Role of natural compounds in preventing and treating breast cancer

Natural compounds targeting YAP/TAZ axis in cancer: Current state of art and challenges

Cancer has become a burgeoning global healthcare concern marked by its exponential growth and significant economic ramifications. Though advancements in the treatment modalities have increased the overall survival and quality of life, there are no definite treatments for the advanced stages of this malady. Hence, understanding the diseases etiologies and the underlying molecular complexities, will usher in the development of innovative therapeutics. Recently, YAP/TAZ transcriptional regulation has been of immense interest due to their role in development, tissue homeostasis and oncogenic transformations. YAP/TAZ axis functions as coactivators within the Hippo signaling cascade, exerting pivotal influence on processes such as proliferation, regeneration, development, and tissue renewal. In cancer, YAP is overexpressed in multiple tumor types and is associated with cancer stem cell attributes, chemoresistance, and metastasis. Activation of YAP/TAZ mirrors the cellular "social" behavior, encompassing factors such as cell adhesion and the mechanical signals transmitted to the cell from tissue structure and the surrounding extracellular matrix. Therefore, it presents a significant vulnerability in the clogs of tumors that could provide a wide window of therapeutic effectiveness. Natural compounds have been utilized extensively as successful interventions in the management of diverse chronic illnesses, including cancer. Owing to their capacity to influence multiple genes and pathways, natural compounds exhibit significant potential either as adjuvant therapy or in combination with conventional treatment options. In this review, we delineate the signaling nexus of YAP/TAZ axis, and present natural compounds as an alternate strategy to target cancer.

Role of beta-(1→3)(1→6)-D-glucan derived from yeast on natural killer (NK) cells and breast cancer cell lines in 2D and 3D cultures

BACKGROUND

Beta-(1,3)(1,6)-D-glucan is a complex polysaccharide, which is found in the cell wall of various fungi, yeasts, bacteria, algae, barley, and oats and has immunomodulatory, anticancer and antiviral effects. In the present study, we investigated the effect of beta-(1,3)(1,6)-D-glucan derived from yeast on the proliferation of primary NK cells and breast cancer cell lines in 2D and 3D models, and on the cytotoxicity of primary NK cells against breast cancer cell lines in 2D and 3D models.

METHODS

In this study, we investigated the effects of different concentrations of yeast-derived beta-(1→3)(1→6)-D-glucan on the proliferation and cytotoxicity of human NK cells and breast cancer cell lines in 2D and 3D models using the XTT cell proliferation assay and the CellTiter-Glo® 2.0 assay to determine the cytotoxicity of human NK cells on breast cancer cell lines in 2D and 3D models.

RESULTS

We found that the co-incubation of NK cells with beta-glucan in the absence of IL2 at 48 h significantly increased the proliferation of NK cells, whereas the co-incubation of NK cells with beta-glucan in the presence of IL2 (70 U/ml) increased the proliferation of NK cells but not significantly. Moreover, beta-glucan significantly inhibited the proliferation of breast cancer cell lines in 2D model and induced a weak, non-significant growth inhibitory effect on breast cancer multicellular tumor spheroids (3D). In addition, the cytotoxicity of NK cells against breast cancer cell lines was examined in 2D and 3D models, and beta-glucan significantly increased the cytotoxicity of NK cells against MCF-7 (in 2D).

CONCLUSIONS

Yeast derived beta-(1,3)(1,6)-D-glucan could contribute to the treatment of cancer by enhancing NK cell immune response as well as contributing to inhibition of breast cancer cell growth.

Potential anticancer effect of free and nanoformulated Deferasirox for breast cancer treatment: in-vitro and in-vivo evaluation

BACKGROUND

Breast cancer (BC) stands as the second-leading cause of mortality among women worldwide. Many chemotherapeutic treatments for BC come with significant adverse effects. Additionally, BC is recognized as one of the most resistant forms of malignancy to treatment. Consequently, there exists a critical need for innovative therapeutic agents that are both highly effective and exhibit reduced toxicity and side effects for patients. Deferasirox (DFX), an iron-chelating drug approved by the FDA for oral use, emerges as a promising contender in the fight against BC proliferation. DFX, primarily administered orally, is utilized to address chronic iron excess resulting from blood transfusions, and it is the inaugural treatment for chronic iron overload syndrome. However, DFX encounters limitations due to its poor water solubility.

AIM

This study aimed at incorporating DFX into lipid nanocapsules (DFX-LNCs) followed by investigating the anticancer effect of the DFX nanoform as compared to free DFX in-vitro and on an orthotopic BC mouse model in-vivo.

