Galectin-3 binding potentials of mouse tumor EHS and human placental laminins

Galectin-3, a lectin which binds to polyalctosamine chains of laminin, has been implicated as a modulator of cell to laminin interactions. In this study, we analyzed the relative binding of galectin-3 to mouse tumor and human placental laminins. Using gel overlay experiments, we have demonstrated that galectin-3 preferentially binds to mouse tumor compared to human placental laminin. We have also demonstrated by Western blotting assays that mouse tumor laminin copurifies with endogenous mouse galectin-3. Lastly, we have demonstrated by periodate Schiff staining that mouse tumor has more sugar residues than human placental laminin. These analyses may explain why laminins purified from normal and tumor cells promote the attachment and spreading of certain cells differently.