Identification Of Natural Compound Derivative For Inhibition Of XLF And Overcoming Chemoresistance In Colorectal Cancer Cells

• Published in: Drug design, development and therapy development and therapy, 2019-11, Vol.13, p.3823-3834
• Main Authors: Liu, Zhuo, Yu, Miao, Fei, Bingyuan, Sun, Jing, Wang, Dongxin
• Format: Article
• Language: English
• Subjects: 5-Fluorouracil; Anesthesiology; Antineoplastic Agents, Phytogenic - chemistry; Antineoplastic Agents, Phytogenic - isolation & purification; Antineoplastic Agents, Phytogenic - pharmacology; Apoptosis; Binding; Bioassays; Biological Products - chemistry; Biological Products - isolation & purification; Biological Products - pharmacology; Biotechnology; Cancer; Cancer cells; Cancer research; Cancer screening; Cancer therapies; Cancer treatment; Cell cycle; Cell Proliferation - drug effects; Cell Survival - drug effects; Chemoresistance; Chemotherapy; Chromatin; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - drug therapy; Colorectal Neoplasms - metabolism; Colorectal Neoplasms - pathology; Comet assay; Crystal structure; Damage detection; Deoxyribonucleic acid; DNA; DNA Repair; DNA Repair Enzymes - antagonists & inhibitors; DNA Repair Enzymes - metabolism; DNA-Binding Proteins - antagonists & inhibitors; DNA-Binding Proteins - metabolism; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Drug Screening Assays, Antitumor; Efficiency; Fluorescence; Fluorouracil; Fractionation; Genetic research; HCT116 Cells; Homologous recombination; Homology; Humans; Identification methods; Inhibitors; Kinases; Libraries; Ligands; Molecular Docking Simulation; Molecular Structure; Non-homologous end joining; Novels; Organic chemistry; Original Research; Oxalic acid; Oxaliplatin; Proteins; Proteolysis; Sensitivity; Structure-Activity Relationship; Sulforhodamine; Time dependence; Toxicity; Tumor Cells, Cultured; virtual screening; xlf inhibitor; Yeast
• ISSN: 1177-8881; 1177-8881
• DOI: 10.2147/DDDT.S215967

A previous study has identified that XRCC4-like factor (XLF) is a potential target to overcome resistance to 5-fluorouracil (5-Fu) and oxaliplatin (OXA) in colorectal cancer (CRC). The purpose of this study is to develop potent XLF inhibitors to chemoresistance in CRC. Virtual screening was adopted to identify novel XLF-binding compounds by initially testing 6800 molecules in Chemical Entities of Biological Interest library. Hit compounds were further validated by Western blot assay. Cell sensitivity to 5-Fu and OXA was measured using sulforhodamine B assay. The effect of XLF inhibitor on DNA repair efficiency was evaluated by comet assay, fluorescent-based nonhomologous end joining (NHEJ) and homologous recombination (HR) reporter assays. DNA-binding activity of NHEJ key factors was examined by chromatin fractionation assay. We identified G3, a novel and potent XLF inhibitor (IC 0.47±0.02 µM). G3 induced XLF protein degradation in CRC cells. Significantly, G3 improved cell sensitivity to 5-Fu and OXA in chemoresistant CRC cell lines. Mechanistically, G3 depleted XLF expression, severely compromised NHEJ efficiency by up to 65% and inhibited NHEJ key factor assembly on DNA. G3 also inhibited HR efficiency in a time-dependent manner. These results suggest that G3 overcomes 5-Fu and OXA resistance in CRC cells by inhibiting XLF expression. Thus, XLF is a promising target and its inhibitor G3 is a potential candidate for treatment of chemoresistant CRC patients.