Figure 4

Suppression of Syndecan-1 expression synergizes with the suppression of β1 integrin expression to stimulate SKOV3 adhesion to rTGFBI. A, SKOV3 cells with stable expression of control non-target or β1 integrin shRNA were transfected with control non-target siRNA or Syndecan-1 siRNA. Flow cytometric analysis of β1 integrin and Syndecan-1 cell surface protein expression was performed. B, Cells were replated on either fibronectin, rTGFBI, or rPOSTN coated tissue culture wells and allowed to adhere for 30 minutes. Results were normalized to poly-L-lysine and represented as percent of non-target control shRNA, *p < 0.05, ***p < 0.001. C, Cell surface biotinylation and immunoprecipitation of β3 integrin from SKOV3 cells expressing either non-target control, β1 integrin, SDC-1, or β1 integrin/SDC-1 siRNA. Western blot analysis was performed against β3 integrin or against biotin using HRP-streptavidin. Arrow indicates αv integrin subunit and arrowhead indicates β3 integrin subunit. D, SKOV3 cells with stable expression of control non-target or β1 integrin shRNA were transfected with control non-target siRNA or Syndecan-4 siRNA. Western blot analysis was performed on RIPA soluble lysates and the membrane was probed with antibodies specific to the indicated proteins. Cells were replated on either fibronectin, rTGFBI, or rPOSTN coated tissue culture wells and allowed to adhere for 30 minutes. Results were normalized to poly-L-lysine and represented as percent of non-target control shRNA. Significance of **p < 0.01 and ***p < 0.001 is compared to control shRNA.