| BackgroundSolid tumor, taking up two thirds of neoplasm in children, is a major cause of death in this group. According to the results of previous research, the death due to tumor is second only to accidents in children aged from 5 to 14 years. And the delayed diagnosis, occurred frequently in those patients, was a main obstacle to improving the rate of survival. Diagnosis of those tumors in time, therefore, is a hot spot of tumor research today.Telomere is a specialized structure at the natural end of an eukaryotic chromosome. Telomerase is a complex reverse transcriptase containing both protein and RNA complements. It binds to TTAGGG telomeric DNA and functions to synthesize telomeric repeats. It is essential for maintenance of telomere length and functions. In humans, telomerase is expressed in most cancers and immortal cell lines but is inactive in normal somatic cells expect for male germ cells, activated lymphocytes and stem cells of regenerating tissues. Telomrase activity has been detected in human blastocysts and in 16- to 18- week fetal tissues (except brain) and was absent by 2 months of neonatal life. Thus telomerase may be integrated to the events that characterize organogenesis in the fetus, and failure to downregulate telomerase activity may permit dysregulated proliferation and the eventualdevelopment of malignancies in childhood.Since Telomerase Repeat Amplification Protocal (TRAP), which was the method with high sensitivity for detecting telomerase activity, set up by Kim and others in 1994, the telomerase activity in malignant tumors of various tissues has been more and more intensively investigated. In recent years, telomerase activity had been detected in the most common cancers, such as in those of the prostase, breast, lung, colon and liver. There was evidence in neuroblastoma, nephroblastoma, breast and gastrointestinal cancers that the presence of high level telomerase correlates with poor prognosis. Telomerase activity could be detected in almost any type of clinical specimen including exfoliated cells and fine needle aspirates. The use of minimally invasive procedures such as fine needle aspiration of breast masses had great promise for distinguishing carcinoma from benign disease. Additional studies found that using cells obtained from washing colon or brushing lung to analyse telomerase activity is more sensitive than cytology. However, using core biopsy cells to analyse telomerase activity in commonly seen solid tumors of children has not been reported. PurposeTo investigate the diagnostic and distinguished significance of the detecting telomerase activity in core biopsy cells obtained from commonly seen solid tumors of children by the qualitative TRAP-silver staining quantitative and TRAP-PCR-ELISA. Materials and methodsThe specimens collected in 34 patients with solid tumors and 4 normal children. The patient group was divided into two subgroups: malignant group (20 patients) and benign group (14 patients) based on the pathological diagnosis.The specimens from core biopsy were washed down in 1ml NS. The specimens were then underwent to pathological examination, and the cells from the extracts were used to analyse the telomerase activity for telomeric repeat amplification protocol (TRAP reaction), 5^L of PCR products were denaturated, hybridizated and measured under the absorption at 450nm (with a reference wavelength of approx.690 nm). The other PCR products were concentrated and analysed by 12% non-denatured polyacrylamide gel electrophoresis. Silver staining was applied to demonstrate thepositive bands of activated telomerase. Results1. The rational concentration of the template's protein is 5|ig.2. Sensitivity of the Telomerase PCR ELISA :Ten K562 cells were detected high telomerase activity (OD: 0.244). Four 293 cells also expressed telomerase activity.3. Telomerase activity:(1). The result of using core biopsy cells in childhood solid tumors to analysetelomerase activity is associated with pathological exami...
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