Introduction. Predicting biologic behaviour of meningioma is difficult, because of lack in reliable markers. Telomerase plays an active role in conferring indefinite life span to tumour cells, and human meningiomas frequently show high telomerase activity, particularly those relapsing. Telomerase activity has been recently investigated also in canine and feline CNS tumours, with partially contradictory results, by hTERT immunohistochemistry, but never by PCR. Methods. Seven meningiomas (six intracranial and one spinal) from three dogs (Boxer, German shepherd, Labrador) and four cats (DSH) were identified by MRI or TC, surgically (5 cases) or post-mortem (2 cases) removed and histologically classified according to human WHO scheme as fibroblastic, multinodular meningothelial-fibroblastic, atypical (dogs), and 2 transitional, meningothelial and psammomatous (cats). Telomerase activity was measured by immunohistochemistry (h-TERT expression) and using the TeloTAGGG Telomerase PCR ELISA assay (TRAP), considering positive those samples with absorbance difference higher than 0.2 units. Results. H-TERT immunohistochemistry showed both nuclear and/or nucleolar positivity in a variable percentage of tumor cells (0-92%), while the TRAP assay demonstrated high telomerase activity in all samples (0.3 to 0.5 DA). All surgical cases are still alive after a short follow-up (two-six months). Conclusions. Both canine and feline meningiomas showed a significant telomerase activity, suggesting an active role of this machinery in tumorigenesis. Neverthless the prognostic relevance of telomerase activity remains to be determined. It should also verified which of the two assays is more reliable, as the observed incongruence could be related to alternative mechanisms leading to telomeric preservation.
The role of telomerase activity in canine and feline meningioma
MANDRIOLI, LUCIANA;PANARESE, SERENA;CESARI, ALESSANDRO;BETTINI, GIULIANO
2008
Abstract
Introduction. Predicting biologic behaviour of meningioma is difficult, because of lack in reliable markers. Telomerase plays an active role in conferring indefinite life span to tumour cells, and human meningiomas frequently show high telomerase activity, particularly those relapsing. Telomerase activity has been recently investigated also in canine and feline CNS tumours, with partially contradictory results, by hTERT immunohistochemistry, but never by PCR. Methods. Seven meningiomas (six intracranial and one spinal) from three dogs (Boxer, German shepherd, Labrador) and four cats (DSH) were identified by MRI or TC, surgically (5 cases) or post-mortem (2 cases) removed and histologically classified according to human WHO scheme as fibroblastic, multinodular meningothelial-fibroblastic, atypical (dogs), and 2 transitional, meningothelial and psammomatous (cats). Telomerase activity was measured by immunohistochemistry (h-TERT expression) and using the TeloTAGGG Telomerase PCR ELISA assay (TRAP), considering positive those samples with absorbance difference higher than 0.2 units. Results. H-TERT immunohistochemistry showed both nuclear and/or nucleolar positivity in a variable percentage of tumor cells (0-92%), while the TRAP assay demonstrated high telomerase activity in all samples (0.3 to 0.5 DA). All surgical cases are still alive after a short follow-up (two-six months). Conclusions. Both canine and feline meningiomas showed a significant telomerase activity, suggesting an active role of this machinery in tumorigenesis. Neverthless the prognostic relevance of telomerase activity remains to be determined. It should also verified which of the two assays is more reliable, as the observed incongruence could be related to alternative mechanisms leading to telomeric preservation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
