title: Comparison of clinicopathological features and hRad21 expression between telomerase-dependent and telomerase-independent colorectal cancer.
abstract: OBJECTIVE
  To investigate the difference of clinicopathological features and expression of hRad21 between telomerase-dependent and telomerase-independent colorectal cancer (CRC).
  
  
  METHODS
  By detecting telomerase activity of surgical specimens using the TRAP method, 251 cases diagnosed as CRC were allocated to the telomerase-dependent and telomerase-independent groups, as appropriate. Expression difference of hRad21 between the two groups was investigated by immunohistochemistry. All patients were followed-up and clinicopathological features were compared.
  
  
  RESULTS
  There were 38 and 213 cases in the telomerase-independent and telomerase-dependent groups, respectively. Expression of hRad21 in the telomerase-independent group is higher than that in the telomerase-dependent group. Clinicopathological analysis indicated that invasion of the rectal wall (T stage) in the telomerase-independent group was more superficial than that in the telomerase group (p=0.022). Age, gender, location of tumor, serum CEA, CA19-9, lymph node metastasis, distant metastasis, TNM stage and tumor differentiation showed no difference between groups. Follow-up indicated a significantly shortened survival time in the telomerase-dependent group (p=0.006).
  
  
  CONCLUSIONS
  Most CRC (84.9%) maintain their telomeres by telomerase, while a minority (15.1%) do so by telomerase-independent pathway. Depth of invasion in the telomerase-independent group was lower than that the telomerase group. Follow-up indicated that patients of telomerase-independent group had a higher survival rate than that of telomerase-dependent group. Expression of hRad21 in telomerase-independent CRC is higher than that of telomerase-dependent group, which suggested that hRad21 may be an important protein involved in telomerase-independent telomere maintenance mechanisms.
authors.affiliation: Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
authors.forename: Bing-Qiang
authors.initials: BQ
authors.lastname: Yi
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.forename: Zhen-Jun
authors.initials: ZJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D018797:Cell Cycle Proteins; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000401:mortality / Q000473:pathology*; D004268:DNA-Binding Proteins; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000032:analysis*; D010750:Phosphoproteins / Q000032:analysis*; D015996:Survival Rate; D019098:Telomerase / Q000032:analysis / Q000502:physiology*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; C429022:RAD21 protein, human; D019098:Telomerase