“Triple-negative breast cancer (TNBC) remains highly aggressive and refractory to conventional treatments, underscoring the need for novel combination strategies.

Here, we employed 2D and 3D in vitro models, transcriptomic profiling, and in vivo xenograft studies to evaluate the anticancer efficacy of cannabinoids combined with the terpene β-caryophyllene (BC) in resistant TNBC models.

Among the tested cannabinoids, cannabichromene (CBC) exhibited the greatest potency, and its combination with BC at sub-toxic concentrations significantly reduced IC₅₀ values, enhanced cytotoxicity in spheroids, and suppressed colony formation and migration. The combination treatment induced pronounced G1 cell cycle arrest and increased apoptotic cell death. Western blot analyses revealed downregulation of PARP, Survivin, mTOR, Vimentin, Glypican-5, and PD-L1, while RNA sequencing demonstrated suppression of proliferative and migratory signaling pathways alongside activation of apoptosis, autophagy, and ferroptosis-related pathways. In vivo, CBC + BC significantly inhibited tumor growth in MDA-MB-231 xenografts, outperforming single-agent treatments.

Collectively, these findings demonstrate that BC synergistically enhances cannabinoid activity, yielding superior antiproliferative and anti-migratory effects, and highlight this combination as a promising therapeutic strategy for resistant TNBC.”

https://pubmed.ncbi.nlm.nih.gov/41898593

“Our findings indicate that BC significantly enhances the anticancer effects of cannabinoids, particularly in resistant TNBC cells.”

https://www.mdpi.com/1422-0067/27/6/2730

“Breast cancer (BCa) remains a leading cause of cancer-related deaths in women worldwide. Triple-negative BCa (TNBC) is highly metastatic with treatment limited by off-target toxicity.

Cannabidiol (CBD) has anti-cancer and anti-inflammatory activity in BCa.

This study addresses the poor oral bioavailability of CBD by utilizing exosomes (Exo) as a drug delivery system.

CBD was loaded onto non-functionalized exosomes and folic acid-functionalized exosomes (FA-Exo), achieving an average CBD drug load of ∼20%. The FA-ExoCBD averaged 136 ± 2.9 nm in size. TNBC cell lines MDA-MB-231 and taxol-resistant MDA-MB-231TR were sensitive to growth inhibition by CBD than estrogen receptor positive (ER+) MCF-7 and its taxol-resistant derivative MCF-7TR. Exosomal formulations (ExoCBD and FA-ExoCBD) demonstrated time-dependent CBD release under physiologically relevant simulated gastric and intestinal conditions and withstand acidic conditions, retained canonical exosomal markers (CD81 and Alix) as well as physical parameters of exosomes including size, PDI and zeta potential.

CBD downregulated key anti-apoptotic and anti-inflammatory markers.

Oral FA-ExoCBD showed enhanced tumor targeting, tumor retention and inhibition of orthotopic MDA-MB-231-tumor growth in NOD Scid mice than ExoCBD or free CBD. RNA-Seq analysis of tumor tissues revealed that both CBD and FA-ExoCBD treatments modulated over 1000 genes, with FA-ExoCBD significantly downregulating IL13RA2 (associated with lung metastasis) and tumor biomarkers TRPM2 and SAMHD1, while upregulating tumor suppressors PRDM1, PCDHGB2, and ICAM1.

These findings highlight the potential of FA-ExoCBD to enhance CBD’s anticancer efficacy through targeted gene modulation. Overall, FA-ExoCBD improves CBD’s therapeutic profile by enhancing efficacy, tumor selectivity, improved bioavailability and anticancer efficacy.”

https://pubmed.ncbi.nlm.nih.gov/41812824

https://www.sciencedirect.com/science/article/abs/pii/S0304383526001795?via%3Dihub

“Background: Breast cancer progression involves key processes such as uncontrolled cell proliferation, resistance to apoptosis, metastasis, and angiogenesis. Cannabidiol (CBD), a non-psy-choactive compound from Cannabis sativa, has shown promise for its anti-cancer properties. This study aimed to explore the interaction of CBD with proteins involved in these processes.

Methods: Molecular docking was performed to assess the binding affinity of CBD to four critical proteins: CDK6 (cell cycle regulator), BCL2 (anti-apoptotic protein), MMP2 (invasion-related en-zyme), and VEGFR2 (angiogenesis-related receptor). Known inhibitors, palbociclib, ABT-199, doxycycline, and axitinib, were used as reference compounds for comparison.

