Cancer cells decorate their surface with a dense layer of sialylated
glycans by upregulating the expression of
sialyltransferases and other glycogenes. Although
sialic acids play a vital role in many
biologic processes, hypersialylation in particular has been shown to contribute to
cancer cell progression and
metastasis. Accordingly, selective strategies to interfere with
sialic acid synthesis might offer a powerful approach in
cancer therapy. In the present study, we assessed the potential of a recently developed fluorinated
sialic acid analogue (P-3F(ax)-Neu5Ac) to block the synthesis of sialoglycans in murine
melanoma cells and the consequences on cell adhesion, migration, and in vivo growth. The results showed that
P-3F(ax)-Neu5Ac readily caused depletion of α2,3-/α2,6-linked
sialic acids in B16F10 cells for several days. Long-term inhibition of sialylation for 28 days was feasible without affecting cell viability or proliferation. Moreover,
P-3F(ax)-Neu5Ac proved to be a highly potent inhibitor of sialylation even at high concentrations of competing
sialyltransferase substrates. P-3F(ax)-Neu5Ac-treated
cancer cells exhibited impaired binding to poly-
l-lysine,
type I collagen, and
fibronectin and diminished migratory capacity. Finally, blocking sialylation of B16F10
tumor cells with this novel
sialic acid analogue reduced their growth in vivo. These results indicate that
P-3F(ax)-Neu5Ac is a powerful glycomimetic capable of inhibiting aberrant sialylation that can potentially be used for anticancer
therapy.