Non-overlapping activities of ADF and cofilin-1 during the migration of metastatic breast tumor cellsReport as inadecuate

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BMC Cell Biology

, 14:45

Directional sensing and cell motility


BackgroundADF-cofilin proteins are key modulators of actin dynamics in metastasis and invasion of cancer cells. Here we focused on the roles of ADF and cofilin-1 individually in the development of polarized migration of rat mammary adenocarcinoma MTLn3 cells, which express nearly equal amounts of each protein. Small interference RNA siRNA technology was used to knockdown KD the expression of ADF and cofilin-1 independently.

ResultsEither ADF KD or cofilin KD caused cell elongation, a reduction in cell area, a decreased ability to form invadopodia, and a decreased percentage of polarized cells after 180 s of epidermal growth factor stimulation. Moreover, ADF KD or cofilin KD increased the rate of cell migration and the time of lamellipodia protrusion but through different mechanisms: lamellipodia protrude more frequently in ADF KD cells and are more persistent in cofilin KD cells. ADF KD cells showed a significant increase in F-actin aggregates, whereas cofilin KD cells showed a significant increase in prominent F-actin bundles and increased cell adhesion. Focal adhesion area and cell adhesion in cofilin KD cells were returned to control levels by expressing exogenous cofilin but not ADF. Return to control rates of cell migration in ADF KD cells was achieved by expression of exogenous ADF but not cofilin, whereas in cofilin KD cells, expression of cofilin efficiently rescued control migration rates.

ConclusionAlthough ADF and cofilin have many redundant functions, each of these isoforms has functional differences that affect F-actin structures, cell adhesion and lamellipodial dynamics, all of which are important determinants of cell migration.

KeywordsADF Cofilin Metastasis Invadopodia Adhesion Lamellipodia Abbreviationsα-MEMα-Modified eagle’s media

ABPsActin binding proteins


ADFActin depolymerizing factor

BSABovine serum albumin

CBSCytoskeleton buffer with sucrose



ECMExtracellular matrix

EGFEpidermal growth factor

EGFREpidermal growth factor receptor

F-actinActin filaments

FBSFetal bovine serum


MOIMultiplicity of infection

PBSPhosphate-buffered saline

PBSTPhosphate-buffered saline containing 0.05% Tween-20

PI3KPhosphatidylinositol 3-kinase

PIP2Phosphatidylinositol 4,5-bisphosphate

PLC-γPhospholipase γ

siRNASmall interference RNA


TAMsTumor associated macrophages

TBSTris-buffered saline

UBUreteric bud

XACXenopus ADF-cofilin.

Electronic supplementary materialThe online version of this article doi:10.1186-1471-2121-14-45 contains supplementary material, which is available to authorized users.

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Author: Lubna H Tahtamouni - Alisa E Shaw - Maram H Hasan - Salem R Yasin - James R Bamburg


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