Quercetin regulates β-catenin signaling and reduces the migration of triple negative breast cancer

Phytochemical insights into flavonoids in cancer: Mechanisms, therapeutic potential, and the case of quercetin

Quercetin, a flavonoid known for its potent antioxidant and anti-inflammatory properties, has gained attention in cancer therapy due to its ability to modulate key molecular pathways involved in tumor progression and immune evasion. This review provides a comprehensive analysis of quercetin's effects on pathways such as PI3K/Akt/mTOR, MAPK/ERK, NF-κB, and JAK/STAT, which are central to cancer cell survival, proliferation, and apoptosis. Through inhibition of PI3K/Akt/mTOR and MAPK/ERK signaling, quercetin promotes apoptosis and reduces proliferation specifically in cancer cells while sparing healthy cells. Additionally, quercetin downregulates NF-κB activity and modulates JAK/STAT signaling, enhancing immune recognition of cancer cells and decreasing inflammation in the tumor microenvironment. Emerging nanoformulation strategies are also discussed, highlighting how nanotechnology can improve quercetin's bioavailability and targeting capabilities. Unlike other reviews, this work uniquely integrates molecular insights with cutting-edge nanoformulations, showcasing quercetin's dual potential as a therapeutic agent and an immune modulator in the evolving landscape of cancer treatment. This review underscores quercetin's multifaceted role in cancer treatment and suggests future directions to optimize its clinical efficacy, particularly in combination with conventional therapies.

Modulation of Wnt/Beta-Catenin Pathway by Major Dietary Phytochemicals Against Breast Cancer Development

Breast cancer is one of the most commonly diagnosed cancers and is the second leading cause of cancer-related deaths among women in the United States. Despite a decrease in mortality associated with breast cancer, there has been a steady increase in its incidence. Development of the mammary gland is normally regulated by such pathways including Wnt, Hedgehog, estrogen and Notch signaling. However, the deregulation of these pathways gives rise to tumor development, and upregulated Wnt activity along with high levels of beta-catenin is correlated with poor prognosis of breast cancer. In addition, beta-catenin-dependent Wnt signaling is enriched in triple-negative breast cancers and is associated with reduced overall survival in breast cancer patients. Various studies have investigated the ability of naturally occurring plant-based agents to reduce incidence and morbidity of breast cancer by regulating critical cell survival pathways to reverse or inhibit the occurrence of clinical disease. The present review focuses on summarizing the role of commonly consumed dietary phytochemicals and their role in regulating Wnt/β-catenin pathway against the development of breast cancer.

Unveiling the Mechanisms and Therapeutic Effects of Xiaoyao Sanjie Decoction in Triple-Negative Breast Cancer: A Network Pharmacology and Experimental Validation Approach

Purpose

Triple-negative breast cancer (TNBC) is a disease associated with high incidence and high mortality, which is a major problem threatening women's health. Xiaoyao Sanjie Decoction (XYSJD) exhibits remarkable therapeutic efficacy on TNBC; however, the underlying mechanism is unclear. This study verified the efficacy of XYSJD and its active component in the treatment of TNBC and explored its potential mechanism.

Methods

Ultra-high performance liquid chromatography-hybrid quadrupole orbitrap mass spectrometry (UHPLC-Q Exactive HFX-MS) was applied to explore the main chemical constituents of XYSJD. The key targets and potential mechanisms of XYSJD in the treatment of TNBC were predicted through network pharmacology, bioinformatics analysis and molecular docking. The effects of XYSJD against TNBC cells were evaluated by CCK-8 assay, EdU assay, wound healing assay, transwell assay, Hoechst-PI staining and flow cytometry. The mechanism of action was validated by Western blot analysis. Finally, the effect and mechanism of XYSJD and Que on TNBC were further verified by the tumor formation model.

Results

UHPLC-Q Exactive HFX-MS identified a total of 9 compounds in XYSJD. Network pharmacological methods identified 206 targets for anti-TNBC. Bioinformatics analysis suggests that the EZH2/AKT1 signaling pathway might play an important role in the effects of XYSJD against TNBC. Gene Ontology enrichment analysis showed that the biological process of XYSJD in TNBC treatment mainly involved apoptosis. XYSJD and Que were observed to have a good anticancer effect in vivo and in vitro. In addition, quercetin could induce the apoptosis of TNBC cells by decreased the expression levels of EZH2/AKT1 signaling pathway. Furthermore, AKT1 overexpression, treatment with the AKT activator (SC79) and EZH2 overexpression could reverse apoptosis induced by quercetin in TNBC cells.

Conclusion

This study revealed the anti-TNBC efficacy of XYSJD. Quercetin, the effective component of XYSJD, promoted apoptosis of TNBC cells via blockade of the EZH2/AKT1 signaling pathway. These findings aim to provide a more reliable basis for the clinical application of XYSJD in the treatment of TNBC.

Epigenetic Properties of Compounds Contained in Functional Foods Against Cancer

Epigenetics encompasses reversible and heritable genomic changes in histones, DNA expression, and non-coding RNAs that occur without modifying the nucleotide DNA sequence. These changes play a critical role in modulating cell function in both healthy and pathological conditions. Dysregulated epigenetic mechanisms are implicated in various diseases, including cardiovascular disorders, neurodegenerative diseases, obesity, and mainly cancer. Therefore, to develop innovative therapeutic strategies, research for compounds able to modulate the complex epigenetic landscape of cancer is rapidly surging. Dietary phytochemicals, mostly flavonoids but also tetraterpenoids, organosulfur compounds, and isothiocyanates, represent biologically active molecules found in vegetables, fruits, medicinal plants, and beverages. These natural organic compounds exhibit epigenetic modulatory properties by influencing the activity of epigenetics key enzymes, such as DNA methyltransferases, histone acetyltransferases and deacetylases, and histone methyltransferases and demethylases. Due to the reversibility of the modifications that they induce, their minimal adverse effects, and their potent epigenetic regulatory activity, dietary phytochemicals hold significant promise as antitumor agents and warrant further investigation. This review aims to consolidate current data on the diverse epigenetic effects of the six major flavonoid subclasses, as well as other natural compounds, in the context of cancer. The goal is to identify new therapeutic epigenetic targets for drug development, whether as stand-alone treatments or in combination with conventional antitumor approaches.

Research progress on the anti-tumor effects of euphorbia humifusa

EH (Euphorbia Humifusa) is commonly known as ground spurge, contains various compounds such as flavonoids, triterpenes, coumarins, sterols, tannins, and phenolic acids. It exerts a wide spectrum of properties including anti-bacterial, anti-inflammatory, Antioxidant, anti-viral, hypoglycemic, and anti-tumor. In this article, we focus on the antitumor effects of EH and its active constituents, providing evidence for further research on this medicinal herb.

The Chemopreventive Impact of Diet-Derived Phytochemicals on the Adipose Tissue and Breast Tumor Microenvironment Secretome

Cancer cells-derived extracellular vesicles can trigger the transformation of adipose-derived mesenchymal stem cells (ADMSC) into a pro-inflammatory, cancer-associated adipocyte (CAA) phenotype. Such secretome-mediated crosstalk between the adipose tissue and the tumor microenvironment (TME) therefore impacts tumor progression and metastatic processes. In addition, emerging roles of diet-derived phytochemicals, especially epigallocatechin-3-gallate (EGCG) among other polyphenols, in modulating exosome-mediated metabolic and inflammatory signaling pathways have been highlighted. Here, we discuss how selected diet-derived phytochemicals could alter the secretome signature as well as the crosstalk dynamics between the adipose tissue and the TME, with a focus on breast cancer. Their broader implication in the chemoprevention of obesity-related cancers is also discussed.

