Targeting of multiple signaling pathways by the Hsp90 inhibitor SNX-2112 in EGFR resistance models as a single agent or in combination with erlotinib

Oncol Res. 2009;18(5-6):229-42. doi: 10.3727/096504009x12596189659240.

Abstract

Inhibition of Hsp90 has emerged as a therapeutic strategy to target NSCLC subtypes, which are refractory to epidermal growth factor receptor (EGFR) inhibitor-based treatment. We report on a novel small molecule inhibitor of Hsp90, SNX-2112, and an orally bioavailable prodrug analog, SNX-5422. In cellular models of wild-type or mutant EGFR (L858R and T790M mutations), SNX-2112 alone and in combination with erlotinib inhibited EGF activation of pAKT(473) and pSTAT3(705). pERK1/2 and pS6 were also potently inhibited by similar treatments. SNX-2112 reduced EGF cross-talk and activation of the c-Met receptor by causing c-Met degradation. In NCI-H1975 xenograft models, SNX-5422 showed activity as a single agent and in combination with erlotinib resulted in prolonged animal survival at reduced compound concentrations relative to either compound alone. These results support the advanced evaluation of SNX-5422 as a treatment for non-small cell lung cancer (NSCLC), especially in cases where the cancer is driven by c-Met amplification or mutated EGFR forms that are resistant to EGFR inhibitors.

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Combined Chemotherapy Protocols
  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / metabolism
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Line, Tumor
  • Disease Models, Animal*
  • Drug Resistance, Neoplasm*
  • ErbB Receptors / antagonists & inhibitors
  • ErbB Receptors / metabolism*
  • Erlotinib Hydrochloride
  • Female
  • HSP90 Heat-Shock Proteins / antagonists & inhibitors*
  • Heterocyclic Compounds, 4 or More Rings / pharmacology*
  • Humans
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Mice
  • Mice, Nude
  • Quinazolines / pharmacology*
  • Signal Transduction / drug effects*
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents
  • HSP90 Heat-Shock Proteins
  • Heterocyclic Compounds, 4 or More Rings
  • Quinazolines
  • SNX 2112
  • Erlotinib Hydrochloride
  • EGFR protein, human
  • ErbB Receptors