Cannabis and cancer: unveiling the potential of a green ally in breast, colorectal, and prostate cancer

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“Cancer comes in second place on the list of causes of death worldwide. In 2018, the 5-year prevalence of breast cancer (BC), prostate cancer (PC), and colorectal cancer (CRC) were 30%, 12.3%, and 10.9%, respectively.

Cannabinoids are chemicals derived from the Cannabis sativa plant; the most investigated cannabinoids are cannabinol, delta 9-tetrahydrocannabinol (Δ9-THC), and cannabidiol. In humans, the endogenous endocannabinoid system consists of endocannabinoids, cannabinoids receptors (CBs), and enzymes that degrade the endocannabinoids.

In this review, we will review the most recent literature for evidence that discusses the role of cannabis in the treatment of the three types of neoplasms mentioned.

Studies have proved that BC cells express CB receptors; many in-vivo studies showed that cannabinoids cause apoptosis and inhibit proliferation and migration. Also, researchers found that treating BC mice with THC and JWH-133 (CB2 receptor agonist) slowed the tumor growth.

Regarding CRC, cannabidiol was found to decrease the viability of chemotherapy-resistant CRC cells and inhibit metastasis by antagonizing the G-protein-coupled receptor 55 (GPR55; a novel cannabinoid receptor) necessary for metastasis. Moreover, cannabidiol had anti-angiogenetic effects by reducing the expression of vascular endothelial growth factor (VEGF) in addition to anti-inflammatory effects.

Finally, studies demonstrated that PC cells highly express CB1 and CB2 receptors and that cannabinoids are capable of inhibiting the release of exosomes and microvesicles related to cancer progression. Cannabinoids also have antiproliferative, anti-invasive, anti-fibroblastic, cell cycle arrest, and proapoptotic effects on PC cells.”

“There is growing evidence supporting the role of Cannabinoids in numerous pathological conditions, including their role in several cancer types such as breast, colorectal, and prostate cancer. Accordingly, cannabinoids could have a promising potential as adjunctive therapy for the treatment of these types of cancers.”

Phytocannabinoids CBD, CBG, and their Derivatives CBD-HQ and CBG-A Induced In Vitro Cytotoxicity in 2D and 3D Colon Cancer Cell Models

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“Phytocannabinoids, compounds found in Cannabis sativa L., are used in oncology and palliative care to reduce the adverse reactions of standard therapies. Cancer patients use formulations of Cannabis sativa L. to manage the anxiety, pain, and nausea associated with cancer treatment, and there is growing evidence that some of them may exhibit anticancer properties.

In this study, we tested the anticancer potential of selected cannabinoids CBD (cannabidiol) and its quinone derivative CBD-HQ (cannabidiol hydroquinone), CBG (cannabigerol) and its acid derivative CBG-A (cannabigerolic acid), as well as a combination of CBD+CBG on the colon cancer cell line SW-620.

The MTT assay was used to determine the cannabinoids’ ability to induce colon cancer cell death. All cannabinoids were cytotoxic at the lowest concentration (3 μg/mL). The half maximal inhibitory concentration (IC50) ranged from 3.90 to 8.24 μg/mL, depending on the substance. Cytotoxicity was confirmed in a 3D spheroidal cell culture with calcein and propidium iodide staining. The amount of intracellular reactive oxygen species (ROS) was examined using a DCF-DA assay. CBG showed the lowest antioxidant activity of all the cannabinoids tested. The level of intracellular ROS decreased only by 0.7-18%. However, CBG-A induced the strongest reduction in ROS level by 31-39%.

Our results suggest that cannabinoids represent an interesting research direction with great implementation potential. These preliminary results represent the beginning of research into the potential of these substances for anticancer treatment and underscore the potential for further research.”

“There is no doubt that phytocannabinoids represent an interesting research direction with great potential for implementation.”

Targeting Colorectal Cancer: Unravelling the Transcriptomic Impact of Cisplatin and High-THC Cannabis Extract

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“Cisplatin and other platinum-derived chemotherapy drugs have been used for the treatment of cancer for a long time and are often combined with other medications. Unfortunately, tumours often develop resistance to cisplatin, forcing scientists to look for alternatives or synergistic combinations with other drugs.

