Effective drug combinations have the potential to strengthen therapeutic efficacy and combat drug resistance. Both melatonin and valproic acid ( VPA ) exhibit antitumor activities in various cancer cells. The aim of this study was to evaluate the cell death pathways initiated by anticancer combinatorial effects of melatonin and VPA in bladder cancer cells. The results demonstrated that the combination of melatonin and VPA leads to significant synergistic growth inhibition of UC 3 bladder cancer cells. Gene expression studies revealed that cotreatment with melatonin and VPA triggered the up‐regulation of certain genes related to apoptosis ( TNFRSF 10A and TNFRSF 10B), autophagy ( BECN , ATG 3 and ATG 5) and necrosis ( MLKL , PARP ‐1 and RIPK 1). The combinatorial treatment increased the expression of endoplasmic reticulum ( ER )‐stress‐related genes ATF 6, IRE 1, EDEM 1 and ER dj4. Cotreatment with melatonin and VPA enhanced the expression of E‐cadherin, and decreased the expression of N ‐cadherin, Fibronectin, Snail and Slug. Furthermore, the Wnt pathway and Raf/ MEK / ERK pathway were activated by combinatorial treatment. However, the effects on the expression of certain genes were not further enhanced in cells following combinatorial treatment in comparison to individual treatment of melatonin or VPA . In summary, these findings provided evidence that cotreatment with melatonin and VPA exerted increased cytotoxicity by regulating cell death pathways in UC 3 bladder cancer cells, but the clinical significance of combinatorial treatment still needs to be further exploited.

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Wnt/β-catenin signaling is a conserved pathway crucially governing development, tissue homeostasis and oncogenesis in metazoan. Through screening, we identified a deubiquitinase (DUB) USP10 as a novel modulator of Wnt/β-catenin signaling. Mechanistically, USP10 binds to Axin1 via conserved motifs and stabilizes Axin1 through K48-linked deubiquitination. And in parallel, USP10 tethers Axin1 and β-catenin physically, via stabilizing the phase separation of Axin1 through its intrinsically-disordered regions, which is regardless of its enzymatic activity. Functionally, we show USP10 prominently regulates zebrafish embryonic development and murine intestinal homeostasis by antagonizing Wnt/β-catenin signaling. Additionally in human colorectal cancer, USP10 substantially represses cancer growth and correlates with Wnt/β-catenin magnitude clinically. Collectively, we discovered USP10 functioning in multiple biological processes through repressing Wnt/β-catenin signaling and unearthed a novel DUB-dependent and -independent dual-regulating mechanism by which USP10 utilizes in Wnt regulation context-dependently. Our study also suggested the potential of USP10 inhibitor in treating Wnt-related diseases.

Frizzled (Fzd) proteins are Wnt receptors and play essential roles in development, homeostasis, and oncogenesis. How Wnt/Fzd signaling is coupled to physiological regulation remains unknown. Cholesterol is reported as a signaling molecule regulating morphogen such as Hedgehog signaling. Despite the elusiveness of the in‐depth mechanism, it is well‐established that pancreatic cancer specially requires abnormal cholesterol metabolism levels for growth. In this study, it is unexpectedly found that among ten Fzds, Fzd5 has a unique capacity to bind cholesterol specifically through its conserved extracellular linker region. Cholesterol‐binding enables Fzd5 palmitoylation, which is indispensable for receptor maturation and trafficking to the plasma membrane. In Wnt‐addicted pancreatic ductal adenocarcinoma (PDAC), cholesterol stimulates tumor growth via Fzd5‐mediated Wnt/β‐catenin signaling. A natural oxysterol, 25‐hydroxylsterol competes with cholesterol and inhibits Fzd5 maturation and Wnt signaling, thereby alleviating PDAC growth. This cholesterol‐receptor interaction and ensuing receptor lipidation uncover a novel mechanism by which Fzd5 acts as a cholesterol sensor and pivotal connection coupling lipid metabolism to morphogen signaling. These findings further suggest that cholesterol‐targeting may provide new therapeutic opportunities for treating Wnt‐dependent cancers.

The microtubule-associated protein tau is closely correlated with hypometabolism in Alzheimer's disease (AD). α-lipoic acid (LA), which is a naturally occurring cofactor in mitochondrial, has been shown to have properties that can inhibit the tau pathology and neuronal damage in our previous research. However, if LA affects glucose metabolism when it reverses tau pathology remains unclear, especially concerning the potential mechanism. Therefore, we make a further study using the P301S mouse model (a tauopathy and AD mouse model which overexpressing fibrillary tau) to gain a clear idea of the aforementioned problems. Here, we found chronic LA administration significantly increased glucose availability by elevating glucose transporter 3 (GLUT3), GLUT4, vascular endothelial growth factor (VEGF) protein and mRNA level, and heme oxygenase-1 (HO-1) protein level in P301S mouse brains. Meanwhile, we found that LA also promoted glycolysis by directly upregulating hexokinase (HK) activity, indirectly by increasing proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and DNA repair enzymes (OGG1/2 and MTH1). Further, we found the underlying mechanism of restored glucose metabolism might involve in the activation of brain-derived neurotrophic factor (BDNF)/tyrosine Kinase receptor B (TrkB)/hypoxia-inducible factor-1α (HIF-1α) signaling pathway by LA treatment.