METHODS

The DFX-LNCs was prepared and imaged using TEM and also characterized in terms of particle size (PS), zeta potential (ZP), and polydispersity index (PDI) using DLS. Moreover, drug release, cytotoxicity, and anticancer effect were assessed in-vitro, and in-vivo.

RESULTS

The results revealed that DFX-LNCs are more cytotoxic than free DFX with IC50 of 4.417 µg/ml and 16.114 µg/ml, respectively, while the plain LNCs didn't show any cytotoxic effect on the 4T1 cell line (IC50 = 122.797 µg/ml). Besides, the apoptotic effect of DFX-LNCs was more pronounced than that of free DFX, as evidenced by Annexin V/PI staining, increased BAX expression, and decreased expression of BcL-2. Moreover, DFX-LNCs showed a superior antitumor effect in-vivo with potent antioxidant and anti-proliferative effects.

CONCLUSION

The newly developed DFX nanoform demonstrated a high potential as a promising therapeutic agent for BC treatment.

Deguelin inhibits the proliferation of human multiple myeloma cells by inducing apoptosis and G2/M cell cycle arrest: Involvement of Akt and p38 MAPK signalling pathway

Deguelin exhibits antiproliferative activity against various cancer cell types. Previous studies have reported that deguelin exhibits pro-apoptotic activity against human cancer cells. The current study aimed at further elaborating the anticancer effects of deguelin against multiple myeloma cells. Cell growth estimations were made through MTT assay. Phase contrast microscopy was used for the analysis of the viability of multiple myeloma cells. Colony formation from multiple myeloma cells was studied using a clonogenic assay. Antioxidative assays for determining levels of glutathione (GSH) and superoxide dismutase (SOD) were carried out after treating multiple myeloma cells with deguelin. The apoptosis of multiple myeloma cells was studied using AO/EB and Annexin V-FITC/PI staining methods. Multiple myeloma cell cycle analysis was performed through flow cytometry. mRNA expression levels were depicted using qRT-PCR. Migration and invasion of multiple myeloma cells were determined with the wound-healing and transwell assays, respectively. Deguelin specifically inhibited the multiple myeloma cell growth while the normal plasma cells were minimally affected. Multiple myeloma cells when treated with deguelin exhibited remarkably lower viability and colony-forming ability. Multiple myeloma cells treated with deguelin produced more SOD and had higher GSH levels. The multiple myeloma cell growth, migration, and invasion were significantly declined by in vitro administration of deguelin. In conclusion, deguelin treatment, when applied in vitro, induced apoptotic cell death and resulted in mitotic cessation at the G2/M phase through modulation of cell cycle regulatory mRNAs in multiple myeloma cells.

Stachydrine represses the proliferation and enhances cell cycle arrest and apoptosis of breast cancer cells via PLA2G2A/DCN axis

Considering the therapeutic efficacy of Stachydrine on breast cancer (BC), this study aims to decipher the relevant mechanism. The effects of Stachydrine on BC cell viability, proliferation and apoptosis were firstly investigated. Then, Bioinformatics was applied to sort out the candidate interacting with Stachydrine as well as its expression and downstream target in BC. Relative expressions of genes of interest as well as proliferation- and apoptosis-related factors in BC cells were quantified through quantitative reverse-transcription PCR and western blot as appropriate. As a result, Stachydrine inhibited the proliferation, down-regulated the expressions of proliferating cell nuclear antigen and CyclinD1, enhanced cell cycle arrest and apoptosis, and up-regulated the levels of Cleaved caspase-3 and Cleaved caspase-9 in BC cells. Phospholipase A2 Group IIA (PLA2G2A) was predicted as the candidate interacting with Stachydrine and to be lowly expressed in BC. PLA2G2A silencing reversed while PLA2G2A overexpression reinforced the effects of Stachydrine. Decorin (DCN) was the downstream target of PLA2G2A and also lowly expressed in BC. PLA2G2A silencing counteracted yet overexpressed PLA2G2A strengthened the promoting effects of Stachydrine on DCN level. Collectively, Stachydrine inhibits the growth of BC cells to promote cell cycle arrest and apoptosis via PLA2G2A/DCN axis.

