Repression of mammosphere formation of human breast cancer cells by soy isoflavone genistein and blueberry polyphenolic acids suggests diet-mediated targeting of cancer stem-like/progenitor cells

Autophagy as a Therapeutic Target in Breast Tumors: The Cancer stem cell perspective

Breast cancer is a heterogeneous disease, with a subpopulation of tumor cells known as breast cancer stem cells (BCSCs) with self-renewal and differentiation abilities that play a critical role in tumor initiation, progression, and therapy resistance. The tumor microenvironment (TME) is a complex area where diverse cancer cells reside creating a highly interactive environment with secreted factors, and the extracellular matrix. Autophagy, a cellular self-digestion process, influences dynamic cellular processes in the tumor TME integrating diverse signals that regulate tumor development and heterogeneity. Autophagy acts as a double-edged sword in the breast TME, with both tumor-promoting and tumor-suppressing roles. Autophagy promotes breast tumorigenesis by regulating tumor cell survival, migration and invasion, metabolic reprogramming, and epithelial-mesenchymal transition (EMT). BCSCs harness autophagy to maintain stemness properties, evade immune surveillance, and resist therapeutic interventions. Conversely, excessive, or dysregulated autophagy may lead to BCSC differentiation or cell death, offering a potential avenue for therapeutic exploration. The molecular mechanisms that regulate autophagy in BCSCs including the mammalian target of rapamycin (mTOR), AMPK, and Beclin-1 signaling pathways may be potential targets for pharmacological intervention in breast cancer. This review provides a comprehensive overview of the relationship between autophagy and BCSCs, highlighting recent advancements in our understanding of their interplay. We also discuss the current state of autophagy-targeting agents and their preclinical and clinical development in BCSCs.

Molecular Pathways of Genistein Activity in Breast Cancer Cells

The most common malignancy in women is breast cancer. During the development of cancer, oncogenic transcription factors facilitate the overproduction of inflammatory cytokines and cell adhesion molecules. Antiapoptotic proteins are markedly upregulated in cancer cells, which promotes tumor development, metastasis, and cell survival. Promising findings have been found in studies on the cell cycle-mediated apoptosis pathway for medication development and treatment. Dietary phytoconstituents have been studied in great detail for their potential to prevent cancer by triggering the body's defense mechanisms. The underlying mechanisms of action may be clarified by considering the role of polyphenols in important cancer signaling pathways. Phenolic acids, flavonoids, tannins, coumarins, lignans, lignins, naphthoquinones, anthraquinones, xanthones, and stilbenes are examples of natural chemicals that are being studied for potential anticancer drugs. These substances are also vital for signaling pathways. This review focuses on innovations in the study of polyphenol genistein's effects on breast cancer cells and presents integrated chemical biology methods to harness mechanisms of action for important therapeutic advances.

Recent developments in targeting breast cancer stem cells (BCSCs): a descriptive review of therapeutic strategies and emerging therapies

Despite recent advancements in the diagnosis and treatment of breast cancer (BC), patient outcomes in terms of survival, recurrence, and disease progression remain suboptimal. A significant factor contributing to these challenges is the cellular heterogeneity within BC, particularly the presence of breast cancer stem cells (BCSCs). These cells are thought to serve as the clonogenic nexus for new tumor growth, owing to their hierarchical organization within the tumor. This descriptive review focuses on the evolving strategies to target BCSCs, which have become a pivotal aspect of therapeutic development. We explore a variety of approaches, including targeting specific tumor surface markers (CD133 and CD44), transporters, heat shock proteins, and critical signaling pathways like Notch, Akt, Hedgehog, KLF4, and Wnt/β-catenin. Additionally, we discuss the modulation of the tumor microenvironment through the CXCR-12/CXCR4 axis, manipulation of pH levels, and targeting hypoxia-inducible factors, vascular endothelial growth factor, and CXCR1/2 receptors. Further, this review focuses on the roles of microRNA expression, strategies to induce apoptosis and differentiation in BCSCs, dietary interventions, dendritic cell vaccination, oncolytic viruses, nanotechnology, immunotherapy, and gene therapy. We particularly focused on studies reporting identification of BCSCs, their unique properties and the efficacy of various therapeutic modalities in targeting these cells. By dissecting these approaches, we aim to provide insights into the complex landscape of BC treatment and the potential pathways for improving patient outcomes through targeted BCSC therapies.

Examination of Primary and Secondary Metabolites Associated with a Plant-Based Diet and Their Impact on Human Health

The consumption of plant-based diets has become a burgeoning trend, and they are increasingly consumed globally owing to their substantial energy intensity and dietetic advantages. Plants possess numerous bioactive components that have been recognized to exhibit manifold health-promoting assets. Comprehension of the synthesis of these primary and secondary metabolites by plants and their method of action against several chronic illnesses is a significant requirement for understanding their benefits to human health and disease prevention. Furthermore, the association of biologically active complexes with plants, humans, disease, medicine, and the underlying mechanisms is unexplored. Therefore, this review portrays various bioactive components derived from plant sources associated with health-promoting traits and their action mechanisms. This review paper predominantly assembles proposed plant-derived bioactive compounds, postulating valuable evidence aimed at perceiving forthcoming approaches, including the selection of potent bioactive components for formulating functional diets that are effective against several human disorders. This meticulous evidence could perhaps provide the basis for the advanced preemptive and therapeutic potential promoting human health. Hence, delivery opens possibilities for purchasers to approach the lucrative practice of plants as a remedy, produce novel products, and access new marketplaces.

