Conjugates of podophyllotoxin and norcantharidin as dual inhibitors of topoisomeraseⅡ and protein phosphatase 2A

  • Eur J Med Chem. 2016 Nov 10:123:568-576. doi: 10.1016/j.ejmech.2016.07.031.
Zhen-Bo Tang  1 Yao-Zhang Chen  2 Jie Zhao  1 Xiao-Wen Guan  1 Yong-Xin Bo  1 Shi-Wu Chen  3 Ling Hui  4
Affiliations
  • 1. School of Pharmacy, Lanzhou University, Lanzhou 730000, China.
  • 2. Department of Parmaceutics, Gansu Provincial Hospital of TCM, Lanzhou 730050, China.
  • 3. School of Pharmacy, Lanzhou University, Lanzhou 730000, China. Electronic address: [email protected].
  • 4. Experimental Center of Medicine, General Hospital of Lanzhou Military Command, Lanzhou 730050, China; Key Laboratory of Stem Cells and Gene Drug of Gansu Province, General Hospital of Lanzhou Military Command, Lanzhou 730050, China. Electronic address: [email protected].
Abstract

A series of novel conjugates of podophyllotoxin and norcantharidin was designed using association strategy, and synthesized by coupling 4'-demethylepipodophyllotoxin with N-amino acid norcantharimides, and their cytotoxicitiy was evaluated against four human tumor cell lines (A-549, HepG2, HeLa and HCT-8) and normal human diploid fibroblast line WI-38. These compounds exhibited potent cytotoxic effects on tumor cell lines, whereas it was less toxic to WI-38 cells than Anticancer drug VP-16 or its parent compound norcantharidin. Furthermore, conjugates 7a, 7c, 7f, 7j, 7k and 7l displayed excellent PP2A inhibition activity with IC50 values of 0.49-9.52 μM. The most potent compound 7l also exhibited topoisomeraseⅡinhibition activity. In addition, compound 7l induced cell-cycle arrest in the G2/M phase in HepG2 by regulating levels of cyclinB1 and cdc2.

Keywords
Cantharidin; Cell-cycle arrest; PP2A; Podophyllotoxin; TOP-Ⅱ.