Results: Cannabidiol exhibited strong binding affinities for CDK6, BCL2, MMP2, and VEGFR2. The docking scores were comparable to those of the respective standard inhibitors, suggesting effec-tive interactions with the active sites of the target proteins.

Discussion: These findings suggest that CBD may simultaneously target multiple cancer-related pathways, offering a potential multi-target therapeutic approach for breast cancer. Its comparable efficacy to standard inhibitors, combined with a favorable safety profile, supports its potential for further development. However, experimental validation through in vitro and in vivo studies is neces-sary to confirm its therapeutic effectiveness.

Conclusion: CBD demonstrates promising multi-target activity against critical signaling molecules in breast cancer and may serve as a safer, natural therapeutic candidate. Further preclinical and clin-ical investigations are warranted.”

https://pubmed.ncbi.nlm.nih.gov/41830580

https://www.eurekaselect.com/article/153254

“Triple-negative breast cancer (TNBC) is highly aggressive with limited treatment options, and resistance to doxorubicin (DOX) further compromises outcomes.

Cannabinoids such as cannabichromene (CBC) and cannabidiol (CBD) possess anticancer properties, but their combined effects in resistant TNBC remain unexplored. This study evaluated the antitumor efficacy of a CBC + CBD combination against DOX-resistant (DOX-RT) TNBC using in vitro, in vivo, and pharmacokinetic models.

Cytotoxicity was assessed in DOX-RT MDA-MB-231 cells using 2D and 3D assays, with synergy confirmed by combination index (CI) analysis. Cell cycle and invasion assays were performed. Xenograft studies were conducted in BALB/c nude mice bearing DOX-RT tumors treated intraperitoneally with CBC (10 mg/kg), CBD (20 mg/kg), or CBC + CBD. Pharmacokinetics were evaluated in rats, complemented by GastroPlus™ simulations.

CBC + CBD synergistically inhibited cell growth induced G0/G1 arrest, and reduced invasiveness by ~ 55% in a Transwell Matrigel invasion assay. In xenografts, combination therapy reduced tumor volume by two-folds compared to single treatments and fourfolds versus control. Western blotting revealed downregulation of MEK/ERK, PI3K/AKT/mTOR, Cyclin D1, CDK6, SOD2, and NF-κB. Pharmacokinetic studies showed co-administration increased Cmax and AUC without altering Tmax, supported by simulations predicting enhanced jejunal absorption. CBC + CBD co-therapy demonstrates synergistic efficacy against resistant TNBC by inhibiting oncogenic pathways and enhancing systemic exposure.

This first study of its kind highlights CBC + CBD as a promising strategy to overcome DOX resistance in TNBC.”

https://pubmed.ncbi.nlm.nih.gov/41670942

https://link.springer.com/article/10.1007/s13346-026-02057-1

“HER2 (human epidermal growth factor receptor 2) is a well-established oncogenic driver and therapeutic target in breast cancer.

Cannabidiol (CBD), a non-psychoactive phytocannabinoid, has demonstrated anticancer potential, yet its mechanisms of action in HER2-positive breast cancer remain insufficiently characterized.

In this study, we examined the effects of CBD on HER2-positive (SK-BR-3, BT-474) and HER2-negative (MCF-7, MDA-MB-231) breast cancer cell lines, with a focus on its interaction with HER2.

CBD selectively reduced the viability of HER2-positive cells, an effect associated with increased intracellular reactive oxygen species (ROS) and a marked reduction in HER2 protein levels. Mechanistically, CBD triggered non-apoptotic cell death pathways, including paraptosis and ferroptosis, as indicated by the modulation of specific molecular markers such as reduced Alix and elevated ATF4 and CHOP for paraptosis, and downregulated GPX4 and SLC7A11 with upregulated TFRC for ferroptosis. HER2 knockdown attenuated CBD-induced cytotoxicity, while HER2 overexpression sensitized cells to CBD, underscoring the HER2-dependence of these effects. Molecular docking predicts the binding conformation and key interactions of ligand with target proteins providing initial insights into potential molecular recognition. Subsequently, molecular dynamics simulations extend this analysis by assessing the stability, flexibility, and energetic characteristics of the ligand-protein complex within a dynamic biological environment.