Role of a Polyphenol-Enriched Blueberry Preparation on Inhibition of Melanoma Cancer Stem Cells and Modulation of MicroRNAs

Melanoma is a type of skin cancer known for its high mortality rate. Cancer stem cells (CSCs) are a subpopulation of cancer cells that significantly contribute to tumour recurrence and differentiation. Epigenetic-specific changes involving miRNAs maintain CSCs. Plant polyphenols have been reported to be involved in cancer chemoprevention and chemotherapy, with miRNAs being the novel effectors in their biological activities. A polyphenol-enriched blueberry preparation (PEBP) derived from fermented blueberries has demonstrated promising chemopreventative properties on breast cancer stem cells by influencing inflammatory pathways and miRNAs. In our current investigation, we seek to unveil the impact of PEBP on inhibiting melanoma development and to elucidate the underlying mechanisms. Our study employs various human cell lines, including an ex vivo cell line derived from a patient's metastatic tumour. We found that it elevates miR-200c, increasing E-cadherin expression and inhibiting miR-210-3p through NF-κB signalling, impacting Epithelial-to-Mesenchymal Transition (EMT), a critical process in cancer progression. PEBP increases the SOCS1 expression, potentially contributing to miR-210-3p inhibition. Experiments involving miRNA manipulation confirm their functional roles. The study suggests that PEBP's anti-inflammatory effects involve regulating miR-200c and miR-210 expression and their targets in EMT-related pathways. The overall aim is to provide evidence-based supportive care and preclinical evaluation of PEBP, offering a promising strategy for skin cancer chemoprevention.

Experimental Studies on the Therapeutic Potential of Vaccinium Berries in Breast Cancer-A Review

Breast cancer (BC) is the largest contributor to cancer deaths in women worldwide. Various parts of plants, including fruits, are known for their therapeutic properties and are used in traditional medicine. Fruit species exhibit anticancer activities due to the presence of bioactive natural compounds such as flavonoids and carotenoids. The Vaccinium spp. are fleshy berry-like drupes and are rich in bioactive compounds, with flavonols, flavanols, chalcones, and phenolic acids as the major groups of compounds. While there is clear evidence linking Vaccinium berries with a decreased risk of BC both in in vivo and in vitro experiments, the exact mechanisms involved in the protective effects of Vaccinium spp. rich extracts on BC cells are not fully understood. Thus, the purpose of this review is to highlight the mechanisms of action involved in the therapeutic potential of Vaccinium berries against BC in experimental models.

Drug repurposing: A novel strategy to target cancer stem cells and therapeutic resistance

Chemotherapy is an effortless and frequently used approach in cancer therapy. However, in most cases, it can only prolong life expectancy and does not guarantee a complete cure. Furthermore, chemotherapy is associated with severe adverse effects, one of the major complications of effective cancer therapy. In addition, newly published research outputs show that cancer stem cells are involved in cancer disease progression, drug resistance, metastasis, and recurrence and that they are functional in the trans-differentiation capacity of cancer stem cells to cancer cells in response to treatments. Novel strategies are therefore required for better management of cancer therapy. The prime approach would be to synthesize and develop novel drugs that need extensive resources, time, and endurance to be brought into therapeutic use. The subsequent approach would be to screen the anti-cancer activity of available non-cancerous drugs. This concept of repurposing non-cancer drugs as an alternative to current cancer therapy has become popular in recent years because using existing anticancer drugs has several adverse effects. Micronutrients have also been investigated for cancer therapy due to their significant anti-cancer effects with negligible or no side effects and availability in food sources. In this paper, we discuss an ideal hypothesis for screening available non-cancerous drugs with anticancer activity, with a focus on cancer stem cells and their clinical application for cancer treatment. Further, drug repurposing and the combination of micronutrients that can target both cancers and cancer stem cells may result in a better therapeutic approach leading to maximum tumor growth control.

The efficacy of natural bioactive compounds against prostate cancer: Molecular targets and synergistic activities

Globally, prostate cancer (PCa) is regarded as a challenging health issue, and the number of PCa patients continues to rise despite the availability of effective treatments in recent decades. The current therapy with chemotherapeutic drugs has been largely ineffective due to multidrug resistance and the conventional treatment has restricted drug accessibility to malignant tissues, necessitating a higher dosage resulting in increased cytotoxicity. Plant-derived bioactive compounds have recently attracted a great deal of attention in the field of PCa treatment due to their potent effects on several molecular targets and synergistic effects with anti-PCa drugs. This review emphasizes the molecular mechanism of phytochemicals on PCa cells, the synergistic effects of compound-drug interactions, and stem cell targeting for PCa treatment. Some potential compounds, such as curcumin, phenethyl-isothiocyanate, fisetin, baicalein, berberine, lutein, and many others, exert an anti-PCa effect via inhibiting proliferation, metastasis, cell cycle progression, and normal apoptosis pathways. In addition, multiple studies have demonstrated that the isolated natural compounds: d-limonene, paeonol, lanreotide, artesunate, and bicalutamide have potential synergistic effects. Further, a significant number of natural compounds effectively target PCa stem cells. However, further high-quality studies are needed to firmly establish the clinical efficacy of these phytochemicals against PCa.

Satureja bachtiarica Induces Cancer Cell Death in Breast and Glioblastoma Cancer in 2D/3D Models and Suppresses Breast Cancer Stem Cells

Overcoming drug resistance and specifically targeting cancer stem cells (CSCs) are critical challenges in improving cancer therapy. Nowadays, the use of novel and native medicinal plants can provide new sources for further investigations for this purpose. The aim of this study was to assess the potential of S. bachtiarica, an endemic plant with diverse medicinal applications, in suppressing and targeting cancer and cancer stem cells in glioblastoma and breast cancer. The effect of S. bachtiarica on viability, migration, invasion, and clonogenic potential of MDAMB-231 and U87-MG cells was assessed in both two- and three-dimensional cell culture models. Additionally, we evaluated its effects on the self-renewal capacity of mammospheres. The experimental outcomes indicated that S. bachtiarica decreased the viability and growth rate of cells and spheroids by inducing apoptosis and inhibited colony formation, migration, and invasion of cells and spheroids. Additionally, colony and sphere-forming ability, as well as the expression of genes associated with EMT and stemness were reduced in mammospheres treated with S. bachtiarica. In conclusion, this study provided valuable insights into the anti-cancer effects of S. bachtiarica, particularly in relation to breast CSCs. Therefore, S. bachtiarica may be a potential adjuvant for the treatment of cancer.

