Synthesis and biological evaluation of novel isoxazole-piperazine hybrids as potential anti-cancer agents with inhibitory effect on liver cancer stem cells

Eur J Med Chem. 2021 Oct 5:221:113489. doi: 10.1016/j.ejmech.2021.113489. Epub 2021 Apr 24.

Abstract

In our effort for the development of novel anticancer therapeutics, a series of isoxazole-piperazine analogues were prepared, and primarily screened for their antiproliferative potential against hepatocellular carcinoma (HCC; Huh7/Mahlavu) and breast (MCF-7) cancer cells. All compounds demonstrated potent to moderate cytotoxicity on all cell lines with IC50 values in the range of 0.09-11.7 μM. Further biological studies with 6a and 13d in HCC cells have shown that both compounds induced G1 or G2/M arrests resulting in apoptotic cell death. Subsequent analysis of proteins involved in cell cycle progression as well as proliferation of HCC cells revealed that 6a and 13d may affect cellular survival pathways differently depending on the mutation profiles of cells (p53 and PTEN), epidermal/mesenchymal characteristics, and activation of cell mechanisms through p53 dependent/independent pathways. Lastly, we have demonstrated the potential anti-stemness properties of these compounds in which the proportion of liver CSCs in Huh7 cells (CD133+/EpCAM+) were significantly reduced by 6a and 13d. Furthermore, both compounds caused a significant reduction in expression of stemness markers, NANOG or OCT4 proteins, in Mahlavu and Huh7 cells, as well as resulted in a decreased sphere formation capacity in Huh7 cells. Together, these novel isoxazole-piperazine derivatives may possess potential as leads for development of effective anti-cancer drugs against HCC cells with stem cell-like properties.

Keywords: Cancer; Cancer stem cell; Isoxazole; Liver; Piperazine.

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • Humans
  • Isoxazoles / chemistry
  • Isoxazoles / pharmacology*
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / pathology
  • Molecular Structure
  • Piperazine / chemistry
  • Piperazine / pharmacology*
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents
  • Isoxazoles
  • Piperazine