Clinical usefulness of telomerase activation and telomere length in head and neck cancer.
BACKGROUND
Telomere shortening at every replication cycle is postulated to limit the life span of human somatic cells. In contrast, activation of telomerase is proposed to be an essential step for cancer cell immortalization. Head and neck cancer is the most common malignancy in the Indian population compared with Western countries. However, there are very few reports on telomerase activity and telomere length in head and neck cancer.


METHODS
Telomerase activation and telomere length alterations were studied in tumor and adjacent normal tissues in 110 patients with head and neck cancer and 40 patients with precancerous/benign conditions. Telomerase activity and telomere lengths were determined by Telomeric Repeat Amplification Protocol (TRAP assay) and Southern blot analysis, respectively.


RESULTS
Telomerase activation was observed in 78.2% of the malignant tissues, 85% of the precancerous tissues, and 53.1% of the adjacent normal tissues. Peak terminal restriction fragment length (TRF) was observed to be significantly lower in malignant tissues compared with the adjacent normal tissues. No significant correlation could be observed between telomerase activation and clinicopathologic characteristics of the patients. Two-year disease-free survival analysis showed that patients showing telomerase activation in the adjacent normal tissues and patients showing higher telomere length in malignant tissues had poor disease-free survival.


CONCLUSIONS
Our results demonstrate the significant clinical usefulness of telomerase activation and telomere length for head and neck cancer patients. These markers may be helpful in predicting the clinical course of the disease and thus in identifying the patients in need of a close follow-up and vigorous adjuvant treatment.
Patel
Mintoo M
MM
Biochemistry Research Section, Division of Research, The Gujarat Cancer Society, Asarwa, Ahmedabad 380016, India. gcriad1@sancharnet.in
Parekh
Lalit J
LJ
Jha
Franky P
FP
Sainger
Rachana N
RN
Patel
Jayendra B
JB
Patel
Devendra D
DD
Shah
Pankaj M
PM
Patel
Prabhudas S
PS
D000293:Adolescent; D000328:Adult; D000368:Aged; D015139:Blotting, Southern; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D011230:Precancerous Conditions / Q000201:enzymology* / Q000473:pathology; D016019:Survival Analysis; D019098:Telomerase / Q000032:analysis / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D019098:Telomerase