Functional biotransformation of phytoestrogens by gut microbiota with impact on cancer treatment

The human gut is a host for trillions of microorganisms, divided into more than 3000 heterogeneous species, which is called the gut microbiota. The gut microbiota composition can be altered by many different endogenous and exogenous factors, especially diet and nutrition. A diet rich in phytoestrogens, a variable group of chemical compounds similar to 17-β-estradiol (E2), the essential female steroid sex hormone is potent to change the composition of gut microbiota. However, the metabolism of phytoestrogens also highly depends on the action of enzymes produced by gut microbiota. Novel studies have shown that phytoestrogens could play an important role in the treatment of different types of cancers, such as breast cancer in women, due to their potential to decrease estrogen levels. This review aims to summarize recent findings about the lively dialogue between phytoestrogens and the gut microbiota and to address their possible future application, especially in treating patients with diagnosed breast cancer. A potential therapeutic approach for the prevention and improving outcomes in breast cancer patients could be based on targeted probiotic supplementation with the use of soy phytoestrogens. A positive effect of probiotics on the outcome and survival of patients with breast cancer has been established. However, more in vivo scientific studies are needed to pave the way for the use of probiotics and phytoestrogens in the clinical practice of breast cancer treatment.

Anticancer Potential of Apigenin and Isovitexin with Focus on Oncogenic Metabolism in Cancer Stem Cells

It has been demonstrated that cancer stem cells (CSCs) go through metabolic changes that differentiate them from non-CSCs. The altered metabolism of CSCs plays a vital role in tumor initiation, progression, immunosuppression, and resistance to conventional therapy. Therefore, defining the role of CSC metabolism in carcinogenesis has emerged as a main focus in cancer research. Two natural flavonoids, apigenin and isovitexin, have been shown to act synergistically with conventional chemotherapeutic drugs by sensitizing CSCs, ultimately leading to improved therapeutic efficacy. The aim of this study is to present a critical and broad evaluation of the anti-CSC capability of apigenin and isovitexin in different cancers as novel and untapped natural compounds for developing drugs. A thorough review of the included literature supports a strong association between anti-CSC activity and treatment with apigenin or isovitexin. Additionally, it has been shown that apigenin or isovitexin affected CSC metabolism and reduced CSCs through various mechanisms, including the suppression of the Wnt/β-catenin signaling pathway, the inhibition of nuclear factor-κB protein expression, and the downregulation of the cell cycle via upregulation of p21 and cyclin-dependent kinases. The findings of this study demonstrate that apigenin and isovitexin are potent candidates for treating cancer due to their antagonistic effects on CSC metabolism.

Effect of Maternal Gradient Nutritional Restriction during Pregnancy on Mammary Gland Development in Offspring

We aimed to investigate the effect of different levels of nutritional restriction on mammary gland development during the embryonic period by gradient nutritional restriction in pregnant female mice. We started the nutritional restriction of 60 female CD-1(ICR) mice from day 9 of gestation based on 100%, 90%, 80%, 70% and 60% of ad libitum intake. After delivery, the weight and body fat of the offspring and the mother were recorded (n = 12). Offspring mammary development and gene expression were explored by whole mount and qPCR. Mammary development patterns of in offspring were constructed using Sholl analysis, principal component analysis (PCA) and regression analysis. We found that: (1) Mild maternal nutritional restriction (90-70% of ad libitum intake) did not affect offspring weight, while body fat percentage was more sensitive to nutritional restriction (lower at 80% ad libitum feeding). (2) A precipitous drop in mammary development and altered developmental patterns occurred when nutritional restriction ranged from 80% to 70% of ad libitum intake. (3) Mild maternal nutritional restriction (90% of ad libitum intake) promoted mammary-development-related gene expression. In conclusion, our results suggest that mild maternal nutritional restriction during gestation contributes to increased embryonic mammary gland development. When maternal nutritional restriction reaches 70% of ad libitum intake, the mammary glands of the offspring show noticeable maldevelopment. Our results help provide a theoretical basis for the effect of maternal nutritional restriction during gestation on offspring mammary development and a reference for the amount of maternal nutritional restriction.

Three-dimensional cell cultures as preclinical models to assess the biological activity of phytochemicals in breast cancer

The demand for the development of three-dimensional (3D) cell culture models in both/either drug screening and/or toxicology is gradually magnified. Natural Products derived from plants are known as phytochemicals and serve as resources for novel drugs and cancer therapy. Typical examples include taxol analogs (i.e., paclitaxel and docetaxel), vinca alkaloids (i.e., vincristine, vinblastine), and camptothecin analogs (topotecan, irinotecan). Breast cancer is the most frequent malignancy in women, with a 70% chance of patients being cured; however, metastatic disease is not considered curable using currently available chemotherapeutic options. In addition, phytochemicals present promising options for overcoming chemotherapy-related problems, such as drug resistance and toxic effects on non-target tissues. In the toxicological evaluation of these natural compounds, 3D cell culture models are a powerful tool for studying their effects on different tissues and organs in similar environments and behave as if they are in vivo conditions. Considering that 3D cell cultures represent a valuable platform for identifying the biological features of tumor cells as well as for screening natural products with antitumoral activity, the present review aims to summarize the most common 3D cell culture methods, focusing on multicellular tumor spheroids (MCTS) of breast cancer cell lines used in the discovery of phytochemicals with anticancer properties in the last ten years.

