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 ( CSC s) 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 ( HNSCC s) patients. Design To identify CSC s in HNSCC s and their clonogenic capacity. Setting In vitro study. Participants Putative CSC s from 29 primary HNSCC s and 19 corresponding node metastases were analyzed. Main outcome measures Immunohistochemical ( IHC ) was performed, and CSC s' 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 CD 44/ CD 133‐ CSC s markers percentage expression in HNSCC tumour‐derived cultures. Results Immunohistochemical showed CD 44 (93.1%) and CD 133 (10.34%) expression; FACS ‐analysis showed the enrichment of CD 44/ CD 133 cancer cells, with the highest clonogenic capacity of CD 44+‐subpopulation; a higher CD 44 rates were documented from N+ subcultures than from original tumours ( P  < 0.05). Conclusions A putative cancer stem‐like cell population is detectable in HNSCC s, and our findings show their in vitro clonogenic capacity by demonstrating that CD 44+‐cultured cells are the main population proliferating obtained by N+ HNSCC metastases, emphasizing their possible role in tumour progression.