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Copyright ©2014 Baishideng Publishing Group Co.
World J Gastroenterol. Feb 28, 2014; 20(8): 1940-1950
Published online Feb 28, 2014. doi: 10.3748/wjg.v20.i8.1940
Table 3 Telomerase as a marker of disease in colorectal cancer
Ref.CasesMain findings
Engelhardt et al[32], 199780 (50 CRCs, 20 polyps, 10 colitis) cancerous and 50 CRC patient-matched non-cancerous mucosa specimensTelomerase activity
Absent in normal tissues
Higher in CRCs than in nonneoplastic lesions
Higher in late-stage than in early-stage tumours
Tatsumoto et al[58], 2000100 CRC and patient-matched non-cancerous mucosa specimensTelomerase activity
Higher in CRC than in adjacent non-cancerous mucosa
Detectable in adjacent non-cancerous mucosa derived from intestinal crypt basal cells
Not correlated with CRC stage or grade
Has prognostic value for OS and DFS (high telomerase activity: poor prognosis)
Niiyama et al[59], 2001140 CRC and patient-matched non-cancerous mucosa specimens; 20 adenomasTERT mRNA and telomerase activity
Higher in CRCs than in adenomas
Higher in adenomas than in normal mucosa
Naito et al[60], 200166 (50 adenomas, 6 mucosal carcinomas, 10 invasive carcinomas) specimensPositive correlation between TERT mRNA and telomerase activity
TERT levels increase with adenoma-carcinoma sequence
Gertler et al[61], 200257 CRC and patient-matched non-cancerous mucosa specimensBoth CRC and adjacent non-cancerous mucosa are positive for TERT
TERT levels lower in tumours than in non-cancerous mucosa in most cases
TERT levels not correlated with tumour stage
TERT has prognostic value for OD and DFS (high telomerase activity: poor prognosis)
Kawanishi-Tabata et al[62], 2002122 CRCs, stage II(52 colon, 70 rectum)80% of CRC are telomerase-positive
Higher percentage of telomerase-positive tumours in the colon than in the rectum
High telomerase activity: Good prognosis
Ghori et al[63], 200230 CRCs and 20 patient-matched non-cancerous mucosa specimensTelomerase activity
Higher in CRCs than in adjacent non-cancerous mucosa
Correlated with Duke's stage
Boldrini et al[64], 200236 CRC and patient-matched non-cancerous mucosa specimens, 8 adenomatous polyps, 9 dysplastic polypsTelomerase activity
Absent in normal mucosa and adenomas
Higher in CRCs than in dysplastic polyps
Higher in late-stage than in early-stage tumours
Maláska et al[65], 200441 CRC and patient-matched non-cancerous mucosa specimensTelomerase activity
Present in 83% of CRCs
Absent or at very low level in normal mucosa
Higher in metastatic tumours
Boldrini et al[66], 200443 CRCsTERT levels and telomerase activity higher in tumours with mutated TP53
Sanz-Casla et al[67], 2005103 CRCsTelomerase activity increases with tumour progression (Duke's stage)
Higher percentage of telomerase-positive tumours in the colon than in the rectum
Telomerase activity has prognostic value for DFS (high telomerase activity: poor prognosis)
Garcia-Aranda et al[38], 200691 CRC and patient-matched non-cancerous mucosa specimensTelomerase activity
Present in 81% of CRCs
Present at very low levels in 15% of normal samples
Not correlated with tumour progression
No prognostic value
Vidaurreta et al[68], 200797 CRCsTelomerase activity
Present both in MSI and MSS tumours
Has prognostic value for OS (high telomere activity: poor prognosis)
Bautista et al[69], 2007108 rectal cancer and patient-matched non-cancerous mucosa specimensTelomerase activity
Higher in rectal cancer than in normal mucosa
Not correlated with tumour stage and grade
Has prognostic value for DFS and OS
Terrin et al[55], 200885 CRC and 42 patient-matched non-cancerous mucosa specimens, 49 plasma samplesTERT levels
Higher in CRCs than in adjacent non-cancerous mucosa
Increase with tumour stage and grade
Not correlated with MSI status
Not correlated with tumour location
Plasma TERT levels correlated with tumour TERT levels
Valls Bautista et al[70], 20096 cases, each with cancer, polyps and normal mucosa; 8 polyps and normal mucosaTelomerase activity
Increases with adenoma-carcinoma sequence
Kojima et al[71], 2011106 CRC and paired adjacent non-cancerous mucosa specimensElongation of the 3’OH of telomere by telomerase may increase Malignant potential of cancer cells
Telomerase activity has prognostic values for OS (telomeraseactivated without 3'OH shortened telomeres: poor prognosis)
Safont et al[72], 201148 CRC and adjacent non-cancerous mucosa specimens and 48 plasma samplesPlasma TERT levels correlated with tumour TERT levels
Higher circulating TERT levels in stage IV tumours
No correlation between telomerase expression and prognosis
Bertorelle et al[73], 2013137 CRCsTERT levels:
Increase with tumour stage and grade
Not correlated with MSI status
Not correlated with tumour location
Have prognostic value for OS and for both OS and DFS for stage II patients (high TERT levels: poor prognosis)