Inhibitory Effects of Ursolic Acid on the Stemness and Progression of Human Breast Cancer Cells by Modulating Argonaute-2

The stemness and metastasis of cancer cells are crucial features in determining cancer progression. Argonaute-2 (AGO2) overexpression was reported to be associated with microRNA (miRNA) biogenesis, supporting the self-renewal and differentiation characteristics of cancer stem cells (CSCs). Ursolic acid (UA), a triterpene compound, has multiple biological functions, including anticancer activity. In this study, we find that UA inhibits the proliferation of MDA-MB-231 and MCF-7 breast cancer cell lines using the CCK-8 assay. UA induced a significant decrease in the fraction of CSC in which it was examined by changes in the expression of stemness biomarkers, including the Nanog and Oct4 genes. UA altered invasion and migration capacities by significant decreases in the levels of epithelial-to-mesenchymal transition (EMT) proteins of slug and vimentin. Furthermore, the co-reduction in oncogenic miRNA levels (miR-9 and miR-221) was a result of the down-modulation in AGO2 in breast cancer cells in vitro. Mechanically, UA increases PTEN expression to inactivate the FAK/PI3K/Akt/mTOR signaling pathway and the decreased level of c-Myc in quantitative RT-PCR and Western blot imaging analyses. Our current understanding of the anticancer potential of UA in interrupting between EMT programming and the state of CSC suggests that UA can contribute to improvements in the clinical practice of breast cancer.

Destroying the Shield of Cancer Stem Cells: Natural Compounds as Promising Players in Cancer Therapy

In a scenario where eco-sustainability and a reduction in chemotherapeutic drug waste are certainly a prerogative to safeguard the biosphere, the use of natural products (NPs) represents an alternative therapeutic approach to counteract cancer diseases. The presence of a heterogeneous cancer stem cell (CSC) population within a tumor bulk is related to disease recurrence and therapy resistance. For this reason, CSC targeting presents a promising strategy for hampering cancer recurrence. Increasing evidence shows that NPs can inhibit crucial signaling pathways involved in the maintenance of CSC stemness and sensitize CSCs to standard chemotherapeutic treatments. Moreover, their limited toxicity and low costs for large-scale production could accelerate the use of NPs in clinical settings. In this review, we will summarize the most relevant studies regarding the effects of NPs derived from major natural sources, e.g., food, botanical, and marine species, on CSCs, elucidating their use in pre-clinical and clinical studies.

Targeting Breast Cancer Stem Cells Using Naturally Occurring Phytoestrogens

Breast cancer therapies have made significant strides in improving survival for patients over the past decades. However, recurrence and drug resistance continue to challenge long-term recurrence-free and overall survival rates. Mounting evidence supports the cancer stem cell model in which the existence of a small population of breast cancer stem cells (BCSCs) within the tumor enables these cells to evade conventional therapies and repopulate the tumor, giving rise to more aggressive, recurrent tumors. Thus, successful breast cancer therapy would need to target these BCSCs, as well the tumor bulk cells. Since the Women’s Health Initiative study reported an increased risk of breast cancer with the use of conventional hormone replacement therapy in postmenopausal women, many have turned their attention to phytoestrogens as a natural alternative. Phytoestrogens are plant compounds that share structural similarities with human estrogens and can bind to the estrogen receptors to alter the endocrine responses. Recent studies have found that phytoestrogens can also target BCSCs and have the potential to complement conventional therapy eradicating BCSCs. This review summarized the latest findings of different phytoestrogens and their effect on BCSCs, along with their mechanisms of action, including selective estrogen receptor binding and inhibition of molecular pathways used by BCSCs. The latest results of phytoestrogens in clinical trials are also discussed to further evaluate the use of phytoestrogen in the treatment and prevention of breast cancer.

Targeting Breast Cancer-Derived Stem Cells by Dietary Phytochemicals: A Strategy for Cancer Prevention and Treatment

Breast cancer is heterogeneous disease with variable prognosis and therapeutic response. Approximately, 70% of diagnosed breast cancer represents the luminal A subtype. This subpopulation has a fair prognosis with a lower rate of relapse than the other clinical subtypes. Acquisition of stemness in luminal A subtype modifies the phenotype plasticity to accomplish increased aggressiveness and therapeutic resistance. Therefore, targeting luminal A-derived breast cancer stem cells (BCSCs) could be a promising strategy for its prevention and treatment. Extensive studies reveal that dietary phytochemicals have the potential to target BCSCs by modulating the molecular and signal transduction pathways. Dietary phytochemicals alone or in combination with standard therapeutic modalities exert higher efficacy in targeting BCSCs through changes in stemness, self-renewal properties and hypoxia-related factors. These combinations offer achieving higher radio- and chemo- sensitization through alteration in the key signaling pathways such as AMPK, STAT3, NF-ĸB, Hedgehog, PI3K/Akt/mTOR, Notch, GSK3β, and Wnt related to cancer stemness and drug resistance. In this review, we highlight the concept of targeting luminal A-derived BCSCs with dietary phytochemicals by summarizing the pathways and underlying mechanism(s) involved during therapeutic resistance.

