The liver is a particularly favorable site for metastasis because it is metabolically active and continuously processes nutrients, including fatty acids. Cancer cells arriving in the organ encounter an environment that can provide both energy and molecular signals supporting their survival. Although scientists have increasingly recognized that tumors use local nutrients to grow, the new study examines a less understood question: how does the liver’s nutrient-rich environment influence the battle between metastatic cancer cells and immune cells?

The researchers focused on palmitate, a saturated fatty acid found naturally in the liver and used by cells in several essential biological processes. One of those processes is palmitoylation, a reversible chemical modification in which palmitate is attached to proteins. Palmitoylation can change a protein’s stability, location, or interactions with other molecules, allowing cells to fine-tune signaling pathways. In metastatic cancer cells, the team found that palmitate was attached to laminin-511 through the activity of DHHC17, an enzyme belonging to a family of palmitoyltransferases that regulate protein modification.

Laminin-511 is part of the extracellular matrix, the network of proteins surrounding cells. It helps organize tissue structure and can influence how cells move, attach, invade neighboring tissues, and establish new tumors. The researchers found that palmitoylation made laminin-511 more stable. As a result, metastatic cancer cells were able to produce a more persistent molecular environment around them, one capable of influencing nearby immune cells rather than merely supporting the physical growth and movement of the tumor.

The most important effect was observed in neutrophils. These white blood cells are best known for rapidly responding to infections, but they can also recognize and destroy cancer cells under the right conditions. Their behavior, however, is highly dependent on signals from the surrounding tissue. When exposed to laminin-511 modified by the cancer-cell palmitoylation pathway, neutrophils became less effective at attacking tumor cells. Instead, they showed an increased tendency to produce neutrophil extracellular traps, or NETs.

NETs are web-like structures made from DNA and antimicrobial proteins that neutrophils release to capture and immobilize pathogens. In cancer, however, NETs can have harmful effects. They may shield tumor cells from immune attack, support their attachment to tissues, and create conditions that promote metastatic growth. The study indicates that palmitate-driven stabilization of laminin-511 pushes neutrophils away from direct antitumor activity and toward a state that can assist the tumor.

To test whether DHHC17 was responsible for this immune suppression, the researchers manipulated the enzyme in experimental models of liver metastasis. Reducing DHHC17 activity weakened the pathway that stabilizes laminin-511 and led to smaller metastatic lesions. Crucially, the effect depended on the presence of neutrophils. This finding suggests that DHHC17 is not simply promoting cancer-cell growth in isolation; rather, metastatic cells use the enzyme and its downstream effects on laminin-511 to interfere with immune destruction.

The results reveal a form of immune evasion in which cancer cells do not need to eliminate neutrophils to benefit from them. Instead, they reshape the local molecular environment and redirect the cells’ behavior. “Rather than acting directly on the cancer cell alone, this pathway allows tumor cells to disarm neutrophils and undermine one of the body’s natural defense mechanisms against cancer,” said first author Anke Vandekeere of the VIB-KU Leuven Center for Cancer Research. The discovery adds to growing evidence that the extracellular matrix is an active participant in cancer progression, not simply a structural framework surrounding tumors.

The findings also raise the possibility that targeting palmitoylation could produce a dual therapeutic effect. Inhibiting DHHC17 or related components of the pathway might reduce tumor-promoting signals from laminin-511 while restoring the ability of neutrophils to kill metastatic cells. Such an approach would differ from strategies designed to remove neutrophils altogether. A previous clinical trial testing neutrophil depletion did not improve immunotherapy outcomes in patients with solid tumors, suggesting that reprogramming these immune cells may be more effective than eliminating them.

The study was an experimental investigation conducted in animals, so its therapeutic implications remain to be tested in human patients. Nevertheless, it offers a mechanistic explanation for how the liver’s metabolic environment can influence immune behavior during metastasis. By identifying DHHC17, palmitoylated laminin-511, and neutrophil dysfunction as connected parts of the same process, the researchers have highlighted a potential vulnerability in liver metastases. Future therapies that block this pathway could help transform neutrophils from tumor accomplices back into active defenders against metastatic cancer.

Subject of Research: Animals

Article Title: Palmitate promotes liver metastases by decreasing neutrophil antitumour behaviour

News Publication Date: 5 August 2026

Web References: https://doi.org/10.1038/s42255-026-01582-0

References: Nature Metabolism, DOI: 10.1038/s42255-026-01582-0

Keywords: Liver metastases, palmitate, palmitoylation, DHHC17, laminin-511, neutrophils, NETs, cancer immunology, immune evasion, tumor microenvironment, metastatic cancer, liver cancer research

Breast cancer remains a leading cause of cancer-related mortality worldwide, with metastasis representing the most formidable challenge in clinical management. Among metastatic sites, the liver is notorious for harboring secondary tumors that are often resistant to existing therapies. Understanding the molecular drivers that enable breast cancer cells to colonize the liver is therefore crucial. This study identifies MSLN, or mesothelin, as a pivotal mediator in this process, orchestrating intracellular signaling events that promote tumor spread and survival in hepatic tissue.

MSLN is a glycoprotein normally expressed in mesothelial cells but is aberrantly overexpressed in several malignancies, including pancreatic and ovarian cancer. Its role in breast cancer metastasis has been less clear until now. The research team, led by Dr. Jiang Chen and colleagues, deployed an integrative approach combining patient-derived samples, in vitro cellular models, and in vivo metastasis assays to dissect MSLN’s functional contributions.

