“Objectives: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited treatment options. Cannabidiol (CBD) has demonstrated anticancer potential, but its clinical application is hindered by poor solubility and nonspecific distribution. This study aimed to develop a folic acid-modified chitosan (FA-CS) nanoparticle system to enhance the targeted delivery and therapeutic efficacy of CBD against TNBC.
Methods: FA-CS@CBD nanoparticles were synthesized and characterized for morphology, size distribution, zeta potential, and stability. Their in vitro anticancer effects were evaluated through cytotoxicity, cellular uptake, apoptosis, and reactive oxygen species (ROS) assays in 4T1 breast cancer cells. The in vivo antitumour efficacy and systemic toxicity were assessed using a TNBC mouse model.
Key findings: FA-CS@CBD nanoparticles exhibited uniform morphology, stable physicochemical properties, and efficient cellular uptake. Compared to free CBD, the nanoparticles significantly enhanced ROS production, induced apoptosis, and inhibited migration in 4T1 cells. In vivo studies demonstrated strong tumour-targeting capability and a tumour inhibition rate of 68.07%, with minimal systemic toxicity.
Conclusions: The FA-CS@CBD nanoparticle system improved the targeted delivery and therapeutic effects of CBD against TNBC while maintaining favorable biocompatibility. These findings highlight the potential of FA-CS-based nanocarriers for enhancing CBD clinical application in breast cancer therapy.”
“Cellular plasticity enables cancer cells to escape therapy by adopting stem-like or alternate lineage states. Here, we identify a mechanism by which cannabinoid receptor 2 (CB2R) activation promotes irreversible lineage commitment in breast cancer. Using patient-derived and murine organoids, we show that brief, low-dose exposure to CB2R agonists—either phytogenic or synthetic—induces a basal-to-luminal transition, accompanied by reduced self-renewal, invasiveness, and tumor-initiating potential. These changes are retained under conditions that normally promote dedifferentiation, including fibroblast co-culture, immune pressure, and mechanical shear stress.
Mechanistically, CB2R engagement initiates a transient chromatin remodeling program, marked by early expression of pluripotency-associated genes followed by silencing and differentiation commitment. This epigenetically stabilized state renders tumor cells more responsive to tamoxifen and limits the emergence of resistant clones.
Our findings uncover a previously unrecognized role for CB2R in modulating cancer cell identity and suggest new opportunities to constrain tumor plasticity by directing differentiation through a drug-responsive pathway.”
“Tumor adaptability relies on the ability of cancer cells to dedifferentiate and acquire stem-like features, fueling therapeutic resistance and metastasis. Differentiation therapy aims to reprogram tumor cells into more mature, less aggressive states to counteract this plasticity.
Here, we identify cannabinoid receptor 2 (CB2R) as a novel therapeutic target that promotes sustained differentiation in breast cancer. Using tumor-derived organoids from both mouse models and patient biopsies, we show that brief, low-dose exposure to phytogenic or synthetic CB2R ligands induces a basal-to-luminal switch, suppresses stemness, and reduces invasiveness and self-renewal. These phenotypic changes are associated with decreased tumor initiation and aggressiveness in vivo .
Transcriptomic profiling reveals that CB2R activation initiates transient chromatin remodeling and epigenetic reprogramming, resulting in a stably differentiated state. Importantly, CB2R-driven differentiation sensitizes tumor cells to tamoxifen, enabling lower therapeutic doses with improved efficacy-supporting the principles of adaptive therapy aimed at long-term disease control.
Our findings position CB2R modulation as a promising non-cytotoxic strategy to restrict cancer plasticity and enhance the effectiveness of existing breast cancer treatments.”
“Introduction: Aromatase inhibitor (AI) therapy reduces breast cancer recurrence risk. However, some patients stop treatment early because of AI-associated musculoskeletal symptoms (AIMSS). AIMSS is due in part to systemic inflammation. Cannabidiol (CBD) has anti-nociceptive and anti-inflammatory properties, making it a potential treatment option for AIMSS.