Genistein, a Potential Phytochemical against Breast Cancer Treatment-Insight into the Molecular Mechanisms

Breast cancer (BC) is one of the most common malignancies in women. Although widespread successful synthetic drugs are available, natural compounds can also be considered as significant anticancer agents for treating BC. Some natural compounds have similar effects as synthetic drugs with fewer side effects on normal cells. Therefore, we aimed to unravel and analyze several molecular mechanisms of genistein (GNT) against BC. GNT is a type of dietary phytoestrogen included in the flavonoid group with a similar structure to estrogen that might provide a strong alternative and complementary medicine to existing chemotherapeutic drugs. Previous research reported that GNT could target the estrogen receptor (ER) human epidermal growth factor receptor-2 (HER2) and several signaling molecules against multiple BC cell lines and sensitize cancer cell lines to this compound when used at an optimal inhibitory concentration. More specifically, GNT mediates the anticancer mechanism through apoptosis induction, arresting the cell cycle, inhibiting angiogenesis and metastasis, mammosphere formation, and targeting and suppressing tumor growth factors. Furthermore, it acts via upregulating tumor suppressor genes and downregulating oncogenes in vitro and animal model studies. In addition, this phytochemical synergistically reverses the resistance mechanism of standard chemotherapeutic drugs, increasing their efficacy against BC. Overall, in this review, we discuss several molecular interactions of GNT with numerous cellular targets in the BC model and show its anticancer activities alone and synergistically. We conclude that GNT can have favorable therapeutic advantages when standard drugs are not available in the pharma markets.

Genistein: A Potent Anti-Breast Cancer Agent

Genistein is an isoflavonoid present in high quantities in soybeans. Possessing a wide range of bioactives, it is being studied extensively for its tumoricidal effects. Investigations into mechanisms of the anti-cancer activity have revealed many pathways including induction of cell proliferation, suppression of tyrosine kinases, regulation of Hedgehog-Gli1 signaling, modulation of epigenetic activities, seizing of cell cycle and Akt and MEK signaling pathways, among others via which the cancer cell proliferation can be controlled. Notwithstanding, the observed activities have been time- and dose-dependent. In addition, genistein has also shown varying results in women depending on the physiological parameters, such as the early or post-menopausal states.

A fluorescent aptasensor based on copper nanoclusters for optical detection of CD44 exon v10, an important isoform in metastatic breast cancer

Recent studies suggest that breast cancer cells express various CD44 isoforms. CD44 is an integral transmembrane protein encoded by a single 20-exon gene. Exon v10 of CD44 plays a critical role in promoting cancer metastasis, so sensitive detection of this isoform helps in early diagnosis of metastatic breast cancer and facilitates the treatment process. This study aimed to use v10-specific aptamers to set up an optical aptasensor based on fluorescent metal nanoclusters. For this purpose, nanoclusters of silver, gold, and copper were prepared by different CD44 v10 DNA aptamers as molecular templates. UV-vis, TEM, and fluorescence spectrometer results confirmed the accuracy and quality of the synthesized aptamer-templated nanoclusters (Apt-NCs). Finally, we compared the performance of the as-prepared Apt-NCs in response to different cultured cell lines. According to the results, the optical response of M-Apt4-CuNCs was more efficient and correlated well with the concentrations of CD44 v10-enriched cells. The detection limit of the aptasensor was 40 ± 5 cells per mL.

A Nuclear-Directed Ribonuclease Variant Targets Cancer Stem Cells and Inhibits Migration and Invasion of Breast Cancer Cells

Simple Summary

During the past decades the achievements made in treating cancers have significantly improved the survival of patients. However, cancer is still one of the leading causes of mortality. It is suggested that treatment failure is mediated by a subpopulation of tumor cells named cancer stem cells that can survive after treatment and promote cancer relapse. Targeting these cells is important to improve cancer therapy. The aim of our study is to determine the effect of a human ribonuclease variant on breast cancer cells grown in 3D and on cancer stem cells. Moreover, we study its effect on the ability of breast cancer cells to migrate and produce metastasis, responsible for about 90% of cancer deaths. We show that this ribonuclease arrests tumor cells grown in 3D without affecting normal breast cells, and this significantly inhibits cancer stem cell development. Additionally, it reduces the migratory and invasive capacities of tumor cells.

Abstract

Despite the significant advances in cancer research made in recent years, this disease remains one of the leading causes of death worldwide. In part, this is due to the fact that after therapy, a subpopulation of self-renewing tumor cells can survive and promote cancer relapse, resistance to therapies and metastasis. Targeting these cancer stem cells (CSCs) is therefore essential to improve the clinical outcome of cancer patients. In this sense, multi-targeted drugs may be promising agents targeting CSC-associated multifocal effects. We have previously constructed different human pancreatic ribonuclease (RNase) variants that are cytotoxic for tumor cells due to a non-classical nuclear localization signal introduced in their sequence. These cytotoxic RNases affect the expression of multiple genes involved in deregulated metabolic and signaling pathways in cancer cells and are highly cytotoxic for multidrug-resistant tumor cell lines. Here, we show that these cytotoxic nuclear-directed RNases are highly selective for tumor cell lines grown in 3D, inhibit CSCs’ development and diminish the self-renewal capacity of the CSCs population. Moreover, these human RNase variants reduce the migration and invasiveness of highly invasive breast cancer cells and downregulate N-cadherin expression.

Targeting cancer stem cells by nutraceuticals for cancer therapy

Accumulating evidence has demonstrated that cancer stem cells (CSCs) play an essential role in tumor progression and reoccurrence and drug resistance. Multiple signaling pathways have been revealed to be critically participated in CSC development and maintenance. Emerging evidence indicates that numerous chemopreventive compounds, also known as nutraceuticals, could eliminate CSCs in part via regulating several signaling pathways. Therefore, in this review, we will describe the some natural chemopreventive agents that target CSCs in a variety of human malignancies, including soy isoflavone, curcumin, resveratrol, tea polyphenols, sulforaphane, quercetin, indole-3-carbinol, 3,3'-diindolylmethane, withaferin A, apigenin, etc. Moreover, we discuss that eliminating CSCs by nutraceuticals might be a promising strategy for treating human cancer via overcoming drug resistance and reducing tumor reoccurrence.

