title: Expression of smoothened protein in colon cancer and its prognostic value for postoperative liver metastasis.
abstract: BACKGROUDS: The hedgehog (Hh) signaling pathway is composed of patched (PTCH) and smoothened (SMO), two transmembrane proteins, and downstream glioma-associated oncogene homolog (Gli) transcription factors. Hh signaling plays a pathological role in the occurrence and development of various cancers.
  
  
  METHODS
  To investigate the expression of SMO protein in colon cancer and its association with clinicopathological parameters and postoperative liver metastasis, immunohistochemistry was performed with paraffin-embedded specimens of 96 cases. Relationships between SMO protein expression and clinicopathological parameters, postoperative liver metastasis were analyzed.
  
  
  RESULTS
  IHC examination showed that SMO protein expression was significantly increased in colon cancer tissues compared to normal colon tissues (P = 0.042), positively related to lymph node metastases (P = 0.018) and higher T stages (P = 0.026). Postoperative live metastasis-free survival was significantly longer in the low SMO expression group than in those with high SMO expression (48.7 ± 8.02 months vs 28.0 ± 6.86 months, P=0.036). Multivariate analysis showed SMO expression level to be an independent prognostic factor for postoperative live metastasis-free survival (95% confidence interval [CI] =1.46-2.82, P = 0.008).
  
  
  CONCLUSIONS
  Our results suggest that in patients with colon cancer, the SMO expression level is an independent biomarker for postoperative liver metastasis, and SMO might play an important role in colon cancer progression.
authors.affiliation: Department of General Surgery, Second Hospital of Shandong University, Jinan, China. dingyinlu@126.com
authors.forename: Yin-Lu
authors.initials: YL
authors.lastname: Ding
authors.forename: Qi-San
authors.initials: QS
authors.lastname: Wang
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Zhao
authors.forename: Lei
authors.initials: L
authors.lastname: Xiang
mesh_terms: D016022:Case-Control Studies; D003106:Colon / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008113:Liver Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000556:secondary / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011183:Postoperative Complications; D011379:Prognosis; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D000072086:Smoothened Receptor; D015996:Survival Rate; D046888:Tissue Array Analysis
chemical_list: D043562:Receptors, G-Protein-Coupled; C491023:SMO protein, human; D000072086:Smoothened Receptor