Coptisine suppresses oral squamous cell carcinoma via regulating the JAK2/STAT3 to induce mitochondrial dysfunction in cancer cells and promote macrophage polarization to M1.

Coptisine (COP) is an isoquinoline alkaloid with anti-tumor potential. However, its function and specific mechanisms in oral squamous cell carcinoma (OSCC), particularly its role in regulating the tumor microenvironment, remain unclear. The optimal intervention dose of COP was determined using the Cell Counting Kit-8 (CCK-8) assay. The effects of COP on the malignant phenotype of OSCC cells were evaluated by wound healing assay, flow cytometry, and Transwell assays. Mitochondrial function was evaluated using Seahorse energy metabolic analysis, commercial assay kits, and reactive oxygen species (ROS) detection. A co-culture system of THP-1-derived macrophages and OSCC cells was established, and the polarization phenotype was analyzed using flow cytometry and Western blotting. The mitochondrial-targeted antioxidant MitoQ, the pathway inhibitor AG490, and the activator Colivelin were used in rescue experiments to demonstrate the key roles of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) axis. COP at concentrations of 25, 50 and 100 μM significantly suppressed proliferation and epithelial-mesenchymal transition (EMT) and promoted apoptosis in OSCC cells. Mechanistically, COP inhibited JAK2/STAT3 signaling, reduced adenosine triphosphate (ATP) production and mitochondrial membrane potential (MMP), and increased ROS levels, thereby inducing mitochondrial dysfunction and ultimately inhibiting the growth of SCC-9 cells; MitoQ reversed these effects. Within the tumor microenvironment, COP also inhibited the JAK2/STAT3 pathway in macrophages, promoted its polarization toward M1 type, and inhibited its conversion to M2 type. Co-culture with M1 macrophages significantly attenuated the malignant phenotype of SCC-9 cells, which was reversed by Colivelin. In summary, COP exerts dual anti-OSCC effects by inducing mitochondrial dysfunction and oxidative stress through inhibition of the JAK2/STAT3 signaling pathway, as well as by promoting the polarization of macrophages toward the M1 anti-tumor phenotype via the same pathway.