title: Transcriptional regulation of KiSS-1 gene expression in metastatic melanoma by specificity protein-1 and its coactivator DRIP-130.
abstract: Loss of the metastasis suppressor gene, KiSS-1 has been strongly correlated to the progression of metastases in numerous types of cancers. The mechanism through which KiSS-1 is lost during metastasis, however, is still not completely known. Previous studies have shown that genetic material on human chromosome 6q16.3-q23 is essential for KiSS-1 expression in normal tissues. Additionally, microcell-mediated transfer of this chromosome in cancerous tissue results in rescued expression of KiSS-1 and reduced metastatic phenotype. Here, we show that loss of Sp1-coactivator protein DRIP-130, which is encoded by human chromosome 6q16.3-q23, results in reduced KiSS-1 promoter activation in highly malignant melanoma cells. Co-expression of Sp1 and DRIP-130 not only rescues KiSS-1 expression, but also induces an inhibition of the invasive and migratory behavior in highly metastatic melanoma cells, similar to the overexpression of KiSS-1 metastasis suppressor gene in those cells. Furthermore, we demonstrate that KiSS-1 expression is regulated by Sp1 elements within the first 100-bp region of the KiSS-1 promoter and that targeted deletion of a single GC-rich region spanning -93 to -58 interrupts Sp1- and DRIP-130-modulated transcriptional control of KiSS-1 expression. Our results thus suggest that DRIP-130 is a key regulator in KiSS-1 transactivation in normal tissue, and that the loss of DRIP-130 expression, as a result of the gross loss of human chromosome 6q16.3-q23, provokes increased tumor metastasis.
authors.affiliation: Institute of Biosciences and Technology, and Department of Molecular and Cellular Medicine, Texas A&M University System Health Science Center, Houston, TX 77030, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Mitchell
authors.forename: L J
authors.initials: LJ
authors.lastname: Stafford
authors.forename: D
authors.initials: D
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Bar-Eli
authors.forename: M
authors.initials: M
authors.lastname: Liu
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D045744:Cell Line, Tumor; D017931:DNA Primers; D024202:Electrophoretic Mobility Shift Assay; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D059648:Kisspeptins; D056892:Mediator Complex; D008545:Melanoma / Q000235:genetics* / Q000473:pathology; D009362:Neoplasm Metastasis; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016329:Sp1 Transcription Factor / Q000502:physiology*; D015534:Trans-Activators / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D017931:DNA Primers; C106628:KISS1 protein, human; D059648:Kisspeptins; C492159:MED23 protein, human; D056892:Mediator Complex; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins