title: The association between telomerase, p53, and clinical staging in colorectal cancer.
abstract: BACKGROUND
  A proposed etiology of tumor activation involves p53 mutations while telomerase may serve as a key enzyme for maintenance of tumor cell proliferation.
  
  
  METHODS
  Telomerase activity levels were measured in colorectal adenocarcinomas and corresponding normal tissue using a modified telomeric repeat amplification protocol, and p53 mutations were identified using immunohistochemical staining. Results were compared with staging data using regression analysis.
  
  
  RESULTS
  Telomerase activity was present in 23 of 23 (100%) of the tumors and only 2 (9%) of normal specimens (P <0.0001). The p53 mutations were present in 18 of 23 (78%) of the tumors. No significant correlation between p53 mutations, telomerase activity levels, and staging was found.
  
  
  CONCLUSIONS
  Telomerase activity in 100% of the tumors suggests telomerase activation is a universal event in colorectal tumor progression; however, telomerase activity appears to be independent of p53 mutations and clinical staging.
authors.affiliation: Department of General Surgery, Madigan Army Medical Center, Tacoma, Washington 98431, USA.
authors.forename: T
authors.initials: T
authors.lastname: Brown
authors.forename: W
authors.initials: W
authors.lastname: Aldous
authors.forename: R
authors.initials: R
authors.lastname: Lance
authors.forename: J
authors.initials: J
authors.lastname: Blaser
authors.forename: T
authors.initials: T
authors.lastname: Baker
authors.forename: W
authors.initials: W
authors.lastname: Williard
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D000368:Aged; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D004796:Clinical Enzyme Tests / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009367:Neoplasm Staging; D011446:Prospective Studies; D012044:Regression Analysis; D012091:Repetitive Sequences, Nucleic Acid; D019098:Telomerase / Q000032:analysis* / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000032:analysis* / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D016159:Tumor Suppressor Protein p53; D019098:Telomerase