Antiproliferative activity and apoptosis‑inducing effects of Trametes polyzona polysaccharides against human breast cancer cells

Fungal polysaccharides have garnered interest due to their biological activities in terms of anticancer properties and antioxidant activity. The present study aimed to evaluate the anticancer properties and antioxidant activity of a newly isolated white-rot fungus, Trametes polyzona CU07 from Thailand. Crude T. polyzona polysaccharides (CTPPs) were extracted from mycelia using hot water. The chemical properties, including total carbohydrates, molecular weight and protein content, and Fourier-transform infrared spectroscopy analysis, were then investigated. The antioxidant activity was determined against the radicals 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The anticancer properties were evaluated in MCF-7 breast cancer (BC) cells, whereas the 293 cell line was used as a control. The inhibitory effects of CTPPs on viability were determined by MTT assay, followed by BrdU incorporation assay to assess cell proliferation. The induction of apoptosis was determined by flow cytometry. CTPPs were considered polysaccharide-protein conjugates, which had molecular weights in the range of 0.3-22,528 kDa. They contained ~50 and 37% carbohydrate and protein, respectively, with glucose as the main monosaccharide component. Notably, CTPPs had high antioxidant activity against ABTS, and had a significant inhibitory effect on the MCF-7 cell line with a half-maximal inhibitory concentration value of 0.58 mg/ml. However, they exhibited little effect on the 293 cell line. The BrdU incorporation assay demonstrated that CTPPs inhibited proliferation by ~20% compared with that in untreated cells. CTPPs also induced early- and late-stage apoptosis of MCF-7 cells. These results indicated that the CTPPs may exhibit potential antiproliferative and antioxidant activity, and apoptosis-inducing effects against human BC cells.

Myricetin 3-rhamnoside retards the proliferation of hormone-independent breast cancer cells by targeting hyaluronidase

Breast cancer is the second-leading cause of cancer-related death in women and the most often diagnosed malignancy. As the majority of chemotherapeutic medications are associated with recurrence, drug resistance, and side effects, scientists are shifting to beneficial agents for prevention and treatment, such as natural molecules. Myricetin 3-rhamnoside, a natural flavonol glycoside is known for diverse pharmacological activities but fewer reports describe the antiproliferative ability. The study aims to investigate the antiproliferative efficacy and target [hyaluronidase (HYAL) and ornithine decarboxylase (ODC), two poor breast cancer prognostic markers] modulatory potential of myricetin 3-rhamnoside on breast cancer cell lines using cytotoxicity assays and in silico docking, molecular dynamics analysis, cell-free and cell-based test methods. Myricetin 3-rhamnoside significantly retard the growth of MDA-MB-231 cells in SRB (IC50 88.64 ± 7.14 µM) and MTT (56.26 ± 8.50 µM) assay. It suppressed the transition of cells to the S-phase by inducing arrest in the G0/G1 phase with a fold change of 1.10. It shows robust binding interaction with ODC (-7.90 kcal/mol) and HYAL (-9.46 kcal/mol) and inhibits ODC (15.22 ± 2.61 µM) and HYAL (11.92 ± 2.89 µM) activity, but in a cell-based assay, the prominent response was observed against HYAL (21.46 ± 4.03 µM). Besides, it shows a 1.38 fold-down regulation of HYAL and forms a stable complex with HYAL. The binding pocket for myricetin 3-rhamnoside and the simulation pocket during the simulation are identical, indicating that myricetin 3-rhamnoside is actively blocking hyaluronidase. The computational prediction suggests it is a safe molecule. These observations imply that myricetin 3-rhamnoside could be used as a pharmacophore to design and synthesize a novel and safe agent for managing hormone-independent breast cancer.Communicated by Ramaswamy H. Sarma.

Betulinic acid in the treatment of breast cancer: Application and mechanism progress

Betulinic acid (BA) is a pentacyclic triterpene compound, which can be obtained by separation, chemical synthesis and biotransformation. BA has excellent biological activities, especially its role in the treatment of breast cancer deserves attention. Its mechanisms mainly include inducing mitochondrial oxidative stress, regulating specific protein (Sp) transcription factors, inhibiting breast cancer metastasis, inhibiting glucose metabolism and NF-κB pathway. In addition, BA can also increase the sensitivity of breast cancer cells to other chemotherapy drugs such as paclitaxel and reduce its toxic side effects. This article reviews the application and possible mechanism of BA in the treatment of breast cancer.

