In-Vitro Evaluation of ACTB Modulation: Implications for Biomarker Discovery, Drug Response Prediction, and Overcoming Chemoresistance in Breast Cancer Models

Abstract

Breast cancer chemoresistance remains a major impediment to successful treatment, driven by complex genetic, epigenetic, and cellular mechanisms that enable tumor cells to survive and adapt in the face of cytotoxic therapies. ACTB (β-actin), a key cytoskeletal protein, plays a critical role in processes such as cell migration, polarity, and the epithelial–mesenchymal transition (EMT), all of which contribute to tumor progression and resistance phenotypes. Its overexpression and dynamic cytoskeletal remodeling enhance invasive behavior and are linked to poor clinical outcomes, particularly in aggressive subtypes like triple-negative breast cancer (TNBC).​

This review focuses on in-vitro strategies for modulating ACTB expression and function, highlighting techniques such as CRISPR/Cas9-mediated knockout and siRNA silencing as predominant tools for dissecting its role in breast cancer chemoresistance. Pharmacological inhibition and expression modulation models further expand understanding of ACTB’s influence on drug responses. The use of 2D and 3D breast cancer cell models, including spheroids and organoids, facilitates controlled evaluation of ACTB modulation effects on cellular behavior and therapeutic susceptibility.

Key findings summarized include biomarker implications where ACTB expression levels correlate with sensitivity to agents such as doxorubicin and paclitaxel, demonstrated by shifts in IC50 values across modulated cell lines. Importantly, ACTB depletion sensitizes TNBC models to various chemotherapy and targeted drugs, highlighting its potential as a biomarker and therapeutic target to reverse resistance. Integration of high-content screening and omics data enriches predictive modeling and mechanistic understanding.

In conclusion, these in-vitro insights form a vital translational bridge, advancing precision oncology approaches by enabling biomarker discovery, prediction of drug responses, and development of resistance-reversal strategies targeting ACTB in breast cancer. Continued refinement of these models promises to accelerate clinical personalization and improve outcomes for patients facing resistant tumors.