A study conducted in breast cancer cells found that (valproic acid) inhibits CIP2A/c-MYC/PI3K/Akt/mTOR signaling molecules and PD-L1

Abstract

Resistant cells significantly undermine the efficacy of breast cancer treatment. CIP2A and PD-L1 are among the major therapeutic challenges in breast cancer, as they are key drivers of drug resistance and immune evasion, respectively. Hence, identifying agents—particularly epigenetic drugs—that can suppress these factors by altering gene expression is of great interest. This study aimed to evaluate the molecular mechanisms and effects of valproic acid (VPA), a histone deacetylase inhibitor, on CIP2A and PD-L1 expression in the MCF-7 breast cancer cell line. VPA inhibited MCF-7 cell proliferation in a dose- and time-dependent manner. Treatment with VPA resulted in downregulation of CIP2A and its downstream signaling molecules c-MYC, PI3K, AKT, and mTOR. Moreover, VPA treatment reduced PD-L1 expression in MCF-7 cells. These findings suggest that VPA may offer a novel approach to addressing challenges associated with CIP2A and PD-L1. Therefore, either as a monotherapy or in combination with existing treatments, VPA could represent a promising strategy for enhancing the efficacy of breast cancer therapy.