Updates on the anticancer potential of garlic organosulfur compounds and their nanoformulations: Plant therapeutics in cancer management

Garlic (Allium sativum L.) possesses numerous pharmacological potential, including antibacterial, antiarthritic, antithrombotic, anticancer, hypoglycemic, and hypolipidemic effects. The anti-cancer action of garlic is likely the best researched of the many advantageous pharmacological effects, and its use offers significant protection against the risk of developing cancer. A few active metabolites of garlic have been reported to be essential in the destruction of malignant cells due to their multi-targeted activities and lack of significant toxicity. The bioactive compounds in garlic having anticancer properties include diallyl trisulfide, allicin, allyl mercaptan diallyl disulfide, and diallyl sulphide. Different garlic-derived constituents and their nanoformulations have been tested for their effects against various cancers including skin, ovarian, prostate, gastric, breast, and lung, colorectal, liver, oral, and pancreatic cancer. The objective of this review is to summarize the antitumor activity and associated mechanisms of the organosulfur compounds of garlic in breast carcinoma. Breast cancer continues to have a significant impact on the total number of cancer deaths worldwide. Global measures are required to reduce its growing burden, particularly in developing nations where incidence is increasing quickly and fatality rates are still high. It has been demonstrated that garlic extract, its bioactive compounds, and their use in nanoformulations can prevent breast cancer in all of its stages, including initiation, promotion, and progression. Additionally, these bioactive compounds affect cell signaling for cell cycle arrest and survival along with lipid peroxidation, nitric oxide synthase activity, epidermal growth factor receptor, nuclear factor kappa B (NF-κB), and protein kinase C in breast carcinoma. Hence, this review deciphers the anticancer potential of garlic components and its nanoformulations against several breast cancer thereby projecting it as a potent drug candidate for efficient breast cancer management.

Targeted Therapy and Mechanisms of Drug Resistance in Breast Cancer

Breast cancer is the most common cause of cancer-related death in women worldwide. Multidrug resistance (MDR) has been a large hurdle in reducing BC death rates. The drug resistance mechanisms include increased drug efflux, enhanced DNA repair, senescence escape, epigenetic alterations, tumor heterogeneity, tumor microenvironment (TME), and the epithelial-to-mesenchymal transition (EMT), which make it challenging to overcome. This review aims to explain the mechanisms of resistance in BC further, identify viable drug targets, and elucidate how those targets relate to the progression of BC and drug resistance.

Frankincense oil-loaded nanoemulsion formulation of paclitaxel and erucin: A synergistic combination for ameliorating drug resistance in breast cancer: In vitro and in vivo study

Nanoformulation-based combinational drug delivery systems are well known to overcome drug resistance in cancer management. Among them, nanoemulsions are well-known and thermodynamically stable drug delivery systems suitable for carrying hydrophobic drugs and phytoconstituents to tackle drug-resistant cancers. In the present study, we have investigated the effect of paclitaxel in combination with erucin (natural isothiocyanate isolated from the seeds of Eruca sativa) loaded in the frankincense oil-based nanoemulsion formulation. The choice of frankincense oil for the current study was based on reported research investigations stating its magnificient therapeutic potential against breast cancer. Optimized nanoemulsion of paclitaxel (PTX) and erucin (ER) combination (EPNE) provided sustained release and exhibited enhanced cytotoxicity towards human epithelial breast cancer cells (T-47D) as compared to individual ER and PTX. EPNE was further assessed for its antitumor activity in the 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast cancer mice model. EPNE significantly decreased the levels of hepatic and renal parameters along with oxidative stress in breast cancer mice. Furthermore, EPNE also showed decreased levels of inflammatory cytokines TNF-α, IL-6. Histopathological examinations revealed restoration of the tumorous breast to normal tissues in EPNE-treated breast cancer mice. Therefore, EPNE can act as a viable lead and therapeutic option for drug-resistant breast cancer.

Natural compounds may contribute in preventing SARS-CoV-2 infection: a narrative review

Coronavirus pandemic infection is the most important health issue worldwide. Coronavirus disease 2019 is a contagious disease characterized by severe acute respiratory syndrome coronavirus 2. To date, excluding the possibility of vaccination, against SARS-CoV-2 infection it is possible to act only with supportive care and non-virus-specific treatments in order to improve the patient's symptoms. Pharmaceutical industry is investigating effects of medicinal plants, phytochemical extracts and aromatic herbs to find out natural substances which may act as antiviral drugs. Several studies have revealed how these substances may interfere with the viral life cycle, viral entry, replication, assembly or discharge, as well as virus-specific host targets or stimulating the host immune system, reducing oxidative stress and inflammatory response. A natural compound can be used as a prophylaxis by people professionally exposed to the risk of contagion and/or positive patients not in intensive care. The aim of this paper is to perform a narrative review of current literature in order to summarize the most studied natural compounds and their modes of action.

