Biology subjects

Ong, V.

Publications and source records attributed to Ong, V..

5 recordsLinked to original sources

bioRxiv2026

A Novel Drug Candidate that Selectively Targets the Critical Androgen Receptor-ELK1 Growth Axis in Advanced and Drug-Resistant Prostate Cancer

Androgen receptor (AR)-dependent prostate cancer (PCa) cells require co-activation of ELK1 by AR to activate a critical set of cell cycle and mitosis genes, regardless of hormone - sensitivity. A small molecule antagonist (KCI807) that inhibits AR-dependent growth by selectively binding to AR and blocking its association with ELK1 is limited as a drug by auto-induced metabolism. Using structure-activity data, consistent with modeling a physically mapped KCI807 binding pocket, we developed a new class of compounds with a different core structure comprising 5-Hydroxy-2-(3-hydroxyphenyl)-1-methylquinolin-4(1H)-one (KCI830), with variable N- substituents. The compound with a N-2,2,2-trifluoroethyl substitution (KCI838) was the fastest acting and most potent inhibitor of AR-dependent cell growth and colony formation in PCa model cells, including exclusively AR splice variant-dependent and other enzalutamide-resistant cells, without affecting growth of AR-negative cell lines. Critical tests were conducted to establish that KCI838 recapitulates the previously elucidated mode of action of KCI807. KCI838 selectively inhibited ELK1-dependent vs. androgen response element (ARE)-driven promoter and gene activation by AR. KCI838 blocked AR binding to ELK1 in situ tested by BRET assay. Increasing the total cellular AR by [~]2-fold using ectopic AR expression caused the predicted change in drug dose-response profile for growth, implicating AR as the exclusive target for the activity of KCI838. KCI838s molecular scaffold conferred reduced enzyme induction in primary human hepatocytes and weakened interactions with human UGT1A1 and CYP1A2. In mice bearing an aggressive, enzalutamide-resistant patient-derived PCa tumor xenograft characteristically overexpressing prostatic acid phosphatase, daily bolus injections of a soluble 3phosphate monoester prodrug of KCI838 (KCI838PME) progressively inhibited tumor growth, concomitant with tumor accumulation of active hydrophobic drug, without significant toxicity. Additionally, ALZET osmotic pumps were used to establish proof-of-concept for reversible in vivo anti-tumor activity of KCI838PME administered in a low dose, controlled release mode. The results warrant investigation of KCI838PME in a controlled-release formulation, to treat PCa that is resistant to current AR-targeted therapies while obviating the need for testosterone suppression.

cancer biology↗

bioRxiv2026

Analyzing how habitat degradation drives extinction dynamics using physiologically-structured population models

Elucidating how habitat degradation facilitates extinction is critical for effective conservation efforts. Here, we propose integrating physiologically-structured population models into stochastic population viability analyses to assess how differing consequences of habitat degradation interact to drive extinction dynamics in a focal population. Using the isolated spectacled caiman Caiman crocodilus population/ecomorph from the Apaporis River as a case study, we find that threatening the resource base, which individuals increasingly rely upon, to outgrow vulnerable size ranges and mature accelerates extinction. We also found that when habitat degradation impacts both the primary adult and juvenile resource bases, this can have marked synergistic effects on threatening population viability. By contrast, destroying nesting sites has only a small effect on accelerating the impact of deteriorating prey availability. Through integrating community-level feedback between habitat degradation/change and population dynamics/structure, our approach provides a comparative framework for assessing the relative importance of distinct mechanisms through which habitat degradation ultimately drives extinction risk.

ecology↗

bioRxiv2025

Genomic and Transcriptomic Landscapes of MEN1-Wild-Type Low-Grade Metastatic Pancreatic NETs Uncover Key Oncogenic Drivers and Targetable Pathways

