Time- and Dose-Resolved DIA-PASEF Proteomics Maps the Transition from Adaptive Stress to Apoptotic Collapse in Melittin-Treated MDA-MB-231 Cells.

Melittin, the cytolytic peptide of honeybee venom, exhibits potent anticancer activity in triple-negative breast cancer (TNBC), yet the molecular programs underlying its cytotoxic effects remain incompletely defined. To address this gap, MDA-MB-231 TNBC cells were exposed to melittin at half-maximal inhibitory concentration(half IC50) and IC50 across early(0.5, 1, and 2 h), mid(3, 4 h), and late (12, 24 h) time windows. Proteomic profiling was performed using label-free data-independent acquisition(DIA) parallel accumulation-serial fragmentation(PASEF). Approximately 5800 proteins were quantified, revealing distinct dose-dependent stress responses. An integrative exploratory framework combining time-resolved log2 fold-change trajectories, area-under-the-curve(AUC) based temporal prioritization, and independent heatmap visualization identified proteins associated with melittin-induced stress remodeling. Half IC50 exposure showed a transient stress-adaptive signature characterized by chromatin remodeling(HMGN2, H2AZ1), structural and RNA-associated buffering(LRRC7), and indirect mitochondrial quality-control signaling(CPAMD8, SPATA4), which progressively weakened over time. In contrast, IC50 treatment induced rapid chromatin remodeling dominated by histone H1 variants(H1.4, H1.2), early RNA instability(LRRC7), and late-stage cytoskeletal disassembly marked by MICAL3 induction, consistent with progression toward apoptosis. These trajectories paralleled dose-dependent apoptotic phenotypes. Overall, data suggest that melittin elicits dose- and time-dependent proteomic stress responses in TNBC cells and identify candidate trajectory-associated proteins and pathways linked to adaptive stress remodeling or progression toward cytotoxic collapse.