Phytocannabinoids in Triple Negative Breast Cancer Treatment: Current Knowledge and Future Insights

Anticancer Research: 43 (3)

“Triple negative breast cancer (TNBC) represents an aggressive subtype of breast cancer, which is deficient in estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression. Thus, TNBC cells are unable to respond to the conventional hormonal therapies, making chemotherapy the only therapeutic choice. Patients with TNBC develop metastasis and recurrence over time and have reduced survival compared to patients with other subtypes of breast cancer. Therefore, there is a need for innovative therapies. Data emerged from pre-clinical studies, highlighted various antitumor activities of plant-derived Cannabis sativa and synthetic cannabinoids (CBs), including delta-9-tetrahydrocannabinol (THC) and non-psychoactive cannabidiol (CBD). On the contrary, some studies indicated that CBs might also promote tumor progression. At present, clinical studies on the effects of CBs from Cannabis sativa in cancer patients are few. In the present study, we reviewed known and possible interactions between cannabinoids and TNBC therapies.”

“Overall, apart from the need for other studies aimed to dissect the molecular pathways underlying the antitumor CBs’ properties, phytocannabinoids should be considered as potential agents for inhibiting TNBC progression.”

Comparative changes in breast cancer cell proliferation and signalling following somatostatin and cannabidiol treatment

Biochemical and Biophysical Research Communications

“Breast cancer is the most commonly diagnosed cancer and a leading cause of cancer-related death among women worldwide. Somatostatin (SST) and Cannabinoids have an anti-proliferative and pro-apoptotic effect, but the mechanisms of their actions remain elusive.

In the present study, we have evaluated the effects of SST, Cannabidiol (CBD) alone or in combination on receptor expression, cell proliferation and apoptosis and related downstream signalling pathways in MDA-MB-231 and MCF-7 breast cancer cells.

The results presented here demonstrate the cell type and agonist-dependent changes in receptor expression at the cell membrane, inhibition of cell proliferation and increased apoptosis following treatment with SST and CBD alone and in combination. In comparison to MDA-MB-231 cells, MCF-7 cells treated with SST alone and in combination with CBD exhibited inhibition of phosphorylated Protein Kinase B (pAKT) and phosphorylated-Phosphoinositide 3-Kinase (pPI3K) expression. Importantly, inhibition of PI3K/AKT activation was accompanied by enhanced PTEN expression in MCF-7 cells.

These results highlight the possible interaction between SSTR and CBR subtypes with the implication in the modulation of receptor expression, cell viability and signal transduction pathways in a breast cancer cell type-dependent manner.”

“Marijuana (or cannabis) is a source of large numbers of compounds known as phytocannabinoids, such as delta-9-tetrahydrocannabinol (Δ9-THC) and Cannabidiol (CBD) that have therapeutic implications in cancer, pain, inflammation and neurological diseases.”

Structural analysis of cannabinoids against EGFR-TK leads a novel target against EGFR-driven cell lines

Current Research in Pharmacology and Drug Discovery

“Epidermal growth factor receptor (EGFR) is a member of the ErbB family of proteins and are involved in downstream signal transduction, plays prominent roles in cell growth regulation, proliferation, and the differentiation of many cell types. They are correlated with the stage and severity of cancer. Therefore, EGFRs are targeted proteins for the design of new drugs to treat cancers that overexpress these proteins. Currently, several bioactive natural extracts are being studied for therapeutic purposes.

Cannabis has been reported in many studies to have beneficial medicinal effects, such as anti-inflammatory, analgesic, antibacterial, and anti-inflammatory effects, and antitumor activity. However, it is unclear whether cannabinoids reduce intracellular signaling by inhibiting tyrosine kinase phosphorylation. In this study, cannabinoids (CBD, CBG, and CBN) were simulated for binding to the EGFR-intracellular domain to evaluate the binding energy and binding mode based on molecular docking simulation.

The results showed that the binding site was almost always located at the kinase active site. In addition, the compounds were tested for binding affinity and demonstrated their ability to inhibit kinase enzymes. Furthermore, the compounds potently inhibited cellular survival and apoptosis induction in either of the EGFR-overexpressing cell lines.”

“Cannabinoids reduced cell viability in EGFR-positive cells A431 and A549 by decreasing the tyrosine-kinase phosphorylation activity of EGFR.•

In silico analysis shows that cannabinoids bind to the active site of the EGFR-tyrosine kinase by the hydrophobic interaction and hydrogen bonding.•

CBD and CBG significantly induce cancer cells apoptosis in EGFR-positive cell A431.•

The consistent findings suggested that CBD and CBG could be developed as natural tumor-targeting agents for EGFR-positive cancers.

