title: In Silico Identification and In Vitro and In Vivo Validation of Anti-Psychotic Drug Fluspirilene as a Potential CDK2 Inhibitor and a Candidate Anti-Cancer Drug.
abstract: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Surgical resection and conventional chemotherapy and radiotherapy ultimately fail due to tumor recurrence and HCC's resistance. The development of novel therapies against HCC is thus urgently required. The cyclin-dependent kinase (CDK) pathways are important and well-established targets for cancer treatment. In particular, CDK2 is a key factor regulating the cell cycle G1 to S transition and a hallmark for cancers. In this study, we utilized our free and open-source protein-ligand docking software, idock, prospectively to identify potential CDK2 inhibitors from 4,311 FDA-approved small molecule drugs using a repurposing strategy and an ensemble docking methodology. Sorted by average idock score, nine compounds were purchased and tested in vitro. Among them, the anti-psychotic drug fluspirilene exhibited the highest anti-proliferative effect in human hepatocellular carcinoma HepG2 and Huh7 cells. We demonstrated for the first time that fluspirilene treatment significantly increased the percentage of cells in G1 phase, and decreased the expressions of CDK2, cyclin E and Rb, as well as the phosphorylations of CDK2 on Thr160 and Rb on Ser795. We also examined the anti-cancer effect of fluspirilene in vivo in BALB/C nude mice subcutaneously xenografted with human hepatocellular carcinoma Huh7 cells. Our results showed that oral fluspirilene treatment significantly inhibited tumor growth. Fluspirilene (15 mg/kg) exhibited strong anti-tumor activity, comparable to that of the leading cancer drug 5-fluorouracil (10 mg/kg). Moreover, the cocktail treatment with fluspirilene and 5-fluorouracil exhibited the highest therapeutic effect. These results suggested for the first time that fluspirilene is a potential CDK2 inhibitor and a candidate anti-cancer drug for the treatment of human hepatocellular carcinoma. In view of the fact that fluspirilene has a long history of safe human use, our discovery of fluspirilene as a potential anti-HCC drug may present an immediately applicable clinical therapy.
authors.affiliation: Biotechnology Center, Kunming Medical University, Kunming, Yunnan, China; Department of Medicine, Southwest Guizhou Vocational and Technical College for Nationalities, Guizhou, China.
authors.forename: Xi-Nan
authors.initials: XN
authors.lastname: Shi
authors.affiliation: Department of Computer Science and Engineering, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Hongjian
authors.initials: H
authors.lastname: Li
authors.affiliation: The Cancer Biotherapy Institute of Jiangsu Province, Xuzhou Medical College, Xuzhou, China; School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yao
authors.affiliation: Biotechnology Center, Kunming Medical University, Kunming, Yunnan, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Biotechnology Center, Kunming Medical University, Kunming, Yunnan, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Computer Science and Engineering, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Kwong-Sak
authors.initials: KS
authors.lastname: Leung
authors.affiliation: Biotechnology Center, Kunming Medical University, Kunming, Yunnan, China; School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Hsiang-fu
authors.initials: HF
authors.lastname: Kung
authors.affiliation: Biotechnology Center, Kunming Medical University, Kunming, Yunnan, China.
authors.forename: Di
authors.initials: D
authors.lastname: Lu
authors.affiliation: Department of Computer Science and Engineering, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Man-Hon
authors.initials: MH
authors.lastname: Wong
authors.affiliation: Shenzhen Key Lab of Translational Medicine of Tumor, School of Medicine, Shenzhen University, Shenzhen, China; Biotechnology Center, Kunming Medical University, Kunming, Yunnan, China.
authors.forename: Marie Chia-mi
authors.initials: MC
authors.lastname: Lin
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D003198:Computer Simulation; D051357:Cyclin-Dependent Kinase 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005260:Female; D005484:Fluspirilene / Q000494:pharmacology*; D016193:G1 Phase / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D062105:Molecular Docking Simulation; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016196:S Phase / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: D014150:Antipsychotic Agents; D009363:Neoplasm Proteins; D005484:Fluspirilene; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2