Evaluation of the Role of MAP4K4 in Focal Adhesion Dynamics and Regulation of Cell Migration of Breast Cancer Cell Line MDA-MB-231.

Abstract

In the migration and metastasis of cancer cells, it is necessary to rotate the focal adhesion (FA). MAP4K4 plays a vital role in the formation of cytoskeletal regeneration, but its role in regulating FA dynamics and cancer cell migration is not well understood. This present aimed to investigate the role of MAP4K4 in regulating FA dynamics and cell migration in the human breast cancer cell line. For this purpose, different variants, including MAP4K4 (wild type), partial active mutation kinase (MAP4K4-T178D), mutant with inactivated or reduced activity kinase (MAP4K4-T178A) and inactive kinase mutation (MAP4K4-K54R) was used in the evaluation. GFP-paxillin was also used as a marker in basal breast cancer cells (MDA-MB-231) in determining FA dynamics. Time-lapse and confocal microscopes were used to record FA dynamics and cell migration. The present study's findings showed that cells expressing MAP4K4-K54R, MAP4K4-T178D and MAP4K4-T178A type slowly down the FA turnover rates and had much larger FAs than those expressing WT MAP4K4 in MDA-MB-231 breast cancer cell line. Furthermore, inhibiting MAP4K4 strongly inhibited FA formation and reduced cell migration speed. In conclusion, MAP4K4 regulates FA dynamics and cancer cell migration, most probably through activating FA proteins and cytoskeleton.