Mesenchymal circulating tumor cells (CTCs) and OCT4 mRNA expression in CTCs for prognosis prediction in patients with non-small-cell lung cancer.

Abstract

Circulating tumor cells (CTCs) with epithelial-to-mesenchymal transition (EMT) phenotypes might be related to tumor progression while OCT4 expression is involved in tumor metastasis and poor prognosis. But the possible clinical significance of EMT phenotypes of CTCs from non-small-cell lung cancer (NSCLC) patients has still to be demonstrated. Furthermore, none has been investigated the expression of OCT4 in CTCs. We therefore identified the EMT phenotype-based subsets of CTCs and determined the OCT4 expression status of CTCs in NSCLC patients, to explore their possible clinical relevance. 37 NSCLC patients and ten healthy volunteers were enrolled, respectively. The Canpatrol™ CTC enrichment technique was used to isolate and identify the EMT phenotype-based subsets of CTCs. OCT4 expression in each CTC was also determined. Results were correlated with patients' clinico-pathological features. CTCs were detected in 33 of 37 (89.2%) NSCLC patients, and no CTCs were identified in ten healthy volunteers. Three CTCs phenotypes, including epithelial, biophenotypic, and mesenchymal CTCs were identified based on the expression of EMT markers. Mesenchymal CTCs were more commonly found in patients with distant metastasis. Patients with distant metastasis tended to have a higher median CTCs number. OCT4-positive was observed in 21 of 28 (75.0%) patients. High expression of OCT4 tended to occur in advanced patients as well as in distant metastatic patients. The findings suggest that identification of CTCs by EMT markers as well as evaluation of OCT4 expression status by assessment of OCT4 expression in CTCs could serve as potential adjuncts for evaluating metastasis and prognosis in NSCLC patients.