Email updates

Keep up to date with the latest news and content from BMC Cancer and BioMed Central.

Open Access Highly Accessed Research article

Properties of resistant cells generated from lung cancer cell lines treated with EGFR inhibitors

Gargi Ghosh13, Xiaojun Lian1, Stephen J Kron2 and Sean P Palecek1*

Author Affiliations

1 Department of Chemical and Biological Engineering, University of Wisconsin, Madison, 1415 Engineering Drive, Madison, WI 53706, USA

2 Ludwig Center for Metastasis Research, University of Chicago, Chicago, IL 60637, USA

3 Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128, USA

For all author emails, please log on.

BMC Cancer 2012, 12:95  doi:10.1186/1471-2407-12-95

Published: 20 March 2012

Abstract

Background

Epidermal growth factor receptor (EGFR) signaling plays an important role in non-small cell lung cancer (NSCLC) and therapeutics targeted against EGFR have been effective in treating a subset of patients bearing somatic EFGR mutations. However, the cancer eventually progresses during treatment with EGFR inhibitors, even in the patients who respond to these drugs initially. Recent studies have identified that the acquisition of resistance in approximately 50% of cases is due to generation of a secondary mutation (T790M) in the EGFR kinase domain. In about 20% of the cases, resistance is associated with the amplification of MET kinase. In the remaining 30-40% of the cases, the mechanism underpinning the therapeutic resistance is unknown.

Methods

An erlotinib resistant subline (H1650-ER1) was generated upon continuous exposure of NSCLC cell line NCI-H1650 to erlotinib. Cancer stem cell like traits including expression of stem cell markers, enhanced ability to self-renew and differentiate, and increased tumorigenicity in vitro were assessed in erlotinib resistant H1650-ER1 cells.

Results

The erlotinib resistant subline contained a population of cells with properties similar to cancer stem cells. These cells were found to be less sensitive towards erlotinib treatment as measured by cell proliferation and generation of tumor spheres in the presence of erlotinib.

Conclusions

Our findings suggest that in cases of NSCLC accompanied by mutant EGFR, treatment targeting inhibition of EGFR kinase activity in differentiated cancer cells may generate a population of cancer cells with stem cell properties.

Keywords:
EGFR tyrosine kinase; Erlotinib; Cancer stem cells; Tumor spheroids; Side population