| Telomere is located at the physical end of eukaryotic chromosome which consists of G-rich 6-bp repetitive DNA sequence. Telomerase is a RNA-dependent DNA polymerase-reverse transcriptase, which can synthesize telomere DNA sequence and add to the chomosome 3'-end. Deficiency of telomerase activity expression in normal cells can lead to the loss of telomere segments and cells' aging and apoptosis. Malignant tumors can get a chance of unlimited proliferation due to the activation of telomerase and thereby overcoming the shortening of telomere. Telomerase activation is regarded as the molecular basis of unlimited proliferation of malignant tumors. It is of great significance to the pathogenesis of malignant tumors.T lymphocytes are the major immuno-cative cells, which participate in the immunoreaction against tumour. Not only do they play a great role in cell immunity, but also do they play role in immunoregulation. The regulation is realized by its subsets cells.On the surface of erythrocytes, there are many substance participating in the immunoreaction, such as CR1, CR3, CD59,CD58, DAF, SOD enzyme and so on.They all take part in the complex regulation of immunonetwork. Red cells have the function of immune adherence. They can adhere,transport and eliminate immune complex in circulation. They take part in the regulation of immune activity of T, B, NK, LAK cell and phagocytes, too. Therefore red cells are an important role in the body's immunity against tumour.Telomerase activity of tissue and T-lymphocyte subsets of peripheral blood and erythrocyte immune were detected in 92 patients with gastric cancer and colorectal cancer. The methods of a modified telomeric repeat amplification protocol(TRAP) and the methods of TRAP-ELISA, direct immunofiurescent staining technique with flow cytometry(FCM)and immune adherence rosette were used in this research, compared with 61 cases of normal tissue and healthy blood donor as control. The results show: (1)The value of telomerase activity highly expressed in gastric cancer and colorectal cancer patients than those of 61 cases adjacent normal tissue (P<0.01); (2) no significance between differentiation degree, lymph node metastases and telomerase activity level in cancer patients was found (P>0.05) ; (3) Telomerase activity in cancer patients was relative with clinical stages (P<0.05) ; (4) The value of RBC-C3bRR was lower and RBC-ICR was higher in the group of cancer patients ascompared with the group of normal control (P<0.01); (5) The value of CD4+, CD4+/CD8+were lower in cancer patients than 60 healthy normal control and the value of CD8+ was not statistical different between two groups (P>0.05); (6) Not only was the RBC-C3bRR, CD4+and CD4+/CD8+ ratio lower and RBC-ICR higher in the gastric cancer group than the control groups found(P<0.01), but also a remarkable significance in different stages was found(P<0.05), A positive correlation between RBC-CjbRR and the ratio of CD4+/CD8+ was found in the gastric cancer groups. (7) no significance between the methods of sliver staining TRAP and the methods of TRAP-ELISA was founded (P>0.05).Telomerase activity that was highly expressed in gastric cancer and colorectal cancer showed telomerase activity was related to occurrence and progression of gastrointestinal malignant diseases. The decreased CD4+ and CD4+/CD8+ratio indicated immune function by T-lymphocyte was depressed and immune balance was interrupted. The reduce of RBC-C3bRR and increase of RBC-ICR showed that ability of immune adherence of red cells was significantly depressed in the patients with malignant tumours. The results in whole immune system function and the anti-tumour-immune activity depressed.This study showed that detection of telomerase activity and immune function have important significance in clinical diagnosis and therapy evaluatd and prognosis assessment of gastrointestinal malignant tumour.It provides a simple and exact method and might be used as a marker for tumor diagnosis and therapy. |
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