Anticancer effects of carboxymethylated (1→3)(1→6)-β-D-glucan (botryosphaeran) on multicellular tumor spheroids of MCF-7 cells as a model of breast cancer

Breast cancer is the most common cancer worldwide among the female population. The fungal exopolysaccharide botryosphaeran is a (1→3)(1→6)-β-D-glucan with limited solubility in water that can be promoted through carboxymethylation. Thus, the aim of this study was to examine in-vitro anticancer effects of carboxymethylated-botryosphaeran (CM-BOT) on breast cancer MCF-7 cells cultivated in multicellular tumor spheroids (MCTS). CM-BOT (≥ 600 µ/ml) decreased the viability (resazurin assay) of MCF-7 grown in monolayers after 24 hr incubation. Although CM-BOT did not markedly alter viability of MCTS in the resazurin assay after 24, 48 or 72 hr, CM-BOT ≥ 600 µg/ml produced cell-death by apoptosis after 72 hr utilizing the triple staining assay and labeling dead cells with propidium iodide, which can also be visualized on the architecture of MCTS. CM-BOT (1000 µg/ml) inhibited cell proliferation, which resulted in MCTSs with smaller diameters than controls. CM-BOT at all concentrations examined decreased the ability of MCF-7 to form colonies and to migrate in the extracellular matrix. This is the first report using MCTS-architecture to study anti-tumor effects of β-glucans. Our findings are important in the search for compounds for use in breast cancer therapy, or as adjuvants in reducing the adverse effects of mammary tumor chemotherapy.

Natural products modulating interleukins and other inflammatory mediators in tumor-bearing animals: A systematic review

BACKGROUND

Cancer is a group of diseases characterized by abnormal cell growth and proliferation. Natural products are a potentially important source for bioactive phytochemicals in the management of cancer, which regulate a broad range of biological events via the modulation of interleukins (ILs), pro- and anti-inflammatory modulators, and other cancer hallmark-mediated signaling pathways.

PURPOSE

To systematically review the literature to identify in vivo studies investigating the anticancer properties of medicinal plants and natural molecules as modulators of ILs and their related pro- and anti-inflammatory signaling markers in tumor-bearing animals.

METHODS

Articles published in English were searched, without any constraint in respect of countries. The electronic databases PubMed, Embase, Scopus, and Web of Science were used for the literature search for studies published between January 2010 and January 2022. The search terms used included medicinal plants, anticancer, antineoplasic agent, ILs, cytokine, and their combinations. A manual search to detect any articles not found in the databases was also made. The identified studies were then critically reviewed and relevant data were extracted and summarized.

RESULTS

Natural products were found to modulate ILs, including IL-1β, IL-2, IL-4, IL-6, IL-8, IL-18, IL-23, and IL-12, and interferon gamma; increase tissue inhibitor metalloprotease; decrease vascular endothelial growth factor, tumor necrosis factor alpha, granulocyte macrophage colony-stimulating factor, and nuclear factor kappa B; augment immunity by increasing the major histocompatibility complexes II and CD4+, cluster of differentiation 8 + T cell and class II trans-activator expression; and heighten the action of antioxidant enzymes, which are involved in the detoxification of free radicals and reactive oxygen species.

CONCLUSION

Natural products discussed in this review show great potential to regulate ILs and weaken associated pro- and anti-inflammatory signaling markers in tumor-bearing animals. Flavonoids, polyphenols, polysaccharides, alkaloids and tannins are important phytochemicals in the modulation of ILs, especially pro-inflammatory ones. However, in terms of future research, the importance of clinical trials to investigate their beneficial properties should be warranted.

