Flemiphilippinin A induces paraptosis in lung cancer cells via c-Myc-driven endoplasmic reticulum stress and CHOP-mediated mitochondrial dysfunction

Background: Lung Cancer persists as the foremost malignancy in terms of both incidence and mortality on a global scale. Paraptosis, a unique type of regulated cell death, differs from Apoptosis in its reliance on protein synthesis and its morphological hallmarks, characterized by cytoplasmic vacuole formation and distension of the endoplasmic reticulum (ER) or mitochondrial swelling. Flemiphilippinin A (Flp-A), a bioactive compound isolated from Flemingia prostrata, exhibits potent antitumor activity against lung Cancer. However, the precise molecular mechanism underlying Flp-A's anti-lung Cancer effects-as well as its direct cellular targets-remain unclear, leaving a critical gap in current research.

Purpose: To reveal the therapeutic role and molecular mechanism of Flp-A in lung carcinoma and, for the initial time, evaluate its effects on gefitinib resistance in lung carcinoma cells.

Methods: The efficacy and mechanism of Flp-A were probed through in vitro and in vivo experiments. In vitro assays included the MTT assay, plate cloning assay, EdU proliferation assay, cell morphology analysis, Western blotting, transcriptome Sequencing, JC-1 staining, ROS detection, Seahorse energy metabolism analysis, immunofluorescence, molecular docking, and CETSA to evaluate the therapeutic effects and mechanistic action of Flp-A on lung carcinoma. In vivo experiments were conducted using a mouse xenograft model of lung Cancer to assess the antitumor efficacy, systemic toxicity, and underlying mechanisms of Flp-A.

Results: This study illustrated the therapeutic potential of Flp-A against lung carcinoma through in vitro and in vivo experiments. Our findings revealed that Flp-A triggers Paraptosis in lung The evidence points to the possibility that Flp-A can enhance the specificity of drug-resistant lung carcinoma cells to gefitinib. cells by targeting c-Myc and hyperactivating endoplasmic reticulum (ER) stress. Furthermore, excessive ER stress created a glutamine-deficient environment, which promoted CHOP accumulation in mitochondria. This led to mitochondrial membrane potential disruption, increased ROS production, and inhibition of mitochondrial Oxidative Phosphorylation. Additionally, we observed that low concentrations of Flp-A combined with gefitinib triggered excessive ER stress and activated Paraptosis in gefitinib-resistant lung Cancer cells. The evidence points to the possibility that Flp-A can enhance the sensitivity of drug-resistant lung carcinoma cells to gefitinib.

Conclusion: This research demonstrates that Flp-A exerts potent anti-tumor effects against lung Cancer by targeting c-Myc to induce excessive ER stress and mediating mitochondrial dysfunction through CHOP, ultimately triggering Paraptosis. Furthermore, Flp-A increases sensitivity of lung carcinoma cells to gefitinib through Paraptosis induction. Our work provides the first evidence for Flp-A's anti-lung Cancer mechanism via the Paraptosis pathway and confirms its safety profile. Additionally, we reveal Flp-A's capacity to bypass gefitinib resistance in lung carcinoma. These findings position Flp-A as a encouraging novel medical agent for lung Cancer treatment, particularly for addressing drug resistance.

C-Myc; CHOP; ER stress; Flemiphilippinin A; Paraptosis.