Cyclic lipopeptide nano-assemblies induce mitochondrial apoptosis and suppress migration in hepatocellular carcinoma cells with mitochondrial perturbation and Snail2 downregulation.

Cyclic lipopeptides represent a promising class of bioactive molecules with potential anticancer applications. Here, we investigate the anti-hepatoma activity and mechanism of B-Lb, a cyclic lipopeptide featuring a heptapeptide backbone and a unique fatty acid tail. Our study reveals that the fatty acid tail is indispensable for B-Lb's bioactivity, as its removal or substitution abolishes cytotoxicity and alters self-assembly morphology. B-Lb undergoes concentration-dependent self-assembly into nanorods, a process directed by its hydrophobic tail. In vitro, B-Lb potently inhibits the proliferation of SMMC-7721 hepatocellular carcinoma cells (IC50 = 5.852 μM), an effect associated with mitochondrial apoptosis. B-Lb-induced cytotoxicity was accompanied by mitochondrial perturbation, including changes consistent with mPTP opening, a reduced Bcl-2/Bax ratio, and marked alterations in mitochondrial morphology. Furthermore, B-Lb suppresses cell migration by downregulating the pro-metastatic transcription factor Snail2. In a murine xenograft model, B-Lb (30 mg/kg) demonstrates robust antitumor efficacy, inducing significant tumor necrosis and reducing Ki67 proliferation index without causing treatment-associated body-weight loss, suggesting acceptable gross tolerability under the tested conditions. Exploratory differential protein expression analysis further suggests potential alterations in glycolysis, cytoskeletal integrity, and nucleic acid homeostasis associated with the response to B-Lb. Collectively, our findings establish B-Lb as a potent, self-assembling cyclic lipopeptide that acts on multiple facets of hepatoma cell biology, including proliferation, mitochondrial integrity, and migration, highlighting its potential as a novel therapeutic candidate for hepatocellular carcinoma.