Rac1 and Cdc42 are downstream effectors involved in LPA- and S1P-induced HT1080 invasion of 3D collagen matrices. (A) HT1080 cells were transfected with siRNAs targeting the genes indicated and allowed to invade in the presence either LPA or S1P (1 μM). Data are expressed as mean numbers of invading cells per HPF (20×) (± S.D.) from a minimum of 20 fields. Statistical significance of means was determined using t-test where * = p < 0.01 relative to Luciferase (Luc) control for each lipid. LMNA = Lamin A/C. (B) siRNA transfected HT1080 cell lysates were prepared for Western blot analysis. Lysates were probed for Lamin A/C, RhoA, Rac1, and Cdc42 to demonstrate siRNA specificity and probed for Actin as a loading control.