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Telomeric Repeat Amplification Protocol (telomeric + repeat_amplification_protocol)
Selected AbstractsTelomerase activity in small cell esophageal carcinomaDISEASES OF THE ESOPHAGUS, Issue 2 2001V. Chow Small cell carcinoma of the esophagus is a rare and aggressive malignant tumor. Telomerase activation is common in human cancers. There is a lack of data on telomerase activity in esophageal small cell cancers. The present report studied the role of telomerase activity in esophageal small cell carcinoma. The clinicopathologic data of five patients with small cell carcinoma of the esophagus who underwent primary surgical treatment between 1991 and 2000 were studied. Telomeric repeat amplification protocol assays were used to investigate telomerase activity in these tumors. The proliferative activity (MIB-1) and p53 expression of these tumors were also studied using immunohistochemistry and correlated with the telomerase activity. All five small cell carcinomas showed detectable telomerase activity in the primary tumor. Two out of the five morphologically normal esophageal mucosae adjacent to the primary tumor had detectable telomerase activity. There was no correlation between the p53 expression, tumor stage, survival of patients, and the presence of telomerase activity. High MIB-1 expression in esophageal small cell carcinomas was associated with high telomerase activity. Telomerase activation is common in small cell carcinoma of the esophagus. This fact may find application in anti-telomerase treatment for this aggressive tumor. [source] Genistein induces cell growth inhibition in prostate cancer through the suppression of telomerase activityINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2005HIDEKI OUCHI Abstract Aim:, To clarify the mechanism of the anticancer effect of genistein, we examined the effect of genistein on telomerase activity in prostate cancer cells. We hypothesized that genistein may exert its anticancer effect by modifying telomerase activity in prostate cancer cells. Methods:, Prostate cancer (LNCaP) cells were cultured with genistein and the number of viable cells was counted. Growth medium was also collected to measure prostate-specific antigen (PSA) concentration. Polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay and reverse transcriptase (RT)-PCR analysis were performed to investigate telomerase activity and the expression of human telomerase reverse transcriptase (hTERT), c-myc and p21 mRNA. To examine the possibility that hTERT transcriptional activity is modulated by genistein, transient cell transfection studies were performed by using luciferase reporter assay. Telomere repeat amplification protocol (TRAP) assay and PCR analysis of hTERT were performed in androgen independent cells, DU-145. Results:, Cell growth of LNCaP was inhibited by genistein and PSA secretion was similarly reduced. In TRAP assay, the telomerase activity of LNCaP cells was reduced by genistein. Reverse transcriptase-PCR analysis revealed that the expression of hTERT and c-myc mRNA was down-regulated by genistein, whereas p21 mRNA increased in response to genistein. Luciferase reporter assay revealed that genistein reduced the transcriptional activity of hTERT. In DU-145 cells, telomerase activity and the expression of hTERT mRNA were also reduced by genistein. Conclusion:, The current study elucidated the molecular mechanism of cell growth inhibition by genistein. The antiproliferative effects of genistein seem to be exerted on the hTERT transcriptional activity via different molecular pathways. [source] The influence of reactivation of the telomerase in tumour tissue on the prognosis of squamous cell carcinomas in the head and neckJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 9 2004S. Koscielny Background:, The reactivation of the telomerase seems to be an important step in the carcinogenesis of most human cancer types. Cell clones, which express this enzyme, get the ability of indefinite proliferation, means become immortal. Methods:, In this study, 80 patients with squamous cell carcinomas (SSC) in oral cavity, oropharynx, hypopharynx and larynx were recorded prospectively concerning a possible correlation of telomerase activity and clinical and prognostic factors. Telomerase activity was analysed by a modified telomeric repeat amplification protocol (TRAP) assay. Results:, In 75% of the tumour tissues the telomerase was demonstrated independently of the localization of the tumour. The known clinical prognostic factors did not show any correlation to the expression rate of the telomerase activity in the tumour tissues. Also, reactivated telomerase did not affect the tumour-dependent survival. Only the number of lymph node metastases was in tendency higher in patients with telomerase-positive tumours. The number and timeframe of local and regional recurrences was not influenced by the telomerase status. Conclusions:, Although telomerase seems to be an important part of the carcinogenesis of SCC our data show that the reactivation of telomerase in tumour tissue did not have any prognostic significance for these tumours. The tendency that tumours with active telomerase developed lymph node metastases in a higher number should be evaluated by further enlarged studies for its clinical relevance. [source] Telomerase Activity Is Upregulated in Laryngeal Squamous Cell Carcinoma,THE LARYNGOSCOPE, Issue 3 2000Aongus J. Curran MB, FRCSI Objective/Hypothesis The immortalizing enzyme telomerase has been linked to carcinogenesis and is being targeted as a novel molecular marker. This study investigated telomerase expression in patients with laryngeal