The expression of hTERT mRNA and cellular immunity in gastric cancer and precancerosis.

aimTo observe the expression of Human telomerase reverse transcriptase (hTERT) in gastric carcinomas and precancerosis lesions, to evaluate the immune state of such patients, and to then study the clinical significance of hTERT and immune state for the diagnosis, treatment and prognosis of gastric cancer.

methodsIn situ hybridization was used to detect the expression of hTERT mRNA in 116 endoscopic of gastric mucosa. Analyzed tissue samples were as follows: 30 cases of chronic superficial gastritis (CSG), 44 of precancerosis lesions (including 27 of chronic atrophic gastritis, 8 of adenomatous polyp and 9 of gastric ulcer) and 42 of gastric cancer (GC). In addition, the T lymphocyte subsets (CD3(+), CD4(+), CD8(+), CD4(+)/CD8(+)) and natural killer cells (NK) in peripheral blood were determined by flow cytometric analysis (FCM) in 30 cases of CSG, 27 of precancerosis (chronic atrophic gastritis, CAG), and 42 of GC. The data were compared with those of normal control (NC).

resultsThe detected positive rate of hTERT varied as follows: 86 % (36/42) in GC, 36 % (16/44) in precancerosis lesions and 0 % (0/30) in CSG. The expression of hTERT mRNA was not associated with patient gender, tumor location, macroscopic type, lymph node metastasis, or degree of differentiation. It was found that the CD3(+), CD4(+) of the CSG group were lower than that of NC (P<0.05). Meanwhile, the T lymphocyte subsets (CD3(+), CD4(+), CD4(+)/CD8(+) ratio) and NK cells of CAG were remarkably lower than that of NC and CSG groups (P<0.05-0.01). Values of T cells and NK cells of the GC group were significantly abnormal when compared with the CAG group (P<0.05-0.01). Furthermore, with tumor progression, the function of T cells was weakened gradually.

conclusionThe expression of telomerase may be a crucial step in gastric carcinogenesis and increased hTERT mRNA may serve as a novel marker for diagnosis of GC. The immune state of patients with GC and precancerosis was somewhat depressed, which indicates the importance of cellular immunological assays in cancer patients.