Figure 2. Knockdown of Spry1 decreases MDA-MB-231 cell growth, colony formation, migration and invasion.

Human Spry1 shRNAs or non-targeting control shRNA lentiviruses were used to generate Spry1 knockdown (S1kd) or control non-targeting (NT) cell lines. (A) Lysates from NT or S1kd cells were immunoblotted to examine the effectiveness of shRNAs. The same blot was reused for probing Tubulin. (B) Cell growth curve analysis shows loss of Spry1 suppressed cell growth. (C) EdU labeling followed by FACS shows that knockdown of Spry1 decreased MDA-MB-231 cell proliferation. (D) Representative images from at least three independent scratch assays show suppressing Spry1 expression inhibited cell migration into the denuded area. (E) Quantification of cell migration capacity. (F) Representative images from at least three independent Matrigel invasion assays show that knockdown of Spry1 decreased MDA-MB-231 cell matrix invasion towards serum. (G) Quantification of the level of cell invasion. (H) Representative images from at least three independent soft-agar colony formation assays show that S1kd cells formed fewer and smaller colonies compared to NT cells. (I,J) Quantification of the colony number and size from the soft-agar assays. *p < 0.05, **p < 0.01 relative to controls.