VALD-3 Induces GSDME-Dependent Pyroptosis via ROS/JNK/Bax Pathway in Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is a particularly aggressive subtype of breast cancer, known for its high malignancy, elevated risk of recurrence and metastasis, and limited therapeutic options, resulting in the poorest prognosis among breast cancer types. This study explores the anticancer effects of VALD-3, a Schiff base ligand derivative, on breast cancer cells. While VALD-3 exhibited cytotoxic effects on both triple-negative breast cancer (TNBC) and estrogen receptor-positive (ER+) MCF-7 cells, it more potently inhibited TNBC cell viability. More importantly, VALD-3 induced characteristic pyroptotic features selectively in TNBC cells, including cell swelling, balloon-like protrusions, and the release of inflammatory cytokines due to pore formation in the plasma membrane, ultimately inhibiting tumor growth. Mechanistically, VALD-3 increased reactive oxygen species (ROS) levels and JNK phosphorylation, leading to the recruitment of Bax to the mitochondria and the formation of a Bax-Bcl-2 heterodimer, which facilitated cytochrome c release into the cytoplasm. This cascade activated caspase-3 and triggered gasdermin E(GSDME)- dependent pyroptosis in TNBC cells. Thus, VALD-3 treatment initiated the ROS/JNK/Bax-mitochondrial apoptosis pathway, leading to caspase-3 activation and GSDME cleavage, thereby executing pyroptosis. These findings suggest that GSDME-dependent pyroptosis is a novel mechanism by which VALD-3 eradicates cancer cells and offer new insights into potential clinical applications for anticancer therapies.