Colorectal cancer (CRC) is among the most prevalent cancers worldwide, and dysregulated lipid metabolism is a hallmark of CRC. In particular, alterations in lipid metabolism in the circulating and non-circulating tumor tissues contribute to CRC development and progression. However, the precise molecular mechanisms that link lipid metabolic reprogramming to CRC pathogenesis remain unclear. CRC cell lines and a mouse xenograft model were used to investigate the roles of RING finger protein 14 (RNF14) palmitoylation, zinc finger DHHC-type palmitoyltransferase 9 (ZDHHC9), general control of amino acid synthesis 5-like 2 (GCN5), and Yin Yang 1 (YY1) in regulating lipid metabolism. Adenoviral transduction was used to introduce wild-type and palmitoylation-deficient RNF14 constructs. Protein expression, post-translational modifications, and protein–protein interactions were analyzed using western blotting, immunoprecipitation, and immunofluorescence. RNF14 palmitoylation levels were measured using an acyl resin-assisted capture assay. Cell viability was examined using the Cell Counting Kit-8 assay. Palmitoylation of RNF14 at cysteine 407 stabilized the protein by preventing ubiquitin-mediated degradation, thereby enhancing lipid metabolism and promoting tumor growth. This palmitoylation reaction was catalyzed by ZDHHC9. Silencing ZDHHC9 disrupted RNF14 palmitoylation, impaired lipid metabolism, and strongly suppressed tumor progression. Furthermore, the GCN5-mediated acetylation of YY1 activated ZDHHC9 expression, thereby forming a regulatory axis that enhanced RNF14 palmitoylation and lipid metabolic reprogramming. This study reveals a novel palmitoylation-dependent mechanism that regulates lipid metabolism in CRC. Accordingly, targeting the GCN5–YY1–ZDHHC9–RNF14 axis may be a promising therapeutic strategy against CRC.
The α7 nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel mediating cholinergic signaling. Its implication in neurological disorders and inflammation has spurred the development of synthetic effectors, either orthosteric agonists acting on the extracellular domain, or positive allosteric modulators (PAMs) acting at the transmembrane domain. In this context, endogenous polyunsaturated free fatty acids (PUFAs) were early recognized to modulate the receptor function, but their site of action remained unexplored. Here, we characterized a series of PUFAs by two-electrode voltage-clamp (TEVC) electrophysiology and used coarse-grained molecular dynamics (CG-MD) simulations coupled to mutational analysis to identify their binding sites. Data reveal that PUFAs are negative allosteric modulators (NAMs) whose strength depends on the length and degree of unsaturation of the hydrophobic tail and the polarity of the head group. Combined CG-MD and mutational data identified a major “structural” intrasubunit M1/M4 site which does not contribute to the NAM effect, and a minor intersubunit M3 + /M1- site where mutations strongly impair NAM activity. The M3 + /M1- site overlaps with the site for synthetic PAMs, showing a common hotspot for positive and negative allosteric modulation with implications for drug design and functional regulation in physiological conditions.
Astrocytes play central role in regulation of neural homeostasis and are increasingly implicated in the pathogenesis of neurodegenerative disease. Emerging evidence links the transcription factor GLIS3-/- to several neurological disorders and to astrocyte biology; however, its precise role in astrocytes remains unclear. Here, we define GLIS3-/- as a critical regulator of astrocyte differentiation and gene expression. We first show that GLIS3-/- is robustly expressed in mouse-derived astrocytes, as assessed by RT-qPCR and immunofluorescence. Using GLIS3-knockout human embryonic stem cells (hESCs), we further demonstrate that loss of GLIS3-/- markedly impairs astrocyte differentiation, evidenced by reduced expression of canonical astrocyte markers. Conversely, exogenous GLIS3-/- restores the induction of astrocyte-specific genes, establishing a critical role for GLIS3-/- in astrocyte lineage differentiation. Integrative transcriptomic and cistromic analyses revealed that GLIS3-/- directly controls a core astrocyte transcriptional program, including GFAP, SLC1A2, NFIA, and ATF3, and acts in concert with lineage-determining factors such as STAT3, NFIA, and SOX9. Pathway analysis further identifies GLIS3-dependent regulation of multiple genes, including SLC1A2, GRIA4, GRIA2, SLC38A2, and KCNJ10, with roles in glutamate and potassium homeostasis, synaptic transmission, and synapse formation, processes essential for brain function and frequently disrupted in neurological disease. Together, these findings position GLIS3-/- as an upstream regulator of astrocyte identity and function and suggest that its dysregulation may contribute to astrocyte-mediated neurodegenerative mechanisms. GLIS3-/- therefore emerges as a potential therapeutic target in astrocyte-associated neurological disorders.