Methods: Women with stage 0-3 hormone receptor-positive breast cancer experiencing AIMSS enrolled in this phase 2 clinical trial. Patients received CBD (Epidiolex), titrated over 4 weeks to 100 mg BID, for a total of 15 weeks. Patient-reported outcomes were collected serially. The primary endpoint was the number of patients with at least a 2-point reduction in worst pain from baseline to 15 weeks. Statistical analysis was completed using paired t-tests and linear mixed models.
Results: Of 39 eligible patients, 28 completed protocol-directed study treatment. Eleven discontinued treatment due to toxicity (n = 5) or per patient preference (n = 6). Seventeen of 39 patients met the primary endpoint (43.6%, 95% CI [28%, 60%]). Worst pain improved 0.13 per week of treatment (p < 0.001) for all patients; average improvement in worst pain was 1.95 points at the end of 15 weeks. Of the 28 patients who completed the study, average reduction in worst pain was 2.36 points (95% CI [-3.22, -1.49]) between baseline and Week 15.
Conclusion: Treatment with CBD was safe, tolerable, and associated with improvement in joint pain for a subset of patients. Additional studies are needed to further understand the impact of CBD on AIMSS and which patients are most likely to benefit from CBD treatment.”
“Treatment with CBD was associated with an improvement in AIMSS for a subset of patients. Use of CBD was safe and tolerable for women with hormone receptor-positive breast cancer.”
“Endocrine therapy for estrogen receptor-positive (ER+) breast cancer has significantly improved over the last decades. However, it presents some limitations that make the search for novel therapeutic options mandatory.
Several studies have been conducted to understand the anti-tumor potential of cannabinoids in breast cancer. Yet, most of them are focused on the major phytocannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). However, Cannabis has other minor phytocannabinoids whose anti-cancer properties are still to be elucidated.
Here, we investigated the mechanisms of action of four minor cannabinoids, cannabigerol (CBG), cannabidivarin (CBDV), cannabinol (CBN), and cannabichromene (CBC), in 2D and 3D ER+ breast cancer models.
These cannabinoids dysregulate MCF-7aro cell cycle progression, induce apoptosis by different mechanisms, and inhibit the growth of MCF-7aro spheroids. CBG exerts its effects through a down-regulation of both ER and AR protein levels, while CBDV reduces aromatase protein levels. CBN and CBC simultaneously affect the three targets, ER, aromatase, and AR.
In fact, CBN and CBC present an AR-dependent cell death, down-regulate aromatase levels, and act as ER negative regulators impairing cancer cell growth. CBN caused the most pronounced effects.
Overall, this study highlights the anti-cancer properties and the therapeutic potential of these minor cannabinoids in ER+ breast cancer.”
“Cannabidiol (CBD) has shown promise in treating cancers with an inflammatory microenvironment.
Although it has been demonstrated that IL-1β induces epithelial-mesenchymal transition (EMT) of MCF-7 cells and CBD reverts this process, in restoring the epithelial non-invasive phenotype, there is limited understanding of how this cannabinoid regulates these processes.
In this work, MCF-7 cells were induced to adopt an aggressive phenotype (6D cells), which was reversed by CBD.
Then, protein expression was analyzed by mass spectrometry to compare 6D vs. MCF-7 cells and 6D+CBD vs. 6D cells proteomes. Novel proteins associated with EMT and CBD signaling were identified. Twenty-four of them were oppositely regulated by IL-1β and CBD, suggesting new points of crosstalk between the IL-1β and CBD signaling pathways.
From the data, two protein networks were constructed: one related to EMT with 58 up-regulated proteins and another with 21 related to CBD signaling. The first one showed the proteins BRCA1, MSN, and CORO1A as the key axis that contributes to the establishment of a mesenchymal phenotype. In the CBD signaling, the key axis was formed by SUPT16H, SETD2, and H2BC12, which suggests epigenetic regulation by CBD in the restoration of an epithelial phenotype of breast cancer cells, providing new targets for anticancer therapy.”