A Review of Twenty Years of Research on the Regulation of Signaling Pathways by Natural Products in Breast Cancer

Breast cancer (BC) is the second leading cause of death among women, and it has become a global health issue due to the increasing number of cases. Different treatment options, including radiotherapy, surgery, chemotherapy and anti-estrogen therapy, aromatase inhibitors, anti-angiogenesis drugs, and anthracyclines, are available for BC treatment. However, due to its high occurrence and disease progression, effective therapeutic options for metastatic BC are still lacking. Considering this scenario, there is an urgent need for an effective therapeutic strategy to meet the current challenges of BC. Natural products have been screened as anticancer agents as they are cost-effective, possess low toxicity and fewer side effects, and are considered alternative therapeutic options for BC therapy. Natural products showed anticancer activities against BC through the inhibition of angiogenesis, cell migrations, proliferations, and tumor growth; cell cycle arrest by inducing apoptosis and cell death, the downstream regulation of signaling pathways (such as Notch, NF-κB, PI3K/Akt/mTOR, MAPK/ERK, and NFAT-MDM2), and the regulation of EMT processes. Natural products also acted synergistically to overcome the drug resistance issue, thus improving their efficacy as an emerging therapeutic option for BC therapy. This review focused on the emerging roles of novel natural products and derived bioactive compounds as therapeutic agents against BC. The present review also discussed the mechanism of action through signaling pathways and the synergistic approach of natural compounds to improve their efficacy. We discussed the recent in vivo and in vitro studies for exploring the overexpression of oncogenes in the case of BC and the current status of newly discovered natural products in clinical investigations.

Natural Small Molecules in Breast Cancer Treatment: Understandings from a Therapeutic Viewpoint

Breast cancer (BrCa) is the most common malignancy in women and the second most significant cause of death from cancer. BrCa is one of the most challenging malignancies to treat, and it accounts for a large percentage of cancer-related deaths. The number of cases requiring more effective BrCa therapy has increased dramatically. Scientists are looking for more productive agents, such as organic combinations, for BrCa prevention and treatment because most chemotherapeutic agents are linked to cancer metastasis, the resistance of the drugs, and side effects. Natural compounds produced by living organisms promote apoptosis and inhibit metastasis, slowing the spread of cancer. As a result, these compounds may delay the spread of BrCa, enhancing survival rates and reducing the number of deaths caused by BrCa. Several natural compounds inhibit BrCa production while lowering cancer cell proliferation and triggering cell death. Natural compounds, in addition to therapeutic approaches, are efficient and potential agents for treating BrCa. This review highlights the natural compounds demonstrated in various studies to have anticancer properties in BrCa cells. Future research into biological anti-BrCa agents may pave the way for a new era in BrCa treatment, with natural anti-BrCa drugs playing a key role in improving BrCa patient survival rates.

Novel possibility for cutaneous melanoma treatment by means of rosmarinic acid action on purinergic signaling

Cancer cases have increased significantly in Brazil and worldwide, with cutaneous melanoma (CM) being responsible for nearly 57,000 deaths in the world. Thus, this review article aims at exploring and proposed hypotheses with respect to the possibility that RA can be a promising and alternative compound to be used as an adjuvant in melanoma treatment, acting on purinergic signaling. The scarcity of articles evidencing the action of this compound in this signaling pathway requires further studies. Considering diverse evidence found in the literature, we hypothesize that RA can be an effective candidate for the treatment of CM acting as a modulating molecule of purinergic cellular pathway through P2X7 blocking, mitigating the Warburg effect, and as antagonic molecule of the P2Y12 receptor, reducing the formation of adhesive molecules that prevent adherence in tumor cells. In this way, our proposals for CM treatment based on targeting purinergic signaling permeate the integral practice, going from intracell to extracell. Undoubtedly, much is still to be discovered and elucidated about this promising compound, this paper being an interesting work baseline to support more research studies.

Gamma-tocotrienol Synergistically Promotes the Anti-proliferative and Pro-apoptotic Effects of Etoposide on Breast Cancer Cell Lines

BACKGROUND

Breast Cancer is one of the most commonly diagnosed cancers worldwide and a major cause of death among women. Although chemotherapeutic agents remain the keystones in cancer therapy, significant side effects have failed to provide a safe and tolerable treatment for cancer patients. Dietary antioxidant vitamins were extensively investigated over the past years and their relevance in cancer chemotherapy remains to be elucidated.

OBJECTIVE

In the current study, we aimed to investigate the anti-proliferative and apoptotic effects of combining γ-tocotrienol, a member of the vitamin E family, with the chemotherapeutic drug etoposide in MCF-7 and MDA-MB-231 breast cancer cell lines.

METHODS

The antiproliferative effect of etoposide combined with γ-tocotrienol was measured using MTS viability reagent. The pro-apoptotic effect was elucidated through Cell Death ELISA and dual Annexin V/PI staining followed by flow cytometric analysis.

