Hepatocellular carcinoma, the most common form of primary liver cancer, remains one of the leading causes of cancer-related death worldwide. Treatment options are limited, particularly for patients diagnosed at intermediate or advanced stages, and resistance to existing therapies is a persistent clinical challenge. The PI3K/AKT/mTOR pathway, a central signaling axis that governs cell survival, growth, and metabolism, is frequently hyperactivated in liver cancer, making it an attractive therapeutic target. Dactolisib, also known by its research code NVP-BEZ235, was designed to shut down this pathway at two points at once, blocking both phosphoinositide 3-kinase and the mechanistic target of rapamycin. Previous studies have shown that the compound can sensitize liver tumors to other drugs, including sorafenib, regorafenib, and paclitaxel, but its toxicity profile and delivery challenges have motivated researchers to look for partners that might amplify its effects at lower doses.

That is where the kale comes in. Over the past decade, plant-derived exosome-like nanoparticles, or PELNs, have emerged as a fascinating class of naturally occurring nanocarriers. These lipid-bounded vesicles, typically ranging in size from tens to a few hundred nanometers, are produced by plant cells and can be isolated from juices and tissue extracts using techniques such as ultracentrifugation, size characterization by nanoparticle tracking analysis, and imaging by atomic force microscopy. Unlike synthetic nanoparticles, PELNs tend to exhibit low toxicity, resist degradation in the digestive tract, and can cross biological barriers, which has fueled interest in using them both as drug delivery vehicles and as therapeutic agents in their own right. Vesicles isolated from ginger, cabbage, grape, and cardamom have all shown biological activities ranging from anti-inflammatory effects to direct antiproliferative action against cancer cell lines.

Kale, a member of the Brassica oleracea species, is particularly rich in bioactive compounds, including glucosinolates and their breakdown product sulforaphane, which have documented antiproliferative, pro-apoptotic, and antioxidant properties in laboratory studies. The Turkish research team isolated exosome-like nanovesicles from kale and tested them on Hep3B cells, a well-established hepatocellular carcinoma line. When applied alone, the kale vesicles did not significantly reduce cell viability, indicating that on their own they are not potently cytotoxic to these tumor cells. That might sound like a failure, but it set the stage for the study’s central discovery: the vesicles appear to act as a sensitizer rather than a standalone killer.

When the researchers combined the kale-derived nanovesicles with dactolisib, the picture changed markedly. The combination produced a clear decrease in Hep3B cell viability, and molecular analysis revealed why. Genes involved in cell survival and drug resistance, including AKT, mTOR, and MDM2, were downregulated following the combined treatment. MDM2 is a critical negative regulator of the tumor suppressor protein p53, and its suppression removes one of the main brakes on apoptotic cell death. Consistent with this, the team observed significant increases in the mRNA levels of TP53, the gene encoding p53, and CASP3, which encodes caspase-3, the executioner enzyme that dismantles the cell during apoptosis. Flow cytometry confirmed that the treated cells were indeed undergoing programmed cell death at substantially higher rates than untreated controls.

Immunofluorescence staining provided visual confirmation at the protein level. Cells receiving the combination treatment showed increased fluorescence for cleaved caspase-3, the activated form of the enzyme, and for NRF2, a transcription factor that serves as the master regulator of the cellular antioxidant response. The rise in NRF2 fluorescence is intriguing because it suggests the cells were mounting a stress response even as they were being pushed into apoptosis. The dual activation of the death machinery and the oxidative stress defense system hints at a complex interplay between the drug, the vesicles, and the tumor cell’s internal chemistry.

Perhaps the most novel aspect of the study lies in its examination of iron homeostasis. Iron metabolism has become a hot topic in cancer biology because rapidly dividing tumor cells have elevated iron demands, and because iron, particularly in its ferrous Fe2+ form, drives the lipid peroxidation reactions that define ferroptosis, a recently discovered form of regulated cell death distinct from apoptosis. The researchers measured intracellular reactive oxygen species and ferrous iron levels after treatment and found that the combination decreased both. At first glance, reduced ROS and reduced Fe2+ might seem counterintuitive for a cancer-killing treatment, but the pattern is diagnostic. Ferroptosis is characterized by surging iron-dependent oxidative damage, whereas apoptosis proceeds through caspase activation without requiring iron accumulation. The simultaneous drop in ROS and Fe2+, together with the rise in caspase-3 and p53 signaling, indicates that the combination induces apoptosis rather than ferroptosis in Hep3B cells.

This distinction matters for therapeutic development. Different modes of cell death engage different immune responses and can be more or less effective depending on the tumor context. Apoptosis is generally considered immunologically quiet, whereas ferroptosis can be inflammatory, and understanding which pathway a treatment triggers helps predict how it might behave in a living organism and how it could be combined with immunotherapies. By demonstrating that the kale vesicle and dactolisib combination steers cells down the apoptotic route while modulating redox and iron balance, the study provides a mechanistic map that future work can build upon. The findings also add to a growing body of evidence that plant-derived nanovesicles can influence metal ion homeostasis and oxidative stress regulation in ways that complement synthetic drugs.

The authors are careful to frame the work as an early-stage cell culture study. Hep3B is a single cell line, and hepatocellular carcinoma is a heterogeneous disease with multiple molecular subtypes; results in one model do not guarantee success in others. The team notes that further studies using additional HCC models are required to evaluate the broader therapeutic potential of the approach, and translating the findings into a clinical setting would require testing in animal models, optimization of dosing, assessment of biodistribution and safety, and ultimately human trials. Nevertheless, the concept of using edible plant vesicles to potentiate a targeted kinase inhibitor is appealing from a safety and cost perspective, since PELNs can be produced from agricultural sources at relatively low expense and carry a favorable toxicity profile compared with many synthetic nanocarriers.

The research also contributes to the rapidly expanding field of exosome therapeutics more broadly. Extracellular vesicles have been hailed as natural delivery systems capable of carrying proteins, lipids, and nucleic acids between cells, and engineering them for drug delivery is a major goal of nanomedicine. The Yeditepe study suggests a complementary strategy: rather than loading vesicles with cargo, researchers can exploit the intrinsic bioactivity of plant vesicles to reprogram tumor cell signaling and make existing drugs work better. If subsequent studies confirm that kale-derived nanovesicles can sensitize liver tumors to PI3K/mTOR inhibition in vivo, the humble leafy green could find an unexpected second career at the frontier of cancer nanomedicine, turning a supermarket staple into a laboratory tool for fighting one of the world’s deadliest cancers.

Subject of Research: Kale-derived exosome-like nanovesicles combined with dactolisib induce apoptosis and modulate iron homeostasis in hepatocellular carcinoma cells

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

Article References: Değirmenci, N. S., Zor, Z., Pedük, D., Yıldırım, Z., Padar, G., Şahin, F., & Ulu, Z. Ö. (2026). Combination of kale-derived exosomes and dactolisib promotes apoptosis and modulates iron homeostasis in Hep3B hepatocellular carcinoma cells. Molecular Biology Reports, 53(1), Article 1652. https://doi.org/10.1007/s11033-026-12828-1

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12828-1

Keywords: kale, exosomes, plant-derived nanoparticles, dactolisib, hepatocellular carcinoma, apoptosis, PI3K/mTOR pathway, iron homeostasis, ferroptosis, reactive oxygen species, NRF2, nanomedicine