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Objective To determine the expression of human telomerase reverse transcriptase (hTERT) and P53 in thyroid carcinoma and its relationship with development and prognosis of the carcinoma. Methods Totally 90 cases of thyroid specimens (60 thyroid carcinomas, 10 thyroid adenomas, 10 goitres and 10 normal thyroid tissues) were studied by SP immunohistochemical method. Results Positive immunoreactivity of hTERT and P53 was higher in thyroid carcinoma (P<0.05). The positive rates of hTERT and P53 were higher in undifferentiated carcinomas, carcinomas with lymph nodes metastasis or at stage Ⅲ+Ⅳ than in well-differentiated carcinomas, carcinomas without lymph nodes metastasis or at stage Ⅰ+Ⅱ (P<0.05). The expression of hTERT was significantly related with that of P53 (P<0.05). Conclusion Over-expressed hTERT and P53 may be related to the carcinogenesis and progression of thyroid carcinoma and hTERT expression is related to P53 protein. Examination of expression of hTERT and P53 proteins may be helpful to judge the thyroid cancer's behavior and prognosis.
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Objective: To determine the expression of human telomerase reverse transcriptase (hTERT) and P53 in thyroid carcinoma and its relationship with development and prognosis of the carcinoma. Methods: Totally 90 cases of thyroid specimens (60 thyroid carcinomas, 10 thyroid adenomas, 10 goitres and 10 normal thyroid tissues) were studied by SP immunohistochemical method. Results: Positive immunoreactivity of hTERT and P53 was higher in thyroid carcinoma (P<0.05). The positive rates of hTERT and P53 were higher in undifferentiated carcinomas, carcinomas with lymph nodes metastasis or at stage III + IV than in well-differentiated carcinomas, carcinomas without lymph nodes metastasis or at stage I + II (P<0.05). The expression of hTERT was significantly related with that of P53 (P<0.05). Conclusion: Over-expressed hTERT and P53 may be related to the carcinogenesis and progression of thyroid carcinoma and hTERT expression is related to P53 protein. Examination of expression of hTERT and P53 proteins may be helpful to judge the thyroid cancer's behavior and prognosis.
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PURPOSE: Telomerase is expressed by most malignancies including thyroid cancer. In this study, to evaluate the telomerase activity, we determine the expression of human telomerase reverse transcriptase (hTERT) in benign and malignant thyroid tumors. METHODS: We examined the clinical data such as age, sex, and recurrence status of 100 patients that underwent thyroidectomy. Also, we reviewed the pathological data of the tissues (tumor size, lymph nodes, capsular invasion, perivascular invasion, perilymphatic invasion etc.). We checked hTERT expression by Allred scoring system using immunohistochemical staining. RESULTS: 21 patients had benign thyroid nodules and 79 patients had malignant nodules. The average size of benign tumors and malignant tumors were 3.1+/-1.1 cm and 2.1+/-1.7 cm, respectively. The hTERT expression was higher in malignant tumors (82.3%) than in benign tumors (9.5%) and that difference was statistically significant. In metastatic lymph nodes status of thyroid cancers, 45 of 65 patients (69.2%) had lymphatic metastases in hTERT positive group, which is much higher than hTERT negative group (P=0.001). CONCLUSION: In our study, hTERT expression may be used as a prognostic biologic marker in thyroid cancer and also in the diagnosis of malignancy.
Subject(s)
Humans , Biomarkers , Lymph Nodes , Lymphatic Metastasis , Recurrence , Telomerase , Thyroid Gland , Thyroid Neoplasms , Thyroid Nodule , ThyroidectomyABSTRACT
The de novo transcription of hTERT gene represents a rate-limiting step in the activation of human telomerase.The expression of hTERT is strictly regulated with several oncogene products and tumor suppressor gene products in normal cells.The construction of a reverse-transcriptional virus vector that contains the promoter of hTERT without losing its specificity can dramatically augment the expressions of anticancer genes in telomerase-positive cancer cells,which prompts the use of an hTERT promoter for anticancer gene therapies.Firstly,we briefly introduce the structure and regulation of hTERT gene,and then we also review the present knowledge of its biological function in cancer progression.
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To detect the expression of telomerase subunits human telomerase reverse transcriptase, human telomerase associated protein 1 and human telomerase RNA) in gastric cancer and to examine the role that different telomerase subunits play in the gastric carcinogenesis, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect telomerase subunits messenger RNA in 24 samples of gastric cancer and corresponding non-cancerous tissue. The results showed that the positive rate of hTERT mRNA from gastric cancer and corresponding non-cancerous tissues was 100 % and 25 %, respectively. The former was significantly higher than the latter (χ2 =26.4, P＜0.01). The positive rate of hTEP1 mRNA from gastric cancer and corresponding non-cancerous tissues was 100 % and 91.7 %, respectively and no significant difference was found between them (χ2 =2.1, P＞0.05). The positive rates of hTR for gastric cancer and corresponding non-cancerous tissues were both 100 % and no significant difference existed between them. It is concluded that in contrast to hTEP1 and hTR, the up-regulation of hTERT mRNA expression may play a more important role in the development of gastric cancer.
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Objective To investigate the effect of recombinant human tumor necrosis factor (rhTNF) on telomerase activity in hepatoma cell line HepG2 cells and HepG1 6 cells. Methods TRAP ELISA method was used to determine the telomerase activity in HepG2 and HepG1 6 cells which were treated by different concentrations of rhTNF; plasmid which had been inserted 800 bp of the hTERT promoter was transiently transfected into HepG2 cells by Lipofect, and different concentrations of rhTNF were added into culture media 2 hours later, then the activity of the hTERT promoter was tested 48 hours after transfection. Results The telomerase activity of HepG2 was suppressed by rhTNF in a dose dependent manner. The expression of hTERT promoter was inhibited linearly with the dose of rhTNF within the range of 10～1 000 IU/ml. Conclusions Above results suggest that the anti tumor activity of rhTNF may attribute to its inhibitory effect on hTERT promoter expression.
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Objective To investigate the effects of anti-sense hTERT on the expression of VEGF and the receptor in SGC7901 cells, and study the influence in angiogenesis and progression in gastric carcinoma. Methods SGC7901 cell line was transfected by the recombinant virus containing sense and anti-sense hTERT cDNA. Then the expression of VEGF-C and Flt-4 was observed with RT-PCR, distribution of cell cycles was determined with flow cytometry. The expression of VEGF-C and Flt-4 protein was assessed with immunohistochemistry. Result The distribution of cell cycle of antisense hTERT transfected SGC7901 cells was changed, and the mRNA and protein expression of VEGF-C and Flt-4 was significantly down-regulated. Conclusion Anti-sense hTERT can act as an agent for inhibiting VEGF-C and Flt-4 mRNA and protein level, and it blocks tumor angiogenesis and lymphogenous metastasis.
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AIM To investigate the effects of apoptosis and the expression of telomerase hTERT mRNA activity of HL-60 cells treated with As 2O 3 in different concentrations. METHODS HL-60 cells was cultured with As 2O 3 in different concentrations for 48 hours, then, cell apoptosis was detected with flow cytometry and the expression of telomerase hTERT mRNA was determined with RT-PCR respectively. RESULTS The percentage of the apoptosis in HL-60 cells were 2 28%?0 40%?2 55%?0 22% and 47 57%?2 79% respectively, as the cells were treated with 0 1 ?mol?L -1,1 0 ?mol?L -1,5 0 ?mol?L -1 As 2O 3 for 48 hours. The difference was significant between 5 0 ?mol?L -1 and 0 1～1 0 ?mol?L -1 groups(P