YAP Inactivation by Soft Mechanotransduction Relieves MAFG for Tumor Cell Dedifferentiation.

Area of Science:

• Oncology
• Biophysics
• Cell Biology

Background:

• Solid tumor cells exist in a dynamic mechanical microenvironment.
• Mechanotransduction by the extracellular matrix influences tumor cell development, but mechanisms are unclear.

Purpose of the Study:

• To investigate how extracellular matrix mechanics regulate tumor cell differentiation.
• To elucidate the molecular pathways involved in mechanotransduction-induced tumor cell dedifferentiation.

Main Methods:

• Investigated the effect of matrix stiffness on tumor cell phenotype.
• Utilized molecular biology techniques to identify key signaling proteins (integrin β8, RhoGDI1, RhoA, YAP, MAFG).
• Analyzed the expression of stemness genes (NANOG, SOX2, NESTIN).

Main Results:

• Soft matrix mechanical force induced dedifferentiation of moderately stiff tumor cells into stem-cell-like cells.
• Integrin β8 transduced mechanical signals, leading to RhoA inactivation via RhoGDI1 and subsequent YAP inactivation.
• YAP inactivation released MAFG inhibition, promoting the transcription of stemness genes and restoring integrin β8 expression, forming a feedback loop.
• MAFG expression correlated with poorer patient prognosis.

Conclusions:

• Mechanical forces from the extracellular matrix play a critical role in regulating tumor cell dedifferentiation.
• A novel signaling axis involving integrin β8, RhoA, YAP, and MAFG mediates this mechanotransduction process.
• Findings offer new therapeutic targets for cancer treatment by modulating the tumor mechanical microenvironment.