ABSTRACT
Measurement of telomerase activity in clinically obtained tumor samples may provide important information for use as both a diagnostic marker and a prognostic indicator for patient outcome. In order to evaluate telomerase activity in tumor tissue without radiolabeling the product, we developed a simple telomeric repeat amplification protocol-silver-staining assay that is less time-consuming, is safe and requires minimal equipment. In addition, we determined the sensitivity of the silver-staining method by using extracts of telomerase-positive thyroid carcinoma cell lines which were serially diluted from 5,000 to 10 cells. Telomerase activity was also assayed in 19 thyroid tumors, 2 normal controls and 27 bone marrow aspirates. The results indicate that the technique permits the detection of telomerase activity from 5000 to as few as 10 cells. We propose that it could be immediately applicable in many laboratories due to the minimal amount of equipment required
Subject(s)
Humans , Silver Staining , Telomerase , Telomere , Thyroid Neoplasms , Enzyme Activation , Biomarkers, Tumor/metabolism , Sensitivity and Specificity , Telomerase , Tumor Cells, CulturedABSTRACT
Consistent cytogenetic abnormalities have been identified in a variety of human cancer cells and some of them are related to patient prognosis. Fluorescence "in situ" hybridization (FISH) is a new methodology which can be used to detect cytogenetic anormalies within interphase cells. We present several aspects of FISH methodology and its application in several examples, including trisomy 8 detection with high specificity and sensitivity in patients with myeloid leukemias; trisomy 12 detection with higher efficiency than conventional cytogenetics in patients with chronic lymphocytic leukemia; assessment of engraftment success, chimerism, and relapse in opposite sex bone marrow transplantation; and correlation of trisomy 7 with survival time in patients with prostate tumors. We discuss also some aspects of neroblastoma tumors, one of the most frequent malignant solid tumor in childhood. At diagnosis the patient's age and tumor stage are the major prognostic factors. Favorable prognosis is associated with triploid karyotype, lack of 1p abnormalities and absence of N-myc amplication, whereas unfavorable prognosis is associated with pseudodiploid or tetraploid karyotype, 1p deletion and N-myc amplication. These abnormalities can be investigated quickly and effectively in interphase cells using FISH.
Subject(s)
Humans , Cytogenetics/methods , Neoplasms/genetics , Neuroblastoma/genetics , Centromere , Chromosomes, Human, Pair 2 , Genes, myc , In Situ Hybridization, Fluorescence , Interphase , PrognosisABSTRACT
Descrevemos um paciente portador de retinoblastoma bilateral associado a retardo mental. Seu estudo citogenético em linfócitos do sangue periférico detectou uma deficiência parcial do cromossomo 13. Seu estudo quantitativo da enzima D-esterase em hemolisado revelou valores inferiores aos de seus pais