Natural Products as a Promising Therapeutic Strategy to Target Cancer Stem Cells

Cancer is still a deadly disease, and its treatment desperately needs to be managed in a very sophisticated way through fast-developing novel strategies. Most of the cancer cases eventually develop into recurrencies, for which cancer stem cells (CSCs) are thought to be responsible. They are considered as a subpopulation of all cancer cells of tumor tissue with aberrant regulation of self-renewal, unbalanced proliferation, and cell death properties. Moreover, CSCs show a serious degree of resistance to chemotherapy or radiotherapy and immune surveillance as well. Therefore, new classes of drugs are rushing into the market each year, which makes the cost of therapy increase dramatically. Natural products are also becoming a new research area as a diverse chemical library to suppress CSCs. Some of the products even show promise in this regard. So, the near future could witness the introduction of natural products as a source of new chemotherapy modalities, which may result in the development of novel anticancer drugs. They could also be a reasonably-priced alternative to highly expensive current treatments. Nowadays, considering the effects of natural compounds on targeting surface markers, signaling pathways, apoptosis, and escape from immunosurveillance have been a highly intriguing area in preclinical and clinical research. In this review, we present scientific advances regarding their potential use in the inhibition of CSCs and the mechanisms by which they kill the CSCs.

Probiotics for the Chemoprotective Role Against the Toxic Effect of Cancer Chemotherapy

BACKGROUND

The processes of chemo- and radiation therapy-based clinical management of different types of cancers are associated with toxicity and side effects of chemotherapeutic agents. So, there is always an unmet need to explore agents to reduce such risk factors. Among these, natural products have generated much attention because of their potent antioxidant and antitumor effects. In the past, some breakthrough outcomes established that various bacteria in the human intestinal gut are bearing growth-promoting attributes and suppressing the conversion of pro-carcinogens into carcinogens. Hence, probiotics integrated approaches are nowadays being explored as rationalized therapeutics in the clinical management of cancer.

METHODS

Here, published literature was explored to review chemoprotective roles of probiotics against toxic and side effects of chemotherapeutics.

RESULTS

Apart from excellent anti-cancer abilities, probiotics are bearing and alleviate toxicity and side effects of chemotherapeutics, with a high degree of safety and efficiency.

CONCLUSION

Preclinical and clinical evidence suggested that due to the chemoprotective roles of probiotics against side effects and toxicity of chemotherapeutics, their integration in chemotherapy would be a judicious approach.

Potential Health Benefits of Plant Food-Derived Bioactive Components: An Overview

Plant foods are consumed worldwide due to their immense energy density and nutritive value. Their consumption has been following an increasing trend due to several metabolic disorders linked to non-vegetarian diets. In addition to their nutritive value, plant foods contain several bioactive constituents that have been shown to possess health-promoting properties. Plant-derived bioactive compounds, such as biologically active proteins, polyphenols, phytosterols, biogenic amines, carotenoids, etc., have been reported to be beneficial for human health, for instance in cases of cancer, cardiovascular diseases, and diabetes, as well as for people with gut, immune function, and neurodegenerative disorders. Previous studies have reported that bioactive components possess antioxidative, anti-inflammatory, and immunomodulatory properties, in addition to improving intestinal barrier functioning etc., which contribute to their ability to mitigate the pathological impact of various human diseases. This review describes the bioactive components derived from fruit, vegetables, cereals, and other plant sources with health promoting attributes, and the mechanisms responsible for the bioactive properties of some of these plant components. This review mainly compiles the potential of food derived bioactive compounds, providing information for researchers that may be valuable for devising future strategies such as choosing promising bioactive ingredients to make functional foods for various non-communicable disorders.

The Great Escape: The Power of Cancer Stem Cells to Evade Programmed Cell Death

Cancer is one of the primary causes of death worldwide. Tumour malignancy is related to tumor heterogeneity, which has been suggested to be due to a small subpopulation of tumor cells named cancer stem cells (CSCs). CSCs exert a key role in metastasis development, tumor recurrence, and also epithelial-mesenchymal transition, apoptotic resistance, self-renewal, tumorigenesis, differentiation, and drug resistance. Several current therapies fail to eradicate tumors due to the ability of CSCs to escape different programmed cell deaths. Thus, developing CSC-selective and programmed death-inducing therapeutic approaches appears to be of primary importance. In this review, we discuss the main programmed cell death occurring in cancer and the promising CSC-targeting agents developed in recent years. Even if the reported studies are encouraging, further investigations are necessary to establish a combination of agents able to eradicate CSCs or inhibit their growth and proliferation.

Natural and herbal compounds targeting breast cancer, a review based on cancer stem cells

Cancer stem cells (CSCs) are known as the major reason for therapy resistance. Recently, natural herbal compounds are suggested to have a significant role in inhibiting the breast cancer stem cells (BCSCs). The aim of this study was to explore the effective natural herbal compounds against BCSCs.This review article was designed based on the BCSCs, mechanisms of therapy resistance and natural herbal compounds effective to inhibit their activity. Therefore, Science direct, PubMed and Scopus databases were explored and related original articles were investigated from 2010 to 2019. BCSCs use different mechanisms including special membrane transporters, anti-apoptotic, pro-survival, and self-renewal- related signaling pathways. Natural herbal compounds could disturb these mechanisms, therefore may inhibit or eradicate the BCSCs. Studies show that a broad range of plants, either as a food or medicine, contain anti-cancer agents that phenolic components and their different derivatives share a large quantity. Natural herbal compounds play a pivotal role in the eradication of BCSCs, through the inhibition of biological activities and induction of apoptosis. Although it is necessary to conduct more clinical investigation.

