Combination of kale-derived exosomes and dactolisib promotes apoptosis and modulates iron homeostasis in Hep3B hepatocellular carcinoma cells.

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, and available treatments remain limited. Plant-derived exosome-like nanoparticles (PELNs) are promising natural nanocarriers due to their low toxicity and ability to cross biological barriers. Brassica oleracea (kale) contains bioactive compounds, including glucosinolates and sulforaphane, with known antiproliferative, pro-apoptotic, and antioxidant properties.

METHODS

This study investigated the effects of kale-derived exosome-like nanovesicles (K-Exo) and dactolisib (Dacto), a dual PI3K/mTOR inhibitor, alone and in combination in Hep3B cells. Cell viability, apoptosis, intracellular reactive oxygen species (ROS), ferrous iron (Fe²⁺) levels, and the expression of genes associated with PI3K/AKT/mTOR signaling and apoptosis were evaluated. Cleaved caspase-3 and NRF2 protein expression were also assessed by immunofluorescence staining.

RESULTS

K-Exo alone did not significantly reduce cell viability, whereas Dacto + K-Exo decreased Hep3B cell viability. The combination downregulated genes involved in cell survival and drug resistance, including AKT, mTOR, and MDM2. Apoptosis was supported by significant increases in TP53 and CASP3 mRNA levels and confirmed by flow cytometry. Immunofluorescence showed increased cleaved caspase-3 and NRF2 fluorescence in the combination group. The combined treatment also affected iron homeostasis and oxidative stress regulation.

CONCLUSIONS

Decreased ROS and Fe²⁺ levels, together with increased expression of apoptosis-related genes, indicate that Dacto + K-Exo induces apoptosis rather than ferroptosis in Hep3B cells. These findings suggest that the combination may promote apoptosis and modulate cellular redox and iron balance in this HCC cell line. However, further studies using additional HCC models are required to evaluate the broader therapeutic potential of this approach.