title: Head and neck cancer stem cells: the effect of HPV--an in vitro and mouse study.
abstract: OBJECTIVE
  To determine if the behavior of cancer stem cells (CSCs) is affected by human papillomavirus (HPV) status.
  
  
  METHODS
  An in vitro and in vivo analysis of HPV and CSCs.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  We isolated CSCs from HPV-positive and HPV-negative cell lines. Two HPV-negative cell lines underwent lentiviral transduction of E6/E7. Chemoresistence was determined using colony formation assays. Native HPV-positive and HPV E6/E7-transduced cells were compared for lung colonization after tail vein injection in NOD/SCID mice.
  
  
  RESULTS
  The proportion of CSC is not significantly different in HPV-positive or HPV-negative head and neck squamous cell carcinoma (HNSCC) cell lines. The HNSCC CSCs are more resistant to cisplatin than the non-CSCs, but there were no significant differences between HPV-positive and HPV-negative cells. The HPV-negative cancer cells yielded low colony formation after cell sorting. After transduction with HPV E6/E7, increased colony formation was observed in both CSCs and non-CSCs. Results from tail vein injections yielded no differences in development of lung colonies between HPV E6/E7-transduced cells and nontransduced cells.
  
  
  CONCLUSIONS
  Human papillomavirus status does not correlate with the proportion of CSCs present in HNSCC. The HPV-positive cells and those transduced with HPV E6/E7 have a greater clonogenicity than HPV-negative cells. The HNSCC CSCs are more resistant to cisplatin than non-CSCs. This suggests that common chemotherapeutic agents may shrink tumor bulk by eliminating non-CSCs, whereas CSCs have mechanisms that facilitate evasion of cell death. Human papillomavirus status does not affect CSC response to cisplatin therapy, suggesting that other factors explain the better outcomes for patients with HPV-positive cancer.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Alice L
authors.initials: AL
authors.lastname: Tang
authors.forename: John H
authors.initials: JH
authors.lastname: Owen
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Hauff
authors.forename: Jung Je
authors.initials: JJ
authors.lastname: Park
authors.forename: Silvana
authors.initials: S
authors.lastname: Papagerakis
authors.forename: Carol R
authors.initials: CR
authors.lastname: Bradford
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Carey
authors.forename: Mark E
authors.initials: ME
authors.lastname: Prince
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000821:virology; D052162:Human papillomavirus 16 / Q000502:physiology*; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009374:Neoplasms, Experimental / Q000378:metabolism / Q000473:pathology* / Q000821:virology; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology* / Q000821:virology; D030361:Papillomavirus Infections / Q000378:metabolism / Q000473:pathology* / Q000821:virology
keywords: ALDH; HPV; cancer stem cells; chemotherapy; head and neck cancer