| Renal neoplasm, accounting for 2%~3% of all general tumors, is the second most common genitourinary neoplasm in China, which is only next to carcinoma of the bladder. In general, over the past decade years, the incidence and mortality rate of neoplasms of the kidney have been steadily increasing. Extensive application of modern diagnostic imaging has led to the diagnosis of tiny malignant tumors of the kidney in patients without any clinical signs or symptoms. With the development and application of molecular biology in clinical medicine, diagnosis of tumors has molecular and cellular tools, and it also makes prevention and early treatment of renal neoplasms with molecular methods possible, in the other hand, the basic study of telomerase activity in the renal neoplasms is research outcome of the utilization of the modern molecular methods in the renal neoplasms.Telomerase is a retrotranscriptase that synthesizes telomeric DNA into chromosomal ends using a segment of its RNA component as a template. The reactivation of telomerase can maintain telomere length, protect the telomericfunction and endow cell the immortal ability. The functions of telomere and telomerase on cell immortality, tumorigenesis, and tumor progression have been studied widely. Since the development of Telomere Repeat Amplification Protocol (TRAP) by Kim et al in 1994, numbers of studies for telomerase activities in various tissues and cell types have been performed. Data showed that activation of telomerase is highly and specificly related to malignant tumors, and now it is one of the most popular tumor markers.In the present research, we detected the telomerase activity of 32 renal malignant tumors, paraneoplasm tissues, and 6 normal renal tissues with PCR-based Telomerase-PCR-ELISA and compared their differences. The malignant tumor group was classified into different subgroups according to clinical & pathological features, the relationship between telomerse activity and tumor grades was determined, and the value of telomerase activity in dignosis and prognosis prediction of renal malignant tumors was evaluated. Materials and Methods:1.32 Renal malignant tumors and paraneoplasm tissues, 6 normal kidney tissues are obtained from Dept. Of Urology, The First Affiliated Hospital, Medical College, ZheJiang University during 2000.11~2001.8, and confirmed pathologically, paranoeplasm tissues are the tissues 2 cm away from tumor margins.2. Sample collection: Each sample was collected quickly after nephrectomy or tumor excision, rinse the samples with saline buffer, cut 0.5×0.5 cm tumor tissues within pseudo-membrane and was put into a steriled Eppendorf tube and stored in -80℃ refrigeratory. Cut the same size of tissues from 2 cm outside of the pseudomemrane and keep them at -80oC immediately too.3. Telomerase-PCR-ELISA assay Frozen tissues were homogenized in lysis reagent where the protein was abstracted (which contains telomerase). After protein quantitation, 10ug protein was added in reaction mixture for elongation of telomeric sequence by telomerase and PCR amplification. The PCR product was denatured and hybridized to a digoxigenin-(DIG)-labeled, telomeric repeat-specific detection probe. The resulting product was detected with an antibody against digoxigenin (anti-DIG-POD) that was conjugated to peroxidase. Finally the probe was visualized by virtue of peroxidase metabolizing TMB to form a colored reaction product.4. Set AA=A450-A690 as telomerase activity. A450 represents absorptant value at UV length 450; and A690 is the value at 690. The larger the AA , the higher the telomerase activity.5. Statistical method: Chi-square test (X2 test), telomerse activity has significant difference between two groups when P<0.01 or P<0.05.Results1. Telomerase activity was positive in 26 renal malignant rumor tissues and negative in 6, the total positive rate being 81.25%. In 32 samples of the paraneoplasm tissues and 6 normal renal cortex tissu...
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