RESUMO
Expression of BIRC5 (survivin), a member of the inhibitor of apoptosis protein (IAP) family, is elevated in fetal tissues and in various human cancers. Mechanisms up-regulating BIRC5 in cancer are poorly understood. Here, we show that overexpression of BIRC5 induces a high proliferation level in MCF-7 breast tumor cells. In a population of 191 breast carcinomas, BIRC5 expression is not affected by BIRC5 promoter polymorphism at -31, or BIRC5 gene copy number. However, a significant correlation was found between expression of demethylase (dMTase) and expression of BIRC5. In addition, among 13 chromosomal regions tested for allelic loss [loss of heterozygosity (LOH)], two regions close to D3S1478 and D6S264 were related to BIRC5 expression. In tumors with LOH at D3S1478 and/or D6S264, BIRC5 expression was significantly increased. These regions have been suggested to harbor tumor suppressor genes and/or common fragile sites that may play a role in increasing genetic instability. These results suggest that genes located near D3S1478 and D6S264 might work by inhibiting, directly or indirectly, BIRC5 expression and thus their loss leads to its up-regulation. In addition, BIRC5 expression may induce breast tumor proliferation by promoting genetic instability. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.
Assuntos
Neoplasias da Mama/genética , Dosagem de Genes , Perda de Heterozigosidade , Proteínas Associadas aos Microtúbulos/genética , Proteínas de Neoplasias/genética , Western Blotting , Proliferação de Células , Humanos , Técnicas Imunoenzimáticas , Proteínas Inibidoras de Apoptose , Repetições de Microssatélites , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Neoplasias/metabolismo , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Survivina , Transfecção , Células Tumorais CultivadasRESUMO
We here show adequate species identification for bacterial isolates of the genus Nocardia spp. through VITEK mass spectrometry. Application of a specific sample preparation method in combination with a robust matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) database leads to 94% accurate identification to the species level on a set of 164 isolates. The possibility to identify Nocardia spp. using MALDI-TOF MS will be available in the next release of VITEK MS update (IVD Version 3.0).