Substituted titanocenes induce caspase-dependent apoptosis in human epidermoid carcinoma cells in vitro and exhibit antitumour activity in vivo

Br J Cancer. 2007 Nov 5;97(9):1234-41. doi: 10.1038/sj.bjc.6604021. Epub 2007 Oct 9.

Abstract

Titanocene compounds are a novel series of agents that exhibit cytotoxic effects in a variety of human cancer cells in vitro and in vivo. In this study, the antiproliferative activity of two titanocenes (Titanocenes X and Y) was evaluated in human epidermoid cancer cells in vitro. Titanocenes X and Y induce apoptotic cell death in epidermoid cancer cells, with IC50 values that are comparable to cisplatin. Characterisation of the cell death pathway induced by titanocene compounds in A431 cells revealed that apoptosis is preceded by cell cycle arrest and the inhibition of cell proliferation. The induction of apoptosis is dependent on the activation of caspase-3 and -7 but not caspase-8. Furthermore, the antitumour activity of Titanocene Y was tested in an A431 xenograft model of epidermoid cancer. Results indicate that Titanocene Y significantly reduced the growth of A431 xenografts with an antitumour effect similar to cisplatin. These results suggest that titanocenes represent a novel series of promising antitumour agents.

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Blotting, Western
  • Body Weight / drug effects
  • Carcinoma, Squamous Cell / drug therapy
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology*
  • Caspase 3 / metabolism*
  • Cell Cycle / drug effects
  • Cell Proliferation / drug effects
  • Female
  • HeLa Cells / drug effects
  • Humans
  • Inhibitory Concentration 50
  • Mice
  • Mice, Nude
  • Organometallic Compounds / chemistry
  • Organometallic Compounds / pharmacology*
  • Titanium / chemistry
  • Titanium / pharmacology
  • Tumor Cells, Cultured / drug effects

Substances

  • Antineoplastic Agents
  • Organometallic Compounds
  • Titanocene Y
  • titanocene
  • Titanium
  • Caspase 3