Combination of the ERK inhibitor AZD6244 and low-dose sorafenib in a xenograft model of human renal cell carcinoma

Int J Oncol. 2012 Aug;41(2):712-20. doi: 10.3892/ijo.2012.1494. Epub 2012 May 23.

Abstract

Sorafenib, a multikinase inhibitor, is currently used as monotherapy for advanced renal cell carcinoma (RCC). However, adverse effects associated with its use have been experienced by some patients. In this study, we examined the antitumor and antiangiogenic activities of low-dose sorafenib in combination with the MEK inhibitor AZD6244 (sorafenib/AZD6244) in a preclinical model of RCC. Primary RCC 08-0910 and RCC 786-0 cells as well as patient-derived RCC models were used to study the antitumor and antiangiogenic activities of sorafenib/AZD6244. Changes of biomarkers relevant to angiogenesis and cell cycle were determined by western immunoblotting. Microvessel density, apoptosis and cell proliferation were analyzed by immunohistochemistry. Treatment of RCC 786-0 cells with sorafenib/AZD6244 resulted in G1 cell cycle arrest and blockade of serum-induced cell migration. Sorafenib/AZD6244 induced apoptosis in primary RCC 08-0910 cells at low concentrations. In vivo addition of AZD6244 to sorafenib significantly augmented the antitumor activity of sorafenib and allowed dose reduction of sorafenib without compromising its antitumor activity. Sorafenib/AZD6244 potently inhibited angiogenesis and phosphorylation of VEGFR-2, PDGFR-β and ERK, p90RSK, p70S6K, cdk-2 and retinoblastoma. Sorafenib/AZD6244 also caused upregulation of p27, Bad and Bim but downregulation of survivin and cyclin B1. These resulted in a reduction in cellular proliferation and the induction of tumor cell apoptosis. Our findings showed that AZD6244 and sorafenib complement each other to inhibit tumor growth. This study provides sound evidence for the clinical investigation of low-dose sorafenib in combination with AZD6244 in patients with advanced RCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / administration & dosage
  • Animals
  • Antineoplastic Combined Chemotherapy Protocols / pharmacology
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Benzenesulfonates / administration & dosage
  • Benzimidazoles / administration & dosage
  • Carcinoma, Renal Cell / drug therapy*
  • Carcinoma, Renal Cell / metabolism
  • Carcinoma, Renal Cell / pathology
  • Cell Proliferation / drug effects
  • Humans
  • Kidney Neoplasms / drug therapy*
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • Mice
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Niacinamide / analogs & derivatives
  • Phenylurea Compounds
  • Phosphorylation
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / metabolism
  • Protein Processing, Post-Translational / drug effects
  • Pyridines / administration & dosage
  • Receptor, Platelet-Derived Growth Factor beta / metabolism
  • Sorafenib
  • Tumor Burden / drug effects
  • Tumor Cells, Cultured
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism
  • Xenograft Model Antitumor Assays

Substances

  • AZD 6244
  • Angiogenesis Inhibitors
  • Benzenesulfonates
  • Benzimidazoles
  • Phenylurea Compounds
  • Pyridines
  • Niacinamide
  • Sorafenib
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • Receptor, Platelet-Derived Growth Factor beta
  • Vascular Endothelial Growth Factor Receptor-2
  • Mitogen-Activated Protein Kinase 3