dos Santos Mariana Lopes, Palanch Carolina Gonçalves, Salaorni Sibeli, Da Silva Wilson Araujo, Nagai Maria Aparecida
Disciplina de Oncologia, Departamento de Radiologia da Faculdade de Medicina da Universidade de São Paulo, CEP 01246-903, São Paulo, Brazil.
Int J Oncol. 2006 Jun;28(6):1441-61.
Over-expression of ERBB2, a member of the family of transmembrane receptor tyrosine kinases, occurs in 15-30% of primary breast tumors and is associated with poor prognosis and chemoresistance to a variety of anticancer drugs. In this study, aiming to identify differentially-expressed genes involved in erbB2-mediated transformation of the breast, we generated SAGE libraries from two human mammary cell lines, derived from normal luminal cells, expressing different levels of erbB2. The parental cell line HB4a expresses basal levels and the C5.2 expresses high levels of erbB2. A total of 161,632 tags was generated by sequencing, 81,684 from HB4a cells (30,854 unique tags) and 79,948 from C5.2 cells (30,568 unique tags). The comparison between the HB4a and C5.2 libraries revealed 334 distinct transcripts more expressed in HB4a cells and 328 distinct transcripts more expressed in C5.2 cells. The expression pattern of some of these transcripts was further validated by RT-PCR. The C5.2 cell line, which over-express ERBB2, showed in comparison to HB4a cells a higher percentage of genes involved in transport, RNA processing, apoptosis and protein folding. A higher percentage of the genes more expressed in HB4a cells compared to C5.2 were found to be involved in signal transduction and cytoskeleton organization. The use of SAGE analysis allowed us to identify a significant number of genes implicated in different cellular pathways up- or down-regulated in the presence of ERBB2 over-expression, including genes not previously implicated in breast cancer that could be considered as potential candidate markers for prognosis and therapy.
跨膜受体酪氨酸激酶家族成员ERBB2在15%-30%的原发性乳腺癌中过表达，与预后不良及对多种抗癌药物的化疗耐药相关。在本研究中，为了鉴定参与erbB2介导的乳腺转化的差异表达基因，我们从两个人类乳腺细胞系构建了SAGE文库，这两个细胞系源自正常管腔细胞，表达不同水平的erbB2。亲代细胞系HB4a表达基础水平的erbB2，C5.2细胞系则高水平表达erbB2。通过测序共产生了161,632个标签，其中81,684个来自HB4a细胞（30,854个独特标签），79,948个来自C5.2细胞（30,568个独特标签）。HB4a文库与C5.2文库的比较显示，有334个不同的转录本在HB4a细胞中表达更多，328个不同的转录本在C5.2细胞中表达更多。其中一些转录本的表达模式通过RT-PCR进一步验证。与HB4a细胞相比，过表达ERBB2的C5.2细胞系在参与转运、RNA加工、凋亡和蛋白质折叠的基因方面表现出更高的比例。与C5.2细胞相比，在HB4a细胞中表达更多的基因中有更高比例的基因参与信号转导和细胞骨架组织。SAGE分析的使用使我们能够鉴定出大量在ERBB2过表达情况下上调或下调的不同细胞途径中涉及的基因，包括一些以前未涉及乳腺癌的基因，这些基因可被视为预后和治疗的潜在候选标志物。
