Knockdown of LAMB3 suppressed radioresistance in nasopharyngeal carcinoma via deactivating NRF2 signaling pathway.

Nasopharyngeal carcinoma (NPC) is a prevalent malignancy in Southeast Asia and Southern China. Laminin subunit beta-3 (LAMB3) has been validated to participate in diverse cancers. Nevertheless, the role and mechanism of LAMB3 in NPC remain unclear. In this study, LAMB3 expression is upregulated in NPC cells and tissues. Interestingly, knockdown of LAMB3 promoted apoptosis and reduced the radioresistance of NPC cells. Besides, shLAMB3 enhanced X-ray-induced reactive oxygen species (ROS) accumulation. Mechanically, knockdown of LAMB3 deactivated nuclear factor erythroid-2-related factor 2 (NRF2) signaling pathway via enhancing forkhead box 3 (FOXO3) expression. In rescue experiments, suppression of NRF2 signaling pathway abrogated shLAMB3-induced NPC cell apoptosis and ROS accumulation under X-ray treatment. Similarly, LAMB3 knockdown restrains NPC tumor growth and reduces radioresistance in vivo. Thus, these findings concluded that knockdown of LAMB3 enhanced apoptosis and ROS accumulation, and suppressed radioresistance in NPC via enhancing FOXO3 expression and deactivating NRF2 signaling pathway, facilitating the development of novel strategies for NPC radioresistance.