SND1 acts upstream of SLUG to regulate the epithelial-mesenchymal transition (EMT) in SKOV3 cells.

Staphylococcal nuclease domain-containing protein 1 (SND1) has been reported as an oncoprotein in a variety of cancers involving multiple processes, including proliferation, angiogenesis, and metastasis. However, the mechanisms underlying metastasis remain largely unknown. Herein, by using the ovarian cancer cell line SKOV3, which has high metastasis ability, we showed that loss-of-function of SND1 dramatically suppressed the invasion and migration of SKOV3 cells. We then performed gene expression profiles and further verified (by use of quantitative PCR and Western blot analysis) that loss-of-function of SND1 resulted in up-regulation of epithelial markers, such as epithelial cadherin and claudin 1, and down-regulation of mesenchymal markers, including neural cadherin and vimentin. Moreover, we illustrated that SLUG, a key transcription factor implicated in epithelial-mesenchymal transition and metastasis, acts as an essential effector of the SND1-promoted epithelial-mesenchymal transition process via regulating N-CAD and VIM expression (or E-CAD and CLDN1). The underlying molecular mechanisms illustrated that SND1 regulates the gene transcriptional activation of SLUG by increasing chromatin accessibility through the recruitment of the acetyltransferases GCN5 and CBP/p300 to the SLUG promoter proximal region. Overall, SND1 was identified as a novel upstream regulator of SLUG, which plays important roles in regulating the E-CAD/N-CAD expression switch. [ABSTRACT FROM AUTHOR]