RESULTS

Our results showed that etoposide significantly decreased the cell growth of both cell lines with MDA-MB-231 cells being more sensitive to etoposide treatment than MCF-7. Moreover, the simultaneous treatment of both breast cancer cell lines with low doses of γ-tocotrienol and etoposide induced a synergistic antiproliferative effect (CI<1). Furthermore, the combination therapy significantly increased the percentage of total apoptotic cells in the MDA-MB-231 cell line and the degree of DNA fragmentation as compared to treatment with either compound alone.

CONCLUSION

In conclusion, our results provide evidence for the profound anti-tumorigenic effect of combined etoposide and γ-tocotrienol in the breast cancer cell lines.

The role of vulpinic acid as a natural compound in the regulation of breast cancer-associated miRNAs

Background

Breast cancer is the most frequently diagnosed cancer, and no effective treatment solution has yet been found. The number of studies based on the research of novel natural compounds in the treatment of breast cancer has been increasing in recent years. The anticancer properties of natural compounds are related to the regulation of microRNA (miRNA) expression. Therefore, changing the profile of miRNAs with the use of natural products is very important in cancer treatment. However, the role of vulpinic acid and related miRNAs in breast cancer progression remains unknown. Vulpinic acid, methyl (as2E)-2-(3-hydroxy-5-oxo-4-phenylfuran-2-ylidene)-2 phenylacetate, is a natural product extracted from the lichen species and shows an anticancer effect on different cancer cells.

Methods

This study examines the effects of vulpinic acid on the miRNA levels of breast cancer (MCF-7) cells and its relationship with cell proliferation and apoptosis levels. The antiproliferative effect of vulpinic acid was screened against MCF-7 breast cancer cells and MCF-12A breast epithelial cells using the xCELLigence real-time cell analysis system. We analyzed the altered miRNA expression profile in MCF-7 breast cancer cells versus MCF-12A cells following their response to vulpinic acid through microarray analysis. The microarray analysis results were confirmed through quantitative real-time PCR and bioinformatics analysis.

Results

The results of the miRNA array and bioinformatic analyses demonstrated that 12 miRNAs were specifically responsive to vulpinic acid in MCF-7 breast cancer cells. This is the first study to reveal that vulpinic acid inhibits the expression of 12 miRNAs and suppresses breast cancer cell proliferation. The study also revealed that vulpinic acid may downregulate the expression of 12 miRNAs by repressing the FOXO-3 gene. The miRNA targets were mainly found to play a role in the apoptosis, cell cycle and MAPK pathways. Moreover, Bcl-2, Bax, procaspase-3 and procaspase-9 protein levels were assessed by western blot analysis for validation of apoptosis at the protein level.

Conclusion

This study revealed the molecular mechanisms of vulpinic acid on breast cancer and showed that vulpinic acid regulates apoptosis signaling pathways by decreasing the expression of miRNAs. The miRNA expression patterns illuminate the underlying effect of vulpinic acid in breast cancer treatment.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40659-021-00360-4.

Nano-Based Drug Delivery and Targeting to Overcome Drug Resistance of Ovarian Cancers

Ovarian cancer (OvCa) is a destructive malignancy due to difficulties in early detection and late advanced-stage diagnoses, leading to high morbidity and mortality rates for women. Currently, the quality treatment for OvCa includes tumor debulking surgery and intravenous platinum-based chemotherapy. However, numerous patients either succumb to the disease or undergo relapse due to drug resistance, such as to platinum drugs. There are several mechanisms that cause cancer cells' resistance to chemotherapy, such as inactivation of the drug, alteration of the drug targets, enhancement of DNA repair of drug-induced damage, and multidrug resistance (MDR). Some targeted therapies, such as nanoparticles, and some non-targeted therapies, such as natural products, reverse MDR. Nanoparticle targeting can lead to the reversal of MDR by allowing direct access for agents to specific tumor sites. Natural products have many anti-cancer properties that adversely regulate the factors contributing to MDR. The present review displays the current problems in OvCa treatments that lead to resistance and proposes using nanotechnology and natural products to overcome drug resistance.

Tocotrienols as an Anti-Breast Cancer Agent

In the past few years, breast cancer has become the most prevalent type of cancer. The majority of patients receive combinatorial chemotherapy treatments, which may result in increased risk of developing drug resistance, a reduced quality of life, and substantial side effects. Treatment modalities that could lessen the physical toll of standard treatments or act in synergy with chemotherapeutic treatments would benefit women worldwide. Research into tocotrienols has thus far demonstrated their potential to be such an agent, with tocotrienols surpassing the pharmacological potential of tocopherols. Further research using in vitro and preclinical breast cancer models to support clinical trials is needed. This review uses bibliometric analysis to highlight this gap in research and summarizes the current and future landscape of tocotrienols as an anti-breast cancer agent.

