Fraxetin inhibits the growth of colon adenocarcinoma cells via the Janus kinase 2/signal transducer and activator of transcription 3 signalling pathway. (August 2020)

• Record Type: Journal Article
• Authors: Ren, Shuo; Xing, Yanwei; Wang, Chengbo; Jiang, Fengqi; Liu, Guangyu; Li, Ziyi; Jiang, Tao; Zhu, Yuekun; Piao, Daxun
• Is Part Of: International journal of biochemistry & cell biology. Volume 125(2020)
• Publication Date: 2020-08
• Subjects: CRC colorectal cancer -- COAD colon adenocarcinoma -- STAT signal transducer and activator of transcription -- JAK Janus kinase -- EMT epithelial-to-mesenchymal transition -- HPLC high performance liquid chromatography -- IMS mitochondrial intermembrane space -- MDR multidrug resistance -- MOMP mitochondrial outer membrane permeabilization -- Ab antibody -- Rb retinoblastoma -- NCM normal colonic mucosa -- CDKs cyclin-dependent kinases -- CCK-8 Cell Counting Kit-8 -- Bcl B-cell lymphoma -- BAX Bcl-2-associated X -- SRC sarcoma -- Skp2 S-phase kinase associated protein 2 -- P27Kip1 P27 kinase inhibitor protein 1 -- PI propidium iodide -- FITC fluorescein isothiocyanate -- FACTS Fast Analytical Continuum Treatment of Solvation -- RT-qPCR reverse transcription-quantitative polymerase chain reaction; Colon adenocarcinoma -- Fraxetin -- Proliferation -- Phosphorylation -- STAT; Biochemistry -- Periodicals; Cytology -- Periodicals; Biochemistry -- Periodicals; Cell Biology -- Periodicals; Biochimie -- Périodiques; Cytologie -- Périodiques; Biochimie; Cytologie; Biochemistry; Cytology; Ressource Internet (Descripteur de forme); Périodique électronique (Descripteur de forme); Periodicals; 572.05
• DOI: 10.1016/j.biocel.2020.105777
• Languages: English
• ISSNs: 1357-2725

Abstract

Highlights: Fraxetin is a selective tumoricidal drug at low micromolar concentrations. Fraxetin regulates the cell cycle by modulating crosstalk between STAT3 and Skp2/P27. Fraxetin suppresses the proliferation of COAD cells by intrinsic apoptosis pathway. Fraxetin inhibits the JAK2/STAT3 pathway by targeting pivotal tyrosine residues. Abstract: Objective: Fraxetin, extracted from the bark of Fraxinus rhynchophylla, has been shown to exhibit antitumour and anti-inflammatory pharmacological properties. However, the mechanism underlying its anticancer activity towards colon adenocarcinoma (COAD) is not well understood. We aimed to determine the antitumour effect of fraxetin on COAD cell lines and elucidate its biochemical and molecular targets. Methods: The cell lines HCT116 and DLD-1 were used to evaluate the in vitro antitumour efficacy of fraxetin. Cytotoxicity and viability were assessed by CCK-8 and plate colony formation assays. Flow cytometry was used to assess apoptosis and cell cycle progression in fraxetin-treated COAD cells. Western blot, RT-qPCR, molecular docking, immunohistochemical, and immunofluorescence analyses were used to gain insights into cellular and molecular mechanisms. Preclinical curative effects were evaluated in nude mouse xenograft models. Results: Fraxetin significantly inhibited COAD cell proliferation in both dose- and time-dependent manners, specifically by inducing S-phase cell cycle arrest and triggering intrinsic apoptosis. Additionally, the level of p-JAK2 was decreased by fraxetin via the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signalling pathway. Interestingly, in COAD cells, fraxetin directly targeted the Y 1007 and Y 1008 residues of JAK2 to suppress its auto- or transphosphorylation, leading to decreased activation of its downstream effector STAT3 and blocking its nuclear translocation. Finally, fraxetin exhibited good tumour growth suppression activity and low toxicity. Conclusions: Fraxetin inhibits the proliferation of COAD cells by regulating the JAK2/STAT3 signalling pathway, providing evidence that targeting JAK2 with fraxetin may offer a novel potential auxiliary therapy for COAD treatment.