Role of flavonoids in inhibiting triple-negative breast cancer

Increasing incidences of metastasis or recurrence (or both) in triple-negative breast cancer (TNBC) are a growing concern worldwide, as these events are intricately linked to higher mortality rates in patients with advanced breast cancer. Flavonoids possess several pharmaceutical advantages with multi-level, multi-target, and coordinated intervention abilities for treating TNBC, making them viable for preventing tumor growth and TNBC metastasis. This review focused on the primary mechanisms by which flavonoids from traditional Chinese medicine extracts inhibit TNBC, including apoptosis, blocking of cell cycle and movement, regulation of extracellular matrix degradation, promotion of anti-angiogenesis, inhibition of aerobic glycolysis, and improvement in tumor microenvironment. This review aims to improve the knowledge of flavonoids as a promising pharmacological intervention for patients with TNBC.

Natural products and derivatives for breast cancer treatment: From drug discovery to molecular mechanism

BACKGROUND

Breast cancer stands as the most common malignancy among women globally and a leading cause of cancer-related mortality. Conventional treatments, such as surgery, hormone therapy, radiotherapy, chemotherapy, and small-molecule targeted therapy, often fall short of addressing the complexity and heterogeneity of certain breast cancer subtypes, leading to drug resistance and metastatic progression. Thus, the search for novel therapeutic targets and agents is imperative. Given their low toxicity and abundant variety, natural products and their derivatives are increasingly considered valuable sources for small-molecule anticancer drugs.

PURPOSE

This review aims to elucidate the pharmacological impacts and underlying mechanisms of active compounds found in select natural products and their derivatives, primarily focusing on breast cancer treatment. It intends to underscore the potential of these substances in combating breast cancer and guide future research directions for the development of natural product-based therapeutics.

METHODS

We conducted comprehensive searches in electronic databases such as PubMed, Web of Science, and Scopus until October 2023, using keywords such as 'breast cancer', 'natural products', 'derivatives', 'mechanism', 'signaling pathways', and various keyword combinations.

RESULTS

The review presents a spectrum of phytochemicals, including but not limited to flavonoids, polyphenols, and alkaloids, and examines their actions in various animal and cellular models of breast cancer. The anticancer effects of these natural products and derivatives are manifested through diverse mechanisms, including induction of cell death via apoptosis and autophagy, and suppression of tumor angiogenesis.

CONCLUSION

An increasing array of natural products and their derivatives are proving effective against breast cancer. Future therapeutic strategies can benefit from strategic enhancement of the anticancer properties of natural compounds, optimization for targeted action, improved bioavailability, and minimized side effects. The forthcoming research on natural products should prioritize these facets to maximize their therapeutic potential.

Ethanolic extract of Euphorbia royleana Boiss. reduces metastasis of breast cancer cells and inhibits tumor progression in vivo

Metastasis is the most devastating attribute of breast cancer (BC) that leads to high mortality. It is a complex process of tumor cell migration, invasion, and angiogenesis. In this study, we evaluated the effect of ERA on BC metastasis and BC progression in vivo. The transwell invasion/migration and wound healing assays showed that ERA treatment significantly reduced the invasion and migration of BC cell lines. The expression of mesenchymal (E-cadherin and N-cadherin), matrix metalloproteinases (MMP2, MMP9), and stemness markers (Oct3) were down-regulated by ERA. Furthermore, ERA down-regulated angiogenic chemokines (CXCL1/2/3, CXCL5, and CXCL12) expression in the highly metastatic MDA-MB-231 cell line. The clonogenic survival of BC cells was also reduced by ERA treatment. Strikingly, ERA prevented DMBA-induced tumor growth in Swiss albino mice as depicted by a high animal survival rate (84%) in the ERA group and histopathological analysis. Conclusively, this study revealed that ERA possesses anti-metastatic potential and also reduces the growth of BC in vivo. Moreover, the GC-MS data revealed the presence of biologically active compounds (Lupeol, Phytol, phytosterol) and some rare (9, 19-Cyclolanost) phyto metabolites in ERA extract. However, further studies are suggestive to identify and isolate the therapeutic agents from ERA to combat BC and metastasis.

Effects of quercetin on the DNA methylation pattern in tumor therapy: an updated review

Quercetin is a unique bioactive flavonoid, and is an excellent antioxidant and has anti-tumor effects by regulating different tumor-related processes like proliferation, apoptosis, invasion, and spread. The latest investigations reveal that quercetin may have the capability to influence DNA methylation modification, one of the primary factors in the development of tumors. Despite the fact that quercetin has significant therapeutic properties, its use as an anti-tumor medicine is constrained by its poor solubility, short half-life, and ineffective tumor targeting. Here, we review the structure and properties of quercetin, its capacity for DNA methylation modification in tumors, and the possibility of nanoscale delivery of quercetin for future tumor treatment.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Determination of In Vitro and In Vivo Effects of Taxifolin and Epirubicin on Epithelial-Mesenchymal Transition in Mouse Breast Cancer Cells

Background: One of the most significant characteristics of cancer is epithelial-mesenchymal transition and research on the relationship between phenolic compounds and anticancer medications and epithelial-mesenchymal transition is widespread. Methods: In order to investigate the potential effects of Taxifolin on enhancing the effectiveness of Epirubicin in treating breast cancer, specifically in 4T1 cells and an allograft BALB/c model, the effects of Taxifolin and Epirubicin, both individually and in combination, were examined. Cell viability assays and cytotoxicity assays in 4T1 cells were performed. In addition, 4T1 cells were implanted into female BALB/c mice to conduct in vivo studies and evaluate the therapeutic efficacy of Taxifolin and Epirubicin alone or in combination. Tumor volumes and histological analysis were also assessed in mice. To further understand the mechanisms involved, we examined the messenger RNA and protein levels of epithelial-mesenchymal transition-related genes, as well as active Caspase-3/7 levels, using quantitative real-time polymerase chain reaction, western blot, and enzyme-linked immunosorbent assays, respectively. Results: In vitro results demonstrated that the coadministration of Taxifolin and Epirubicin reduced cell viability and cytotoxicity in 4T1 cell lines. In vivo, coadministration of Taxifolin and Epirubicin suppressed tumor growth in BALB/c mice with 4T1 breast cancer cells. Additionally, this combination treatment significantly increased the levels of active caspase-3/7 and downregulated the messenger RNA and protein levels of N-cadherin, β-catenin, vimentin, snail, and slug, but upregulated the E-cadherin gene. It significantly decreased the messenger RNA levels of the Zeb1 and Zeb2 genes. Conclusion: The in vitro and in vivo results of our study indicate that the concurrent use of Epirubicin with Taxifolin has supportive effects on breast cancer treatment.

Quercetin in Oncology: A Phytochemical with Immense Therapeutic Potential

Quercetin is a natural flavonoid with various pharmacological actions such as anti-inflammatory, antioxidant, antimicrobial, anticancer, antiviral, antidiabetic, cardioprotective, neuroprotective, and antiviral activities. Looking at these enormous potentials, researchers have explored how they can be used to manage numerous cancers. It's been studied for cancer management due to its anti-angiogenesis, anti-metastatic, and antiproliferative mechanisms. Despite having these proven pharmacological activities, the clinical use of quercetin is limited due to its first-- pass metabolism, poor solubility, and bioavailability. To address these shortcomings, researchers have fabricated various nanocarriers-based formulations to fight cancer. The present review overshadows the pharmacological potential, mechanisms, and application of nanoformulations against different cancers. Teaser: Explore the potential of Quercetin, a natural flavonoid with diverse pharmacological activities, and its nanoformulations in managing various cancers.

Molecular targets and therapeutic strategies for triple-negative breast cancer

Triple-negative breast cancer (TNBC) is known for its heterogeneous complexity and is often difficult to treat. TNBC lacks the expression of major hormonal receptors like estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 and is further subdivided into androgen receptor (AR) positive and AR negative. In contrast, AR negative is also known as quadruple-negative breast cancer (QNBC). Compared to AR-positive TNBC, QNBC has a great scarcity of prognostic biomarkers and therapeutic targets. QNBC shows excessive cellular growth and proliferation of tumor cells due to increased expression of growth factors like EGF and various surface proteins. This study briefly reviews the limited data available as protein biomarkers that can be used as molecular targets in treating TNBC as well as QNBC. Targeted therapy and immune checkpoint inhibitors have recently changed cancer treatment. Many studies in medicinal chemistry continue to focus on the synthesis of novel compounds to discover new antiproliferative medicines capable of treating TNBC despite the abundance of treatments currently on the market. Drug repurposing is one of the therapeutic methods for TNBC that has been examined. Moreover, some additional micronutrients, nutraceuticals, and functional foods may be able to lower cancer risk or slow the spread of malignant diseases that have already been diagnosed with cancer. Finally, nanomedicines, or applications of nanotechnology in medicine, introduce nanoparticles with variable chemistry and architecture for the treatment of cancer. This review emphasizes the most recent research on nutraceuticals, medication repositioning, and novel therapeutic strategies for the treatment of TNBC.

