Pan Chen,Dongshun Li,Yixin Chen,Jiahong Sun,Kaili Fu,Lihuan Guan,Huizhen Zhang,Yiming Jiang,Xi Li,Xuezhen Zeng,Xiao Chen,Min Huang,Huichang Bi
Background and Purpose The tumour suppressor p53 is traditionally recognized as a surveillance molecule to preserve genome integrity. Recent studies have demonstrated that it contributes to metabolic diseases. Here, we investigated the role of p53 in the regulation of bile acid disposition and cholestasis. Experimental Approach The bile acid disposition-related gene expression profile affected by p53 activation was assessed in mouse primary hepatocytes with p53 depletion and in Trp53 -null mice. Dual luciferase reporter assay was used to detect the transcriptional activities of target genes. Anticholestatic effects of p53 activator doxorubicin were investigated in a 0.5% cholic acid-fed mouse model of cholestasis. Changes in bile acids were evaluated using metabolomics analysis. Key Results Doxorubicin-mediated p53 activation induced Cyp2b10 , Sult2a1 and Abcc2/3/4 expression in mice in vitro and in vivo . ABCC3 and CYP2B6 (human orthologue of Cyp2b10 ) were identified as direct p53 target genes. Doxorubicin attenuated cholic acid-induced cholestasis in mice, as demonstrated by shrunken gall bladder, decreased serum total bile acid and total bilirubin levels and alkaline phosphatase activity. Targeted metabolomics analysis revealed that doxorubicin enhanced the excretion of bile acid metabolites from serum and liver to intestine and faeces. Up-regulation of Cyp2b10 , Sult2a1 and Abcc2/3/4 expression was further confirmed in cholestatic mice. Cholic acid-induced cholestatic injury was aggravated in p53-deficient mice and levels of bile acid in intestine and faeces were decreased. Conclusions and Implications Our findings suggest a novel role of p53 in promoting bile acid disposition and alleviating cholestatic syndrome, which provides a potential therapeutic target for cholestasis.
Background/Objectives: Breast cancer is the most prevalent malignancy among women, and paclitaxel (PTX) is a first-line chemotherapeutic, but chemoresistance driven by ATP-binding cassette (ABC) transporters limits its efficacy. Single-target ABC inhibitors fail due to toxicity and cooperative transporter activity, creating an urgent need for safe multi-target strategies. Membrane cholesterol-rich lipid rafts support ABC transporter function, making cholesterol a key chemoresistance target. This study explored a cholesterol-targeted approach for overcoming PTX resistance.Methods: A PTX-resistant breast cancer line (MCF-7/PTX) showing ABCB1/ABCC3 co-upregulation and enriched cholesterol rafts was established. The effects of Polyphyllin H (PPH), a steroidal saponin fromParis polyphylla, were compared with lovastatin, a biosynthetic cholesterol inhibitor. In vitro and in vivo assays investigated Polyphyllin H’s cholesterol binding and effects on transporters, PTX accumulation, and tumor growth.Results: PPH directly binds membrane cholesterol, disrupting lipid rafts, downregulating ABCB1/ABCC3, reducing drug efflux, and increasing intracellular PTX to restore sensitivity. PPH showed superior cholesterol-binding and resistance-reversal efficacy than lovastatin, with faster, stronger PTX-enhanced cytotoxicity and tumor suppression.Conclusions: PPH reverses PTX resistance by targeting cholesterol-lipid rafts to inhibit multiple ABC transporters. This offers a safer adjuvant for PTX-based breast cancer therapy and a translational framework for other drug-resistant malignancies.
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