Cofilin overexpression affects actin cytoskeleton organization and migration of human colon adenocarcinoma cells

Abstract

The dynamic reorganization of actin cytoskeleton is regulated by a large number of actin-binding proteins. Among them, the interaction of ADF/cofilin with monomeric and filamentous actin is very important, since it severs actin filaments. It also positively influences actin treadmilling. The activity of ADF/cofilin is reversibly regulated by phosphorylation and dephosphorylation at Ser-3, with the phosphorylated form (P-cofilin) being inactive. Here, we studied the effects of overexpression of cofilin and two cofilin variants in the human colon adenocarcinoma LS180 cell line. We have generated the LS180 cells expressing three different cofilin variants: WT (wild type), Ser 3 Ala (S3A) (constitutively active) or Ser 3 Asp (S3D) (constitutively inactive cofilin). The cells expressing WT cofilin were characterized by abundant cell spreading and colocalization of cofilin with the submembranous F-actin. Similar effects were observed in cells expressing S3A cofilin. In contrast, LS180 cells expressing S3D cofilin remained longitudinal in morphology and cofilin was equally distributed within the cell body. Furthermore, the migration ability of LS180 cells expressing different cofilin mutants was analyzed. In comparison to control cells, we have noticed a significant, approximately fourfold increase in the migration factor value of cells overexpressing WT type cofilin. The overexpression of S3D cofilin resulted in an almost complete inhibition of cell motility. The estimation of actin pool in the cytosol of LS180 cells expressing S3A cofilin has shown a significantly lower level of total actin in reference to control cells. The opposite effect was observed in LS180 cells overexpressing S3D cofilin. In summary, the results of our experiments indicate that phosphorylation “status” of cofilin is a factor affecting the actin cytoskeleton organization and migration abilities of colon adenocarcinoma LS180 cells.

Cofilin Drives Cell-Invasive and Metastatic Responses to TGF-β in Prostate Cancer

“…More importantly of direct clinically relevance are the data demonstrating a significant increase in cofilin expression in human prostate cancer metastasis (to lymph nodes), compared with primary tumors (same patient cohort). Changes in cofilin expression have been reported in other human malignancies, including colon and ovarian cancer (45-48). Loss of the epithelial marker E-cadherin is associated with a more invasive phenotype in prostate cancer cells and high-grade and metastatic prostate cancer, as originally established (49).…”

Over-expression of cofilin-1 suppressed growth and invasion of cancer cells is associated with up-regulation of let-7 microRNA

“…et al have reported that over-expression of cofilin-1 mediated motility of glioblastoma cells is concentration dependent [8]. However, another report shows that over-expression of serine-3 phosphorylated mutant cofilin-1 (S3D) results in an almost complete inhibition of cell motility in human colon adenocarcinoma cells [51]. Although wild-type cofilin-1 was induced to express in our cell model, it can be normally phosphorylated on serine-3 [6].…”

Varying effects of EGF, HGF and TGFβ on formation of invadopodia and invasiveness of melanoma cell lines of different origin

“…29 To our knowledge, lower concentrations are not used. Our previous experience 21,30 indicates that the optimal EGF concentration to stimulate cell migration/invasion is 31 ng/mL (5 nM). We decided to use HGF at the same concentration as EGF.…”