title: CD44-negative cells in head and neck squamous carcinoma also have stem-cell like traits.
abstract: CD44 is generally accepted as a surrogate marker for head and neck squamous carcinoma cancer stem cells (HNSC CSCs) and only CD44+ HNSC cells have tumour initiating capacity. However, a recent report suggested that CSCs themselves might be heterogenous due to various genetic alterations. Here, we compared in vitro stem-like cell characteristics, chemoresistance and in vivo tumour formation capacity of CD44+ and CD44- HNSC cells obtained from primary HNSC patient specimens. CD44- HNSC spheroid cells generated spheroid cells again after seeding of single-dissociated spheroid CD44- HNSC cells. Immunocytochemistry assays revealed that various stem cell markers, including octamer-binding transcription factor 4 (OCT4), sex determining region Y-box 2 (SOX2) and nestin were up-regulated in CD44- spheroid cells, similar to CD44+ spheroid cells. Furthermore, CD44- spheroid cells appeared to be chemoresistant to cisplatin and showed increased levels of ABCG2, similar to CD44+ spheroid cells. Of most interest, as few as 1000 CD44- spheroid cells were able to give rise to tumours in nude mice. The collective data indicate that the cell surface marker CD44 cannot be used as a selective marker of spheroid-forming, tumour-initiating or chemoresistant cell populations, and further indicate the limitation of current HNSC CSC identification methods using the CD44 cell surface marker.
authors: School of Life Sciences and Biotechnology, Korea University, Republic of Korea.
authors: Se-Yeong
authors: SY
authors: Oh
authors: Hyun Jung
authors: HJ
authors: Kang
authors: Young Sook
authors: YS
authors: Kim
authors: Hyunggee
authors: H
authors: Kim
authors: Young Chang
authors: YC
authors: Lim
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D005434:Flow Cytometry; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014183:Transplantation, Heterologous
chemical_list: D018960:Hyaluronan Receptors