Journal
INTERNATIONAL JOURNAL OF CANCER
Volume 124, Issue 8, Pages 1778-1784Publisher
WILEY
DOI: 10.1002/ijc.24150
Keywords
MET; amplification; EGFR; gefitinib; lung cancer
Categories
Funding
- Ministry of Education, Culture, Sports, Science and Technology of Japan [18790993]
- Specialized Program of Research Excellence in Lung Cancer [P50CA70907, P01CA58187]
- Genome Canada/British Columbia and Canadian Institutes of Health Research
- Grants-in-Aid for Scientific Research [18790993] Funding Source: KAKEN
Ask authors/readers for more resources
We analyzed MET protein and copy number in NSCLC with or without EGFR mutations untreated with EGFR tyrosine kinase inhibitors (TKIs). MET copy number was examined in 28 NSCLC and 4 human bronchial epithelial cell lines (HBEC) and 100 primary tumors using quantitative real-time PCR. Positive results were confirmed by array comparative genomic hybridization and fluorescence in-situ hybridization. Total and phospho-MET protein expression was determined in 24 NSCLC and 2 HBEC cell lines using Western blot. EGFR mutations were examined for exon 19 deletions, T790M, and L858R. Knockdown of EGFR with siRNA was performed to examine the relation between EGFR and MET activation. High-level MET amplification was observed in 3 of 28 NSCLC cell lines and in 2 of 100 primary lung tumors that had not been treated with EGFR-TKIs. MET protein was highly expressed and phosphorylated in all the 3 cell lines with high MET amplification. In contrast, 6 NSCLC cell lines showed phosphoMET among 21 NSCLC cell lines without MET amplification (p = 0.042). Furthermore, those 6 cell lines harboring phospho-MET expression without MET amplification were all EGFR mutant (p = 0.0039). siRNA-mediated knockdown of EGFR abolished phospho-MET expression in examined 3 EGFR mutant cell lines of which MET gene copy number was not amplified. By contrast, phospho-MET expression in 2 cell lines with amplified MET gene was not down-regulated by knockdown of EGFR. Our results indicated that MET amplification was present in untreated NSCLC and EGFR mutation or MET amplification activated MET protein in NSCLC. (C) 2008 Wiley-Liss. Inc.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available