Wnt5A exerts immunomodulatory activity in the human ovarian cancer cell line SKOV-3

The purpose of this study was three fold: (1) to reveal the implications of Wnt5A for cytokine and chemokine production by human ovarian cancer cell line SKOV-3 cells, (2) to determine the influence of Wnt5A on chemotactic SKOV-3 cell migration, and (3) to assess the effect of inflammatory mediators on Wnt5A expression levels and to describe its underlying molecular mechanisms. A cytokine array was performed using a conditioned medium harvested from SKOV-3 cells transfected with specific siRNAs against Wnt5A or with scrambled siRNA and a transfection reagent alone as negative controls for 48 h. Chemotactic cell migration was performed using transwells. Inflammation-induced Wnt5A expression was determined by treating cells with recombinant human (rh) IL-1 beta, IFN beta, or TNF alpha alone or in combination with STAT3 and NF-kappa B inhibitors for different time durations. The cytokine array showed the suppression of GCSF, GM-CSF, IL-1 alpha, IL-2, IL-13, and MCP-3 production, whereas cell RANTES and IL-7 showed increased levels in Wnt5A knock-down cells compared with those in controls. Chemotactic migration decreased significantly when the conditioned medium from Wnt5A knock-down cells was applied to the upper chamber of the transwell. Compared with the control, there were 30-fold and five-fold increases in Wnt5A mRNA levels in cells treated, with rhIL-1 beta and rhIFN beta, respectively after 8 h (P<0.001). Compared with the control, TNF-alpha had a 1.8- fold increased levels of Wnt5A mRNA after 4 h (P<0.01). Both NF-kappa B and STAT3 inhibitors decreased inflammation-induced Wnt5A expression. This study revealed a previously unrecognized immunomodulatory role of endogenous Wnt5A in ovarian cancer cells, which could further influence chemotactic cell migration.