These findings demonstrate that the cannabinoids could be transformed into unique natural compounds for use in the development of anti-EGFR-positive cancer therapies.”

Study of potential inhibition of the estrogen receptor α by cannabinoids using an in silico approach: Agonist vs antagonist mechanism

Computers in Biology and Medicine

“Breast cancer is the main cancer type with more than 2.2 million cases in 2020, and is the principal cause of death in women; with 685000 deaths in 2020 worldwide. The estrogen receptor is involved at least in 70% of breast cancer diagnoses, and the agonist and antagonist properties of the drug in this receptor play a pivotal role in the control of this illness.

This work evaluated the agonist and antagonist mechanisms of 30 cannabinoids by employing molecular docking and dynamic simulations. Compounds with docking scores < -8 kcal/mol were analyzed by molecular dynamic simulation at 300 ns, and relevant insights are given about the protein’s structural changes, centered on the helicity in alpha-helices H3, H8, H11, and H12.

Cannabicitran was the cannabinoid that presented the best relative binding-free energy (-34.96 kcal/mol), and based on rational modification, we found a new natural-based compound with relative binding-free energy (-44.83 kcal/mol) better than the controls hydroxytamoxifen and acolbifen. Structure modifications that could increase biological activity are suggested.”

The role of Cannabidiol and tetrahydrocannabivarin to overcome doxorubicin resistance in MDA-MB-231 xenografts in athymic nude mice


“The significant resistance to currently available chemotherapeutics makes treatment for TNBC a key clinical concern. Herein, we studied the anti-cancer potentials of synthetic cannabidiol (CBD) and Tetrahydrocannabivarin (THCV) when used alone or in combination with doxorubicin (DOX) against MDA-MB-231 resistant cells. Pre-treatment with CBD and THCV significantly increased the cytotoxicity of DOX in MDA-MB-231 2D and 3D cultures that were DOX-resistant. Transcriptomics and Proteomics studies revealed that CBD and THCV, by downregulating PD-L1, TGF-β, sp1, NLRP3, P38-MAPK, and upregulating AMPK induced apoptosis leading to improved DOX’s chemosensitivity against DOX resistant MDA-MB-231 tumors in BALB/c nude mice. CBD/THCV in combination with DOX significantly inhibited H3k4 methylation and H2K5 acetylation as demonstrated by western blotting and RT-PCR. Based on these findings, CBD and THCV appear to counteract histone modifications and their subsequent effects on DOX, resulting in chemo-sensitization against MDA-MB-231 resistant cancers.”

“Cannabis anecdotally has been a folklore medicine for a longtime to treat a variety of disease states. In recent years, the therapeutic use of cannabis and cannabinoids has garnered more acceptance in the public domain. Several Phyto-cannabinoids are available from the the plant Cannabis sativa along with terpenes and they target the endocannabinoid system and several other biological pathways. Hence, these agents can possibly have a array of therapeutic effects on the central nervous system and peripheral immune, cardiovascular, reproductive, and ocular systems.

Our findings show that CBD and THCV were found to overcome resistance against MDA-MB-231 resistant cell line in vitro in 2D and 3D cultures by several folds. Further, both these agents in combination with DOX showed synergism as determined by the isobolographic method.”

Role of Cannabidiol for Improvement of the Quality of Life in Cancer Patients: Potential and Challenges


“There is currently a growing interest in the use of cannabidiol (CBD) to alleviate the symptoms caused by cancer, including pain, sleep disruption, and anxiety. CBD is often self-administered as an over-the-counter supplement, and patients have reported benefits from its use. However, despite the progress made, the mechanisms underlying CBD’s anti-cancer activity remain divergent and unclear. Herein, we provide a comprehensive review of molecular mechanisms to determine convergent anti-cancer actions of CBD from pre-clinical and clinical studies. In vitro studies have begun to elucidate the molecular targets of CBD and provide evidence of CBD’s anti-tumor properties in cell and mouse models of cancer. Furthermore, several clinical trials have been completed testing CBD’s efficacy in treating cancer-related pain. However, most use a mixture of CBD and the psychoactive, tetrahydrocannabinol (THC), and/or use variable dosing that is not consistent between individual patients. Despite these limitations, significant reductions in pain and opioid use have been reported in cancer patients using CBD or CBD+THC. Additionally, significant improvements in quality-of-life measures and patients’ overall satisfaction with their treatment have been reported. Thus, there is growing evidence suggesting that CBD might be useful to improve the overall quality of life of cancer patients by both alleviating cancer symptoms and by synergizing with cancer therapies to improve their efficacy. However, many questions remain unanswered regarding the use of CBD in cancer treatment, including the optimal dose, effective combinations with other drugs, and which biomarkers/clinical presentation of symptoms may guide its use.”

