Background: MUC1 plays a role in mediation of signaling initiated by growth factors. Results: Siglec-9-positive cells are associated with MUC1-positive tumor cells in tumor tissues, and Siglec-9 binds to MUC1. Conclusion: MUC1-mediated signaling occurs by direct binding of Siglec-9 to MUC1. Significance: Multiple signaling pathway through MUC1 can be advantageous to adjust to various conditions of tumor microenvironments.

No abstract

Background: Molecular mechanism by which MUC1 promotes cancer cell invasion is unclear. Results: MUC1 forms a complex with NF-B p65 transcription factor and binds to urokinase-type plasminogen activator (uPA) promoter, and thereby induces uPA expression. Conclusion: uPA induced by MUC1 promotes cancer cell invasion. Significance: uPA is a useful target for inhibiting invasion by MUC1-expressing cancer cells.

Background: Regulation of TLR4-mediated signaling is critical for maintaining the immune response at an appropriate level. Results: CD14 is an endogenous ligand for CD33, and their binding inhibits uptake of LPS and TLR4-mediated signaling. Conclusion: CD14 controls TLR4-mediated signaling through the ligation with CD33. Significance: CD33 plays an essential role in regulation of TLR4-mediated signaling.

No abstract