Xianlinglianxiafang Inhibited the growth and metastasis of triple-negative breast cancer via activating PPARγ/AMPK signaling pathway

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by high invasion and metastasis rates. Xian-Ling-Lian-Xia formula (XLLX) is a traditional Chinese medicine prescription widely used in China for treating TNBC. Clinical studies have shown that XLLX significantly reduces the recurrence and metastasis rate of TNBC and improves disease-free survival. However, the potential molecular mechanisms of XLLX on TNBC are not clear yet. Here, we investigated the effects of XLLX on TNBC using a mouse model and tumor cell lines. The results showed that XLLX significantly inhibited the proliferation, migration, and invasion abilities of TNBC cell lines MDA-MB-231 and 4T1 in vitro, induced apoptosis, and regulated the expression of proliferation, apoptosis, and EMT marker proteins in tumor cells. In in vivo experiments, XLLX treatment significantly reduced the progression of TNBC tumors and lung metastasis. Transcriptomics reveals that XLLX treatment significantly enriched differentially expressed genes in the peroxisome proliferator-activated receptor gamma (PPARγ) and AMP-dependent protein kinase (AMPK) signaling pathways. The western blot results confirmed that XLLX significantly upregulated the protein expression of PPARγ and p-AMPK in TNBC cells, tumors, and lung tissues. It is noteworthy that GW9662 (a PPARγ inhibitor) and Compound C (an AMPK inhibitor) partially reversed the anti-proliferation and anti-metastasis effects of XLLX in TNBC cells. Therefore, XLLX may effectively inhibit the growth and metastasis of TNBC by activating the PPARγ/AMPK signaling pathway.

The anticancer mechanism of action of selected polyphenols in triple-negative breast cancer (TNBC)

Breast cancer is a leadingcause of cancer-related deaths in women globally, with triple-negative breast cancer (TNBC) being an aggressive subtype that lacks targeted therapies and is associated with a poor prognosis. Polyphenols, naturally occurring compounds in plants, have been investigated as a potential therapeutic strategy for TNBC. This review provides an overview of the anticancer effects of polyphenols in TNBC and their mechanisms of action. Several polyphenols, including resveratrol, quercetin, kaempferol, genistein, epigallocatechin-3-gallate, apigenin, fisetin, hesperetin and luteolin, have been shown to inhibit TNBC cell proliferation, induce cell cycle arrest, promote apoptosis, and suppress migration/invasion in preclinical models. The molecular mechanisms underlying their anticancer effects involve the modulation of several signalling pathways, such as PI3K/Akt, MAPK, STATT, and NF-κB pathways. Polyphenols also exhibit synergistic effects with chemotherapy drugs, making them promising candidates for combination therapy. The review also highlights clinical trials investigating the potential use of polyphenols, individually or in combination therapy, against breast cancer. This review deepens the under-standing of the mechanism of action of respective polyphenols and provides valuable insights into the potential use of polyphenols as a therapeutic strategy for TNBC, and lays the groundwork for future research in this area.

Nano Drug Delivery Strategies for an Oral Bioenhanced Quercetin Formulation

Quercetin, a naturally occurring flavonoid, has been credited with a wide spectrum of therapeutic properties. However, the oral use of quercetin is limited due to its poor water solubility, low bioavailability, rapid metabolism, and rapid plasma clearance. Quercetin has been studied extensively when used with various nanodelivery systems for enhancing quercetin bioavailability. To enhance its oral bioavailability and efficacy, various quercetin-loaded nanosystems such as nanosuspensions, polymer nanoparticles, metal nanoparticles, emulsions, liposomes or phytosomes, micelles, solid lipid nanoparticles, and other lipid-based nanoparticles have been investigated in in-vitro cells, in-vivo animal models, and humans. Among the aforementioned nanosystems, quercetin phytosomes are attracting more interest and are available on the market. The present review covers insights into the possibilities of harnessing quercetin for several therapeutic applications and a special focus on anticancer applications and the clinical benefits of nanoquercetin formulations.

Anti-Cancer Potential of Phytochemicals: The Regulation of the Epithelial-Mesenchymal Transition

A biological process called epithelial-mesenchymal transition (EMT) allows epithelial cells to change into mesenchymal cells and acquire some cancer stem cell properties. EMT contributes significantly to the metastasis, invasion, and development of treatment resistance in cancer cells. Current research has demonstrated that phytochemicals are emerging as a potential source of safe and efficient anti-cancer medications. Phytochemicals could disrupt signaling pathways related to malignant cell metastasis and drug resistance by suppressing or reversing the EMT process. In this review, we briefly describe the pathophysiological properties and the molecular mechanisms of EMT in the progression of cancers, then summarize phytochemicals with diverse structures that could block the EMT process in different types of cancer. Hopefully, these will provide some guidance for future research on phytochemicals targeting EMT.

Targeting Senescence as a Therapeutic Opportunity for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is associated with an elevated risk of recurrence and poor prognosis. Historically, only chemotherapy was available as systemic treatment, but immunotherapy and targeted therapies currently offer prolonged benefits. TNBC is a group of diseases with heterogeneous treatment sensitivity, and resistance is inevitable and early for a large proportion of the intrinsic subtypes. Although senescence induction by anticancer therapy offers an immediate favorable clinical outcome once the rate of tumor progression reduces, these cells are commonly dysfunctional and metabolically active, culminating in treatment-resistant repopulation associated with worse prognosis. This heterogeneous response can also occur without therapeutic pressure in response to damage or oncogenic stress, playing a relevant role in the carcinogenesis. Remarkably, there is preclinical and exploratory clinical evidence to support a relevant role of senescence in treatment resistance. Therefore, targeting senescent cells has been a scientific effort in many malignant tumors using a variety of targets and strategies, including increasing proapoptotic and decreasing antiapoptotic stimuli. Despite promising results, there are some challenges to applying this technology, including the best schedule of combination, assessment of senescence, specific vulnerabilities, and the best clinical scenarios. This review provides an overview of senescence in TNBC with a focus on future-proofing senotherapy strategies.

Quercetin modulates signal transductions and targets non-coding RNAs against cancer development

In recent decades, various investigations have indicated that natural compounds have great potential in the prevention and treatment of different chronic disorders including different types of cancer. As a bioactive flavonoid, Quercetin (Qu) is a dietary ingredient enjoying high pharmacological values and health-promoting effects due to its antioxidant and anti-inflammatory characterization. Conclusive in vitro and in vivo evidence has revealed that Qu has great potential in cancer prevention and development. Qu exerts its anticancer influences by altering various cellular processes such as apoptosis, autophagy, angiogenesis, metastasis, cell cycle, and proliferation. In this way, Qu by targeting numerous signaling pathways as well as non-coding RNAs regulates several cellular mechanisms to suppress cancer occurrence and promotion. This review aimed to summarize the impact of Qu on the molecular pathways and non-coding RNAs in modulating various cancer-associated cellular mechanisms.

