ORIGINAL ARTICLE CD133-Positive Cells from Non-Small Cell Lung Cancer Show Distinct Sensitivity to Cisplatin and Afatinib Angela Alama • Rosaria Gangemi • Silvano Ferrini • Gaia Barisione • Anna Maria Orengo • Mauro Truini • Maria Giovanna Dal Bello • Francesco Grossi Received: 15 May 2014 / Accepted: 7 October 2014 Ó L. Hirszfeld Institute of Immunology and Experimental Therapy, Wroclaw, Poland 2015 Abstract The standard of care for advanced non-small cell lung cancer (NSCLC) consists in cisplatin-combina- tion chemotherapy. In patients bearing tumors with activating mutations of the epidermal growth factor re- ceptor (EGFR), the inhibition of the EGFR intracellular tyrosine kinase can induce up to 80 % response rates. However, both therapeutic strategies will eventually lead to recurrent disease due to the development of drug resis- tance. The identification of rare cancer stem-like cells able to repopulate the tumor, after failure to standard treatment modalities, has led to characterize these cells as potential therapeutic targets. This article will address the role of the CD133/EpCAM stem cell-related markers and explore cell sensitivity to cisplatin and to the EGFR-tyrosine kinase inhibitor, afatinib. Three human NSCLC cell lines, one wild-type (A549) and two harboring EGFR mutations (H1650 and H1975), as well as 20 NSCLC primary cul- tures, were grown in non-differentiating culture conditions for stem cell enrichment. Flow-cytometry analyses of CD133 and EpCAM and cell sensitivity to cisplatin and afatinib were performed. Moreover, the expression of ac- tivated EGFR was assessed by Western blot. The cell lines and primary cultures grown in non-differentiating culture conditions were enriched with CD133/EpCAM-positive cells and were significantly more resistant to cisplatin and more sensitive to afatinib as compared to the differentiated counterpart. In addition, increased EGFR-phosphorylation in non-differentiated cultures was observed. The present findings suggest that afatinib might be beneficial for pa- tients bearing tumors with constitutively activated EGFR, to target chemo-resistant CD133/EpCAM-positive cancer stem cells. Keywords NSCLC Á CD133 Á EpCAM Á Cisplatin Á Afatinib Á Drug-resistance Introduction Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death in both men and women in the US and accounts for approximately 85 % of all cases of lung cancer (Ferlay et al. 2010). The treatment of NSCLC is determined by stage, being surgery the treatment of choice for early and localized disease. Multimodal cisplatin-based chemotherapy has become the standard of care for patients with advanced and metastatic neoplasms (Cufer et al. 2013). Recent advances in lung cancer biology revealed a number of molecular markers, which can be potentially targeted by novel agents. Among all, activating epidermal A. Alama and R. Gangemi equally contributed to this work. Electronic supplementary material The online version of this article (doi:10.1007/s00005-015-0330-5) contains supplementary material, which is available to authorized users. A. Alama (&) Á M. G. D. Bello Á F. Grossi Lung Cancer Unit, IRCCS A.O.U. San Martino-IST, National Institute for Cancer Research, Largo Rosanna Benzi, 10, 16132 Genoa, Italy e-mail: angela.alama@hsanmartino.it R. Gangemi Á S. Ferrini Á G. Barisione Á A. M. Orengo Laboratory of Bio-therapy, IRCCS A.O.U. San Martino-IST, National Institute for Cancer Research, Largo Rosanna Benzi, 10, 16132 Genoa, Italy M. Truini Department of Pathology, IRCCS A.O.U. San Martino-IST, National Institute for Cancer Research, Largo Rosanna Benzi, 10, 16132 Genoa, Italy Arch. Immunol. Ther. Exp. DOI 10.1007/s00005-015-0330-5 123