Expression of telomerase RNA in oesophageal and oral cancer.
BACKGROUND
Telomerase is detectable in 85% of cancers, but is largely repressed in normal tissues. Human telomerase RNA (hTR) inhibition is a promising anti-cancer strategy, but requires differential expression between malignant and normal tissue.


METHODS
Archival paraffin sections from 48 oral squamous cell carcinomas (SCC) (23 floor of mouth, 25 tongue) and 56 oesophageal carcinomas (41 SCC, 15 adenocarcinomas) were evaluated for hTR expression using a radiolabelled riboprobe. Results were compared with expression in controls and adjacent histologically normal tissue. Statistical analysis was by the chi2 test.


RESULTS
hTR was detectable in 76% of oral SCC overall (floor of mouth 65%, tongue 88%, P=0.61), and in 54% of oesophageal cancers (SCC 51%, adenocarcinoma 60%, P=0.56). Detectable hTR expression was significantly more frequent in oral SCC than oesophageal SCC (P=0.01). hTR expression was only detected in normal tissue at low levels in basal squamous epithelium. There was agreement of hTR expression between 8/9 surgically excised carcinomas and their initial diagnostic biopsies.


CONCLUSIONS
Tumour-specific hTR expression confirms hTR inhibition as a possible therapeutic strategy in some if not all oesophageal and oral cancers. Generally concordant hTR status between biopsy and resection suggest that biopsy may have a role in selecting candidates for telomerase inhibition therapy.
Downey
M G
MG
University Departments of Medical Oncology, Pathology and Surgery, University of Glasgow, UK.
Going
J J
JJ
Stuart
R C
RC
Keith
W N
WN
D000230:Adenocarcinoma / Q000201:enzymology*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D004848:Epithelium / Q000201:enzymology; D004938:Esophageal Neoplasms / Q000201:enzymology*; D015870:Gene Expression; D006801:Humans; D017403:In Situ Hybridization; D009060:Mouth Floor / Q000201:enzymology; D009062:Mouth Neoplasms / Q000201:enzymology*; D015347:RNA Probes; D012334:RNA, Neoplasm / Q000032:analysis / Q000378:metabolism*; D019098:Telomerase / Q000096:biosynthesis* / Q000235:genetics; D014062:Tongue Neoplasms / Q000201:enzymology
D015347:RNA Probes; D012334:RNA, Neoplasm; D019098:Telomerase