Telomerase Activity in Human Renal Cell Carcinoma with Reference to Clinicopathologic Features

Objective: To study the telomerase activity in human renal cell carcinoma and to evaluate the correlation with the clinicobiologic features of the neogrowth.Methods: The telomerase activity was studied by means of a modified telomeric repeat amplification protocol (TRAP) in 32 renal cell carcinoma tissues, 32 normal renal tissues and 32 paracancer tissues and its correlation with the clinicopathologic features of the tumor was evaluated.Results: Telomerase activity was strongly positive in 17, positive in 12 and negative in 3 cases of renal cell carcinoma tissues, the total positive rate being 91%. Telomerase activity was weakly positive (6%) in only 2 out of 32 samples of normal renal cortex tissues and positive in 6 paracancer tissues (19%), the difference was conspicuous (P<0.01).Conclusion: The positive rate of telomerase activity was significantly higher in renal cell carcinoma tissues and might serve as a prognostic marker for estimating the biologic characteristics of renal cell carcinoma.

Dynamic alteration of telomerase expression and its diagnostic significance in liver or peripheral blood for hepatocellular carcinoma

AIM： To investigate the dynamic alteration of telomerase expression during development of hepatocellular carcinoma （HCC） and its diagnostic implications in liver tissues or peripheral blood mononuclear cells for HCC. METHODS： Dynamic expressions of liver telomerase during malignant transformation of hepatocytes were observed in Sprague-Dawly （SD） rats fed with 0.05% of 2-fluoenyacetamide （2-FAA）. Total RNA and telomerase were extracted from rat or human liver tissues. The telomerase activities in livers and in circulating blood were detected by a telomeric repeat amplification protocol-enzyme-linked immunosorbent assay （TRAP- ELISA）, and its diagnostic value was investigated in patients with benign or malignant liver diseases. RESULTS： The hepatoma model displayed the dynamic expression of hepatic telomerase during HCC development. The telomerase activities were consistent with liver total RNA levels （r = 0.83, P 〈 0.01） at the stages of degeneration, precancerosis, and cancerization of hepatocytes. In HCC patients, the telomerase levels in HCC tissues were significantly higher than in their adjacent non-cancerous tissues, but liver total RNA levels were lower in the former than in the latter. Although the circulating telomerase of HCC patients was abnormally expressed among patients with chronic liver diseases, the telomerase activity was a non-specific marker for HCC diagnosis, because the incidence was 15.7% in normal control, 25% in chronic hepatitis, 45.9% in liver cirrhosis, and 85.2% in HCC, respectively when absorbance value of telomerase activity was more than 0.2. If the value was over 0.6, the incidence was 60% in HCC group and 0% in any of the others （P 〈 0.01） except in two cases with liver cirrhosis. However, the combination of circulating telomerase with serum alpha-fetoprotein level could increase the positive rate and the accuracy （92.6%, 125 of 135） of HCC diagnosis. CONCLUSION： The overexpression of telomerase is associated with HCC development, and its abnormality in liver tissues or in peripheral blood could be a useful marker for diagnosis and prognosis of HCC.

DETECTION OF TELOMERASE ACTIVITY IN BREAST CARCINOMA

Objective: To investigate the significance of telomerase activity in breast carcinoma with its respect to axillary lymph node status Methods: Telomerase activity was analyzed in 88 breast carcinomas and 16 benign breast lesions, using polymerase chain reaction (PCR) based telomeric repeat amplification protocol (TRAP) assay Results: Telomerase activity was detected in 75 (85%) of 88 breast carcinomas (including three breast carcinomas in situ which were all positive for telomerase activity), whereas in benign breast lesions analyzed only 2(12 5%) of 16 cases were positive for telomerase activity The difference between the two groups was statistically significant ( P <0 001) Besides, telomerase activity was expressed significantly higher in node positive breast carcinoma (93%) than in node negative ones (77%) ( P <0 05) Conclusion: Our results suggest that telomerase activation plays an important role during breast carcinoma development It is possible that this enzyme may serve as an early indication of breast carcinoma

Detection of Telomerase Activity and Expression of TERT Gene in Antler of Sika Deer

[ Objective] To observe the expression of telomerase in antler of sika deer during growth stage and thus to provide a new line for revealing the mechanisms of development and regeneration of antlers. [Method] The updated TRAP （Telomedc repeat amplification protocol） argentumdying method was used to detect the activity of telomerase in mesenchyme, precartilage, cartilage and ossification tissue of antler tip during the growth stage. Reverse transcription polymerase chain reaction （RT-PCR） was used to detect the expression of telomerase reverse transcriptase （TERT） in these cells. I-Result] The activity of telomerase was detected in the mesanchyme, precartilage and cartilage but not in the sclerotic tissue. The relative telomerase activity in the mesanchyme, precartilage and cartilage was 91.2, 46.4 and 13.7, respectively. In addition, the results of the expression of TERT gene also supported the detection result of telomerase activity. I-Conclmionl During growth phase, telomerase is expressed in multiplication area of deer antlers, and its activity decreases gradually with further differentiation of cells in antlers. Therefore, telomerase may play a key role in develoomant and rsoaneration of antlers.