The protoapigenone analog WYC0209 targets CD133+ cells: A potential adjuvant agent against cancer stem cells in urothelial cancer therapy

Urothelial carcinoma (UC) is one of the highest incidence cancers that rank the fourth commonly diagnosed tumors worldwide. The unresectable lesions that are resistant to therapeutic interventions is the major cause leading to death. Previous studies had shown that the resistance and metastatic consequence may arise from cancer stem-like cells population. The phytochemical flavonoids have promised bioactivity and potent anti-carcinogenic effects, and trap great attentions for cancer chemoprevention and/or adjuvant chemotherapy. However, the mechanisms of flavonoids on cancer stemness is still obscured. In this study, we analyzed the biofunctional effects of as-prepared flavonoid derivative-WYC0209 on T24, BFTC905 and BFTC909 human UC cell lines. Our results demonstrated that WYC0209 significantly induced anti-cell viability on UC cells through decreased Akt/NFkB signaling. Moreover, WYC0209 enhanced the cell apoptosis through activated the caspase-3 activity and inactivated Bcl-xL expression. Interestingly, WYC0209 dramatically inhibited the cancer stem cells (CSCs) traits, including attenuation of side population and tumorsphere formation in which were through declined EMT-CSCs markers including MDR1, ABCG2 and BMI-1. We further validated the effects of WYC0209 on several CSC surface markers including CD133, CD44, SOX-2 and Nanog. Our results showed that WYC0209 markedly inhibited CD133 expressions in both transcriptional and translational levels. High expression levels of CD133 was also demonstrated in human upper tract UC specimens. In summary, our study showed that WYC0209 may potentially as an adjuvant agent to against CD133-driven UC CSCs and provide a beneficial strategy to against UC cancer therapeutics resistant.

Molecular Insights Into Therapeutic Potential of Autophagy Modulation by Natural Products for Cancer Stem Cells

Autophagy, a cellular self-digestion process that is activated in response to stress, has a functional role in tumor formation and progression. Cancer stem cells (CSCs) accounting for a minor proportion of total cancer cells-have distinct self-renewal and differentiation abilities and promote metastasis. Researchers have shown that a numeral number of natural products using traditional experimental methods have been revealed to target CSCs. However, the specific role of autophagy with respect to CSCs and tumorigenesis using natural products are still unknown. Currently, CSCs are considered to be one of the causative reasons underlying the failure of anticancer treatment as a result of tumor recurrence, metastasis, and chemo- or radio-resistance. Autophagy may play a dual role in CSC-related resistance to anticancer treatment; it is responsible for cell fate determination and the targeted degradation of transcription factors via growth arrest. It has been established that autophagy promotes drug resistance, dormancy, and stemness and maintenance of CSCs. Surprisingly, numerous studies have also suggested that autophagy can facilitate the loss of stemness in CSCs. Here, we review current progress in research related to the multifaceted connections between autophagy modulation and CSCs control using natural products. Overall, we emphasize the importance of understanding the role of autophagy in the maintenance of different CSCs and implications of this connection for the development of new strategies for cancer treatment targeting natural products.

Targeting Breast Cancer Stem Cells: A Methodological Perspective

Cancer Stem Cells (CSCs) constitute a subpopulation at the top of the tumor cell hierarchy that contributes to tumor heterogeneity and is uniquely capable of seeding new tumors. Because of their biological properties, CSCs have been pointed out as therapeutic targets for the development of new therapies against breast cancer. The identification of drugs that selectively target breast CSCs requires a clear understanding of their biological functions and the experimental methods to evaluate such hallmarks. Herein, we review the methods to study breast CSCs properties and discuss their value in the preclinical evaluation of CSC-targeting drugs.

Dissecting the prevention of estrogen-dependent breast carcinogenesis through Nrf2-dependent and independent mechanisms

Breast cancer is the most common malignancy among women worldwide. Various studies indicate that prolonged exposure to elevated levels of estrogens is associated with development of breast cancer. Both estrogen receptor-dependent and independent mechanisms can contribute to the carcinogenic effects of estrogens. Among them, the oxidative metabolism of estrogens plays a key role in the initiation of estradiol-induced breast cancer by generation of reactive estrogen quinones as well as the associated formation of oxygen free radicals. These genotoxic metabolites can react with DNA to form unstable DNA adducts which generate mutations leading to the initiation of breast cancer. A variety of endogenous and exogenous factors can alter estrogen homeostasis and generate genotoxic metabolites. The use of specific phytochemicals and dietary supplements can inhibit the risk of breast cancer not only by the modulation of several estrogen-activating enzymes (CYP19, CYP1B1) but also through the induction of various cytoprotective enzymes (eg, SOD3, NQO1, glutathione S-transferases, OGG-1, catechol-O-methyltransferases, CYP1B1A, etc.) that reestablish the homeostatic balance of estrogen metabolism via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent and independent mechanisms.

Prevention of breast cancer by dietary polyphenols-role of cancer stem cells

Breast cancer is a common malignancy with poor prognosis. Cancer cells are heterogeneous and cancer stem cells (CSCs) are primarily responsible for tumor relapse, treatment-resistance and metastasis, so for breast cancer stem cells (BCSCs). Diets are known to be associated with carcinogenesis. Food-derived polyphenols are able to attenuate the formation and virulence of BCSCs, implying that these compounds and their analogs might be promising agents for preventing breast cancer. In the present review, we summarized the origin and surface markers of BCSCs and possible mechanisms responsible for the inhibitory effects of polyphenols on BCSCs. The suppressive effects of common dietary polyphenols against BCSCs, such as curcumin, epigallocatechin gallate (EGCG) and related polyphenolic compounds were further discussed.

