Expression of human telomerase RNA is an early event of stomach carcinogenesis.
Expression of human telomerase RNA (hTR) and telomerase activity in gastric cancer and corresponding non-cancerous mucosa were studied. Telomerase activity was detected in 23 (88%) of 26 carcinoma tissues. Although all tumor specimens and non-cancerous mucosa expressed various levels of hTR, 21 (81%) of 26 cases expressed hTR at a higher level in the tumor than that in the corresponding mucosa. All 8 gastric carcinoma cell lines also expressed hTR at high levels. Nine (35%) of 26 non-cancerous mucosa showed telomerase activity and all of them contained intestinal metaplasia. The incidence of telomerase-positive mucosa in grade 2 intestinal metaplasia was significantly higher than that in grade 0 or grade 1 intestinal metaplasia, whereas hTR overexpression was found in grade 0 or grade 1 intestinal metaplasia as well as grade 2 intestinal metaplasia. The degree of Helicobacter pylori infection increased in parallel with the level of hTR expression and telomerase positivity. These results overall suggest that Helicobacter pylori infection may be a strong trigger for hTR overexpression in intestinal metaplasia, and this may lead to telomerase reactivation.
Kuniyasu
H
H
First Department of Pathology, Hiroshima University School of Medicine.
Domen
T
T
Hamamoto
T
T
Yokozaki
H
H
Yasui
W
W
Tahara
H
H
Tahara
E
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004789:Enzyme Activation; D005260:Female; D016481:Helicobacter Infections / Q000201:enzymology*; D016480:Helicobacter pylori; D006801:Humans; D007413:Intestinal Mucosa / Q000201:enzymology / Q000382:microbiology / Q000473:pathology; D008297:Male; D008679:Metaplasia / Q000201:enzymology / Q000382:microbiology; D008875:Middle Aged; D011230:Precancerous Conditions / Q000201:enzymology* / Q000382:microbiology; D012313:RNA / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000382:microbiology; D019098:Telomerase / Q000235:genetics* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D012313:RNA; D019098:Telomerase