squamous cell carcinoma and correlated telomerase activity with conventional prognostic parameters. Study Design A consecutive series of patients with laryngeal squamous cell carcinoma undergoing surgical salvage for persistent or progressive disease after failed radiation therapy. Methods Twenty patient samples of laryngeal squamous cell carcinoma and 20 adjacent histologically normal mucosal samples were assayed using the telomeric repeat amplification protocol (TRAP) method for detection of telomerase activity. The leukemic cell line, K562, acted as a positive control and the human fibroblast line, Hs21Fs, as a negative control. A sample was classified as telomerase positive when an RNase-sensitive hexameric repeat ladder was observed. Absence of laddering was considered a negative result. Results Seventeen of 20 (85%) tumor samples and 4 of 20 (20%) adjacent histologically normal samples were telomerase positive. No statistically significant difference was observed when densitometric readings were compared by T category, tumor grade, or site (by ANOVA). Conclusions Although telomerase activity is present in laryngeal cancer, levels of activation do not correlate with conventional parameters used for prognostication. Our study indicates that the marker may be a useful adjunctive method in the diagnosis of malignancy after radiation failure. [source] A study comparing various noninvasive methods of detecting bladder cancer in urineBJU INTERNATIONAL, Issue 4 2002A. Saad Objectives To compare the nuclear matrix protein (NMP)-22 assay, bladder tumour specific antigen (BTAstat) test, telomerase activity (using the telomeric repeat amplification protocol assay, TRAP) and a haemoglobin dipstick test for their ability to replace voided urine cytology (VUC) for detecting bladder cancer. Patients and methods The study included 120 urological patients prospectively recruited and assessed before surgery. A single freshly voided urine sample (,100 mL) was collected from each patient and aliquoted for each test. All assays were conducted according to the manufactures' guidelines; 79 patients were tested for telomerase activity. The results were then compared with VUC and the diagnosis confirmed by cystoscopy and histology. Results Fifty-two patients had histologically confirmed transitional cell carcinoma. The overall sensitivity for BTAstat, NMP22, telomerase, VUC and dipstick testing was 63%, 81%, 84%, 48% and 50%, respectively. Combining the results for telomerase and NMP22 gave a sensitivity of 100%. For G1 tumours the respective sensitivities were 23%, 62%, 56%, 23% and 15%, for G2 tumours, 68%, 86%, 92%, 50% and 41% and for G3 tumours 88%, 88%, 100%, 71% and 82%. For pTa tumours the respective detection rates were 48%, 70%, 84%, 39% and 30%, for pT1 tumours 80%, 90%, 90%, 50% and 50%, for pT2/pTis tumours, 100/100%, 100/100%, 100/100%, 88/100% and 88/83%. The overall specificity for the respective tests was 82%, 87%, 93%, 87% and 54%; combining the results of NMP22 and telomerase activity increased the specificity to 96%. Conclusions There was significantly better detection than VUC when using the NMP22 and TRAP assay, especially for well-differentiated (P < 0.001 and 0.0027, respectively) and superficial tumours (P < 0.001 and 0.034, respectively). Combining the results of NMP22 and telomerase activity yielded values comparable with cystoscopy. [source] A highly sensitive and quantitative telomerase activity assay with pancreatic juice is useful for diagnosis of pancreatic carcinoma without problems due to polymerase chain reaction inhibitorsCANCER, Issue 10 2004Analysis of 100 samples of pancreatic juice from consecutive patients Abstract BACKGROUND Early detection of pancreatic carcinoma is difficult even with current diagnostic tools. Novel biomarkers and detection techniques are urgently needed. Telomerase activity is a promising diagnostic marker. However, the conventional telomeric repeat amplification protocol (TRAP) assay is not suitable for clinical application because of its complexity, time-consuming nature, and the effects of polymerase chain reaction (PCR) inhibitors in samples leading to difficulties in quantification. METHODS The authors used a hybridization protection assay in combination with TRAP (TRAP/HPA) to investigate the effects of PCR inhibitors in pancreatic juice on quantification of telomerase activity. They analyzed 117 consecutive samples of pancreatic juice to determine the feasibility of TRAP/HPA for diagnosis of pancreatic carcinoma. RESULTS The authors found that TRAP/HPA was 1000-fold more sensitive than the conventional TRAP assay, and that the effects of PCR inhibitors could be avoided by diluting samples. In a large analysis of pancreatic juice samples with TRAP/HPA, 17 samples were excluded from the final analysis because of insufficient follow-up periods or inadequate treatment of the samples. Relative telomerase activity (RTA) in samples from patients with pancreatic carcinoma was significantly higher in comparison to samples from patients with pancreatitis and 13 (61.9%) of 21 samples from patients with pancreatic carcinoma showed high RTA (> 4 U). Meanwhile, high RTAs were observed in 4 of 35 (11.4%) samples from patients with intraductal papillary mucinous tumor and in 1 of 40 samples (2.5%) fom patients without malignant disease. CONCLUSIONS TRAP/HPA accurately evaluated weak telomerase activity in pancreatic juice samples without the problem due to PCR inhibitors. This large analysis of nonselected pancreatic juice samples suggested that TRAP/HPA is a promising approach for the diagnosis of pancreatic carcinoma. Cancer 2004. © 2004 American Cancer Society. [source] | ||||||||||