title: Characterization of the biological activity of a potent small molecule Hec1 inhibitor TAI-1.
abstract: BACKGROUND
  Hec1 (NDC80) is an integral part of the kinetochore and is overexpressed in a variety of human cancers, making it an attractive molecular target for the design of novel anticancer therapeutics. A highly potent first-in-class compound targeting Hec1, TAI-1, was identified and is characterized in this study to determine its potential as an anticancer agent for clinical utility.
  
  
  METHODS
  The in vitro potency, cancer cell specificity, synergy activity, and markers for response of TAI-1 were evaluated with cell lines. Mechanism of action was confirmed with western blotting and immunofluorescent staining. The in vivo potency of TAI-1 was evaluated in three xenograft models in mice. Preliminary toxicity was evaluated in mice. Specificity to the target was tested with a kinase panel. Cardiac safety was evaluated with hERG assay. Clinical correlation was performed with human gene database.
  
  
  RESULTS
  TAI-1 showed strong potency across a broad spectrum of tumor cells. TAI-1 disrupted Hec1-Nek2 protein interaction, led to Nek2 degradation, induced significant chromosomal misalignment in metaphase, and induced apoptotic cell death. TAI-1 was effective orally in in vivo animal models of triple negative breast cancer, colon cancer and liver cancer. Preliminary toxicity shows no effect on the body weights, organ weights, and blood indices at efficacious doses. TAI-1 shows high specificity to cancer cells and to target and had no effect on the cardiac channel hERG. TAI-1 is synergistic with doxorubicin, topotecan and paclitaxel in leukemia, breast and liver cancer cells. Sensitivity to TAI-1 was associated with the status of RB and P53 gene. Knockdown of RB and P53 in cancer cells increased sensitivity to TAI-1. Hec1-overexpressing molecular subtypes of human lung cancer were identified.
  
  
  CONCLUSIONS
  The excellent potency, safety and synergistic profiles of this potent first-in-class Hec1-targeted small molecule TAI-1 show its potential for clinically utility in anti-cancer treatment regimens.
authors.affiliation: Taivex Therapeutics Corporation, 17th Floor, No, 3, Yuanqu Street, Nangang District, Taipei City 115, Taiwan. lynnhuang.lh245@gmail.com.
authors.forename: Lynn Y L
authors.initials: LY
authors.lastname: Huang
authors.forename: Ying-Shuan
authors.initials: YS
authors.lastname: Lee
authors.forename: Jiann-Jyh
authors.initials: JJ
authors.lastname: Huang
authors.forename: Chia-chi
authors.initials: CC
authors.lastname: Chang
authors.forename: Jia-Ming
authors.initials: JM
authors.lastname: Chang
authors.forename: Shih-Hsien
authors.initials: SH
authors.lastname: Chuang
authors.forename: Kuo-Jang
authors.initials: KJ
authors.lastname: Kao
authors.forename: Yung-Jen
authors.initials: YJ
authors.lastname: Tsai
authors.forename: Pei-Yi
authors.initials: PY
authors.lastname: Tsai
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Liu
authors.forename: Her-Sheng
authors.initials: HS
authors.lastname: Lin
authors.forename: Johnson Y N
authors.initials: JY
authors.lastname: Lau
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D061605:Administration, Intravenous; D000284:Administration, Oral; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000633:toxicity; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D045744:Cell Line, Tumor; D003598:Cytoskeletal Proteins; D004357:Drug Synergism; D005260:Female; D055785:Gene Knockdown Techniques; D008175:Lung Neoplasms / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D000072379:NIMA-Related Kinases; D009536:Niacinamide / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D059748:Proteolysis; D016160:Retinoblastoma Protein / Q000235:genetics / Q000378:metabolism; D013844:Thiazoles / Q000008:administration & dosage* / Q000633:toxicity; D047368:Tumor Burden; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D003598:Cytoskeletal Proteins; C120529:NDC80 protein, human; D009687:Nuclear Proteins; D016160:Retinoblastoma Protein; C000591009:TAI-1 compound; C495901:TP53 protein, human; D013844:Thiazoles; D016159:Tumor Suppressor Protein p53; D009536:Niacinamide; C089441:NEK2 protein, human; D000072379:NIMA-Related Kinases; D017346:Protein Serine-Threonine Kinases