Identification of stem-like cells in non-small cell lung cancer cells with specific peptides

• Specific binding peptides for lung CSCs/CSLCs were identified.
• Specific binding peptides were used to isolate and analyze lung CSCs/CSLCs.
• Subpopulation of lung CSCs/CSLCs categorized by binding peptides was characterized.

Recent studies indicate that tumor maintenance, metastasis and drug-resistance are mainly conducted by a small subset of cancer cells which are termed cancer stem cells (CSCs) or cancer stem-like cells (CSLCs). Successful identification of CSCs/CSLCs might lead to discovery of the novel and effective therapeutic targets for cancers. In our study, lung CSCs/CSLCs were enriched by sphere-forming assay. Screening and selection of specific binding peptides for lung CSCs/CSLCs were performed with bacterial surface display method. Selected peptide named HCBP-1 exhibited highest specific binding capability as examined by flow cytometry and fluorescence microscopy. Drug-resistant lung CSCs/CSLCs might be characterized with HCBP-1 peptide and several microRNAs related to the stem-like properties were discriminatively expressed in HCBP-1+ subpopulation. Moreover, at least two distinct subpopulations in H460 tumor sphere cells could be distinguished by HCBP-1 peptide. Thus, a new method was established to identify lung CSCs/CSLCs, which provided robust approaches for the research of CSCs/CSLCs.