Dear Editor,
The study by Aoki et al. proposes a novel hepatocellular carcinoma (HCC) subclassification based on metabolic zonation and signaling pathways [
1]. While conceptually innovative, several fundamental flaws undermine its validity and clinical relevance.
The authors use Hallmark gene sets (e.g., “BILE_ACID_ METABOLISM,” “GLYCOLYSIS”) to define subclasses but fail to address inherent biological interdependencies. Bile acid and fatty acid metabolism are physiologically linked in perivenous hepatocytes via shared regulators (e.g., FXR/RXR) [
2]. Clustering these as independent variables artificially separates overlapping biology, creating non-distinct subgroups. This circular approach likely amplifies spurious associations between “rich metabolism” and favorable outcomes.
The Wnt/β-catenin-High subclass (19.9% of cases) is paradoxically linked to both microtrabecular histology (indicating differentiation) and CTNNB1 exon 3 mutations (D32-S37), which typically correlate with poor differentiation and immune exclusion [
3]. Despite this, the authors report a median recurrence free survival of 29.3 months for this group—contradicting established literature where Wnt-mutant HCCs show early recurrence [
4]. The data lack adjustment for confounding factors (e.g., hepatitis B virus status), suggesting survival outcomes are misattributed.
The IL6-JAK-STAT3-High and K-RAS-High subclasses (25% and 15.4%) are presented as distinct entities. However, IL6 activates RAS/MAPK signaling in HCC, and STAT3-KRAS crosstalk is well-documented [
5]. The authors provide no functional evidence (e.g., phospho-protein assays) to justify their separation, raising concerns that clustering artifacts mimic biological subgroups.
The glycolysis subclass (39.7%) is split into PI3K/mTORHigh and NOTCH/TGF-β-High groups. Yet PI3K/mTOR induces HIF-1α and glycolytic enzymes, while TGF-β suppresses mTOR via PTEN—creating a biologically implau-sible dichotomy. The absence of differential survival (overall survival: 51.8 vs. 97.3 months, P=not significant) further questions their clinical distinctness.
The claim that PI3K/mTOR-High tumors “resemble fetal liver” relies solely on MYC expression. Fetal hepatogenesis involves NOTCH, Wnt, and HGF/MET signaling—none comprehensively profiled [
6]. Without single-cell comparative transcriptomics, this assertion remains speculative.
In conclusion, the study’s subclassification suffers from reductionist clustering of non-independent pathways, biologically contradictory groupings, and unvalidated claims. A systems biology approach integrating spatial transcriptomics and phosphoproteomics is needed to resolve these issues.
FOOTNOTES
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Authors’ contributions
Q. L conceived the work. All authors contributed substantially to discussion of the content. Y-Z. X wrote the article. All authors reviewed and/or edited the manuscript before submission. All authors approve the final version of the manuscript.
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Conflicts of Interest
The authors have no conflicts to disclose.
Abbreviations
REFERENCES
- 1. Aoki T, Nishida N, Kurebayashi Y, Sakai K, Fujiwara N, Tsurusaki M, et al. Molecular classification of hepatocellular carcinoma based on zoned metabolic feature and oncogenic signaling pathway. Clin Mol Hepatol 2025;31:981-1002.
- 2. Halpern KB, Shenhav R, Matcovitch-Natan O, Toth B, Lemze D, Golan M, et al. Single-cell spatial reconstruction reveals global division of labour in the mammalian liver. Nature 2017;542:352-356.
- 3. Sia D, Jiao Y, Martinez-Quetglas I, Kuchuk O, Villacorta-Martin C, Castro de Moura M, et al. Identification of an immune-specific class of hepatocellular carcinoma, based on molecular features. Gastroenterology 2017;153:812-826.
- 4. Montironi C, Castet F, Haber PK, Pinyol R, Torres-Martin M, Torrens L, et al. Inflamed and non-inflamed classes of HCC: a revised immunogenomic classification. Gut 2023;72:129-140.
- 5. Xu J, Lin H, Wu G, Zhu M, Li M. IL-6/STAT3 Is a promising therapeutic target for hepatocellular carcinoma. Front Oncol 2021;11:760971.
- 6. Zhu C, Tabas I, Schwabe RF, Pajvani UB. Maladaptive regeneration - the reawakening of developmental pathways in NASH and fibrosis. Nat Rev Gastroenterol Hepatol 2021;18:131-142.
Citations
Citations to this article as recorded by
- Correspondence to letter to the editor on “Molecular classification of hepatocellular carcinoma based on zoned metabolic feature and oncogenic signaling pathway”
Tomoko Aoki, Naoshi Nishida, Masatoshi Kudo
Clinical and Molecular Hepatology.2026; 32(2): e241. CrossRef