In this work, we attempted to find a potential synergistic effect between cisplatin and cannabinoid delta-9-THC, as well as the high-THC Cannabis sativa extract, for the treatment of HT-29, HCT-116, and LS-174T colorectal cancer cell lines. However, we found that combinations of the high-THC cannabis extract with cisplatin worked antagonistically on the tested colorectal cancer cell lines. To elucidate the mechanisms of drug interactions and the distinct impacts of individual treatments, we conducted a comprehensive transcriptomic analysis of affected pathways within the colorectal cancer cell line HT-29.

Our primary objective was to gain a deeper understanding of the underlying molecular mechanisms associated with each treatment modality and their potential interactions. Our findings revealed an antagonistic interaction between cisplatin and high-THC cannabis extract, which could be linked to alterations in gene transcription associated with cell death (BCL2BADcaspase 10), DNA repair pathways (Rad52), and cancer pathways related to drug resistance.”

“There is a need for new and better ways to prevent and treat it, possibly by combining different drugs. Recent research suggests that cannabinoids could be promising in this regard.”

Water Extracts from Industrial Hemp Waste Inhibit the Adhesion and Development of Candida Biofilm and Showed Antioxidant Activity on HT-29 Colon Cancer Cells

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“The evolution of regulatory perspectives regarding the health and nutritional properties of industrial hemp-based products (Cannabis sativa L.) has pushed research to focus on the development of new methods for both the extraction and formulation of the bioactive compounds present in hemp extracts. While the psychoactive and medicinal properties of hemp-derived cannabinoid extracts are well known, much less has been investigated on the functional and antimicrobial properties of hemp extracts.

Within the hemp value chain, various agricultural wastes and by-products are generated. These materials can be valorised through eco-innovations, ultimately promoting sustainable economic development. In this study, we explored the use of waste from industrial light cannabis production for the extraction of bioactive compounds without the addition of chemicals. The five extracts obtained were tested for their antimicrobial activity on both planktonic and sessile cells of pathogenic strains of the Candida albicansCandida parapsilosis, and Candida tropicalis species and for their antioxidant activity on HT-29 colon cancer cells under oxidative stress.

Our results demonstrated that these extracts display interesting properties both as antioxidants and in hindering the development of fungal biofilm, paving the way for further investigations into the sustainable valorisation of hemp waste for different biomedical applications.”

Platinum (IV) drugs with cannabidiol inducing mitochondrial dysfunction and synergistically enhancing anti-tumor effects

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“Chemotherapy resistance is an insurmountable problem in clinical anticancer therapy. Although Oxaliplatin is an effective chemotherapeutic agent for the treatment of colorectal cancer (CRC), it still suffers from serious toxicities as well as drug resistance. In this work, three Oxaliplatin tetravalent platinum prodrugs(O1-O3) and three novel mixed ammine/amine analogs(C1-C3) were constructed, introducing cannabidiol with anti-tumor activity in their axial position.

All Pt(IV) prodrugs exhibited potent antitumor effects in a variety of tumor cell lines, especially in HCT-116 cells, where complex O3 showed strong inhibitory effects with the half maximal inhibitory concentrations (IC50) value of 6.02 ± 0.69 μM and about 2.6 times higher than that of Oxaliplatin. Further studies revealed that complex O3 decreased cellular mitochondrial membrane potential in a concentration-dependent manner and enhanced reactive oxygen species (ROS) accumulation by decreasing the expression of catalase, superoxide dismutase 2 (SOD2) and superoxide dismutase 3 (SOD3). Complex O3 induces mitochondrial dysfunction and upregulates the pro-apoptotic protein Noxa, ultimately leading to severe DNA damage. The upregulation of Phosphorylated histone protein H2AX (γ-H2AX) expression is clear evidence. In addition, O3 inhibits the expression of RAD51 protein and prevents DNA damage repair, thus overcoming drug resistance.

This strategy of combining bioactive molecules cannabidiol with platinum drugs to improve therapeutic efficacy and overcome drug resistance has been proven to be very effective and deserves further investigation.”

“The cannabidiol was introduced into the platinum antitumor drugs, and the Pt(IV) complexes O1-O3 and C1- C3 were synthesized.

•Complex O3 is highly cytotoxic to all cancer cells and cannabidiol exerts a synergistic antitumor effect with Oxaliplatin.”

Canonical DDR activation by EMT inducing agent 5-Fluorouracil is modulated by a cannabinoid based combinatorial approach via inducing autophagy and suppression of vimentin expression

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“Anastasis cascade including induction of Epithelial to Mesenchymal Transition (EMT), DNA repair, and stimulation of pro-survival mediators collectively exaggerate therapy resistance in cancer prognosis. The extensive implications of DNA-damaging agents are clinically proven futile for the rapid development of disease recurrence during treatment regime.