Mechanism of epithelial-mesenchymal transition in cancer and its regulation by natural compounds

Epithelial-mesenchymal transition (EMT) is a complex process with a primordial role in cellular transformation whereby an epithelial cell transforms and acquires a mesenchymal phenotype. This transformation plays a pivotal role in tumor progression and self-renewal, and exacerbates resistance to apoptosis and chemotherapy. EMT can be initiated and promoted by deregulated oncogenic signaling pathways, hypoxia, and cells in the tumor microenvironment, resulting in a loss-of-epithelial cell polarity, cell-cell adhesion, and enhanced invasive/migratory properties. Numerous transcriptional regulators, such as Snail, Slug, Twist, and ZEB1/ZEB2 induce EMT through the downregulation of epithelial markers and gain-of-expression of the mesenchymal markers. Additionally, signaling cascades such as Wnt/β-catenin, Notch, Sonic hedgehog, nuclear factor kappa B, receptor tyrosine kinases, PI3K/AKT/mTOR, Hippo, and transforming growth factor-β pathways regulate EMT whereas they are often deregulated in cancers leading to aberrant EMT. Furthermore, noncoding RNAs, tumor-derived exosomes, and epigenetic alterations are also involved in the modulation of EMT. Therefore, the regulation of EMT is a vital strategy to control the aggressive metastatic characteristics of tumor cells. Despite the vast amount of preclinical data on EMT in cancer progression, there is a lack of clinical translation at the therapeutic level. In this review, we have discussed thoroughly the role of the aforementioned transcription factors, noncoding RNAs (microRNAs, long noncoding RNA, circular RNA), signaling pathways, epigenetic modifications, and tumor-derived exosomes in the regulation of EMT in cancers. We have also emphasized the contribution of EMT to drug resistance and possible therapeutic interventions using plant-derived natural products, their semi-synthetic derivatives, and nano-formulations that are described as promising EMT blockers.

The Role of Selective Flavonoids on Triple-Negative Breast Cancer: An Update

Among the many types of breast cancer (BC), Triple-Negative Breast Cancer (TNBC) is the most alarming. It lacks receptors for the three main biomarkers: estrogen, progesterone, and human epidermal growth factor, hence the name TNBC. This makes its treatment a challenge. Surgical procedures and chemotherapy, performed either alone or in combination, seem to be the primary therapeutic possibilities; however, they are accompanied by severe complications. Currently, the formulation of drugs using natural products has been playing an important role in the pharmaceutical industries, owing to the drugs’ increased efficacies and significantly lessened side effects. Hence, treating TNBC with chemotherapeutic drugs developed using natural products such as flavonoids in the near future is much warranted. Flavonoids are metabolic compounds largely present in all plants, vegetables, and fruits, such as blueberries, onions, (which are widely used to make red wine,) chocolates, etc. Flavonoids are known to have enormous health benefits, such as anticancer, antiviral, anti-inflammatory, and antiallergic properties. They are known to arrest the cell cycle of the tumor cells and induces apoptosis by modulating Bcl-2, Bax, and Caspase activity. They show a considerable effect on cell proliferation and viability and angiogenesis. Various studies were performed at both the biochemical and molecular levels. The importance of flavonoids in cancer treatment and its methods of extraction and purification to date have been reported as individual publications. However, this review article explains the potentiality of flavonoids against TNBC in the preclinical levels and also emphasizes their molecular mechanism of action, along with a brief introduction to its methods of extraction, isolation, and purification in general, emphasizing the fact that its quantum of yield if enhanced and its possible synergistic effects with existing chemotherapeutics may pave the way for better anticancer agents of natural origin and significantly lessened side-effects.

A pHe sensitive nanodrug for collaborative penetration and inhibition of metastatic tumors

Current chemotherapies for metastatic tumors are seriously restricted by limited drug infiltration and deficient disturbance of metastasis-associated complex pathways involving tumor cell autocrine as well as paracrine loops in the microenvironment (TME). Of note, cancer-associated fibroblasts (CAFs) play a predominant role in shaping TME favoring drug resistance and metastasis. Herein, we constructed a tumor extracellular pH (pH_e) sensitive methotrexate-chitosan conjugate (MTX-GC-DEAP) and co-assembled it with quercetin (QUE) to achieve co-delivered nanodrugs (MTX-GC-DEAP/QUE). The pH_e sensitive protonation and disassembly enabled MTX-GC-DEAP/QUE for stroma-specific delivery of QUE and positive-charged MTX-GC-DEAP molecular conjugates, thereby achieving deep tumor penetration via the combination of QUE-mediated CAF inactivation and adsorption-mediated transcytosis. On the basis of significantly promoted drug availability, a strengthened "omnidirectional" inhibition of pre-metastatic initiation was generated both in vitro and in vivo from the CAF inactivation-mediated reversion of metastasis-promoting environments as well as the inhibition of epithelial-mesenchymal transition, local and blood vessel invasion via QUE-mediated direct regulation on tumor cells. Our tailor-designed versatile nanodrug provides a deep insight into potentiating multi-faceted penetration of multi-mechanism-based regulating agents for intensive metastasis inhibition.

New Visions on Natural Products and Cancer Therapy: Autophagy and Related Regulatory Pathways

Macroautophagy (autophagy) has been a highly conserved process throughout evolution and allows cells to degrade aggregated/misfolded proteins, dysfunctional or superfluous organelles and damaged macromolecules, in order to recycle them for biosynthetic and/or energetic purposes to preserve cellular homeostasis and health. Changes in autophagy are indeed correlated with several pathological disorders such as neurodegenerative and cardiovascular diseases, infections, cancer and inflammatory diseases. Conversely, autophagy controls both apoptosis and the unfolded protein response (UPR) in the cells. Therefore, any changes in the autophagy pathway will affect both the UPR and apoptosis. Recent evidence has shown that several natural products can modulate (induce or inhibit) the autophagy pathway. Natural products may target different regulatory components of the autophagy pathway, including specific kinases or phosphatases. In this review, we evaluated ~100 natural compounds and plant species and their impact on different types of cancers via the autophagy pathway. We also discuss the impact of these compounds on the UPR and apoptosis via the autophagy pathway. A multitude of preclinical findings have shown the function of botanicals in regulating cell autophagy and its potential impact on cancer therapy; however, the number of related clinical trials to date remains low. In this regard, further pre-clinical and clinical studies are warranted to better clarify the utility of natural compounds and their modulatory effects on autophagy, as fine-tuning of autophagy could be translated into therapeutic applications for several cancers.

Quercetin Suppresses Human Glioblastoma Migration and Invasion via GSK3β/β-catenin/ZEB1 Signaling Pathway

High invasiveness is a biological and clinical characteristic of glioblastoma and predicts poor prognosis of patients. Quercetin, a natural flavonoid compound, exhibits anticancer activity. However, we have a limited understanding of the possible underlying mechanism of quercetin in glioblastoma. In this study, we investigated the anticancer effect of quercetin in human glioblastoma cells. Our results showed that quercetin markedly suppressed the viability of glioblastoma cells in vitro and in vivo, and significantly inhibited glioblastoma cell migration and invasion. Moreover, quercetin reversed EMT-like mesenchymal phenotype and reduced the expression levels of EMT-related markers. Furthermore, we found that quercetin suppressed GSK-3β/β-catenin/ZEB1 signaling in glioblastoma. Taken together, our results demonstrate that quercetin inhibited migration and invasion of human glioma cells by suppressing GSK3β/β-catenin/ZEB1 signaling. Our study provides evidence that quercetin is a promising therapeutic natural compound to treat glioblastoma.

