Journal: Developmental Cell
Article Title: Reciprocal Repression between Sox3 and Snail Transcription Factors Defines Embryonic Territories at Gastrulation
doi: 10.1016/j.devcel.2011.07.005
Figure Lengend Snippet: The Antagonistic Relationship between Sox3 and Snail Factors Is Conserved in Human Cancer Cells (A) Expression of Sox3 and Snail1 in different human cancer cell lines. Epithelial MCF7 cells express high levels of Sox3 and low levels of Snail1 . Conversely, mesenchymal MDA231, MDA435, and A375P lines are almost devoid of Sox3 transcripts and show high Snail1 expression. (B) Efficient Sox3 downregulation by specific siRNA in MCF7 cells is accompanied by an increase in Snail1 and associated mesenchymal markers Adam12 and Fibronectin and a decrease in the epithelial marker Claudin1 . (C) TGF-β mediated Snail1 induction in MCF7 cells is accompanied by a decrease in Sox3 expression. This decrease is Snail1-dependent, as it is prevented by transfection with Snail1 siRNA. (D and E) Sox3 stable overexpression in MDA435 leads to morphological changes compatible with a partial mesenchymal to epithelial transition (D). These morphological changes are associated with a decrease in Snail2 expression and an increase in E-cadherin expression (E). (F) The migratory behavior of MDA435-Sox3 stable transfectants was tested in culture using a wound healing assay. Control MDA435 cells cover the wound in 12 hr, in clear contrast with Sox3-expressing cells. (G) Invasive behavior of MDA435-Sox3 cells. The nuclei of cells that invaded the collagen matrix were stained with DAPI and quantified. MDA435 cells expressing Sox3 significantly decreased their invasive properties. (H) Diagram showing the relationship between Snail and Sox3 factors in gastrulating embryos and in cancer cells. In gastrulating embryos, the mutual repression between Sox3 and Snail1 regulates the decision to ingress at the primitive streak. Sox3 expressing cells do not ingress, ensuring the development of ectodermal derivatives in developing embryos. In cancer cells, Snail induces EMT and its expression correlates with invasive properties. Sox3 represses Snail, thereby preventing EMT to maintain epithelial integrity.
Article Snippet: MCF7, MDA231, MDA435, and A375P human tumor cell lines were purchased from the ATCC (Virginia, USA) and were cultured in DMEM supplemented with 10% heat inactivated serum and 0.1% penicillin-streptomycine (Invitrogen).
Techniques: Expressing, Marker, Transfection, Over Expression, Wound Healing Assay, Control, Staining
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