Bufalin

Oral cancer (OC) is a malignant tumor that arises at the mucosal tissues of the oral cavity and is commonly treated with surgical resection. Bufalin is one of the most potent anticancer monomers extracted from bufonis venenum and has been shown to have anticancer effects against a wide range of cancers, including lung cancer, gastric cancer and hepatocellular carcinomas. However, there are fewer studies on the role of bufalin in OC and a lack of clear targets. Moreover, bufalin is more difficult to apply clinically due to its cardiac glycoside effects. Notably, oral cancer is a facial tumor, and bufalin acts first in the oral tissues and does not need to go through the blood circulation to reach the heart, which greatly mitigates the risk and overcomes the major limitation. The effects of bufalin on the proliferation and migration of oral cancer cells were detected by CCK-8 assay, wound healing assay, transwell assay and Western blot. Potential direct interacting proteins of bufalin were screened by human proteomic microarray, and the binding sites were predicted using molecular docking technology. In vitro and vivo biological experiments were performed to verify the role of bufalin direct interacting protein and the mechanism by which bufalin targets this protein to inhibit OC metastasis. The results showed that bufalin inhibited the proliferation and migration of OC cell lines from Cal-27, HN30 and SCC-15 cultured in vitro. METTL17, a direct-interacting protein of bufalin, has several potential binding sites with bufalin. METTL17 is highly expressed in OC and promotes OC occurrence and development in vitro and vivo through activation of the JAK1/STAT3 signaling pathway. Bufalin reversed the promotional effect of METTL17 on OC by down-regulating METTL17 expression. These results provide a new rationale for bufalin as a promising drug for the treatment of OC and avoid the difficulty that bufalin has a strong cardiac glycosides effect on the heart through the bloodstream.

Colorectal cancer, a highly invasive malignancy, poses significant treatment challenges due to the immunosuppressive tumor microenvironment. Tumor-associated macrophages, which primarily exhibit the M2 phenotype, play a key role in cancer progression and immune evasion. Reprogramming these M2 macrophages to the tumor-suppressive M1 phenotype represents a promising therapeutic approach to enhance antitumor immunity. In this study, we developed a calcium lactate nanoparticle-based delivery system (CLBRP) to codeliver bufalin, a potent Na⁺/K⁺-ATPase inhibitor with anticancer properties, and CRISPR-Cas9, which targets the immune checkpoint CD47. The system releases its payload under low pH conditions typical of the tumor microenvironment, increasing extracellular Ca²⁺ and intracellular osmotic pressure, thereby inducing pyroptosis and immunogenic cell death. Bufalin induces cancer cell apoptosis, inhibits Na⁺/K⁺-ATPase, and triggers pyroptosis, which activates a strong immune response. Additionally, bufalin and D-lactic acid synergistically promote macrophage repolarization to the M1 phenotype. CRISPR-Cas9-mediated editing of the CD47 gene on tumor cells blocks antiphagocytic signals, enhancing M1 macrophage phagocytosis and increasing the antitumor immune response. This multimodal strategy triggers strong local antitumor effects and controls metastatic lesions via systemic immune activation, demonstrating significant potential for colorectal cancer treatment. Furthermore, this approach offers a new direction for overcoming resistance to immunotherapies and improving clinical outcomes.