"Expressão gênica do fator de indução de proteólise (PIF) e de sua forma variante (PIF-SV) em células normais e malignas" / Genetic expression of proteolsys-inducing factor (PIF) and its splicing form (PIF-SV) in normal and tumor cells

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Proteolysis-inducing factor (PIF) is a 24 kDa glycoprotein identified in plasma of cancer patients and responsible for muscle catabolism associated with the process of cancer cachexia. The present study has investigated, using the RT-PCR, RACE-PCR and Real-time PCR techniques, the presence of PIF messages in different cell types derived from normal and tumor tissues. The PIF mRNA expression was examined in 37 tumor and 4 normal tissue samples and detected in 7 of 20 breast tumor cell lines, one colon tumor cell line and in normal breast, placenta and testis tissues. The differential expression of PIF message in metastatic breast cell lines was confirmed by the Real-time PCR technique. A new splicing form of the message, containing one new exon of 64bp, inserted between the exons 4 and 5, was identified in normal breast tissue. This splicing form of PIF is expressed concomitantly with a main form of PIF in breast tumor cell lines and also in normal breast and placenta tissue. These data suggest that PIF exhibits physiological functions in normal tissues. An over-expression and a production of a new splicing form (PIF-SV), seem to contribute in some event leading normal cell to a malignant phenotype.

ASSUNTO(S)

caquexia oncogenes oncogene cachexia câncer de mama proteolysis-induging factor (pi) fator de indução de proteólise (pif) breast cancer

ACESSO AO ARTIGO

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