Molecular mechanism of erlotinib resistance in epidermal growth factor receptor mutant non-small cell lung cancer cell line H1650

• Published in: Zhongguo fei ai za zhi 2012-12, Vol.15 (12), p.689-693
• Main Authors: Han, Ruili, Wang, Xiaoli, Zhong, Diansheng, Zhao, Juan, Chen, Zhe, Sun, Linlin, Wang, Jing, Zhang, Jinbang
• Format: Article
• Language: Chinese
• Subjects: Blotting, Western; Carcinoma, Non-Small-Cell Lung - genetics; Carcinoma, Non-Small-Cell Lung - metabolism; Carcinoma, Non-Small-Cell Lung - pathology; Cell Line, Tumor; Cell Survival - drug effects; Cell Survival - genetics; Chromones - pharmacology; Cytotoxicity; Drug Resistance, Neoplasm - genetics; Enzyme Inhibitors - pharmacology; Epidermal growth factor; Epidermal growth factor receptor; Erlotinib Hydrochloride; Erlotinib resistance; Humans; Kinases; Lung cancer; Lung neoplasms; Lung Neoplasms - genetics; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Morpholines - pharmacology; Mutation; Phosphatidylinositol 3-Kinases - antagonists & inhibitors; Phosphatidylinositol 3-Kinases - metabolism; Phosphorylation; Phosphorylation - drug effects; Protein Kinase Inhibitors - pharmacology; Proto-Oncogene Proteins c-akt - metabolism; PTEN Phosphohydrolase - metabolism; Quinazolines - pharmacology; Receptor, Epidermal Growth Factor - genetics; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction - drug effects
• ISSN: 1009-3419; 1999-6187
• DOI: 10.3779/j.issn.1009-3419.2012.12.02

Epidermal growth factor receptor (EGFR) overexpression and mutations were existed in more than 40% of the lung cancer, and it's the one of molecular targets in clinical treatment. But the EGFR tyrosine kinase inhibitors (TKI)-resistance is becoming a challenging clinical problem as following the application of EGFR-TKIs, Gefitinib or Erlotinib. However, the mechanistic explanation for resistance in the some cases is still lacking. Here we researched the resistance mechanism of H1650 cells. Using real-time RT-PCR to analyze the EGFR mRNA expression level in EGFR wild-type non-small cell lung cancer (NSCLC) cells; MTT analysis detected the cytotoxicity for NSCLC cells to Erlotinib; Western blot analysis examined the mutant situations and the downstream signaling protein phosphorylation level in EGFR-mutant NSCLC cells with the treatment of Erlotinib or/and PI3K inhibitor, LY294002. In the EGFR wild-type NSCLC cells, the expression level of EGFR mRNA varied dramatically and all the cells showed resistant to Erlotinib; In the EGFR-mutant cells, HCC827 and H1650 (the same activating-mutation type), HCC827 cells were Erlotinib-sensitive as well as H1650 demonstrated primary relative resistance. Western blot analysis showed the loss of PTEN and the p-AKT level was not inhibited with the treatment of Erlotinib or/and LY294002 in H1650 cells, while HCC827 cells were no PTEN loss and definitively decrease of p-AKT level. EGFR wild-type NSCLC cells were resistant to Erlotinib no matter of how EGFR mRNA expression level. EGFR-activating mutations correlated with responses to Erlotinib. The PTEN loss and activation of AKT signaling pathway contributed to Erlotinib resistance in EGFR-mutant NSCLC cell line H1650.