“CBD has great potential to improve the lives of cancer patients both by alleviating the symptoms of pain, sleep disturbance, and anxiety, but also by synergistic activity with anti-cancer treatments to reverse or eliminate the growth of tumors causing these symptoms. Pre-clinical evidence in cell and mouse models supports the use of CBD as an anti-cancer therapy; however, clinical knowledge is currently lacking in this area. The effectiveness of CBD has been demonstrated in models of lung, breast, and colon cancer, as well as leukemia and glioblastoma. CBD has been shown to be toxic to cancer cells in vitro, and it is also generally well tolerated in the clinic.”

Anti-cancer effects of selective cannabinoid agonists in pancreatic and breast cancer cells

“Objective: Cancer ranks first among the causes of morbidity and mortality all over the world, and it is expected to continue to be the main cause of death in the coming years. Therefore, new molecular targets and therapeutic strategies are urgently needed. In many cases, some reports show increased levels of endocannabinoids and their receptors in cancer, a condition often associated with tumour aggressiveness. Recent studies have suggested that cannabinoid-1/2 receptors contribute to tumour growth in a variety of cancers, including pancreatic, colon, prostate, and breast cancer. Understanding how cannabinoids can regulate key cellular processes involved in tumorigenesis, such as: cell proliferation and cell death, is crucial to improving existing and new therapeutic approaches for the cancer patients. The present study was aimed to characterize the in-vitro effect of L-759633 (a selective CB2 receptor agonist), ACPA (a selective CB1 receptor agonist) and ACEA (a selective CB1 receptor agonist) on the cell proliferation, clonogenicity, and apoptosis in pancreatic (PANC1) and breast (MDA-MB-231) cancer cells.

Methods: The viability and/or proliferation of cells were detected by MTS assay. A clonogenic survival assay was used to detect the ability of a single cell to grow into a colony. Apoptosis was determined with Annexin V staining (Annexin V-FITC/PI test) and by analyzing the expression of Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl-2).

Results: We found that selective CB1/2 agonists suppressed cell proliferation, clonogenicity and induced proapoptotic function in human PANC1 pancreatic and MDA-MB-231 breast cancer cells. Based on our findings, these agonists led to the inhibition of both cell viability and clonogenic growth in a dose dependent manner. CB1/2 agonists were observed to induce intrinsic apoptotic pathway by upregulating Bax, while downregulating Bcl-2 expression levels.

Conclusion: Our data suggests that CB1/2 agonists have the therapeutic potential through the inhibition of survival of human PANC1 pancreatic and MDA-MB-231 breast cancer cells and also might be linked with further cellular mechanisms for the prevention.”

“Analysis of Anti-Cancer and Anti-Inflammatory Properties of 25 High-THC Cannabis Extracts”

Cannabidiolic acid activates the expression of the PPARβ/δ target genes in MDA-MB-231 cells

Archives of Biochemistry and Biophysics

“Cannabidiolic acid (CBDA) can activate peroxisome proliferator-activated receptor-α (PPARα) and PPARγ. Whether CBDA can activate PPARβ/δ has not been examined sufficiently to date. Since previous studies showed that triple-negative breast cancer cells respond to activation of PPARβ/δ, the present study examined the effect of CBDA in MDA-MB-231 cells and compared the activities of CBDA with known PPARβ/δ agonists/antagonists. Expression of the PPARβ/δ target genes angiopoietin-like 4 (ANGPTL4) and adipocyte differentiation-related protein (ADRP) was increased by CBDA. Interestingly, ligand activation of PPARβ/δ with GW501516 caused an increase in expression of both ANGPTL4 and ADRP, but the magnitude of this effect was markedly increased when co-treated with CBDA. Specificity of these effects were confirmed by showing that CBDA-induced expression of ANGPTL4 and ADRP is mitigated in the presence of either a PPARβ/δ antagonist or an inverse agonist. Results from these studies suggest that CBDA can synergize with PPARβ/δ and might interact with endogenous agonists that modulate PPARβ/δ function.”

