Winklmeier Andreas, Poser Ina, Hoek Keith S, Bosserhoff Anja K
Institute of Pathology, University Regensburg, 93053 Regensburg, Germany.
BMC Cancer. 2009 Feb 12;9:52. doi: 10.1186/1471-2407-9-52.
The C-terminal binding protein 1 (CtBP1) is a known co-repressor of gene transcription. We recently revealed that CtBP1 expression is lost in melanoma cells and melanoma inhibitory activity (MIA) expression is subsequently increased. The present study was performed to evaluate a more general role of CtBP1 in human melanoma and identify further CtBP1-regulated target genes.
Sequence analysis and expression profile of CtBP1 in melanoma cell lines were done by PCR. Boyden Chamber assays and co-immunoprecipitation were performed to investigate the functional role of CtBP1. Gene expression analysis and micro array data were used to define target genes.
Interestingly, we detected an alternative splice product of CtBP1 with unknown function whose expression is induced at reduction of full length CtBP1. Overexpression of full length CtBP1 in melanoma cells had no effect on cell proliferation but did influence cell migration and invasiveness. To understand the effect of CtBP1 we identified putative LEF/TCF target genes found to be strongly expressed in melanoma using DNA microarray analysis. We focused on fourteen genes not previously associated with melanoma. Detailed analysis revealed that most of these were known to be involved in tumor metastasis. Eleven genes had expression profiles associated with melanoma cell invasiveness.
In summary, this study revealed that reduction of CtBP1 expression is correlated with migratory, invasive potential of melanoma cells.
C 末端结合蛋白 1（CtBP1）是一种已知的基因转录共抑制因子。我们最近发现，黑色素瘤细胞中 CtBP1 的表达缺失，随后黑色素瘤抑制活性（MIA）表达增加。本研究旨在评估 CtBP1 在人类黑色素瘤中的更广泛作用，并确定 CtBP1 调控的其他靶基因。
通过聚合酶链反应（PCR）对黑色素瘤细胞系中 CtBP1 的序列分析和表达谱进行检测。采用 Boyden 小室实验和免疫共沉淀法研究 CtBP1 的功能作用。利用基因表达分析和微阵列数据确定靶基因。
有趣的是，我们检测到一种功能未知的 CtBP1 可变剪接产物，其表达在全长 CtBP1 减少时被诱导。在黑色素瘤细胞中过表达全长 CtBP1 对细胞增殖没有影响，但确实影响细胞迁移和侵袭能力。为了解 CtBP1 的作用，我们通过 DNA 微阵列分析鉴定了在黑色素瘤中强烈表达的假定 LEF/TCF 靶基因。我们关注了 14 个以前与黑色素瘤无关的基因。详细分析表明，其中大多数已知参与肿瘤转移。11 个基因的表达谱与黑色素瘤细胞侵袭性相关。
总之，本研究表明 CtBP1 表达的降低与黑色素瘤细胞的迁移、侵袭潜能相关。