Herein we report a glycosidic derivative of Δ9-tetrahydrocannabinol (THC-9-OG) abrogates sub-toxic doses of 5-Fluorouracil (5FU) induced EMT in colon cancer cells nullifying DNA repairing mechanism. Our in vitro and in vivo data strongly proclaims that THC-9-OG could not only abrogated 5FU mediated background EMT activation through stalling matrix degradation as well as murine 4T1 lung metastasis but also strongly diminished Rad-51 repairing mediator along with stimulation of γ-H2AX foci formation.

The combinatorial treatment (5FU + THC-9-OG) in Apc knockout colorectal carcinoma model conferred remission of the crypt progenitor phenotype which was prominently identified in 5FU treatment. Mechanistically, we demonstrated that 5FU plus THC-9-OG significantly attenuated major EMT inducer Vimentin via extensive ROS generation along with autophagy induction via LC3B I-II conversion and p62 degradation in a p-ATM dependent manner. Additionally, Cannabinoid receptor CB1 was responsible for abrogation of Vimentin since we found increase in the expression of γH2AX and decrease in vimentin expression in CB1 agonist (ACEA) plus 5FU treated cells.

Nutshell, our results unveil a new direction of Cannabinoid based combinatorial approach to control background EMT along with robust enhancing of DNA damage potential of sub-toxic concentration of 5FU resulting immense inhibition of distant metastasis coupled with triggering cell death in vitro and in vivo.”

Cannabidiol activates MAPK pathway to induce apoptosis, paraptosis, and autophagy in colorectal cancer cells

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“Mitogen-activated protein kinase (MAPK) activation by natural compounds is known to be involved in the induction of apoptosis, paraptosis, and autophagy.

Cannabidiol (CBD), a bioactive compound found in Cannabis sativa, is endowed with many pharmacological activities. We investigated the cytotoxic effect of CBD in a panel of colorectal cancer (CRC) cells (HT-29, SW480, HCT-116, and HCT-15).

CBD induced significant cytotoxicity as evidenced by the results of MTT assay, live-dead assay, and flow cytometric analysis. Since CBD displayed cytotoxicity against CRC cells, we examined the effect of CBD on apoptosis, paraptosis, and autophagy. CBD decreased the expression of antiapoptotic proteins and increased the Annexin-V-positive as well as TUNEL-positive cells suggesting that CBD induces apoptosis. CBD increased the expression of ATF4 (activating transcription factor 4) and CHOP (CCAAT/enhancer-binding protein homologous protein), elevated endoplasmic reticulum stress, and enhanced reactive oxygen species levels indicating that CBD also promotes paraptosis. CBD also induced the expression of Atg7, phospho-Beclin-1, and LC3 suggesting that CBD also accelerates autophagy.

Since, the MAPK pathway is a common cascade that is involved in the regulation of apoptosis, paraptosis, and autophagy, we investigated the effect of CBD on the activation of JNK, p38, and ERK pathways. CBD activated all the forms of MAPK proteins and pharmacological inhibition of these proteins reverted the observed effects.

Our findings implied that CBD could induce CRC cell death by activating apoptosis, paraptosis, and autophagy through the activation of the MAPK pathway.”

Cannabinoids in Treating Chemotherapy-Induced Nausea and Vomiting, Cancer-Associated Pain, and Tumor Growth

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“Cannabis has been used as an herbal remedy for thousands of years, and recent research indicates promising new uses in medicine. So far, some studies have shown cannabinoids to be safe in helping mitigate some cancer-associated complications, including chemotherapy-induced nausea and vomiting, cancer-associated pain, and tumor growth.

Researchers have been particularly interested in the potential uses of cannabinoids in treating cancer due to their ability to regulate cancer-related cell cycle pathways, prompting many beneficial effects, such as tumor growth prevention, cell cycle obstruction, and cell death.

Cannabinoids have been found to affect tumors of the brain, prostate, colon and rectum, breast, uterus, cervix, thyroid, skin, pancreas, and lymph. However, the full potential of cannabinoids is yet to be understood.

This review discusses current knowledge on the promising applications of cannabinoids in treating three different side effects of cancer-chemotherapy-induced nausea and vomiting, cancer-associated pain, and tumor development.

