Sanguinarine Represses the Growth and Metastasis of Non-small Cell Lung Cancer by Facilitating Ferroptosis

Objective: Ethnopharmacological relevance: Sanguinarine (SAG), a natural benzophenanthridine alkaloid derived from the root of Sanguinaria canadensis Linn. (Bloodroot), possesses a potential anticancer activity. Lung carcinoma is the chief cause of malignancy-related mortality in China. Non-small cell lung carcinoma (NSCLC) is the main subtype of lung carcinoma and accounts for about eighty-five percent of this disease. Current treatment in controlling and curing NSCLC remains deficient.

Aim: The role and underlying mechanism of SAG in repressing the growth and metastasis of NSCLC were explored.

Materials And Methods: The role of SAG in regulating the proliferation and invasion of NSCLC cells was evaluated in vitro and in a xenograft model. After treatment with SAG, Fe concentration, reactive oxygen species (ROS) levels, malondialdehyde (MDA), and glutathione (GSH) content in NSCLC cells were assessed to evaluate the effect of SAG on facilitating ferroptosis.

Results: SAG exhibited a dose- and time-dependent cytotoxicity in A549 and H3122 cells. SAG treatment effectively repressed the growth and metastasis of NSCLC in a xenograft model. We, for the first time, verified that SAG triggered ferroptosis of NSCLC cells, as evidenced by increased Fe concentration, ROS level, and MDA content, and decreased GSH content. Mechanistically, SAG decreased the protein stability of glutathione peroxide 4 (GPX4) through E3 ligase STUB1-mediated ubiquitination and degradation of endogenous GPX4. GPX4 overexpression restored the proliferation and invasion of NSCLC cells treated with SAG through inhibiting ferroptosis.

Conclusion: SAG inhibits the growth and metastasis of NSCLC by regulating STUB1/GPX4-dependent ferroptosis.