Andrographolide Induces ROS-dependent Apoptosis and Suppresses STAT3 Phosphorylation in Primary Effusion Lymphoma Cells

Abstract

BACKGROUND/AIM: Primary effusion lymphoma (PEL) is a rare and aggressive form of non-Hodgkin lymphoma (NHL) with poor prognosis due to resistance to conventional chemotherapy. Andrographolide (AG), a diterpenoid lactone extracted from Andrographis paniculata, has shown anti-tumor activity in several malignancies, but its effects on PEL are unknown. MATERIALS AND METHODS: PEL cell viability was assessed by MTT assay. Apoptosis was evaluated via Annexin V/PI staining and caspase activation. ROS generation was measured by DCFH-DA staining. Protein expression changes were analyzed by Western blotting. To determine the roles of ROS and caspases, cells were co-treated with a reactive oxygen species (ROS) scavenger N-acetyl cysteine (NAC) or the pan-caspase inhibitor Q-VD-OPh. AG's in vivo effects were tested in a xenograft mouse model. RESULTS: AG inhibited PEL cell proliferation in a dose- and time-dependent manner. Apoptosis was mediated via ROS production and caspase activation. STAT3 phosphorylation was suppressed in a ROS-dependent manner. In vivo, AG (500 mg/kg/day, oral gavage) significantly reduced tumor burden without observable toxicity. CONCLUSION: AG exerts anti-tumor effects against PEL by inducing ROS-dependent apoptosis and suppressing STAT3 signaling. These findings suggest that AG may serve as a promising therapeutic agent for PEL.