The Laminin-α1 Chain-Derived Peptide, AG73, Binds to Syndecans on MDA-231 Breast Cancer Cells and Alters Filopodium Formation

Figure 3

Expression of Sdcs 1, 2, and 4 is decreased by 75% at the protein (a, b) and message (c) levels in MDA-231 cells. (a, b) Flow cytometry measuring surface expression of Sdcs in MDA-231: (a) only Sdc 1 expression is decreased at the cell surface when the Sdc 1 expression is silenced in the MDA-231 cells. (b) In Sdc 2 KD cells, only the Sdc 2 surface expression is decreased, and in Sdc 4 KD cells, only the Sdc 4 surface expression is decreased. The decreased expression of these Sdcs is specific. (c) qPCR was used to detect the message levels of each Sdc. The fold change is plotted in comparison to the control. (d) Solid-phase assays were performed with the Sdc KD cells as described in Figure 2(b). Sdcs 1 and 4 bind to AG73 in control cells (NS1 and NS2) as well as the Sdc 2 KD cell lysate. No binding to AG73 was detected in the Sdc 1 and 4 KD cell lysate. Silencing of Sdcs 1 or 4 expression inhibited binding of these receptors to AG73, and thus, binding of the Sdc 1 and 4 antibodies was significantly decreased. Bars: mean OD . MDA-231-Sdc 1 KD cells compared to MDA-231-NS1 cells. MDA-231-Sdc 2 and 4 KD cells compared to MDA-231-NS2 cells. . One-way ANOVA with Bonferroni posttest.

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