Src Promotes Survival and Invasion of Lung Cancers with Epidermal Growth Factor Receptor Abnormalities and Is a Potential Candidate for Molecular-Targeted Therapy

• Published in: Molecular cancer research Vol. 7; no. 6; pp. 923 - 932
• Main Authors: Leung, Elaine Lai-Han, Tam, Issan Yee-San, Tin, Vicky Pui-Chi, Chua, Daniel Tsin-Tien, Sihoe, Alan Dart-Loon, Cheng, Lik-Cheung, Ho, James Chung-Man, Chung, Lap-Ping, Wong, Maria Pik
• Format: Journal Article
• Language: English
• Published: United States American Association for Cancer Research 01.06.2009
• Subjects: Apoptosis - drug effects; Carcinoma, Non-Small-Cell Lung - enzymology; Carcinoma, Non-Small-Cell Lung - genetics; Carcinoma, Non-Small-Cell Lung - pathology; Cell Line, Tumor; Cell Movement - drug effects; EGFR mutation; Gene Amplification; Humans; Immunohistochemistry; Lung Neoplasms - enzymology; Lung Neoplasms - genetics; Lung Neoplasms - pathology; Mutation; Neoplasm Invasiveness; non–small cell lung cancer; Phosphorylation - drug effects; Protein Kinase Inhibitors - pharmacology; Quinazolines - pharmacology; Receptor, Epidermal Growth Factor - antagonists & inhibitors; Receptor, Epidermal Growth Factor - genetics; Receptor, Epidermal Growth Factor - metabolism; Reproducibility of Results; RNA, Small Interfering - genetics; RNA, Small Interfering - metabolism; Src kinase; src-Family Kinases - antagonists & inhibitors; src-Family Kinases - metabolism
• ISSN: 1541-7786; 1557-3125; 1557-3125
• DOI: 10.1158/1541-7786.MCR-09-0003

Molecular-targeted therapy using tyrosine kinase inhibitors against epidermal growth factor receptor (EGFR) is an effective therapy for non–small cell lung cancer that harbor EGFR mutations. This study aimed to investigate the role of Src, a close EGFR associator, as a drug target in NSCLC cells with different EGFR genomic statuses. Src inhibition was achieved using 4-(4′-Phenoxyanilino)-6,7-dimethoxyquinazolinee (SKI-1) and the specificity of action was verified by RNA interference. The results showed that SKI-1 induced significant apoptosis in a dose-dependent manner in cancer cells with high basal Src activation. Activation of FAK and p130Cas was involved in Src-mediated invasion in SKI-1–sensitive cells. SKI-1 inhibited phosphorylation of EGFR as well as EGFR downstream effectors, such as signal transducers and activators of transcription 3/5, extracellular signal-regulated kinase 1/2 and AKT in the mutant cells but not the wild-type cells. This inhibition profile of EGFR implicates that induction of apoptosis and sensitivity of mutant cells to SKI treatment is mediated by EGFR and EGFR downstream pathways. Cotreatment with SKI-1 and gefitinib enhanced apoptosis in cancer cells that contained EGFR mutation and/or amplification. SKI-1 treatment alone induced significant apoptosis in H1975 cells known to be resistant to gefitinib. Src phosphorylation was shown by immunohistochemistry in around 30% of primary lung carcinomas. In 152 adenocarcinomas studied, p-Src was associated with EGFR mutations ( P = 0.029). Overall, the findings indicated that Src could be a useful target for treatment of non–small cell lung cancer. Besides EGFR genomic mutations, other forms of EGFR and related family member abnormalities such as EGFR amplification might enhance SKI sensitivity. (Mol Cancer Res 2009;7(6):923–32)