A Comprehensive Analysis and Anti-Cancer Activities of Quercetin in ROS-Mediated Cancer and Cancer Stem Cells

Reactive oxygen species (ROS) induce carcinogenesis by causing genetic mutations, activating oncogenes, and increasing oxidative stress, all of which affect cell proliferation, survival, and apoptosis. When compared to normal cells, cancer cells have higher levels of ROS, and they are responsible for the maintenance of the cancer phenotype; this unique feature in cancer cells may, therefore, be exploited for targeted therapy. Quercetin (QC), a plant-derived bioflavonoid, is known for its ROS scavenging properties and was recently discovered to have various antitumor properties in a variety of solid tumors. Adaptive stress responses may be induced by persistent ROS stress, allowing cancer cells to survive with high levels of ROS while maintaining cellular viability. However, large amounts of ROS make cancer cells extremely susceptible to quercetin, one of the most available dietary flavonoids. Because of the molecular and metabolic distinctions between malignant and normal cells, targeting ROS metabolism might help overcome medication resistance and achieve therapeutic selectivity while having little or no effect on normal cells. The powerful bioactivity and modulatory role of quercetin has prompted extensive research into the chemical, which has identified a number of pathways that potentially work together to prevent cancer, alongside, QC has a great number of evidences to use as a therapeutic agent in cancer stem cells. This current study has broadly demonstrated the function-mechanistic relationship of quercetin and how it regulates ROS generation to kill cancer and cancer stem cells. Here, we have revealed the regulation and production of ROS in normal cells and cancer cells with a certain signaling mechanism. We demonstrated the specific molecular mechanisms of quercetin including MAPK/ERK1/2, p53, JAK/STAT and TRAIL, AMPKα1/ASK1/p38, RAGE/PI3K/AKT/mTOR axis, HMGB1 and NF-κB, Nrf2-induced signaling pathways and certain cell cycle arrest in cancer cell death, and how they regulate the specific cancer signaling pathways as long-searched cancer therapeutics.

Molecular Mechanisms of Gynostemma pentaphyllum in Prevention and Treatment of Non-Small-Cell Lung Cancer

Objective

Lung cancer represents the leading cause of cancer death on a global scale. Gynostemma pentaphyllum (G. pentaphyllum), a traditional medicinal material with a high medicinal and health value, has recently been reported for its anticancer activity. However, the pharmacological mechanism of G. pentaphyllum in non-small-cell lung cancer (NSCLC) remains to be elucidated.

Methods

The active ingredients of G. pentaphyllum were obtained from the TCMSP database and known therapeutic targets of NSCLC from the GeneCards and OMIM databases. Disease-drug common targets are subjected to protein-protein interaction (PPI), GO enrichment analysis, and KEGG pathway enrichment analysis. A molecular docking strategy was performed to verify the interaction between molecules.

Results

We found a total of 24 compounds of G. pentaphyllum fulfilling OB ≥ 30% concomitant with DL ≥ 0.18 and corresponding 81 target genes in the TCMSP database, with 5062 NSCLC-related genes collected in the GeneCards and OMIM databases. The network consisting of the disease-target compound was obtained, including 8 active ingredients and 69 common targets. The PPI network with 65 nodes and 645 edges was visualized. After functional enrichment analysis, it was revealed that the therapeutic effects of G. pentaphyllum on NSCLC were achieved through response to ketone, gland development, and cellular response to xenobiotic stimulus. After molecular docking analysis, it was revealed that the two active ingredients of G. pentaphyllum, quercetin and rhamnazin, bound well and stably to their targets (MYC, ESR1, and HIF1A).

Conclusion

Our study, based on network pharmacology, identifies active ingredients, targets, and pathways model mechanism of G. pentaphyllum when it is used to treat NSCLC.

Countering Triple Negative Breast Cancer via Impeding Wnt/β-Catenin Signaling, a Phytotherapeutic Approach

Triple negative breast cancer (TNBC) is characterized as a heterogeneous disease with severe malignancy and high mortality. Aberrant Wnt/β-catenin signaling is responsible for self-renewal and mammosphere generation, metastasis and resistance to apoptosis and chemotherapy in TNBC. Nonetheless, in the absence of a targeted therapy, chemotherapy is regarded as the exclusive treatment strategy for the treatment of TNBC. This review aims to provide an unprecedented overview of the plants and herbal derivatives which repress the progression of TNBC through prohibiting the Wnt/β-catenin pathway. Herbal medicine extracts and bioactive compounds (alkaloids, retinoids. flavonoids, terpenes, carotenoids and lignans) alone, in combination with each other and/or with chemotherapy agents could interrupt the various steps of Wnt/β-catenin signaling, i.e., WNT, FZD, LRP, GSK3β, Dsh, APC, β-catenin and TCF/LEF. These phytotherapy agents diminish proliferation, metastasis, breast cancer stem cell self-renewal and induce apoptosis in cell and animal models of TNBC through the down-expression of the downstream target genes of Wnt signaling. Some of the herbal derivatives simultaneously impede Wnt/β-catenin signaling and other overactive pathways in triple negative breast cancer, including: mTORC1; ER stress and SATB1 signaling. The herbal remedies and their bioactive ingredients perform essential roles in the treatment of the very fatal TNBC via repression of Wnt/β-catenin signaling.

Salvia chinensis Benth Inhibits Triple-Negative Breast Cancer Progression by Inducing the DNA Damage Pathway

Objective

Triple-negative breast cancer (TNBC) is distinguished by early recurrence and metastases, a high proclivity for treatment resistance, and a lack of targeted medicines, highlighting the importance of developing innovative therapeutic techniques. Salvia chinensis Benth (SCH) has been widely studied for its anticancer properties in a variety of cancers. However, its significance in TNBC treatment is rarely discussed. Our study investigated the anticancer effect of SCH on TNBC and the underlying mechanisms.

Methods

First, we used clonogenic, cell viability, flow cytometry, and Transwell assays to assess the effect of SCH on TNBC. Bioinformatic studies, especially network pharmacology-based analysis and RNA sequencing analysis, were performed to investigate the constituents of SCH and its molecular mechanisms in the suppression of TNBC. High-performance liquid chromatography and thin-layer chromatography were used to identify two major components, quercetin and β-sitosterol. Then, we discovered the synergistic cytotoxicity of quercetin and β-sitosterol and assessed their synergistic prevention of cell migration and invasion. Breast cancer xenografts were also created using MDA-MB-231 cells to test the synergistic therapeutic impact of quercetin and β-sitosterol on TNBC in vivo. The impact on the DNA damage and repair pathways was investigated using the comet assay and Western blot analysis.

Results

Our findings showed that SCH decreased TNBC cell growth, migration, and invasion while also inducing cell death. We identified quercetin and β-sitosterol as the core active components of SCH based on a network pharmacology study. According to RNA sequencing research, the p53 signaling pathway is also regarded as a critical biological mechanism of SCH treatment. The comet assay consistently showed that SCH significantly increased DNA damage in TNBC cells. Our in vivo and in vitro data revealed that the combination of quercetin and β-sitosterol induced synergistic cytotoxicity and DNA damage in TNBC cells. In particular, SCH particularly blocked the inter-strand cross-link repair mechanism and the double-strand breach repair caused by the homologous recombination pathway, in addition to inducing DNA damage. Treatment with quercetin and β-sitosterol produced similar outcomes.

Conclusion

The current study provides novel insight into the previously unknown therapeutic potential of SCH as a DNA-damaging agent in TNBC.

Quercetin as a JAK-STAT inhibitor: a potential role in solid tumors and neurodegenerative diseases

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is involved in many immunological processes, including cell growth, proliferation, differentiation, apoptosis, and inflammatory responses. Some of these processes can contribute to cancer progression and neurodegeneration. Owing to the complexity of this pathway and its potential crosstalk with alternative pathways, monotherapy as targeted therapy has usually limited long-term efficacy. Currently, the majority of JAK-STAT-targeting drugs are still at preclinical stages. Meanwhile, a variety of plant polyphenols, especially quercetin, exert their inhibitory effects on the JAK-STAT pathway through known and unknown mechanisms. Quercetin has shown prominent inhibitory effects on the JAK-STAT pathway in terms of anti-inflammatory and antitumor activity, as well as control of neurodegenerative diseases. This review discusses the pharmacological effects of quercetin on the JAK-STAT signaling pathway in solid tumors and neurodegenerative diseases.

Signaling Pathways and Natural Compounds in Triple-Negative Breast Cancer Cell Line

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, having a poor prognosis and rapid metastases. TNBC is characterized by the absence of estrogen, progesterone, and human epidermal growth receptor-2 (HER2) expressions and has a five-year survival rate. Compared to other breast cancer subtypes, TNBC patients only respond to conventional chemotherapies, and even then, with limited success. Shortages of chemotherapeutic medication can lead to resistance, pressured index therapy, non-selectivity, and severe adverse effects. Finding targeted treatments for TNBC is difficult owing to the various features of cancer. Hence, identifying the most effective molecular targets in TNBC pathogenesis is essential for predicting response to targeted therapies and preventing TNBC cell metastases. Nowadays, natural compounds have gained attention as TNBC treatments, and have offered new strategies for solving drug resistance. Here, we report a systematic review using the database from Pubmed, Science Direct, MDPI, BioScince, Springer, and Nature for articles screening from 2003 to 2022. This review analyzes relevant signaling pathways and the prospect of utilizing natural compounds as a therapeutic agent to improve TNBC treatments in the future.

