LeftyA decreases Actin Polymerization and Stiffness in Human Endometrial Cancer Cells

Area of Science:

• Cell Biology
• Biochemistry
• Biophysics

Background:

• LeftyA is a cytokine that regulates stemness and embryonic differentiation.
• Cell proliferation and migration depend on actin cytoskeleton dynamics controlled by Rac1 and PAK1.
• Ishikawa cells, a well-differentiated endometrial carcinoma cell line, were used to study LeftyA's effects.

Purpose of the Study:

• To investigate whether LeftyA affects the actin cytoskeleton, shape, and stiffness of Ishikawa cells.
• To determine the impact of LeftyA on the globular to filamentous actin ratio.
• To analyze the effect of LeftyA on Rac1 and PAK1 activity and expression.

Main Methods:

• Western blotting and flow cytometry to assess actin polymerization.
• Quantitative real-time PCR (qRT-PCR) and immunoblotting to measure Rac1 and PAK1 transcript levels and activity.
• Atomic force microscopy (AFM) to quantify cell stiffness, surface area, and volume.

Main Results:

• LeftyA treatment (25 ng/ml for 2 hours) significantly decreased Rac1 and PAK1 transcript levels and activity.
• LeftyA induced actin depolymerization, leading to reduced cell stiffness, surface area, and volume.
• Pharmacological inhibition of Rac1 or PAK1 mimicked LeftyA's effect on actin polymerization.

Conclusions:

• LeftyA disrupts Rac1 and PAK1 activity, causing actin depolymerization.
• LeftyA treatment results in cell softening and shrinkage.
• The findings highlight LeftyA's role in modulating cell mechanical properties through the Rac1/PAK1 pathway.