title: [Expression and significance of p-Stat3 and its downstream gene c-myc in laryngeal squamous cell carcinoma tissue and cell line].
abstract: OBJECTIVE
  To detect the expressions of p-Stat3 and c-myc in human laryngeal squamous cell carcinoma (LSCC) tissue and Hep2 cell line, and to find the relationship between them.
  
  
  METHODS
  Immunohistochemistry was used to detect the expressions of p-Stat3 and c-myc in 60 cases of LSCC and 30 cases of vocal cord polyp tissue. The protein levels of p-Stat3 and c-myc in Hep2 cell line was determined by immunocytochemistry. Western blotting was used to determine the protein levels of p-Stat3 and c-myc in Hep2 after treating with different concentrations of Stattic.
  
  
  RESULTS
  The positive rates of p-Stat3 and c-myc were 65% and 70% in the LSCC tissue, compared with that in the vocal cord polyp tissue, with significant difference (P < 0.05). The expression of p-Stat3 in LSCC tissue was associated with that of c-myc (r = 0.273, P < 0.05). The protein levels of p-Stat3 and c-myc were detected in the Hep2 cell line. Stattic inhibited Stat3 phosphorylation and c-myc in the Hep2 cell line in a concentration-dependent manner.
  
  
  CONCLUSIONS
  p-Stat and c-myc were up regulated in the tissue of laryngeal squamous cell carcinoma and the Hep2 cell line. Stattic inhibits the constitutively active p-Stat3 signaling pathway, and downregulats the expression of c-myc. The strong constitutive p-Stat3 signaling pathway in LSCC makes p-Stat3 a target for the development of novel therapeutic strategies.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Sang
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D006258:Head and Neck Neoplasms / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007822:Laryngeal Neoplasms / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: C489427:MYC protein, human; D016271:Proto-Oncogene Proteins c-myc; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human