“All these results provide new important insights that could help to understand how CBD counteracts the effects of IL-1β and the restoration of the epithelial phenotype as a possible control of cancer progression.”
“Multiple investigations have shown that the different types of cannabinoids, phytocannabinoids, synthetic cannabinoids, and endocannabinoids, possess antiproliferative and anticancer properties.
The cannabinoid type-2 receptor (CB2R) has been proposed as a central player in tumor progression and has been correlated with the aggressiveness of breast cancer. Using immunocytochemistry and confocal microscopy, in the present work, we studied the expression level and subcellular localization of CB2R in two human triple-negative breast cancer (TNBC) cell lines, corresponding to early (stage I, HCC-1395) and metastatic (MDA-MB-231) stages, and they were compared with a non-tumoral mammary epithelial cell line (MCF-10A).
We found that although CB2R was detected at the plasma membrane, it was mainly localized intracellularly, with ~40-fold higher expression in both TNBC cell lines than in MCF-10A (P < 0.0001). Notably, double staining with DAPI or with the nucleoli-specific fluorescent marker (3xnls-mTurquoise2) showed that most of the CB2R overexpressed in the nucleoli of cancer cells.
This finding is supported by the fact that CB2R expression was markedly lower in mitotic cells compared to interphase cells (P < 0.0001). Interestingly, exposure of cancer cells to the specific agonist HU-308 reversed the nucleolar sequestration of CB2R while increasing the presence of the receptor in the nucleoplasm and cytoplasm (P < 0.0001). In addition, we found that this agonist reduced both the cell migration (P < 0.05-0.0001) and proliferation (P < 0.001) of TNBC cells. It remains to determine the function and signaling ability of CB2R in the nucleolus.
Although our study only includes cell lines (tumoral and non-tumoral), we consider that this feature of nucleolar sequestration of CB2R could be a potential diagnostic marker for TNBC from the early stage.”
“Triple-negative breast cancer (TNBC) is an invasive and difficult-to-treat carcinoma that represents 15-20 % of breast malignancies and is frequently diagnosed in younger women. Chemotherapy is the mainstay treatment approach.
Cannabidiol (CBD), the main non-psychoactive cannabinoid, has shown a potential anticancer activity in TNBC, enhancing the effect of conventional antineoplastics.
This research aims to develop in situ forming implants (ISFIs) as a long-acting depot formulation of CBD with potential application in TNBC. This formulation is intended to be administered in the tumor site during neoadjuvant chemotherapeutic regimens, allowing a controlled CBD release. ISFIs were elaborated with 100 mg of polycaprolactone (PCL) and 2.5 mg (2.5-CB-ISFI), 5 mg (5-CB-ISFI) or 10 mg (10-CB-ISFI) of CBD dissolved in 400 µL of NMP. All the formulations exhibited a controlled drug release for around two months. 10-CB-ISFI formulation with the highest CBD content and the most suitable CBD release profile was selected for biological studies.
This formulation inhibited the proliferation and migration of MDA-MB-231 and 4T1 cells and exerted an antiangiogenic effect in ovo. Interestingly, the antiangiogenic activity of 10-CB-ISFI was higher compared with CBD in solution administered at the same concentration, showing vascular inhibition percentages of around 80 % and 60 %, respectively.
Finally, this formulation reduced the growth of MDA-MB-231-derived tumors developed in the chorioallantoic membrane (CAM) model. The single administration of 10-CB-ISFI exhibited a similar antitumor efficacy to the daily administration of CBD in solution (≈60 % tumor growth inhibition).
Therefore, the injectable depot formulation of CBD developed in this work showed a promising utility in TNBC treatment.”
“Cannabinoids have been used as anti-emetic agents in cancer. However, multiple studies suggest that cannabinoids present important anti-tumor actions as well.
