Background A distinct canine lymphoma entity characterized by a small clear cell cytological appearance, a T-zone (TZL) histopathological pattern, and an indolent clinical course has been described. More than 95% of cases show a lack of CD45 expression by flow cytometry (FC). However, the underlying mechanisms have never been investigated. Aim of the present study was to evaluate CD45 protein expression and mRNA amount in canine small clear cells / T-zone lymphomas, in order to deepen the knowledge of the pathogenesis of this phenotypic aberrancy. Materials and methods The degree of CD45 protein expression was evaluated by FC in 18 small clear cells / T-zoneTZL lymphomas by comparing the median fluorescence intensity (MFI) of neoplastic cells to that of residual normal T-lymphocytes in the same lymph node. Immunohistochemistry was performed, with a different antibody clone, on 2 TZLs, 2 reactive hyperplastic lymph nodes and 2 peripheral T-cell lymphomas (PTCL) positive for CD45 by FC. Quantitative real-time RT-PCR was performed on lymph node aspirates from 18 small clear cell lymphomas and 11 controls (either reactive hyperplastic lymph nodes or CD45-positive high grade T-cell lymphomas) collected in RNA-later. Results CD45-MFI of neoplastic cells was less than 1% than that of normal residual T-lymphocytes in the same sample. Neoplastic cells were negative for CD45 labelling on histopathological preparations of TZL, whereas CD45 was expressed in all lymphoid cells in control samples. RT-PCR showed significantly lower amounts of CD45 transcript in small clear cell / TZL samples compared to controls. Conclusions Data strongly suggest that CD45 protein is not expressed by neoplastic cells in canine TZL. Likewise, mRNA seems virtually absent in neoplastic cells: the small amounts of mRNA detected may be attributable to the residual normal population. Future investigations should address the cellular mechanisms causing the lack of gene transcription.
Evaluation of CD45 protein expression and tran script in canine small clear cell / T-zone lymphoma / V. Martini, M. Cozzi, A. Aricò, A. Poggi, F. Riondato, L. Marconato, L. Aresu, S. Comazzi. ((Intervento presentato al convegno Meeting of the European Canine Lymphoma Network tenutosi a Lugano nel 2015.
Evaluation of CD45 protein expression and tran script in canine small clear cell / T-zone lymphoma
V. MartiniPrimo
;M. CozziSecondo
;S. ComazziUltimo
2015
Abstract
Background A distinct canine lymphoma entity characterized by a small clear cell cytological appearance, a T-zone (TZL) histopathological pattern, and an indolent clinical course has been described. More than 95% of cases show a lack of CD45 expression by flow cytometry (FC). However, the underlying mechanisms have never been investigated. Aim of the present study was to evaluate CD45 protein expression and mRNA amount in canine small clear cells / T-zone lymphomas, in order to deepen the knowledge of the pathogenesis of this phenotypic aberrancy. Materials and methods The degree of CD45 protein expression was evaluated by FC in 18 small clear cells / T-zoneTZL lymphomas by comparing the median fluorescence intensity (MFI) of neoplastic cells to that of residual normal T-lymphocytes in the same lymph node. Immunohistochemistry was performed, with a different antibody clone, on 2 TZLs, 2 reactive hyperplastic lymph nodes and 2 peripheral T-cell lymphomas (PTCL) positive for CD45 by FC. Quantitative real-time RT-PCR was performed on lymph node aspirates from 18 small clear cell lymphomas and 11 controls (either reactive hyperplastic lymph nodes or CD45-positive high grade T-cell lymphomas) collected in RNA-later. Results CD45-MFI of neoplastic cells was less than 1% than that of normal residual T-lymphocytes in the same sample. Neoplastic cells were negative for CD45 labelling on histopathological preparations of TZL, whereas CD45 was expressed in all lymphoid cells in control samples. RT-PCR showed significantly lower amounts of CD45 transcript in small clear cell / TZL samples compared to controls. Conclusions Data strongly suggest that CD45 protein is not expressed by neoplastic cells in canine TZL. Likewise, mRNA seems virtually absent in neoplastic cells: the small amounts of mRNA detected may be attributable to the residual normal population. Future investigations should address the cellular mechanisms causing the lack of gene transcription.
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
