Carcinogenesis Advance Access originally published online on February 20, 2006
Carcinogenesis 2006 27(6):1169-1179; doi:10.1093/carcin/bgi363
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Underexpression of transcriptional regulators is common in metastatic breast cancer cells overexpressing Bcl-xL
Centre d'Oncologia Molecular, Institut de Recerca Oncológica, IDIBELL, Hospital Duran i Reynals, Gran Via s/n, Km 2,7, E-08907 L'Hospitalet Ll., Barcelona 1 Grup de Bioinformàtica Estructural (GRIB-IMIM). Universitat Pompeu Fabra. C/Doctor Aiguader, 80, Barcelona 08003, Catalonia and 2 Servei d'Epidemiologia Institut Català d'Oncologia and Laboratorio de Bioestadística y Epidemiologia, Universitat Autónoma de Barcelona, Hospital Duran i Reynals, Gran Via s/n, Km 2,7, L'Hospitalet Ll. 08907, Spain
* To whom correspondence should be addressed. Tel: +34 93 2607429; Fax: +34 93 260 7426; Email: asierra{at}iro.es
Bcl-xL gene induces metastasis in the lung, lymph nodes and bone when breast cancer cells are inoculated in Nude Balb/c mice. In an attempt to identify the molecules required for diverse metastatic foci, we compared gene expression levels in tumor cells and metastatic variants with a cDNA GeneFilter containing 4000 known genes. The transcriptional regulators of
1-fetoprotein transcription factor, TBP-associated factor 172 (TAF-172) and the human zinc finger protein 5 (ZFP5) were downregulated. The expression of TAF-172 was inversely proportional to Bcl-xL expression (ANOVA P < 0.0001) and metastatic activity (ANOVA P < 0.0001). A protein interaction program allowed us to functionally associate Bcl-xL and TAF through TATA-binding protein (TBP), suggesting that Bcl-xL connects metabolic pathways with transcriptional machinery. The prediction included proteins involved in apoptosis, electron transfer, kinases and transcription factors. These results indicate that the selection of diverse metastatic cells from the broad spectrum of tumor cell leads to the underexpression of certain transcriptional regulators that might act as adaptor molecules to different microenvironments, and indicate that the synergistic activity of several genes is needed for the selection process in several metastatic foci.