title: The Wnt5A/protein kinase C pathway mediates motility in melanoma cells via the inhibition of metastasis suppressors and initiation of an epithelial to mesenchymal transition.
abstract: We have shown that Wnt5A increases the motility of melanoma cells. To explore cellular pathways involving Wnt5A, we compared gain-of-function (WNT5A stable transfectants) versus loss-of-function (siRNA knockdown) of WNT5A by microarray analysis. Increasing WNT5A suppressed the expression of several genes, which were re-expressed after small interference RNA-mediated knockdown of WNT5A. Genes affected by WNT5A include KISS-1, a metastasis suppressor, and CD44, involved in tumor cell homing during metastasis. This could be validated at the protein level using both small interference RNA and recombinant Wnt5A (rWnt5A). Among the genes up-regulated by WNT5A was the gene vimentin, associated with an epithelial to mesenchymal transition (EMT), which involves decreases in E-cadherin, due to up-regulation of the transcriptional repressor, Snail. rWnt5A treatment increases Snail and vimentin expression, and decreases E-cadherin, even in the presence of dominant-negativeTCF4, suggesting that this activation is independent of Wnt/beta-catenin signaling. Because Wnt5A can signal via protein kinase C (PKC), the role of PKC in Wnt5A-mediated motility and EMT was also assessed using PKC inhibition and activation studies. Treating cells expressing low levels of Wnt5A with phorbol ester increased Snail expression inhibiting PKC in cells expressing high levels of Wnt5A decreased Snail. Furthermore, inhibition of PKC before Wnt5A treatment blocked Snail expression, implying that Wnt5A can potentiate melanoma metastasis via the induction of EMT in a PKC-dependent manner.
authors.affiliation: Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224, USA.
authors.forename: Samudra K
authors.initials: SK
authors.lastname: Dissanayake
authors.forename: Michael
authors.initials: M
authors.lastname: Wade
authors.forename: Carrie E
authors.initials: CE
authors.lastname: Johnson
authors.forename: Michael P
authors.initials: MP
authors.lastname: O'Connell
authors.forename: Poloko D
authors.initials: PD
authors.lastname: Leotlela
authors.forename: Amanda D
authors.initials: AD
authors.lastname: French
authors.forename: Kavita V
authors.initials: KV
authors.lastname: Shah
authors.forename: Kyle J
authors.initials: KJ
authors.lastname: Hewitt
authors.forename: Devin T
authors.initials: DT
authors.lastname: Rosenthal
authors.forename: Fred E
authors.initials: FE
authors.lastname: Indig
authors.forename: Yuan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Nickoloff
authors.forename: Dennis D
authors.initials: DD
authors.lastname: Taub
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Trent
authors.forename: Randall T
authors.initials: RT
authors.lastname: Moon
authors.forename: Michael
authors.initials: M
authors.lastname: Bittner
authors.forename: Ashani T
authors.initials: AT
authors.lastname: Weeraratna
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D017931:DNA Primers; D004847:Epithelial Cells / Q000166:cytology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008545:Melanoma / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008648:Mesoderm / Q000166:cytology*; D009362:Neoplasm Metastasis; D011493:Protein Kinase C / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D000071818:Wnt-5a Protein
chemical_list: D017931:DNA Primers; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D011493:Protein Kinase C