MET-independent lung cancer cells evading EGFR kinase inhibitors are therapeutically susceptible to BH3 mimetic agents.

Abstract

Targeted therapies for cancer are inherently limited by the inevitable recurrence of resistant disease after initial responses. To define early molecular changes within residual tumor cells that persist after treatment, we analyzed drug-sensitive lung adenocarcinoma cell lines exposed to reversible or irreversible epidermal growth factor receptor (EGFR) inhibitors, alone or in combination with MET-kinase inhibitors, to characterize the adaptive response that engenders drug resistance. Tumor cells displaying early resistance exhibited dependence on MET-independent activation of BCL-2/BCL-XL survival signaling. Further, such cells displayed a quiescence-like state associated with greatly retarded cell proliferation and cytoskeletal functions that were readily reversed after withdrawal of targeted inhibitors. Findings were validated in a xenograft model, showing BCL-2 induction and p-STAT3[Y705] activation within the residual tumor cells surviving the initial antitumor response to targeted therapies. Disrupting the mitochondrial BCL-2/BCL-XL antiapoptotic machinery in early survivor cells using BCL-2 Homology Domain 3 (BH3) mimetic agents such as ABT-737, or by dual RNAi-mediated knockdown of BCL-2/BCL-XL, was sufficient to eradicate the early-resistant lung-tumor-cells evading targeted inhibitors. Similarly, in a xenograft model the preemptive cotreatment of lung tumor cells with an EGFR inhibitor and a BH3 mimetic eradicated early TKI-resistant evaders and ultimately achieved a more durable response with prolonged remission. Our findings prompt prospective clinical investigations using BH3-mimetics combined with targeted receptor kinase inhibitors to optimize and improve clinical outcomes in lung-cancer treatment.

• Authors: Weiwen Fan, Zhe Tang, Lihong Yin, Bei Morrison, Said Hafez-Khayyata, Pingfu Fu, Honglian Huang, Rakesh Bagai, Shan Jiang, Adam Kresak, Scott Howell, Amit Vasanji, Chris A Flask, Balazs Halmos, Henry Koon, Patrick C Ma
• Journal: Cancer research (Cancer Res) Vol. 71 Issue 13 Pg. 4494-505 (Jul 01 2011) ISSN: 1538-7445 [Electronic] United States
• PMID: 21555370 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: ©2011 AACR.

Chemical References

• ((3Z)-N-(3-chlorophenyl)-3-((3,5-dimethyl-4-((4-methylpiperazin-1-yl)carbonyl)-1H-pyrrol-2-yl)methylene)-N-methyl-2-oxo-2,3-dihydro-1H-indole-5-sulfonamide)
• ABT-737
• Bax protein (53-86)
• Biphenyl Compounds
• Indoles
• Nitrophenols
• Peptide Fragments
• Piperazines
• Protein Kinase Inhibitors
• Proto-Oncogene Proteins
• Proto-Oncogene Proteins c-bcl-2
• Quinazolines
• STAT3 Transcription Factor
• Sulfonamides
• bcl-X Protein
• Erlotinib Hydrochloride
• EGFR protein, human
• ErbB Receptors
• Proto-Oncogene Proteins c-met

Topics

• Adenocarcinoma (drug therapy, enzymology)
• Adenocarcinoma of Lung
• Animals
• Biphenyl Compounds (pharmacology)
• Cell Line, Tumor
• Drug Resistance, Neoplasm
• ErbB Receptors (antagonists & inhibitors)
• Erlotinib Hydrochloride
• Humans
• Indoles (pharmacology)
• Lung Neoplasms (drug therapy, enzymology)
• Mice
• Nitrophenols (pharmacology)
• Peptide Fragments (metabolism)
• Piperazines (pharmacology)
• Protein Kinase Inhibitors (pharmacology)
• Proto-Oncogene Proteins (metabolism)
• Proto-Oncogene Proteins c-bcl-2 (metabolism)
• Proto-Oncogene Proteins c-met (metabolism)
• Quinazolines (pharmacology)
• STAT3 Transcription Factor (metabolism)
• Signal Transduction
• Sulfonamides (pharmacology)
• Transplantation, Heterologous
• bcl-X Protein (metabolism)