Lung adenocarcinoma (LUAD) remains one of the most prevalent and lethal malignancies worldwide. Although epithelial-mesenchymal transition (EMT) and glucose metabolic reprogramming are well-established drivers of tumor progression and metastasis, the mechanisms coupling these two processes remain elusive, hindering the development of targeted therapeutic strategies. This study shows that Transforming growth factor-β (TGF-β), a predominant driver of EMT, markedly downregulates the rate-limiting glycolytic enzyme phosphofructokinase-M (PFKM). PFKM suppression acts as a critical metabolic switch in LUAD, shunting glucose carbon flux toward glycogen accumulation and promoting cell survival under glucose deprivation. Notably, PFKM knockdown is sufficient to induce a mesenchymal-like state, significantly enhancing cellular migration and invasion. These findings establish PFKM downregulation as a pivotal node integrating metabolic reprogramming with EMT, revealing an alternative glucose metabolic program distinct from conventional glycolytic enhancement. Collectively, these insights identify PFKM as a promising therapeutic target in LUAD.
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Switch-associated protein 70 (SWAP70) is a unique F-actin binding and bundling protein with multiple domains and broad involvement in various cellular functions. The aim of this study is to investigate the role and mechanism of the SWAP70 in HCC. The expression of SWAP70 in HCC and its prognostic significance were first evaluated using bioinformatics analysis and immunohistochemistry on clinical tissue microarrays. Subsequently, the functional role of SWAP70 in HCC was investigated through both in vitro cell function assays and in vivo mouse experiments. Multi-omics analysis was then employed to explore the underlying mechanism of SWAP70 in HCC. Finally, the therapeutic potential of SWAP70 silencing was assessed in a DEN/CCl₄-induced mouse model of hepatocellular carcinoma. SWAP70 was significantly upregulated in HCC tissues, especially in advanced HCC, and was associated with poor overall survival. SWAP70 promoted HCC cell proliferation in vitro and tumor growth in vivo. Mechanistically, SWAP70 enhanced mitochondrial fatty acid β-oxidation by upregulating carnitine palmitoyltransferase 1A (CPT1A), a rate-limiting enzyme of this pathway. Silencing CPT1A abrogated SWAP70-mediated proliferative effects. Hepatocyte nuclear factor 4 alpha (HNF4A) acts as a transcriptional repressor of SWAP70. Under glucose deficiency, AMP-activated protein kinase (AMPK) activation suppressed HNF4A expression, thereby promoted expression of SWAP70. Silencing SWAP70 delayed the progression of DEN/CCl₄-induced hepatocellular carcinoma in mice. Collectively, SWAP70 is a key regulator of fatty acid metabolism in hepatocellular carcinoma under glucose deficiency. Targeting SWAP70 represents a promising therapeutic strategy. Diagram of the mechanism of SWAP70 in HCC. SWAP70: Switch-associated protein 70, CCl4: carbon tetrachloride, DEN: Diethylnitrosamine, AAV: adeno-associated virus, NADH: Nicotinamide adenine dinucleotide, FADH: Flavin adenine dinucleotide, ATP: adenosine triphosphate, AMPK: Adenosine monophosphate activated protein kinase, p-AMPK: Phosphorylated AMPK, HNF4A: Hepatocyte nuclear factor 4 alpha. 1. SWAP70 is significantly upregulated in hepatocellular carcinoma tissues and correlates with advanced stage and poor prognosis. 2. Under glucose deficiency, activation of the AMPK HNF4A axis increases SWAP70 expression in hepatocellular carcinoma, which in turn enhances CPT1A-mediated fatty acid β-oxidation to drive tumor proliferation and growth. 3. SWAP70 is a key regulator that promotes fatty acid metabolism in hepatocellular carcinoma under glucose scarcity. 4. Silencing SWAP70 delays the progression of DEN/CCl₄ induced hepatocellular carcinoma in mice. Therefore, targeting SWAP70 may represent a promising therapeutic strategy for hepatocellular carcinoma.
