Integrated Network Pharmacology and Proteomics Reveal Anti-tumor Mechanism of Securinine in Ovarian Cancer.

OBJECTIVE: To investigate the effect and underlying mechanism of securinine (Sec) in ovarian cancer (OC) based on network pharmacology, in vivo experiments and proteomics.

METHODS: ES2 cells were treated with different concentrations of Sec (6.25, 12.5, 25, 50, and 100 µmol/L) for 24 h. The cell viability was determined using the MTT assay. ES2 xenograft nude mice were randomly divided into 4 groups (5 mice per group): tumor control, positive control carboplatin (12.5 mg/kg), low-dose of Sec (10 mg/kg), and high-dose of Sec (20 mg/kg). During the treatment period, body weight and tumor volume were monitored. Major organs and tumor tissues were collected for organ index calculation and HE staining. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine were measured using commercial kits. Network pharmacology was used to predict the targets of Sec in OC. The proteomics analysis of tumor tissues was employed to identify key pathways regulated by Sec. The mRNA and protein levels of epidermal growth factor receptor (EGFR), hypoxia-inducible factor alpha (HIF-α), matrix metalloproteinase-9 (MMP9), mechanistic target of rapamycin (mTOR), nuclear factor kappa-B (NF-κB), signal transducer and activator of transcription 3 (STAT3), and the key targets in peroxisome proliferator-activated receptor (PPAR) signaling pathway were determined by qRT-PCR and Western blot, respectively. Molecular docking was used to analyze the interactions between Sec and the core targets.

RESULTS: Sec (6.25-100 µmol/L) inhibited ES2 cell proliferation (P<0.05 or P<0.01). Sec inhibited tumor growth in ES2 xenograft nude mice without toxicity in heart, liver, spleen, lung, and kidneys (P<0.05 or P<0.01). Network pharmacology identified 6 core targets associated with Sec's activity: EGFR, HIF-α, MMP9, mTOR, NF-κB, and STAT3. Proteomics analysis revealed PPAR signaling pathway as a key role. qRT-PCR confirmed that Sec significantly inhibited the mRNA levels of mTOR, NF-κB, STAT3, fatty acid-binding protein 3 (FABP3), FABP4, peroxisome proliferator-activated receptor alpha (PPAR-α), and PPAR-δ (P<0.05 or P<0.01). Western blot analysis demonstrated that Sec markedly suppressed the expression of FABP3, STAT3, and NF-κB (P<0.05 or P<0.01). Molecular docking revealed high binding affinity between Sec and FABP3, FABP4, mTOR, and NF-κB.

CONCLUSION: Sec inhibits OC cell proliferation and tumor growth through the NF-κB and PPAR signaling pathways.