Recent Findings on Thymoquinone and Its Applications as a Nanocarrier for the Treatment of Cancer and Rheumatoid Arthritis

Cancer causes a considerable amount of mortality in the world, while arthritis is an immunological dysregulation with multifactorial pathogenesis including genetic and environmental defects. Both conditions have inflammation as a part of their pathogenesis. Resistance to anticancer and disease-modifying antirheumatic drugs (DMARDs) happens frequently through the generation of energy-dependent transporters, which lead to the expulsion of cellular drug contents. Thymoquinone (TQ) is a bioactive molecule with anticancer as well as anti-inflammatory activities via the downregulation of several chemokines and cytokines. Nevertheless, the pharmacological importance and therapeutic feasibility of thymoquinone are underutilized due to intrinsic pharmacokinetics, including short half-life, inadequate biological stability, poor aqueous solubility, and low bioavailability. Owing to these pharmacokinetic limitations of TQ, nanoformulations have gained remarkable attention in recent years. Therefore, this compilation intends to critically analyze recent advancements in rheumatoid arthritis and cancer delivery of TQ. This literature search revealed that nanocarriers exhibit potential results in achieving targetability, maximizing drug internalization, as well as enhancing the anti-inflammatory and anticancer efficacy of TQ. Additionally, TQ-NPs (thymoquinone nanoparticles) as a therapeutic payload modulated autophagy as well as enhanced the potential of other drugs when given in combination. Moreover, nanoformulations improved pharmacokinetics, drug deposition, using EPR (enhanced permeability and retention) and receptor-mediated delivery, and enhanced anti-inflammatory and anticancer properties. TQ's potential to reduce metal toxicity, its clinical trials and patents have also been discussed.

Selective Targeting of the Hedgehog Signaling Pathway by PBM Nanoparticles in Docetaxel-Resistant Prostate Cancer

An abnormality in hedgehog (Hh) signaling has been implicated in the progression of prostate cancer (PCa) to a more aggressive and therapy-resistant disease. Our assessments of human PCa tissues have shown an overexpression of the Hh pathway molecules, glioma-associated oncogene homolog 1 (GLI-1), and sonic hedgehog (SHH). The effect of the natural compound thymoquinone (TQ) in controlling the expression of Hh signaling molecules in PCa was investigated in this study. We generated planetary ball-milled nanoparticles (PBM-NPs) made with a natural polysaccharide, containing TQ, and coated with an RNA aptamer, A10, which binds to prostate-specific membrane antigen (PSMA). We prepared docetaxel-resistant C4-2B-R and LNCaP-R cells with a high expression of Hh, showing the integration of drug resistance and Hh signaling. Compared to free TQ, A10-TQ-PBM-NPs were more effective in controlling the Hh pathway. Our findings reveal an effective treatment strategy to inhibit the Hh signaling pathway, thereby suppressing PCa progression.

Anti-proliferative activities of Byrsocarpus coccineus Schum. and Thonn. (Connaraceae) using ovarian cancer cell lines

Background

Ovarian cancer (OvCa) is one of the most lethal tumors of gynecologic malignancies, due to lack of early detection, and a high rate of metastasis. The standard treatment for OvCa is surgery and cytotoxic chemotherapy. However, to overcome the high cost and side effects of these treatments, medicinal plants are widely used in developing countries to treat OvCa. Byrsocarpus coccineus plant preparation has been administered to patients traditionally in the management of tumors in Nigeria. In this study, we investigated the anti-proliferative effects of B. coccineus ethanol leaf extract against OVCAR-3 and SW 626 OvCa cell lines. After the treatment of the two cell lines with the extracts, analyses were carried out to determine inhibition of proliferation and expression of cell cycle markers, pro-apoptotic, and anti-apoptotic markers.

Results

Results showed that B. coccineus ethanol leaf extract, significantly inhibited cell migration and colony formation in OVCAR-3 and SW 626 treated cells in a dose-dependent manner. Results also show that B. coccineus ethanol leaf extract modulated the expression of tumor suppressor gene (p53), cell cycle progression, pro- and anti-apoptotic gene, and the pro-inflammatory cytokines.

Conclusions

These results suggest that B. coccineus have anti-proliferative properties and could induce apoptosis. Further investigation will be carried out to isolate bioactive compounds for the treatment of ovarian cancer.