The findings suggest that cannabinoids can be used to address some side effects of cancer and to limit the growth of tumors, though a lack of supporting clinical trials presents a challenge for use on actual patients. An additional challenge will be examining whether any of the over one hundred naturally occurring cannabinoids or dozens of synthetic compounds also exhibit useful clinical properties.

Currently, clinical trials are underway; however, no regulatory agencies have approved cannabinoid use for any cancer symptoms beyond antinausea.”

Metallothionein Family Proteins as Regulators of Zinc Ions Synergistically Enhance the Anticancer Effect of Cannabidiol in Human Colorectal Cancer Cells

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“Cannabidiol (CBD) is a chemical obtained from Cannabis sativa; it has therapeutic effects on anxiety and cognition and anti-inflammatory properties. Although pharmacological applications of CBD in many types of tumors have recently been reported, the mechanism of action of CBD is not yet fully understood. In this study, we perform an mRNA-seq analysis to identify the target genes of CBD after determining the cytotoxic concentrations of CBD using an MTT assay. CBD treatment regulated the expression of genes related to DNA repair and cell division, with metallothionein (MT) family genes being identified as having highly increased expression levels induced by CBD. It was also found that the expression levels of MT family genes were decreased in colorectal cancer tissues compared to those in normal tissues, indicating that the downregulation of MT family genes might be highly associated with colorectal tumor progression. A qPCR experiment revealed that the expression levels of MT family genes were increased by CBD. Moreover, MT family genes were regulated by CBD or crude extract but not by other cannabinoids, suggesting that the expression of MT family genes was specifically induced by CBD. A synergistic effect between CBD and MT gene transfection or zinc ion treatment was found. In conclusion, MT family genes as novel target genes could synergistically increase the anticancer activity of CBD by regulating the zinc ions in human colorectal cancer cells.”

“In conclusion, CBD requires the expression of MT family genes for its anticancer activity during cancer treatment, suggesting that CBD can affect the expression of genes involved in zinc homeostasis via MT family gene expression. These current results suggest that the regulation of zinc levels could play an important role in allowing CBD to exert enhanced anticancer effects. Although CBD treatment has shown anticancer effects on many types of cancers, its molecular mechanism remains unclear. In this study, we explained the possible interactions of MT genes, metal ions, and CBD for anticancer effects. The results of this study might provide an important clue for uncovering the mechanisms involved in the anticancer effects of CBD, such as through the regulation of intracellular homeostasis of metal ions.”

Cell death induction and intracellular vesicle formation in human colorectal cancer cells treated with Δ9-Tetrahydrocannabinol

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“Background: Δ9-Tetrahydrocannabinol (Δ9-THC) is a principal psychoactive extract of Cannabis sativa and has been traditionally used as palliative medicine for neuropathic pain. Cannabidiol (CBD), an extract of hemp species, has recently attracted increased attention as a cancer treatment, but Δ9-THC is also requiring explored pharmacological application.

Objective: This study evaluated the pharmacological effects of Δ9-THC in two human colorectal cancer cell lines. We investigated whether Δ9-THC treatment induces cell death in human colorectal cancer cells.

Methods: We performed an MTT assay to determine the pharmacological concentration of Δ9-THC. Annxein V and Western blot analysis confirmed that Δ9-THC induced apoptosis in colorectal cancer cells. Metabolic activity was evaluated using MitoTracker staining and ATP determination. We investigated vesicle formation by Δ9-THC treatment using GW9662, known as a PPARγ inhibitor.

Results: The MTT assay showed that treatment with 40 μM Δ9-THC and above inhibited the proliferation of colorectal cancer cells. Multiple intracytoplasmic vesicles were detected upon microscopic observation, and fluorescence-activated cell sorting analysis showed cell death via G1 arrest. Δ9-THC treatment increased the expression of cell death marker proteins, including p53, cleaved PARP-1, RIP1, and RIP3, suggesting that Δ9-THC induced the death of colorectal cancer cells. Δ9-THC treatment also reduced ATP production via changes in Bax and Bcl-2. Δ9-THC regulated intracytoplasmic vesicle formation by modulating the expression of PPARγ and clathrin, adding that antiproliferative activity of Δ9-THC was also affected.

Conclusion: In conclusion, Δ9-THC regulated two functional mechanisms, intracellular vesicle formation and cell death. These findings can help to determine how cannabinoids can be used most effectively to improve the efficacy of cancer treatment.”