Dexamethasone Shows Promise Against Therapy-Resistant Breast Cancer Metastases in Preclinical Studies
核心洞察
University of Basel researchers discovered that dexamethasone, a synthetic corticosteroid commonly used to manage chemotherapy side effects, can combat therapy-resistant metastases in estrogen receptor-positive breast cancer.
In preclinical mouse models, dexamethasone significantly reduced liver metastases and prolonged survival by activating glucocorticoid receptors that suppress estrogen receptor production.
The drug's anti-metastatic effects were confirmed in patient-derived tumor organoids, though researchers emphasize the need for clinical validation before potential repurposing.
Researchers at the University of Basel have uncovered a potential new therapeutic application for dexamethasone, a widely-used corticosteroid, in treating therapy-resistant breast cancer metastases. The findings, published in EMBO Molecular Medicine, suggest the drug could directly combat cancer progression rather than merely serving as supportive care for chemotherapy side effects.
Targeting Treatment-Resistant Disease
The study focused on estrogen receptor-positive (ER+) breast cancer, which typically responds well to anti-hormonal therapies that deactivate or degrade the estrogen receptor. However, some tumors develop metastases that no longer respond to hormone therapy, creating a significant clinical challenge.
Professor Mohamed Bentires-Alj from the Department of Biomedicine at the University of Basel and University Hospital Basel led the research team investigating dexamethasone's effects on these treatment-resistant cases. The synthetic compound mimics the body's stress hormone cortisol and has been used clinically for its anti-inflammatory and immunosuppressive properties.
Preclinical Evidence Shows Promise
In mouse models with therapy-resistant ER+ tumors, dexamethasone demonstrated significant anti-metastatic activity. The treatment reduced liver metastases and prolonged animal survival compared to control groups. These results provided the first evidence that dexamethasone might offer direct anti-cancer benefits beyond its traditional supportive role.
The research team conducted detailed mechanistic studies to understand how dexamethasone achieves this therapeutic effect. They found that the drug activates the glucocorticoid receptor, which subsequently suppresses production of the estrogen receptor.
"As a result, the cancer cells lose the main driver of tumor growth," explained Dr. Madhuri Manivannan, the study's lead author.
Patient-Derived Models Confirm Findings
To strengthen their preclinical evidence, researchers tested dexamethasone on patient-derived tumor organoids - miniature laboratory-grown tissue structures that closely mimic real tumor behavior. When dexamethasone was introduced to these organoids, estrogen receptor levels decreased, reinforcing the findings from mouse experiments.
This dual approach using both animal models and human tissue samples provides robust preclinical support for dexamethasone's potential anti-metastatic properties in therapy-resistant ER+ breast cancer.
Clinical Translation Requires Validation
Dr. Charly Jehanno, who led the research project, emphasized the need for clinical confirmation before any therapeutic repurposing. "Dexamethasone could potentially directly support certain breast cancer therapies, not just as a concomitant treatment for nausea and inflammation," he said. "However, these results, particularly the loss of estrogen receptor, need now to be confirmed directly in patients with breast cancer."
If clinical studies validate the metastasis-inhibiting effects observed in preclinical models, dexamethasone could be repurposed as part of breast cancer treatment regimens, offering a cost-effective addition to existing therapeutic options.
Context-Dependent Effects Highlight Personalized Medicine
The researchers stressed that dexamethasone would not be suitable for all breast cancer patients. Previous work by the same team, published in Nature in 2019, demonstrated that dexamethasone actually promotes metastases in triple-negative breast cancer, a different subtype of the disease.
"Dexamethasone is an example of how the same drug can have very different effects on the course of the disease in different forms of breast cancer," Professor Bentires-Alj noted. This finding underscores the critical importance of personalized treatment approaches based on specific tumor characteristics and molecular profiles.