RESUMO
This study was performed to detect amplification of DNA sequences on chromosomes 4p15.2 and 6q23-24, obtained from formalin-fixed, paraffin-embedded, breast-cancer tissues. The prognostic relevance of the amplification was also demonstrated. DNA from formalin-fixed, paraffin-embedded tumor and corresponding normal tissues of 53 patients with breast cancer was extracted and amplified by real-time quantitative PCR technique. Amplification of the DNA sequences on chromosomes 4p15.2 and 6q23-24 was detected in 23 (43%) and 32 (60%) cases, respectively. Thirty-six (68%) cases showed amplification on both or one of the chromosomes. These frequencies are similar to that obtained from fresh samples in our previous study. In addition, amplification of the DNA on chromosomes 4p15.2 and / or 6q23-24 was predominantly observed in tumors with invasive ductal carcinoma. The findings in this study demonstrate that DNA extracted from formalin-fixed, paraffin-embedded breast tumors can be used to determine amplification of DNA sequences on selective chromosomal regions. We also suggest that the amplified DNA on chromosomal regions 4p15.2 and 6q23-24 might be involved in the development and progression of breast cancer.
Assuntos
Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Aberrações Cromossômicas , Cromossomos Humanos Par 4/genética , Cromossomos Humanos Par 6/genética , Análise Mutacional de DNA , DNA de Neoplasias/genética , Progressão da Doença , Feminino , Amplificação de Genes , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Inclusão em Parafina , Reação em Cadeia da Polimerase/métodos , Fixação de TecidosRESUMO
Thirty-three primary breast cancers were analyzed for prognostic markers, Immunohistochemical assay of c-erbB-2 oncoprotein was performed in formalin fixed paraffin-embedded tissue. Enzyme immunoassay and radioreceptor assay for ER and PR were respectively done in tumor cytosol. Pre-opertive blood sample obtained from this group of patients were analyzed for CEA, CA15-3 and MCA levels. About 54% of tumor had c-erbB-2 positive staining. Direct association was observed between tumor size, pathological stage, serum CEA levels and c-erbB-2 expression. No significant association existed between the expression of c-erbB-2 and lymph node invasion, histological type, ER and PR status, serum CA15-3 or MCA levels. Increased incidence of c-erbB-2 overexpression among breast cancer patients with large tumor, more advanced stage and elevated CEA level suggests its value for indicating of greater tumor aggressiveness.