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
Breast cancer is the most common cancer among women worldwide. Genetic alterations prevalent in breast cancer are still being elucidated. In this report, changes in 30 breast cancer tissues, in comparison with normal tissues from Thai patients, were analyzed by arbitrarily primed polymerase chain reaction (AP-PCR). Genetic instability was detected by DNA fingerprinting obtained with 13 of 60 random primers. Of these, at least one amplification band, the incidence ranging from 27 to 80%, was observed in DNA amplified with 8 primers, whereas a band loss was exhibited with from 6 primers, the incidences ranging from 23 to 40%. Likewise, an amplification band amplified from primer D15 was observed in 80% of this patient group and a band loss produced from primer B12 presented in 40% of all cases. These results showed that AP-PCR is effective for the detection of genetic alterations in breast cancer tissues.