Their findings establish that overexpressed MSLN on breast cancer cells acts as an initiator of the EGFR-ERK1/2 signaling cascade. EGFR (epidermal growth factor receptor) is a well-characterized receptor tyrosine kinase implicated in various oncogenic processes. Activation of EGFR triggers downstream ERK1/2 kinases (extracellular signal-regulated kinases), which ultimately regulate gene transcription programs conducive to proliferation, migration, and survival.

The study demonstrated through biochemical assays that MSLN physically interacts with EGFR on the cancer cell surface, enhancing EGFR phosphorylation and subsequent ERK1/2 pathway activation. This crosstalk creates a positive feedback loop that sustains aggressive cellular phenotypes. Disrupting this interaction using targeted inhibitors or genetic silencing of MSLN markedly reduced ERK1/2 activation, curtailing the metastatic capacity of breast cancer cells.

Importantly, animal models of breast cancer metastasis validated these molecular insights. Mice engrafted with breast cancer cells exhibiting high MSLN expression exhibited significantly increased liver metastasis, as revealed by histopathology and bioluminescent imaging. Conversely, blockade of MSLN or downstream signals suppressed metastatic lesion formation, highlighting potential strategic points for intervention.

On a clinical front, the researchers analyzed tumor biopsies from breast cancer patients with known metastatic status. Patients with liver metastases showed elevated MSLN levels and heightened EGFR-ERK1/2 signaling components compared to non-metastatic cases, indicating the clinical relevance of this axis. Such biomarkers could improve prognosis predictions and personalize patient therapies targeting this pathway.

This discovery advances the conceptual framework of how tumor cells adapt to distinct microenvironments during metastasis. The liver microenvironment is rich in growth factors and stromal elements that appear to synergize with MSLN-driven signaling, supporting colonization and outgrowth. Future studies might explore how MSLN modulates interactions with hepatic cellular constituents, potentially unveiling additional targets.

Therapeutically, the study suggests a two-pronged approach: designing agents to inhibit MSLN directly and employing EGFR-ERK1/2 pathway inhibitors more effectively in metastatic breast cancer. Current EGFR inhibitors have faced resistance issues; the findings imply that combination strategies targeting the upstream MSLN could circumvent resistance and improve patient outcomes.

Moreover, the mechanistic clarity provided by this research paves the way for developing diagnostic tests measuring circulating MSLN or related signaling proteins as liquid biopsy markers. Early detection of metastatic propensity could revolutionize follow-up care, shifting the clinical paradigm toward proactive management.

The significance of this work extends beyond breast cancer. Given MSLN’s expression in multiple tumor types, similar mechanisms may underpin metastasis in other malignancies. Thus, the insights generated hold broad implications for oncology, inspiring cross-cancer studies and novel drug discovery efforts.

This study represents a prime example of translational research, moving from molecular biology to animal models and human samples, offering a comprehensive view of cancer metastasis biology. Such integrative studies are vital for tackling the complexity of cancer dissemination, ultimately aiming to reduce the heavy burden of metastatic diseases.

In summary, the elucidation of MSLN-mediated activation of EGFR-ERK1/2 signaling as a driving force for liver metastasis in breast cancer marks a momentous advance. It highlights a previously underappreciated signaling axis that could serve as a linchpin for future diagnostics and therapeutics. As research progresses, targeting the MSLN-EGFR-ERK1/2 pathway may become a cornerstone in the fight against deadly metastatic breast cancer.

This discovery did not happen in isolation; it builds upon decades of cancer signaling research yet uniquely clarifies the metastatic niche specificity to the liver. Understanding why cancer cells metastasize to certain organs remains a fundamental question, and studies like this shine light on the molecular determinants, providing hope for tailored and effective treatments.

The potential to “switch off” metastatic signaling by interfering with MSLN or its downstream effectors also stimulates interest in combination therapies that engage standard treatments with novel molecularly targeted drugs. This integrative approach could mitigate drug resistance, reduce metastasis, and ultimately improve survival rates for breast cancer patients worldwide.

Future efforts will need to focus on validating these findings in larger patient cohorts and clinical trials to translate laboratory insights into effective clinical therapies. Furthermore, the development of specific MSLN inhibitors or monoclonal antibodies suitable for human use will be pivotal steps toward clinical application.

As breast cancer remains a significant public health challenge, innovations addressing metastasis are essential. This study’s elucidation of a critical molecular driver behind liver metastasis inspires renewed vigor in the quest for curative interventions, signaling a hopeful horizon for patients and clinicians alike.

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Subject of Research: Mechanistic investigation of MSLN-mediated activation of EGFR-ERK1/2 signaling pathway driving liver metastasis in breast cancer.

Article Title: MSLN-mediated activation of EGFR-ERK1/2 signaling drives liver metastasis in breast cancer.

Article References:
Chen, J., Lu, Z., Zhang, G. et al. MSLN-mediated activation of EGFR-ERK1/2 signaling drives liver metastasis in breast cancer. Cell Death Discov. 12, 11 (2026). https://doi.org/10.1038/s41420-025-02835-9

Image Credits: AI Generated

DOI: 09 January 2026