Quercetin: a silent retarder of fatty acid oxidation in breast cancer metastasis through steering of mitochondrial CPT1

BACKGROUND

Recent evidence confirmed that the maximum energy in metastatic breast cancer progression is supplied by fatty acid oxidation (FAO) governed by a rate-limiting enzyme, carnitine palmitoyltransferase 1 (CPT1). Therefore, the active limitation of FAO could be an emerging aspect to inhibit breast cancer progression. Herein, for the first time, we have introduced quercetin (QT) from a non-dietary source (Mikania micrantha Kunth) to limit the FAO in triple-negative breast cancer cells (TNBC) through an active targeting of CPT1.

METHODS

Molecular quantification of QT was confirmed through high-performance thin-layer chromatography (HPTLC). Computational docking analyses predicted the binding affinity of QT to CPT1. Cell-based seahorse energy efflux investigated the mitochondrial respiration rate, glycolytic function and ATP production rate. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) investigated the FAO-associated gene expression. Matrigel cell invasion and fluorescence-activated cell sorting analyses investigated anti-metastatic and apoptotic cell death induction activities, respectively. In vivo antitumor activities were checked using the female breast cancer mice (BALB/c) model.

RESULTS

QT resulted in a significant reduction in the intracellular mitochondrial respiration and glycolytic function, limiting extensive ATP production. In turn, QT elevated the reactive oxygen species (ROS) and depleted antioxidant levels to induce anti-metastatic and cell apoptosis activities. qRT-PCR resulted in active healing of altered FAO-associated gene expression which was well predicted through the successful in silico molecular binding potentiality of QT to CPT1. Subsequently, QT has shown excellent in vivo antitumor activities through the altered lipid profile and oxidative stress-healing capabilities.

CONCLUSIONS

All the obtained data significantly grounded the fact that QT could be a promising metabolism-targeted breast cancer therapeutic.

Chemical Structure, Sources and Role of Bioactive Flavonoids in Cancer Prevention: A Review

There has been a major shift in the collective mindset around the world in recent decades, both in terms of food and in terms of the treatment of chronic diseases. Increasing numbers of people are choosing to prevent rather than treat, which is why many consumers are choosing plant-based diets, mainly due to their bioactive compounds. A significant case of bioactive compound is flavonoids-a wide subclass of an even wider class of phytochemicals: polyphenols. Flavonoids are a broad topic of study for researchers due to their potential in the prevention and treatment of a broad range of cancers. The aim of this review is to inform/update the reader on the diversity, accessibility and importance of flavonoids as biomolecules that are essential for optimal health, focusing on the potential of these compounds in the prevention of various types of cancer. Along with conventional sources, this review presents some of the possible methods for obtaining significant amounts of flavonoids based on a slightly different approach, genetic manipulation.

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.

Selenium nanoparticles and quercetin suppress thioacetamide-induced hepatocellular carcinoma in rats: Attenuation of inflammation involvement

The current study investigates the anti-inflammatory and hepatoprotective effects of selenium (Se) formulated as nanoparticles (SeNPs) and in combination with quercetin (QCT) against thioacetamide (TAA)-induced hepatocellular carcinoma (HCC) in rats. ​​​​​​Seventy-two male Sprague-Dawley rats were divided into six groups (n = 12). Three control groups; normal, SeNPs; group received SeNPs only and HCC; group received TAA. In addition, three preventive groups; SeNPs + TAA, QCT + TAA, and QCT + SeNPs + TAA. Induction of HCC was detected histopathologically and by the raise of the serum level of alpha-fetoprotein (AFP). Oxidative stress was evaluated by the hepatic levels of reduced glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) spectrophotometrically. The oncogenic pathway of p53/β-catenin/cyclin D1 was assessed by immunohistochemistry. The inflammatory markers; interleukin-33 (IL-33), IL-6, and IL-1β were assessed by enzyme-linked immune sorbent assay. SeNPs prevented the elevation of serum AFP and hepatic IL-33, IL-1β, and IL-6 in comparison to HCC or QCT + TAA groups. SeNPs + TAA exhibited a lower positive hepatic staining of p53, β-catenin, and cyclin D1 in comparison to HCC or QCT + TAA groups. Moreover, SeNPs improved the overall oxidative balance indicated by low hepatic MDA and enhanced GSH and GPx when compared to HCC or QCT + TAA groups. ​​SeNPs alone and in combination with QCT were found to suppress the progression of HCC in rats via the enhancement of the oxidative stress and then inflammatory status and the prevention of the deregulation of the oncogenic axis pathway of p53/β-catenin/cyclin D.

The Potential for Natural Products to Overcome Cancer Drug Resistance by Modulation of Epithelial-Mesenchymal Transition

The acquisition of resistance and ultimately disease relapse after initial response to chemotherapy put obstacles in the way of cancer therapy. Epithelial-mesenchymal transition (EMT) is a biologic process that epithelial cells alter to mesenchymal cells and acquire fibroblast-like properties. EMT plays a significant role in cancer metastasis, motility, and survival. Recently, emerging evidence suggested that EMT pathways are very important in making drug-resistant involved in cancer. Natural products are gradually emerging as a valuable source of safe and effective anticancer compounds. Natural products could interfere with the different processes implicated in cancer drug resistance by reversing the EMT process. In this review, we illustrate the molecular mechanisms of EMT in the emergence of cancer metastasis. We then present the role of natural compounds in the suppression of EMT pathways in different cancers to overcome cancer cell drug resistance and improve tumor chemotherapy. HighlightsDrug-resistance is one of the obstacles to cancer treatment.EMT signaling pathways have been correlated to tumor invasion, metastasis, and drug-resistance.Various studies on the relationship between EMT and resistance to chemotherapy agents were reviewed.Different anticancer natural products with EMT inhibitory properties and drug resistance reversal effects were compared.

Novel role of the dietary flavonoid fisetin in suppressing rRNA biogenesis

The nucleolus of a cell is a critical cellular compartment that is responsible for ribosome biogenesis and plays a central role in tumor progression. Fisetin, a nutraceutical, is a naturally occurring flavonol from the flavonoid group of polyphenols that has anti-cancer effects. Fisetin negatively impacts several signaling pathways that support tumor progression. However, effect of fisetin on the nucleolus and its functions were unknown. We observed that fisetin is able to physically enter the nucleolus. In the nucleolus, RNA polymerase I (RNA Pol I) mediates the biogenesis of ribosomal RNA. Thus, we investigated the impacts of fisetin on the nucleolus. We observed that breast tumor cells treated with fisetin show a 20-30% decreased nucleolar abundance per cell and a 30-60% downregulation of RNA Pol I transcription activity, as well as a 50-70% reduction in nascent rRNA synthesis, depending on the cell line. Our studies show that fisetin negatively influences MAPK/ERK pathway to impair RNA Pol I activity and rRNA biogenesis. Functionally, we demonstrate that fisetin acts synergistically (CI = 0.4) with RNA Pol I inhibitor, BMH-21 and shows a noteworthy negative impact (60% decrease) on lung colonization of breast cancer cells. Overall, our findings highlight the potential of ribosomal RNA (rRNA) biogenesis as a target for secondary prevention and possible treatment of metastatic disease.

