Detection of putative stem cell markers, CD 44/ CD 133, in primary and lymph node metastases in head and neck squamous cell carcinomas. A preliminary immunohistochemical and in vitro study

OBJECTIVES: Investigators hypothesized that cancer stem cells (CSCs) could play a role in determining cancer progression by metastasizing to cervical lymph node (N+) and then influencing prognosis of head and neck squamous cell carcinomas (HNSCCs) patients. DESIGN: To identify CSCs in HNSCCs and their clonogenic capacity. SETTING: In vitro study. PARTICIPANTS: Putative CSCs from 29 primary HNSCCs and 19 corresponding node metastases were analyzed. MAIN OUTCOME MEASURES: Immunohistochemical (IHC) was performed, and CSCs' clonogenic in vitro capacity was tested; ones epithelial nature of cancer cells forming colonies was confirmed by a second IHC, fluorescence-activated cell sorting (FACS) analysis helped in counting CD44/CD133-CSCs markers percentage expression in HNSCC tumour-derived cultures. RESULTS: Immunohistochemical showed CD44 (93.1%) and CD133 (10.34%) expression; FACS-analysis showed the enrichment of CD44/CD133 cancer cells, with the highest clonogenic capacity of CD44+-subpopulation; a higher CD44 rates were documented from N+ subcultures than from original tumours (P < 0.05). CONCLUSIONS: A putative cancer stem-like cell population is detectable in HNSCCs, and our findings show their in vitro clonogenic capacity by demonstrating that CD44+-cultured cells are the main population proliferating obtained by N+ HNSCC metastases, emphasizing their possible role in tumour progression.