These findings support a model in which CBD downregulates HER2 and, in a HER2-dependent context, promotes paraptosis and ferroptosis. In addition, docking and molecular dynamics analyses suggested a potential interaction between CBD and HER2, providing mechanistic insights into possible molecular recognition relevant to HER2-positive breast cancer.”

https://pubmed.ncbi.nlm.nih.gov/41621547

“These results suggest that CBD targets HER2, offering a new therapeutic strategy for HER2-positive breast cancer management.”

https://www.sciencedirect.com/science/article/abs/pii/S0925443926000256?via%3Dihub

“Background: Triple-negative breast cancer (TNBC) is a highly aggressive subtype lacking targeted therapies, presenting a significant clinical challenge. The epidermal growth factor receptor (EGFR) plays a crucial role in TNBC progression, making it a promising target for therapeutic intervention. This study investigated the potential of cannabidiol (CBD) as a therapeutic agent that targets EGFR and associated signaling pathways in TNBC.

Methods: The TNBC cell lines MDA-MB-468 and MDA-MB-231 were treated with CBD in the presence or absence of epidermal growth factor (EGF). Cell proliferation, FAS protein expression, and activation of the EGFR signaling pathway were assessed. The cytotoxic effects of CBD on TNBC cells and natural killer (NK) cells were also evaluated.

Results: CBD significantly elevated FAS protein expression in MDA-MB-468 cells compared to EGF treatment alone (125.29 ± 5.87% vs. 83.07 ± 1.30%, p < 0.0001). Further molecular analysis revealed that CBD inhibited EGFR signaling by downregulating key oncogenic proteins, including KRAS, PI3K, and AKT. Moreover, CBD enhanced the cytotoxic effects of NK-92 cells, reducing the viability of MDA-MB-468 cells more effectively than EGF alone did (52.12 ± 1.28% vs. 113.69 ± 1.68%, p < 0.0001).

Conclusions: These findings suggest that CBD holds promise as a potential anticancer agent in TNBC by disrupting EGFR signaling and promoting apoptosis. However, further studies are necessary to optimize its therapeutic window and minimize adverse effects, particularly regarding its potential cytotoxicity to immune cells.”

https://pubmed.ncbi.nlm.nih.gov/41188939/

“Our findings underscore the therapeutic potential of CBD in TNBC by targeting EGFR-driven pathways, modulating FAS expression, and enhancing immune-mediated killing. This study offers renewed hope for patients facing this challenging disease, positioning CBD as a potentially potent and multifaceted therapeutic agent.”

https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-025-00340-5

“Breast cancer is the second leading cause of death among women. Although early diagnosis and development of new treatments have improved their prognosis, many patients present innate or acquired resistance to current therapies. New therapeutic approaches are therefore warranted for the management of this disease.

Extensive preclinical research has demonstrated that cannabinoids, the active ingredients of Cannabis sativa, trigger antitumor responses in different models of cancer.

Most of these studies have been conducted with pure compounds, mainly Δ⁹-tetrahydrocannabinol (THC). The cannabis plant, however, produces hundreds of other compounds with their own therapeutic potential and the capability to induce synergic responses when combined, the so-called “entourage effect”.

Here, we compared the antitumor efficacy of pure THC with that of a botanical drug preparation (BDP).

The BDP was more potent than pure THC in producing antitumor responses in cell culture and animal models of ER+/PR+, HER2+ and triple-negative breast cancer. This increased potency was not due to the presence of the 5 most abundant terpenes in the preparation. While pure THC acted by activating cannabinoid CB₂ receptors and generating reactive oxygen species, the BDP modulated different targets and mechanisms of action. The combination of cannabinoids with estrogen receptor- or HER2-targeted therapies (tamoxifen and lapatinib, respectively) or with cisplatin, produced additive antiproliferative responses in cell cultures. Combinations of these treatments in vivo showed no interactions, either positive or negative.

Together, our results suggest that standardized cannabis drug preparations, rather than pure cannabinoids, could be considered as part of the therapeutic armamentarium to manage breast cancer.”

“It is well documented that cannabinoids, the active ingredients of the hemp plant Cannabis sativa, produce antitumor responses in preclinical models of cancer, by tackling different stages of cancer progression such as uncontrolled cancer cell proliferation and survival, angiogenesis and metastasis. The vast majority of these studies has been performed with pure compounds, mainly Δ⁹-tetrahydrocannabinol (THC). The cannabis plant, however, produces hundreds of additional compounds (other cannabinoids, terpenoids, flavonoids, polyphenols, etc.) that have been much less studied but show promising therapeutic properties (anti-proliferative, anti-inflammatory, immune-stimulant, etc.), and/or the potential capability of enhancing some THC actions, the so-called “entourage effect”.

https://www.sciencedirect.com/science/article/abs/pii/S0006295218302387