Open Access

ARTICLE

Glutamic Acid–Chelated Cobalt Stabilizes G-Quadruplexes and Selectively Suppresses Hepatocellular Carcinoma Growth

Kuan-Hao Lin¹, Yu-Ju Lin¹, Yu-Bin Hong¹, Meng-Huai Hsu¹, Zhen-Xiang Liao¹, Shuo-Yu Chang¹, Chiou-Hwa Yuh^1,2,3,4,*

1 Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan
2 Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
3 Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
4 Program in Environmental and Occupational Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan

* Corresponding Author: Chiou-Hwa Yuh. Email:

Oncology Research 2026, 34(4), 21 https://doi.org/10.32604/or.2026.074144

Received 03 October 2025; Accepted 30 January 2026; Issue published 23 March 2026

Abstract

Objectives: Hepatocellular carcinoma (HCC) has limited systemic options with substantial toxicity. G-quadruplex (G4) structures in oncogene promoters are attractive but challenging drug targets. This study aimed to determine whether glutamic acid–chelated cobalt (GACC) is a G4-active scaffold with anti-HCC efficacy and favorable in vivo safety, and whether an AI-guided phenotypic response surface (PRS) can optimize less toxic combinations. Methods: Anticancer activity was tested in HCC cell lines (PLC/PRF/5, Hep3B, HepG2) and non-transformed THLE-2 hepatocytes (CCK-8, IC₅₀). In vivo safety/efficacy were assessed in zebrafish embryo toxicity assays, a Hep3B xenograft model, and a tert-overexpressing transgenic zebrafish model, with hepatotoxicity monitored in a liver-fluorescent reporter line. Target engagement was examined by docking, native PAGE, a KRAS promoter G4 DNA polymerase stop assay, BG4 immunofluorescence, and KRAS qPCR. PRS was used to optimize GACC–metformin–regorafenib combinations. Results: GACC reduced HCC viability (IC₅₀ ~86–115 µM) and showed low embryotoxicity (IC₅₀ 6.87 mM). In zebrafish xenografts, GACC (50 µM) reduced Hep3B tumor fluorescence by ~90% without detectable hepatotoxicity, whereas sorafenib decreased liver size/fluorescence. In tert-overexpressing zebrafish, GACC suppressed proliferation and Wnt/β-catenin–associated transcripts and reduced mitotic figures and nuclear atypia. Mechanistically, GACC increased KRAS promoter polymerase stalling, enhanced nuclear G4 signal, and reduced KRAS transcripts. PRS identified an off-grid triple combination that reduced PLC/PRF/5 viability to 19% while maintaining THLE-2 viability at 52% and preserving zebrafish development. Conclusion: GACC is a G4-active cobalt–glutamate scaffold with anti-HCC activity and favorable zebrafish safety, and a zebrafish-plus-PRS workflow enables rational, less toxic combination design.

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Supplementary Material

Supplementary Material File

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