Telomere repeat amplification protocol (TRAP) in situ reveals telomerase activity in three cell types in effusions: malignant cells, proliferative mesothelial cells, and lymphocytes

Abstract

Telomerase Repeat Amplification Protocol (TRAP) in situ was performed on cytospin preparations from 65 effusions from the serous cavities (45 pleural and 19 ascitic fluids and one pericardial fluid) submitted for routine diagnosis and the results were correlated to cytological morphology. Three types of cells with nuclear fluorescence were identified: malignant cells, hyperplastic mesothelial cell and lymphocytes. Of 38 cytologically malignant effusions, 12 showed strong reactivity in all malignant cells, three strong reactivity in part of the malignant population, whereas 12 showed moderate reactivity in the whole and five in part of the malignant population, respectively. In five malignant effusions weak reactivity was found in all (one case) and in scattered (four cases) malignant cells. Two effusions contained telomerase-negative malignant cells. Two pleural and two ascitic fluids contained proliferative mesothelial cells with weak or, in one case, moderate reactivity. Lymphocytes usually showed weak telomerase activity. Telomerase was expressed in almost all malignant tumours metastatic to serous cavities. Heterogeneity in tumour populations was demonstrated, which may have diagnostic implications, especially in cytology. Weak or moderate reactivity was found in lymphocytes and in some mesothelial proliferations and may explain the low specificity for malignancy sometimes obtained with the TRAP extract method. The weak reactivity found in lymphocytes may reduce the specificity when the extract method is used but causes no diagnostic problem with the TRAP in situ method.

Clinical significance of telomerase activity in peritoneal lavage fluid from patients with gastric cancer and its relationship with cellular proliferation

“…However, the peritoneal lavage fluid can also be contaminated with lymphocytes or other blood cells in the presence of inflammation or ulceration [29] . The presence of these cells may give rise to false-positive results in TRAP assay [30] . Further studies are required to eliminate the above limitations to improve the accuracy of this technique.…”

Weak Telomerase Activity in Malignant Cells in Metastatic Serous Effusions

“…8 When a malignant tumor has spread to the serous cavities the prognosis is usually dismal, but the survival times vary from days to several months. [9][10][11] Telomerase has been shown to be of value as a prognostic marker.…”

“…Thirty-six of the cases are inc luded in a previous study of TRAP in situ activity in malignant and benign effusions. 8 The specimens were obtained and used in agreement with Swedish legislation regarding biologic material originating from patients. The fluids had been submitted fresh to the Department of Pathology and Cytology, Malmö University Hospital, from March 2002 through February 2006.…”

“…8,[18][19][20] Ten milliliters of the fresh fluid were spun (1,500 rpm, 5 minutes), the pellet was resuspended in hypotonic solution (10 mM Tris, 10 mM KCl, 1 mM MgCl 2 ) and carefully mixed and hypertonic solution (274 mM NaCl, 5.4 mM KCl, 16.2 mM Na 2 HPO 4 , 2.9 mM KH 2 PO 4 ) was added. The cell suspension was cytospun (400 rpm, 3 minutes) onto nonfluorescent slides and dried with cold air.…”

Μεταγραφική Έκφραση Της Ανάστροφης Μεταγραφάσης Της Τελομεράσης Και Της 23-Διοξυγονάσης Της Ινδολεαμίνης Στον Καρκίνο Του Πνεύμονα

“…πλευριτικό υγρό [80], [105], [107], [108], [109], [110] [111], [112] περιφερικό αίμα [116] [117], [118], [119], [131] Εικόνα 9: Α. Επίστρωση βρογχικής έκπλυσης (χρώση κατά Παπανικολάου x 800) Β. Αντίστοιχη in situ TRAP assay όπου φαίνονται τα καρκινικά κύτταρα με έντονη πυρηνική αντιδραστικότητα, στο πλακώδες ΚΠ (1) και στο αδενοκαρκίνωμα (2) [96].…”