Sporadic pancreatic neuroendocrine tumors (pNETs) with wild type MEN1 represent a major yet largely ignored subset whose biology and metastatic potential remain poorly understood. Because metastasis can occur despite low histologic grade and modest mutational burden, we hypothesized that metastatic competence in MEN1-wild-type pNETs reflects quantitative reinforcement of shared oncogenic pathways rather than distinct mutational processes. We profiled 75 primary low-grade pNETs by whole-exome and RNA sequencing, including 25 percent with lymph node and/or liver metastasis, and integrated genomic and transcriptomic data to connect pathway lesions with expression state. Metastatic tumors showed a slight increase in mutation frequency but conserved base-substitution spectra relative to non-metastatic cases, and adverse clinicopathologic features were enriched in Grade 2 disease. Aggregating alterations to pathways revealed broad convergence on canonical networks, with transcriptomic analyses demonstrating cohort-wide enrichment of Calcium, WNT, and KRAS/PI3K-AKT programs in metastasis. Intersection of significantly mutated genes with differentially expressed genes identified a focused 29-gene overlap, including RYR1 and ZNF273, that marks these convergent axes and distinguishes metastatic from non-metastatic tumors. Gene set enrichment confirmed preferential activation of Calcium, WNT, and PI3K-AKT signaling in metastatic tumors, consistent with a network-intensity model of progression. Finally, upstream-regulator analysis (iPathwayGuide) and gene-centric perturbation mapping (Gene2Drug) nominated candidate targeted and repurposable agents predicted to reverse the metastatic expression phenotype and flagged drugs unlikely to provide benefit, yielding a prioritized, testable therapeutic shortlist which includes fasudil and spaglumic acid. Convergent, domain-specific mutational patterns in highly mutated genes such as ZNF273 and CLCA1 define a molecular signature that could stratify metastatic risk in low-grade pNETs. Collectively, our data reframe metastasis in MEN1-wild-type low-grade pNETs as a property of pathway state rather than mutation quantity and provide a translational blueprint for biomarker-guided therapy development focused on Calcium, WNT, and KRAS/PI3K hubs.

cancer biology↗

bioRxiv2024

CD388: A universally protective Drug-Fc Conjugate that targets influenza virus neuraminidase

The ability of the influenza virus to elude humoral immunity by rapid antigenic shift presents a sustained and urgent threat to human health. Globally, seasonal influenza causes an estimated 3 - 5 million cases of severe disease and 300,000 - 500,000 deaths annually, with increased potential for mortality during pandemics1. The recent outbreaks of avian H5N1 in bird populations, subsequent spread to cattle and appearance in humans, highlight the need for effective broad-spectrum influenza antivirals for treatment, prophylaxis and pandemic preparedness. The narrow, strain-specific immunity induced by current seasonal vaccines and mismatches between vaccine strains and circulating viruses result in limited vaccine effectiveness (VE) rates2. Furthermore, VE is even lower in immune-compromised and - senescent populations3. Strategies that provide durable, universal influenza protection in healthy and high-risk populations are urgently needed. Here, we describe CD388, a first-in-class antiviral drug-Fc conjugate (DFC) in clinical trials for seasonal influenza prevention (NCT05285137 and NCT05523089). CD388 comprises a multivalent small molecule inhibitor of influenza virus neuraminidase (NA) linked to a CH1-Fc hybrid domain of human IgG1 engineered for extended half-life. CD388 demonstrated potent, universal activity across influenza A and B viruses, including high pathogenicity and NA resistant strains, a low potential for resistance development, and efficacy in lethal mouse infection models. CD388 is the first therapeutic with the potential for universal prevention of influenza A and B in healthy and high-risk populations.

microbiology↗

bioRxiv2020

Nanoparticle-mediated microRNA-145 Delivery for Vascular Smooth Muscle Cell Phenotype Modulation and Atherosclerosis Treatment

Vascular smooth muscle cells (VSMCs) change from contractile to the synthetic phenotype during atherogenesis and 30-70% of cells that make up plaques have been elucidated to be of VSMC origin. MicroRNA-145 (miR-145) is responsible for regulating VSMC phenotypic switching, and low miR-145 levels in circulation have been linked with atherosclerosis. Hence, we developed nanoparticles for targeted delivery of miR-145 by synthesizing micelles co-assembled with miR-145 and the CCR2-binding peptides for plaque targeting. The miR cargo was protected in micelles from premature endosomal degradation and rescued contractile markers in synthetic VSMCs and SMCs isolated from patient arteries in vitro. In ApoE-/- mid-stage atherosclerotic mice, miR-145 micelles halted plaque growth and maintained contractile phenotypes similar to baseline levels. In early-stage atherosclerosis, a single dose of miR-145 micelles prevented lesion growth by 49%. We present the potential of miR-145 micelles as a therapeutic that can be applied longitudinally and intervene throughout atherosclerosis pathogenesis.

bioengineering↗