KPNA3 drives temozolomide resistance in glioblastoma by upregulating MGMT and activating STAT3 to sustain glioma stem cells

Mechanistically, KPNA3 promotes resistance via a dual pathway: it upregulates the expression of the DNA repair enzyme MGMT and activates the STAT3 signaling pathway. KPNA3 knockdown reduced both MGMT levels and STAT3 phosphorylation (Tyr705). Furthermore, pharmacological inhibition of STAT3 mirrored the effect of KPNA3 knockdown by potently inhibiting GSC generation.

Clinically, KPNA3 and p-STAT3 protein levels were positively correlated in high-grade glioma tissues. Collectively, our findings unveil KPNA3 as a central regulator that concurrently enhances DNA repair and sustains the GSC population to foster TMZ resistance, nominating it as a promising therapeutic target for overcoming chemoresistance in GBM.