Repurposing drugs as novel triple negative breast cancer therapeutics

BACKGROUND

Among all the types of breast cancer (BC), triple negative breast cancer (TNBC) is the most aggressive form having high metastasis and recurrence rate with limited treatment options. Conventional treatments such as chemotherapy and radiotherapy have lots of toxic side effects and also no FDA approved therapies are available till now. Repurposing of old clinically approved drugs towards various targets of TNBC is the new approach with lesser side effects and also leads to successful inexpensive drug development with less time consuming. Medicinal plants containg various phytoconstituents (flavonoids, alkaloids, phenols, essential oils, tanins, glycosides, lactones) plays very crucial role in combating various types of diseases and used in drug development process because of having lesser side effects.

OBJECTIVE

The present review focuses in summarization of various categories of repurposed drugs against multitarget of TNBC and also summarizes the phytochemical categories that targets TNBC singly or in combination with synthetic old drugs.

METHODS

Literature information was collected from various databases such as Pubmed, Web of Science, Scopus and Medline to understand and clarify the role and mechanism of repurposed synthetic drugs and phytoconstituents aginst TNBC by using keywords like "breast cancer", "repurposed drugs", "TNBC" and "phytoconstituents".

RESULTS

Various repurposed drugs and phytochemicals targeting different signaling pathways that exerts their cytotoxic activities on TNBC cells ultimately leads to apoptosis of cells and also lowers the recurrence rate and stops the metastasis process.

CONCLUSION

Inhibitory effects seen in different levels, which provides information and evidences to researchers towards drug developments process and thus further more investigations and researches need to be taken to get the better therapeutic treatment options against TNBC.

A Network Pharmacology Analysis of the Systems-Perspective Anticancer Mechanisms of the Herbal Drug FDY2004 for Breast Cancer

Breast cancer is a malignant tumor with high incidence, prevalence, and mortality rates in women. In recent years, herbal drugs have been assessed as anticancer therapy against breast cancer, owing to their promising therapeutic effects and reduced toxicity. However, their pharmacological mechanisms have not been fully explored at the systemic level. Here, we conducted a network pharmacology analysis of the systems-perspective molecular mechanisms of FDY2004, an anticancer herbal formula that consists of Moutan Radicis Cortex, Persicae Semen , and Rhei Radix et Rhizoma, against breast cancer. We determined that FDY2004 may contain 28 active compounds that exert pharmacological effects by targeting 113 breast cancer-related human genes/proteins. Based on the gene ontology terms, the FDY2004 targets were involved in modulating biological processes such as cell growth, cell proliferation, and apoptosis. Pathway enrichment analysis identified various breast cancer-associated pathways that may mediate the anticancer activity of FDY2004, including the PI3K-Akt, MAPK, TNF, HIF-1, focal adhesion, estrogen, ErbB, NF-kappa B, p53, and VEGF signaling pathways. Thus, our analysis offers novel insights into the anticancer properties of herbal drugs for breast cancer treatment from a systemic perspective.

Food-derived natural compounds in the management of chronic diseases via Wnt signaling pathway

Wnt signaling pathway is an evolutionarily conserved pathway that control embryonic development, adult tissue homeostasis, and pathological processes of organisms throughout life. However, dysregulation of the Wnt signaling is associated with the occurrence of chronic diseases. In comparison with the application of chemical drugs as traditional treatment for chronic diseases, dietary agents have unique advantages, such as less side effects, multiple targets, convenience in accessibility and higher acceptability in long-term intervention. In this review, we summarized current progress in manipulating the Wnt signaling using food components and its benefits in managing chronic diseases. The underlying mechanisms of bioactive food components in the management of the disease progression via the Wnt signaling was illustrated. Then, the review focused on the function of dietary pattern (which might act via combination of foods with multiple nutrients or food ingredients) on targeting Wnt signaling at multiple level. The potential caveats and challenges in developing new strategy via modulating Wnt-associated diseases with food-based agents and appropriate dietary pattern are also discussed in detail. This review shed light on the understanding of the regulatory effect of food bioactive components on chronic diseases management through the Wnt signaling, which can be expanded to other specific signaling pathway associated with disease.

A Network Pharmacology Study on the Molecular Mechanisms of FDY003 for Breast Cancer Treatment

Herbal medicines have drawn considerable attention with regard to their potential applications in breast cancer (BC) treatment, a frequently diagnosed malignant disease, considering their anticancer efficacy with relatively less adverse effects. However, their mechanisms of systemic action have not been understood comprehensively. Based on network pharmacology approaches, we attempted to unveil the mechanisms of FDY003, an herbal drug comprised of Lonicera japonica Thunberg, Artemisia capillaris Thunberg, and Cordyceps militaris, against BC at a systemic level. We found that FDY003 exhibited pharmacological effects on human BC cells. Subsequently, detailed data regarding the biochemical components contained in FDY003 were obtained from comprehensive herbal medicine-related databases, including TCMSP and CancerHSP. By evaluating their pharmacokinetic properties, 18 chemical compounds in FDY003 were shown to be potentially active constituents interacting with 140 BC-associated therapeutic targets to produce the pharmacological activity. Gene ontology enrichment analysis using g:Profiler indicated that the FDY003 targets were involved in the modulation of cellular processes, involving the cell proliferation, cell cycle process, and cell apoptosis. Based on a KEGG pathway enrichment analysis, we further revealed that a variety of oncogenic pathways that play key roles in the pathology of BC were significantly enriched with the therapeutic targets of FDY003; these included PI3K-Akt, MAPK, focal adhesion, FoxO, TNF, and estrogen signaling pathways. Here, we present a network-perspective of the molecular mechanisms via which herbal drugs treat BC.

Systems pharmacology in combination with proteomics reveals underlying mechanisms of Xihuang pill against triple-negative breast cancer

Xihuang pill (XHP), a traditional Chinese herbal formula, has been clinically used as an adjuvant therapy against triple-negative breast cancer (TNBC) via inhibiting cancer cell invasion and proliferation, as well as promoting cancer cell apoptosis. However, its anti-TNBC bio-active ingredients and possible mechanisms are still unclear. Herein, the hub bio-active compounds and underlying mechanisms of XHP against TNBC were systematically elucidated by integrating systems pharmacology approach and in vitro proteomics analysis. Using systems pharmacology analysis and molecular docking evaluation, 28 bio-active compounds and 10 potential therapeutic targets of XHP were identified. Functional analysis showed that the core therapeutic targets against TNBC were mainly involved in epidermal growth factor receptor (EGFR)-phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway to prevent cancer cell proliferation and angiogenesis, as well as to enhance cancer cell apoptosis. The in vitro proteomics analysis identified 153 differentially expressed proteins (DEPs), including HASP90AA1, AKT1, and EGFR, which were also identified as therapeutic targets against TNBC through systems pharmacology analysis. Protein function analysis showed that the DEPs were mainly involved in PI3K-AKT signaling pathway, which was consistent with the result of systems pharmacology, suggesting the reliability of systems pharmacology analysis. Taken together, these findings uncover the underlying mechanism of XHP against TNBC, and provide a scientific method for the rational development of traditional Chinese medicine.

Quercetin as an innovative therapeutic tool for cancer chemoprevention: Molecular mechanisms and implications in human health

Cancer is a life-threatening disease afflicting human health worldwide. Recent advances in drug discovery infrastructure and molecular approaches have helped a lot in identifying the novel drug targets for therapeutic intervention. Nevertheless, the morbidity and mortality rates because of this disease keep on rising at an alarming rate. Recently, the use of natural and synthetic molecules as innovative therapeutic tools for cancer prevention has lead to the development of cancer chemoprevention. Cancer chemoprevention is a prophylactic strategy that involves the chronic administration of one or more natural or synthetic agents to block, to inhibit, or to suppress the process of cancer development before it becomes an invasive disease. Quercetin, a dietary bioflavonoid, can specifically retard the growth of cancer cells and behaves as a potent cancer chemopreventive agent. Quercetin has multiple intracellular targets in a cancer cell. Therefore, many mechanisms have been postulated to explain its chemopreventive action. The chemopreventive effects elicited by this natural molecule in different model systems are believed to include antioxidant/pro-oxidant action, regulation of redox homeostasis, apoptosis, cell cycle arrest, anti-inflammatory action, modulation of drug metabolizing enzymes, alterations in gene expression patterns, inhibition of Ras gene expression, and modulation of signal transduction pathways. However, cell signaling networks have recently garnered attention as common molecular target for various chemopreventive effects of quercetin. In this review, we made an attempt to critically summarize the emerging knowledge on the role of quercetin in cancer chemoprevention and the underlying molecular mechanisms implicated in its chemopreventive and therapeutic effects.