Estrogen receptor-positive (ER+) breast cancer is the most diagnosed breast cancer subtype, and despite the success of endocrine therapy, endocrine resistance development is a major challenge, demanding the discovery or implementation of alternative therapeutic approaches.
In line with this, and following our previous work, the benefits of combining the aromatase inhibitors (AIs) used in the clinic, anastrozole (Ana), letrozole (Let), and exemestane (Exe), with cannabinol (CBN) were evaluated. Experiments were performed in MCF-7aro cells and spheroids to assess activity against specific molecular targets and underlying mechanisms of action.
Among the three AIs studied, only the combination of CBN with Exe induced a significant beneficial impact on viability and growth of ER+ breast cancer cells and spheroids.
Our results demonstrated that this combination was more effective than Exe in preventing the expression of aromatase and in modulating ERα and androgen receptor (AR) activity.
In fact, the results revealed that CBN can prevent de novo synthesis of aromatase, surpass Exe’s weak estrogen-like effect, and avoid the unfavorable overexpression of AR. By comparing these two therapeutic strategies, as well as the previously studied combination of Exe plus cannabidiol (CBD), differential transcriptome profiles were detected, which may help to better understand the mechanism of action of cannabinoids and disclose their full potential in breast cancer treatment.
In conclusion, this study strengthens the hypothesis that cannabinoids are important anti-cancer agents with attractive co-adjuvant properties.”
“Background: Breast cancer is one of the most prevalent cancers worldwide, posing significant challenges due to its heterogeneity and the emergence of drug resistance. Cannabidiol (CBD), a non-psychoactive compound derived from Cannabis sativa, has recently gained attention for its potential therapeutic effects in breast cancer.
Objective: This review aims to evaluate the antitumor effects of CBD in breast cancer treatment by synthesizing preclinical and clinical evidence, elucidating its mechanisms of action, and exploring its translational potential.
Methods: A systematic review was conducted following PRISMA guidelines. A comprehensive search was performed across PubMed, Google Scholar, Web of Science, and Scopus databases, using keywords such as “Cannabidiol,” “CBD,” “Breast Cancer,” “Therapeutic Agent,” and “Antitumor Effects.” A total of 1,191 articles were initially identified. After duplicate removal and eligibility screening, 34 studies published between 1998 and 2025 were selected, including in vitro, in vivo, and clinical investigations. Studies were assessed based on PRISMA recommendations, considering inclusion criteria such as CBD’s impact on apoptosis, cell proliferation, tumor progression, and molecular mechanisms.
Results: CBD demonstrated significant anticancer effects, including induction of apoptosis, inhibition of cell proliferation, suppression of metastasis, and modulation of the tumor microenvironment. Mechanistically, CBD modulates key pathways such as PI3K/Akt, mTOR, and PPARγ and interacts with CB1, CB2, and non-cannabinoid receptors. Preclinical studies showed CBD’s efficacy, particularly in triple-negative breast cancer (TNBC), while limited clinical trials highlighted its potential as an adjunct to conventional therapies.
Conclusion: CBD offers a promising therapeutic approach for breast cancer, especially for aggressive subtypes like TNBC. However, challenges such as variability in study design, lack of standardized protocols, and limited clinical validation hinder its clinical application. Future research should focus on conducting robust clinical trials, identifying predictive biomarkers, and optimizing combinatorial therapies to integrate CBD into personalized cancer treatment strategies.”
“CBD holds significant promise as a complementary or standalone therapeutic agent in breast cancer treatment, particularly in TNBC, where conventional options are limited. However, clinical validation through well-designed trials, biomarker identification, and safety profiling remains imperative before widespread clinical adoption. Future studies should focus on optimizing combinatorial therapies, investigating long-term effects, and refining pharmacological formulations to bridge the gap between preclinical findings and clinical application. By addressing these challenges, CBD could potentially redefine breast cancer management strategies, offering a safer, more effective, and targeted approach to treatment.”
