ABSTRACT
Objective:To analyze the inhibiting mechanism of microRNA-199a/b-3p ( miR-199a/b-3p) on cell motility of breast cancer cells.Methods:The expression of PAK4 in MDA-MB-231 cells transfected with miR-199a/b-3p was detected by Western blot.The biology behaviors of MDA-MB-231 cells transfected with miR-199a/b-3p or PAK4 SiRNA were analysed by cell migration assay,invasion assay and protrusion dynamics.Results: MiR-199a/b-3p could suppress the expression of PAK 4 in MDA-MB-231 cells.Comparing with normal control ,miR-199a/b-3p or PAK4 SiRNA could suppress the migration ,invasion and membrane protrusion of MDA-MB-231 cells.Conclusion:miR-199a/b-3p could suppress the expression of PAK4,which are considered key breast cancer suppressors and inhibit the cell motility of breast cancer cells.
ABSTRACT
It has been recently shown that Trypanosoma cruzi trypomastigotes subvert a constitutive membrane repair mechanism to invade HeLa cells. Using a membrane extraction protocol and high-resolution microscopy, the HeLa cytoskeleton and T. cruzi parasites were imaged during the invasion process after 15 min and 45 min. Parasites were initially found under cells and were later observed in the cytoplasm. At later stages, parasite-driven protrusions with parallel filaments were observed, with trypomastigotes at their tips. We conclude that T. cruzi trypomastigotes induce deformations of the cortical actin cytoskeleton shortly after invasion, leading to the formation of pseudopod-like structures.