Classificação morfológico, critérios de malignidade, expressão gênica de C-MYC e imunoistoquímica de C-MYC, p53, p21 e p27 no tumor venéreo transmissível canino
Carregando...
Data
2013-07-19
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
The present concept about carcinogenesis is that normal cells are transformed into
tumor by mutations that activate oncogenes, inhibit tumor suppressor genes or
trigger genetic instability. However, studies suggest that some neoplastic types can
behave like infectious agents and be transmitted from one host to another, similar to
what occurs with the canine transmissible venereal tumor (TVT). The TVT
histogenesis is not fully known, because the studies are controversial and do not
bring about the results elucidating cell line that characterized the neoplasm.
However, research continues in order to elucidate this question and identify the
ancestral genetic TVT. Recently, a cytomorphological classification was proposed for
the TVT, including plasmacytoid types, linfocitoide and mixed. Nevertheless, many
features of the development and behavior of this dogs transmissible neoplasm are
still poorly understood. Accordingly, we evaluated the different morphological
patterns of the tumor, the macroscopic aspects, the criteria of malignancy, the
molecular identification of the tumor, by inserting the element LINE-1 in the C-MYC
gene, the immunohistochemical expression of the C-MYC, p53, p21 and p27, and
the relationship between the proteins C-MYC, p53, p21 and p27, the block of the cell
cycle and apoptosis of tumor cells. The results indicate that the cytological
examination allows better characterization of patterns and cytomorphologic criteria of
malignancy of TVT compared to histological examination, which can identify the
types plasmacytoid, linfocitoide and mixed. It was further observed that the TVT
presents morphological peculiarities that may interfere with tumor behavior and
response to chemotherapy, especially those related to more aggressive and have
been observed in plasmacytoid TVT, cytomorphological most common type of this
tumor. The identification of molecular rearrangement LINE-1/C-MYC features specific
molecular changes for TVT that may be introduced as supplementary diagnostic
method of cancer, especially in highly undifferentiated tumors. Immunohistochemical
analysis and the relationship between C-MYC, p53, p21 and p27 revealed functional
abnormalities in these proteins, interfering with biological events in cell cycle control
and apoptosis, and may thus contribute to the genesis and neoplastic progression.
Descrição
Palavras-chave
Aloenxerto , Apoptose , Cães , Ciclo celular , Citologia , Neoplasia , Reação em cadeia da polimerase , Allograft , Apoptosis , Cell cycle , Cytology , Dogs , Neoplasm , Polymerase chain reaction
Citação
LIMA, Caroline Rocha de Oliveira. Classificação morfológico, critérios de malignidade, expressão gênica de C-MYC e imunoistoquímica de C-MYC, p53, p21 e p27 no tumor venéreo transmissível canino. 2013. 103 f. - Tese (Doutorado em Ciência Animal) - Universidade Federal de Goiás, Goiânia, 2013.