quantitative examination of their growth kinetics. Here, we introduce mass balance imaging (MBI) as a general method to study compositional growth dynamics based on fluorescent images of multicomponent clusters.

View Article and Find Full Text PDF

A key event at the onset of development is the activation of a contractile actomyosin cortex during the oocyte-to-embryo transition. Here we report on the discovery that, in Caenorhabditis elegans oocytes, actomyosin cortex activation is supported by the emergence of thousands of short-lived protein condensates rich in F-actin, N-WASP and the ARP2/3 complex that form an active micro-emulsion. A phase portrait analysis of the dynamics of individual cortical condensates reveals that condensates initially grow and then transition to disassembly before dissolving completely.

View Article and Find Full Text PDF

The phosphonate group is a key pharmacophore in many antiviral, antimicrobial, and antineoplastic drugs. Due to its high polarity and short retention time, detecting and quantifying such phosphonate-containing drugs with LC/MS-based methods are challenging and require derivatization with hazardous reagents. Given the emerging importance of phosphonate-containing drugs, developing a practical, accessible, and safe method for their quantitation in pharmacokinetics (PK) studies is desirable.

View Article and Find Full Text PDF

Remdesivir (GS-5734) is a monophenol, 2-ethylbutylalanine phosphoramidate prodrug of GS-441524 that is FDA-approved for the treatment of patients hospitalized for COVID-19. Despite showing strong, broad-spectrum antiviral activity in preclinical models, the clinical efficacy of remdesivir is mixed. This work highlights the pharmacodynamic discordance of remdesivir between humans and non-human primates, thereby demonstrating that non-human primate disease models overestimate the therapeutic efficacy of phosphoramidate prodrugs.

View Article and Find Full Text PDF

Accelerated glycolysis is the main metabolic change observed in cancer, but the underlying molecular mechanisms and their role in cancer progression remain poorly understood. Here, we show that the deletion of the long noncoding RNA (lncRNA) Neat1 in MMTV-PyVT mice profoundly impairs tumor initiation, growth, and metastasis, specifically switching off the penultimate step of glycolysis. Mechanistically, NEAT1 directly binds and forms a scaffold bridge for the assembly of PGK1/PGAM1/ENO1 complexes and thereby promotes substrate channeling for high and efficient glycolysis.

View Article and Find Full Text PDF

Glycolysis controls cellular energy, redox balance, and biosynthesis. Antiglycolytic therapies are under investigation for treatment of obesity, cancer, aging, autoimmunity, and microbial diseases. Interrupting glycolysis is highly valued as a therapeutic strategy, because glycolytic disruption is generally tolerated in mammals.

View Article and Find Full Text PDF

Remdesivir is a nucleoside monophosphoramidate prodrug that has been FDA approved for coronavirus disease 2019 (COVID-19). However, the clinical efficacy of remdesivir for COVID-19 remains contentious, as several trials have not found statistically significant differences in either time to clinical improvement or mortality between remdesivir-treated and control groups. Similarly, the inability of remdesivir to provide a clinically significant benefit above other investigational agents in patients with Ebola contrasts with strong, curative preclinical data generated in rhesus macaque models.

View Article and Find Full Text PDF

Homozygous deletion of methylthioadenosine phosphorylase (MTAP) in cancers such as glioblastoma represents a potentially targetable vulnerability. Homozygous MTAP-deleted cell lines in culture show elevation of MTAP's substrate metabolite, methylthioadenosine (MTA). High levels of MTA inhibit protein arginine methyltransferase 5 (PRMT5), which sensitizes MTAP-deleted cells to PRMT5 and methionine adenosyltransferase 2A (MAT2A) inhibition.

View Article and Find Full Text PDF

Despite being FDA-approved for COVID-19, the clinical efficacy of remdesivir (Veklury) remains contentious. We previously pointed out pharmacokinetic, pharmacodynamic and toxicology reasons for why its parent nucleoside GS-441524, is better suited for COVID-19 treatment. Here, we assess the oral bioavailability of GS-441524 in beagle dogs and show that plasma concentrations ~24-fold higher than the EC against SARS-CoV-2 are easily and safely sustained.

View Article and Find Full Text PDF

Although many components of the cell division machinery in bacteria have been identified, the mechanisms by which they work together to divide the cell remain poorly understood. Key among these components is the tubulin FtsZ, which forms a Z ring at the midcell. FtsZ recruits the other cell division proteins, collectively called the divisome, and the Z ring constricts as the cell divides.

View Article and Find Full Text PDF