Z Gastroenterol 2007; 45 - A2_31
DOI: 10.1055/s-2007-967821

The dual EGF-/VEGF-receptor tyrosine kinase inhibitor AEE–788 inhibits growth of human hepatocellular carcinoma xenografts in mice

M Ocker 1, K Okamoto 1, D Neureiter 2, B Kaufmann 3, U Haus 3, C Herold 1
  • 1Medizinische Klinik I mit Poliklinik, Universität Erlangen-Nürnberg, Erlangen
  • 2Insitut für Pathologie, Salzburger Landeskliniken, Paracelsus Private Medical University, Salzburg, Österreich
  • 3Novartis Pharma GmbH, Nürnberg

Aims: Treatment for advanced stages of hepatocellular carcinoma (HCC) remains unsatisfactory. HCC is a highly vascularised tumor and also shows enhanced expression of epidermal growth factor receptors. We therefore investigated the effect of AEE–788, a novel inhibitor of the receptor tyrosine kinase activity of the EGF and the VEGF receptor, for HCC treatment in vitro and in a subcutaneous xenograft model in vivo.

Methods: The human HCC cell lines HepG2 and Hep1B were cultured under standard conditions and incubated with different concentrations of AEE–788 (0.1 to 100µM) for 24 to 120h. Cell viability was assessed after trypan blue staining in a Neubauer chamber. Apoptosis was quantified by flow cytometry after propidium iodide staining. For the xenograft model, 5×106 cells were injected subcutaneously into the flank region of male NMRI nude mice (n/group=8). Oral treatment with 50mg/kg AEE–788 thee times per week was started when tumors reached a diameter of 7mm. At the end of treatment, tumor specimens were obtained for further analysis (immunohistochemistry, western blotting).

Results: In vitro, the number of viable cells was rapidly reduced in both cell lines at concentrations of AEE–788 of 10µM or higher, while lower concentrations remained ineffective. Apoptosis induction was observed in a time-dependent manner at concentrations of 10µM or higher. In HepG2, apoptosis rose from 8.8% at 48h to a maximum of 58.4% at 120h at 10µM, and from 24.2% at 24h to 96.3% at 120h at 100µM. In vivo, untreated control tumors doubled their size in 14 days, while AEE–788 treated tumors showed a delayed growth with nearly stable tumor size over the treatment period. All animals survived until the treatment endpoints. Treated animals showed a reversible skin reaction after AEE–788 application.

Conclusions: AEE–788 is a promising novel small molecule inhibitor of the EGF- and the VEGF-pathway and can contribute to treatment of HCC.

EGF - HCC - VEGF