Currently, the telomerase is being considered as a marker of cancer because 90% of cancer cells in human have positive telomerase. The telomarase used to early diagnose, monitor and predict after the treatment. In addition to, telomerase also is objective of many researches to treat the cancer. It had better combine the anti telomerase and chemotherapy
Urologic Neoplasms ; Telomerase

Telomerase is a ribonucleoprotein enzyme. Which is responsible for catalyst for increasing chains of telomere and limitation of shortening the chromosome terminal head. Telomerase has activity for the primary cells but inhibited differentiate cells. Telomerase was considered most significantly as a marker of cancer because 90% of cancer cells in human had positive telomerase. The telomerase was used to early diagnose and monitor as well as predict outcome. The antitelomerase therapy was a proper method to prevent relapsed cancer after the traditional treatments
Urologic Neoplasms ; Telomerase

No abstract available.
Arthritis, Rheumatoid* ; Osteoarthritis ; Telomerase*

No abstract available.
Breast Neoplasms* ; Breast* ; Telomerase*

BACKGROUND: Telomeres are simple repeats elements located at each end of the chromosomes of eukaryotic cells. The main function of telomeres is to cap the chromosome end and protect it from enzymatic attack. Telomerase that facilitates the synthesis of telomere has been detected in not only cancer, but also in precancerous lesion. In this study, we compared the telomerase expression between low-grade and high-grade gastric dysplasia. METHODS: The telomerase expression of 43 patients with gastric dysplasia (22 low-grade and 21 high-grade) was evaluated by immunohistochemical staining in tissues. RESULTS: The telomerase expression was much higher in the tissues from the patients with high-grade gastric dysplasia than in those tissues of the patients with low-grade gastric dysplasia. CONCLUSIONS: Activation of telomerase may be related with the malignant potentiality in gastric cells. Further studies are needed to define the role of telomerase in gastric tumorigenesis.
Carcinogenesis ; Eukaryotic Cells ; Humans ; Immunohistochemistry ; Telomerase* ; Telomere

Humans ; Metabolic Syndrome ; Telomerase ; metabolism ; Telomere

PURPOSE: A sensitive predictive assay is necessary to determine the total radiation dose according to sensitivity of individual cancer cell lines. This study is performed to determine whether the radiation sensitivity is correlated with the changes in telomerase activity after irradiation. MATERIALS AND METHODS: Two colorectal cancer cell lines with different radiation sensitivity were used. In order to confirm the difference in radiation sensitivity, we used a calorimetric assay. Telomerase activities were measured using the PCR-based telomeric repeat amplification protocol (TRAP). RESULTS: We confirmed the difference in radiation sensitivity between NCI-H630 and NCI-H716. Survival fractions at 2 Gy were 0.836 for NCI-H630 and 0.317 for NCI-H716. Telomerase activity increased after irradiation with NCI-H630, which was more resistant to radiation, whereas telomerase activity decreased with NCI-H730. But dose-dependent change of telomerase activity was not confirmed. CONCLUSION: Our results suggested that telomerase activity change after irradiation could be used as a predictive assay for radiation response. Further studies with different cell lines and tumor tissues are necessary.
Cell Line ; Colorectal Neoplasms ; Radiation Tolerance ; Telomerase*

The unique ability of tumour cells to proliferate indefinitely is crucial to neoplastic progression as it allows these cells to express the aggressive properties of cancer without the censure of physiological ageing. This is in contrast to normal somatic cells which are subject to a "mitotic clock," a phenomenon that has been linked to telomeric shortening after each round of cell replication, so that eventually the loss of genetic material reaches a critical stage and the cells undergo senescence and cell death. A study was conducted to investigate the role of telomerase, an RNA-containing enzyme that restores the telomere length, in the neoplastic cell immortalization and progression process. Fresh human tissue samples taken from excision specimens received by the Department of Pathology, University of Malaya Medical Centre, were investigated for telomerase activity using a commercial Telomerase PCR-ELISA kit (Boehringer Mannheim). Specimens comprised 33 breast lesions (10 infiltrating breast adenocarcinoma, 13 fibroadenoma and 10 non-neoplastic breast tissue), 27 colonic lesions (17 colonic adenocarcinoma and 10 non-neoplastic colonic mucosa) and 42 cervical lesions (20 cervical carcinoma and 22 non-neoplastic cervical tissues). Telomerase activity was found in 6 (60%) of 10 breast carcinomas, 6 (46%) of 13 fibroadenomas, none of the 10 nonneoplastic breast samples, 3 (17.6%) of 17 colon carcinomas and none of the 10 non-neoplastic colonic mucosal samples, 12 (60%) of 20 cervical carcinoma and 3 (13.6%) of 22 non-neoplastic cervical samples. 5/10 (50%) Stage I, 4/7 (57%) Stage II, 2/2 (100%) Stage III and 1/1 (100%) Stage IV cervical carcinomas showed telomerase activity. These findings support a contributory role for telomerase in tumourigenesis with activation occurring from neoplastic transformation and increasing with tumour progression.
Telomerase ; seconds ; Breast ; neoplastic cell ; Progression

OBJECTIVE: Recently, telomerase activity was found in normal physiologically regenerating cells as well as cancer cells or germ cells. Human endometrium is also physiologically regenerating tissues and undergoes regular and dynamic changes during the menstrual cycle. So the authors examined normal human endometrial tissues for telomerase activity according to menstrual cycle. METHOD: In the current study, 66 normal human endometrial tissues were analyzed for telomerase activity by a radioisotope polimerase chain reaction-based telomeric repeat amplification protocol assay. RESULTS: Of 27 proliferative phase endometrial samples, 22(81%) expressed telomerase activity, whereas 10 of 23(43%) secretory phase sample, 2 of 10(10%) postmenopausal sample, 1 of 6(17%) pregnant endometrial sample did(P<0.05). 4 of 27(15%) endometrial samples in the proliferative phase expressed high telomerase activity after 100-fold dilution of extract, whereas 1 of 23(4%) from secretory phase, none of the 10 postmenopausal and 6 pregnant endometrial samples did. The highest activity was observed in late proliferative phase. CONCLUSION: This study indicates that normal endometrium expresses telomerase, the activity of which changes dramatically and regularly during the course of the menstrual cycle.
Endometrium* ; Female ; Germ Cells ; Humans ; Menstrual Cycle* ; Telomerase*

PURPOSE: We studied the telomerase activity in normal and cancer tissues of the breast and then compared it to the clinical parameters. MATERIALS AND METHODS: 36 paired normal and cancerous breast tissues were assayed for telomerase activity by PCR-based TRAP assay (telomeric repeat amplification protocol). In 17 cancer tissues, flow cytometric analysis for S-phase fraction was done. RESULTS: None of the normal breast tissue expressed telomerase activity while 23 out of 26 breast cancer tissue expressed telomerase activity (92%). Clinical parameters such as T-factor, tumor grade, hormone receptor expression, mitosis, S-phase fraction did not correlate with telomerase expression. However, telomerase acitvity increased with cancer progression such as; in a state of lymph node metastasis and in an advanced pathological stage. CONCLUSION: Telomerase activity was expressed only from cancer tissues. And this expression increased with cancer progression suggesting a possible therapeutic target in breast cancer.
Breast Neoplasms* ; Breast* ; Lymph Nodes ; Mitosis ; Neoplasm Metastasis ; Telomerase*