Bisphenol A drives thyroid carcinogenesis through oxidative stress-lipid metabolic reprogramming via the PTEN/PI3K/AKT axis: Therapeutic reversal by a curcumin-modified quercetin nanomicelle system.

Bisphenol A (BPA), a pervasive endocrine-disrupting chemical, has been increasingly implicated in thyroid carcinogenesis, yet the links between redox imbalance and metabolic alterations remain incompletely defined. Here, we combined LC-MS/MS quantification of BPA and its major conjugates with in vitro and in vivo thyroid cancer models to examine oxidative stress markers and lipid indices assessed by targeted biochemical assays and to evaluate a curcumin-modified, quercetin-loaded chitosan nanomicelle system (Que@CSNPs-Cur). We observed BPA enrichment in tumor-bearing mice, accompanied by increased lipid indices (free fatty acids, triglycerides, and total cholesterol) and elevated oxidative stress markers (ROS, TOS, and MDA), as assessed by targeted enzymatic and colorimetric assays. At the molecular level, BPA exposure was associated with reduced PTEN expression and increased PI3K/AKT phosphorylation, consistent with enhanced proliferative and invasive phenotypes in papillary thyroid carcinoma cells. Que@CSNPs-Cur restored PTEN levels, reduced PI3K/AKT activation, attenuated redox and lipid indices, and promoted caspase-3-dependent apoptosis. In xenograft mice, Que@CSNPs-Cur suppressed tumor growth, decreased oxidative stress markers and lipid indices, and reduced tumor BPA residue. Collectively, these results suggest that BPA exposure is linked to PTEN/PI3K/AKT dysregulation, oxidative stress and lipid disturbances. Que@CSNPs-Cur is a promising redox-oriented nanotherapeutic strategy for BPA-associated thyroid cancer phenotypes. Notably, the present study does not determine whether oxidative stress is upstream or downstream of PTEN suppression.