Antiangiogenic Activity of Flavonoids: A Systematic Review and Meta-Analysis

Abstract: An imbalance of angiogenesis contributes to many pathologies such as cancer, arthritis and retinopathy, hence molecules that can modulate angiogenesis are of considerable therapeutic importance. Despite many reports on the promising antiangiogenic properties of naturally occurring flavonoids, no flavonoids have progressed to the clinic for this application. This systematic review and meta-analysis therefore evaluates the antiangiogenic activities of a wide range of flavonoids and is presented in two sections. The first part of the study (Systematic overview) included 402 articles identified by searching articles published before May 2020 using ScienceDirect, PubMed and Web of Science databases. From this initial search, different classes of flavonoids with antiangiogenic activities, related pathologies and use of in vitro and/or in/ex vivo angiogenesis assays were identified. In the second part (Meta-analysis), 25 studies concerning the antiangiogenic evaluation of flavonoids using the in vivo chick chorioallantoic membrane (CAM) assay were included, following a targeted search on articles published prior to June 2020. Meta-analysis of 15 out of the 25 eligible studies showed concentration dependent antiangiogenic activity of six compared subclasses of flavonoids with isoflavones, flavonols and flavones being the most active (64 to 80% reduction of blood vessels at 100 µM). Furthermore, the key structural features required for the antiangiogenic activity of flavonoids were derived from the pooled data in a structure activity relationship (SAR) study. All in all, flavonoids are promising candidates for the development of antiangiogenic agents, however further investigations are needed to determine the key structural features responsible for their activity.

Nature-derived compounds modulating Wnt/ -catenin pathway: a preventive and therapeutic opportunity in neoplastic diseases

The Wnt/β-catenin signaling is a conserved pathway that has a crucial role in embryonic and adult life. Dysregulation of the Wnt/β-catenin pathway has been associated with diseases including cancer, and components of the signaling have been proposed as innovative therapeutic targets, mainly for cancer therapy. The attention of the worldwide researchers paid to this issue is increasing, also in view of the therapeutic potential of these agents in diseases, such as Parkinson's disease (PD), for which no cure is existing today. Much evidence indicates that abnormal Wnt/β-catenin signaling is involved in tumor immunology and the targeting of Wnt/β-catenin pathway has been also proposed as an attractive strategy to potentiate cancer immunotherapy. During the last decade, several products, including naturally occurring dietary agents as well as a wide variety of products from plant sources, including curcumin, quercetin, berberin, and ginsenosides, have been identified as potent modulators of the Wnt/β-catenin signaling and have gained interest as promising candidates for the development of chemopreventive or therapeutic drugs for cancer. In this review we make an overview of the nature-derived compounds reported to have antitumor activity by modulating the Wnt/β-catenin signaling, also focusing on extraction methods, chemical features, and bio-activity assays used for the screening of these compounds.

A fine-tuned β-catenin regulation during proliferation of corneal endothelial cells revealed using proteomics analysis

Corneal endothelial (CE) dysfunction is the main indication for corneal transplantation, an invasive procedure with several limitations. Developing novel strategies to re-activate CE regenerative capacity is, therefore, of fundamental importance. This goal has proved to be challenging as corneal endothelial cells (CEnC) are blocked in the G0/G1 phase of the cell cycle in vivo and, albeit retaining proliferative capacity in vitro, this is further hindered by endothelial-to-mesenchymal transition. Herein we investigated the mechanisms regulating CEnC proliferation in vitro. Comparing the proteome of non-proliferating (in vivo-G0/G1) and proliferating (in vitro-G2/M) rabbit CEnC (rCEnC), 77 proteins, out of 3,328 identified, were differentially expressed in the two groups (p < 0.005). Literature and Gene Ontology analysis revealed β-catenin and transforming growth factor (TGF-β) pathways to be correlated with the identified proteins. Treatment of rCEnC with a β-catenin activator and inhibitor showed that β-catenin activation was necessary during rCEnC proliferation, but not sufficient for its induction. Furthermore, both pro-proliferative activity of basic fibroblast growth factor and anti-proliferative effects of TGF-β were regulated through β-catenin. Overall, these results provide novel insights into the molecular basis underlying the proliferation process that CEnC re-activate in vitro, consolidating the role of β-catenin and TGF-β.

1-Chromonyl-5-Imidazolylpentadienone Demonstrates Anti-Cancer Action against TNBC and Exhibits Synergism with Paclitaxel

Curcumin has been well studied for its anti-oxidant, anti-inflammatory, and anti-cancer action. Its potential as a therapy is limited due to its low bioavailability and rapid metabolism. To overcome these challenges, investigators are developing curcumin analogs, nanoparticle formulations, and combining curcumin with other compounds or dietary components. In the present study, we used a 1-chromonyl-5-imidazolylpentadienone named KY-20-22 that contains both the pharmacophore of curcumin and 1,4 benzopyrone (chromone) moiety typical for flavonoids, and also included specific moieties to enhance the bioavailability. When we tested the in vitro effect of KY-20-22 in triple-negative breast cancer (TNBC) cell lines, we found that it decreased the cell survival and colony formation of MDA-MB-231 and MDA-MB-468 cells. An increase in mitochondrial reactive oxygen species was also observed in TNBC cells exposed to KY-20-22. Furthermore, KY-20-22 decreased epithelial-mesenchymal formation (EMT) as evidenced by the modulation of the EMT markers E-cadherin and N-cadherin. Based on the fact that KY-20-22 regulates interleukin-6, a cytokine involved in chemotherapy resistance, we combined it with paclitaxel and found that it synergistically induced anti-proliferative action in TNBC cells. The results from this study suggested that 1-chromonyl-5-imidazolylpentadienone KY-20-22 exhibited anti-cancer action in MDA-MB-231 and MDA-MB-468 cells. Future studies are required to evaluate the anti-cancer ability and bioavailability of KY-20-22 in the TNBC animal model.

Quercetin treatment reduces the severity of renal dysplasia in a beta-catenin dependent manner

Renal dysplasia, the major cause of childhood renal failure, is characterized by defective branching morphogenesis and nephrogenesis. Beta-catenin, a transcription factor and cell adhesion molecule, is markedly increased in the nucleus of kidney cells in human renal dysplasia and contributes to its pathogenesis by altering target genes that are essential for kidney development. Quercetin, a naturally occurring flavonoid, reduces nuclear beta-catenin levels and reduces beta-catenin transcriptional activity. In this study, we utilized wild type and dysplastic mouse kidney organ explants to determine if quercetin reduces beta-catenin activity during kidney development and whether it improves the severity of renal dysplasia. In wild type kidney explants, quercetin treatment resulted in abnormal branching morphogenesis and nephrogenesis in a dose dependent manner. In wild type embryonic kidneys, quercetin reduced nuclear beta-catenin expression and decreased expression of beta-catenin target genes Pax2, Six2, and Gdnf, which are essential for kidney development. Our RD^B mouse model of renal dysplasia recapitulates the overexpression of beta-catenin and histopathological changes observed in human renal dysplasia. RD^B kidneys treated with quercetin resulted in improvements in the overall histopathology, tissue organization, ureteric branching morphogenesis, and nephrogenesis. Quercetin treatment also resulted in reduced nuclear beta-catenin and reduced Pax2 expression. These improvements were associated with the proper organization of vimentin, NCAM, and E-cadherin, and a 45% increase in the number of developing and maturing nephrons. Further, our results show that in human renal dysplasia, beta-catenin, vimentin, and e-cadherin also have abnormal expression patterns. Taken together, these data demonstrate that quercetin treatment reduces nuclear beta-catenin and this is associated with improved epithelial organization of developing nephrons, resulting in increased developing nephrons and a partial rescue of renal dysplasia.