PRDX3 promotes nasopharyngeal carcinoma tumor growth by regulating PINK1/Parkin pathway-dependent lipid peroxidation and mitochondrial dysfunction

Background

Nasopharyngeal carcinoma (NPC) is a challenging malignancy characterized by aggressive progression and limited therapeutic efficacy. Emerging evidence implicates peroxiredoxin 3 (PRDX3), a mitochondrial peroxidase, as a critical regulator of redox homeostasis and mitochondrial integrity. Given its role in modulating cell death through mitochondrial quality control, we investigated the therapeutic potential of targeting PRDX3 in NPC.

Methods

PRDX3 expression patterns were assessed in clinical NPC specimens using immunohistochemical and immunoblotting. Functional studies employed siRNA-mediated PRDX3 knockdown followed by cellular assays: CCK-8 proliferation, clonogenic survival, and mitochondrial parameter quantification (reactive oxygen species flux using DCFH-DA/C11-BODIPY, ATP biosynthesis, membrane polarization, and mtDNA integrity). Molecular interplay between PRDX3 and PTEN-induced kinase 1 (PINK1) was elucidated through co-immunoprecipitation and immunofluorescence analysis. In vivo therapeutic efficacy was validated using a xenograft model to evaluate tumor growth modulation.

Results

Clinical specimens revealed significant PRDX3 overexpression in NPC compared to non-malignant controls. PRDX3 knockdown substantially attenuated malignant behavior and induced mitochondrial dysfunction in NPC cells. Mechanistically, PRDX3 interacted with PINK1 to stabilize Parkin-mediated mitophagic flux. PRDX3 safeguarded against apoptosis by sustaining PINK1/Parkin-dependent mitophagy clearance of damaged mitochondria. In vivo validation confirmed that PRDX3 knockdown suppressed tumor growth.

Conclusion

PRDX3 acts as an upstream activator of the PINK1/Parkin signaling cascade, regulating lipid peroxidation-mediated mitochondrial dysfunction, mitophagy, survival and apoptosis of NPC cell.