RUNX3 mediates Aflatoxin B1-induced hepatocyte apoptosis through modulation of the hippo signaling pathway.

Aflatoxin B1 (AFB1) is a common foodborne mycotoxin that poses a serious threat to human and animal health, particularly through hepatotoxic effects. Although apoptosis is recognized as a central event in AFB1-induced liver injury, the upstream regulatory mechanisms involved remain incompletely understood. Our prior work identified increased runt-related transcription factor 3 (RUNX3) expression as a critical early event in AFB1-induced hepatocellular malignant transformation and demonstrated its potential as a biomarker of both exposure and biological effect in AFB1-exposed populations. However, the precise mechanism by which RUNX3 regulates AFB1-induced hepatocyte apoptosis remains undefined. In this study, we investigated the role of RUNX3 in AFB1-induced hepatocyte apoptosis and explored its functional relationship with the Hippo signaling pathway in two human immortalized hepatocyte cell lines: THLE-2 and L-02. AFB1 exposure significantly increased apoptotic cell death, disrupted mitochondrial membrane potential (ΔΨm), and altered the expression of apoptosis-related proteins, including BAX, BCL2, and CASPASE-3. At the same time, AFB1 treatment increased RUNX3 expression and was accompanied by marked changes in Hippo pathway-related signaling. Silencing RUNX3 significantly attenuated AFB1-induced apoptosis and partially reversed the associated Hippo pathway alterations. Similarly, pharmacological inhibition of the pathway reduced the pro-apoptotic effects of AFB1. Collectively, these findings indicate that RUNX3 mediates AFB1-induced hepatocyte apoptosis through functional modulation of the Hippo signaling pathway. This study provides mechanistic insight into the molecular events underlying AFB1-induced hepatotoxicity and suggests that RUNX3 may serve as a potential biomarker and intervention target in AFB1-related liver injury.