“Cannabidiolic acid (CBDA) is a crucial biologically active component of the fiber-type cannabis plant. Many studies have suggested that CBDA can be used for treating different medical conditions including use as an antibacterial agent, or as an anti-nausea/vomiting agent. Furthermore, CBDA can inhibit cyclooxygenase-2 (COX-2) activity and expression, and thus has potential for treating inflammatory-dependent diseases. Indeed, CBDA-containing products are commonly used in many countries, in particular due to medical and recreational marijuana usage in the United States.”

Analysis of Potential Anti-Cancer Effects of Cannabinol and Cannabidiol using HCC1806 and HEK293 Cell Lines

URSCA 2018

“Humans produce endocannabinoids that act as neuromodulators in the endocannabinoid system. They bind to Gαi protein-coupled cannabinoid receptors to control the release of many neurotransmitters. Cannabinoids receptor 1 (CB1) mediates psychoactive effects through its location mostly in the central nervous system while Cannabinoid receptor 2 (CB2) regulates various immune responses through its location in peripheral tissues.

The endocannabinoid system has been used as a molecular target by research to treat diseases such as multiple sclerosis, cardiovascular disorders, obesity and inflammatory pain. Thus, the endocannabinoid system is a potential molecular target to treat cancer. With the proposed legalization of recreational marijuana and with growing number of patients using cannabis for medicinal purpose, there is an urgent need to provide data on potential medicinal value of cannabis and cannabinoids.

The Cannabis Sativa plant naturally synthesizes numerous different cannabinoids of which (CBN) and cannabidiol (CBD) have promising properties in cancer treatment. CBD is a phytocannabinoid known for its anticonvulsant and anti-nausea properties. Previous research suggests that CBD can target breast cancer cells while preserving normal cells. CBN is another phyotocannabinoid with anti-inflammatory properties that can potentially aid to reduce inflammation resulting from cancer.

This study aims to determine if CBN and CBD have an effect on cancer cells and normal cells. We hypothesize that we may observe an increase in apoptosis of cancer cells treated with the two compounds but no effect or perhaps even a slight increase in normal cell growth. Preliminary data in lab suggests that these compounds have anti-cancer properties and we want to solidify this evidence through repetition of the experiment.”

Hemp ( Cannabis sativa L., Kompolti cv.) and Hop ( Humulus lupulus L., Chinook cv.) Essential Oil and Hydrolate: HS-GC-MS Chemical Investigation and Apoptotic Activity Evaluation


“In this study, essential oils (EOs) and hydrolates (Hys) from Italian hemp (Cannabis sativa L. Kompolti cv.) and hop (Humulus Lupulus L., Chinook cv.) supply chains were chemically characterized and tested to investigate their apoptotic potential for the first time. Headspace-Gas Chromatography-Mass Spectrometry (HS-GC-MS) techniques were performed to describe their volatile chemical profile, highlighting a composition rich in terpene derivatives such as monoterpenes and sesquiterpenes among which β-myrcene, limonene, β-caryophyllene and α-humulene were the main constituents of EOs; in contrast, linalool, cisp-menth-2,8-dien-1-ol, terpinen-4-ol, α-terpineol, caryophyllene oxide, and τ-cadinol were found in the Hys.

The cytotoxicity activity on human leukemia cells (HL60), human neuroblastoma cells (SH-SY5Y), human metastatic adenocarcinoma breast cells (MCF7), human adenocarcinoma breast cells (MDA), and normal breast epithelial cell (MCF10A) for the EOs and Hys was studied by MTT assay and cytofluorimetric analysis and scanning and transmission electron microscopy were performed to define ultrastructural changes and the mechanism of cells death for HL 60 cells.

An induction of the apoptotic mechanism was evidenced for hemp and hop EOs after treatment with the corresponding EC50 dose. In addition, TEM and SEM investigations revealed typical characteristics induced by the apoptotic pathway. Therefore, thanks to the integration of the applied methodologies with the used techniques, this work provides an overview on the metabolomic profile and the apoptotic potential of hemp and hop EOs and, for the first time, also of Hys.

The findings of this preliminary study confirm that the EOs and Hys from Cannabis and Humulus species are sources of bioactive molecules with multiple biological effects yet to be explored.”