The "Yin and Yang" of Natural Compounds in Anticancer Therapy of Triple-Negative Breast Cancers

Among the different types of breast cancers, triple-negative breast cancers (TNBCs) are highly aggressive, do not respond to conventional hormonal/human epidermal growth factor receptor 2 (HER2)-targeted interventions due to the lack of the respective receptor targets, have chances of early recurrence, metastasize, tend to be more invasive in nature, and develop drug resistance. The global burden of TNBCs is increasing regardless of the number of cytotoxic drugs being introduced into the market each year as they have only moderate efficacy and/or unforeseen side effects. Therefore, the demand for more efficient therapeutic interventions, with reduced side effects, for the treatment of TNBCs is rising. While some plant metabolites/derivatives actually induce the risk of cancers, many plant-derived active principles have gained attention as efficient anticancer agents against TNBCs, with fewer adverse side effects. Here we discuss the possible oncogenic molecular pathways in TNBCs and how the purified plant-derived natural compounds specifically target and modulate the genes and/or proteins involved in these aberrant pathways to exhibit their anticancer potential. We have linked the anticancer potential of plant-derived natural compounds (luteolin, chalcones, piperine, deguelin, quercetin, rutin, fisetin, curcumin, resveratrol, and others) to their ability to target multiple dysregulated signaling pathways (such as the Wnt/β-catenin, Notch, NF-κB, PI3K/Akt/mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK) and Hedgehog) leading to suppression of cell growth, proliferation, migration, inflammation, angiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, and activation of apoptosis in TNBCs. Plant-derived compounds in combination with classical chemotherapeutic agents were more efficient in the treatment of TNBCs, possibly with lesser side effects.

Single-Cell Tracking of Breast Cancer Cells Enables Prediction of Sphere Formation from Early Cell Divisions

The mammosphere assay has become widely employed to quantify stem-like cells in a population. However, the problem is there is no standard protocol employed by the field. Cell seeding densities of 1,000 to 100,000 cells/mL have been reported. These high densities lead to cellular aggregation. To address this, we have individually tracked 1,127 single MCF-7 and 696 single T47D human breast tumor cells by eye over the course of 14 days. This tracking has given us detailed information for the commonly used endpoints of 5, 7, and 14 days that is unclouded by cellular aggregation. This includes mean sphere sizes, sphere-forming efficiencies, and a well-defined minimum size for both lines. Importantly, we have correlated early cell division with eventual sphere formation. At 24 hr post seeding, we can predict the total spheres on day 14 with 98% accuracy in both lines. This approach removes cell aggregation and potentially shortens a 5- to 14-day assay to a 24 hours.

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Single-cell tracking removes confounding aggregation from the mammosphere assay

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Tracking reveals sphere-forming efficiencies much higher than commonly reported

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True clonal spheres are smaller than commonly reported

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At 24 hours, tracking can predict total day 14 spheres with 98% accuracy

Targeting ubiquitin-proteasome pathway by natural, in particular polyphenols, anticancer agents: Lessons learned from clinical trials

The ubiquitin-proteasome pathway (UPP) is the main non-lysosomal proteolytic system responsible for degradation of most intracellular proteins, specifically damaged and regulatory proteins. The UPP is implicated in all aspects of the cellular metabolic networks including physiological or pathological conditions. Alterations in the components of the UPP can lead to stabilization of oncoproteins or augmented degradation of tumour suppressor favouring cancer appearance and progression. Polyphenols are natural compounds that can modulate proteasome activity or the expression of proteasome subunits. All together and due to the pleiotropic functions of UPP, there is a great interest in this proteasome system as a promising therapeutic target for the development of novel anti-cancer drugs. In the present review, the main features of the UPP and its implication in cancer development and progression are described, highlighting the importance of bioactive polyphenols that target the UPP as potential anti-cancer agents.

Targeting cancer stem cells with dietary phytochemical - Repositioned drug combinations

The tumor microenvironment is complex with the cancer stem cell (CSC) as a member within its community. This population possesses the capacity to self-renew and to cause cellular heterogeneity of the tumor. CSCs are resistant to conventional anti-proliferative drugs. In order to be curative, it is imperative that CSCs must be eliminated by cancer therapy. A variety of dietary phytochemicals and repositioned drugs can act synergistically with conventional anti-cancer agents. In this review, we advocate the development of a novel approach, namely combination therapy by incorporating both phytochemicals and repositioned drugs to target CSCs. We cover select dietary phytochemicals (curcumin, resveratrol, EGCG, genistein) and repurposed drugs (metformin, niclosamide, thioridazine, chloroquine). Five of the eight (curcumin, resveratrol, EGCG, genistein, metformin) are listed in “The Halifax Project”, that explores “the concept of a low-toxicity ‘broad-spectrum’ therapeutic approach that could simultaneously target many key pathways and mechanisms” [1]. For these compounds, we discuss their mechanisms of action, in which models their anti-CSC activities were identified, as well as advantages, challenges and potentials of combination therapy.

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Cancer stem cells (CSCs) are the culprits for cancer drug resistance and cancer relapse.

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Dietary phytochemicals (curcumin, resveratrol, epigallocatechin gallate) target CSCs.

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Repositioned drugs (metformin, niclosamide, thioridazine) target CSCs.

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Phytochemical-drug combinations targeting CSCs may exhibit synergistic effects.

Polyphenols in Colorectal Cancer: Current State of Knowledge including Clinical Trials and Molecular Mechanism of Action

Polyphenols have been reported to have wide spectrum of biological activities including major impact on initiation, promotion, and progression of cancer by modulating different signalling pathways. Colorectal cancer is the second most major cause of mortality and morbidity among females and the third among males. The objective of this review is to describe the activity of a variety of polyphenols in colorectal cancer in clinical trials, preclinical studies, and primary research. The molecular mechanisms of major polyphenols related to their beneficial effects on colorectal cancer are also addressed. Synthetic modifications and other future directions towards exploiting of natural polyphenols against colorectal cancer are discussed in the last section.

Beyond Conventional Medicine - a Look at Blueberry, a Cancer-Fighting Superfruit

Nearly 40% of men and women will be diagnosed with cancer during their lifetime. Thus, there is a rapidly growing need for novel therapies to combat this deadly disease. One such method is the consumption of blueberries. Long coveted for their powerful antioxidant properties, more recent studies have demonstrated that blueberries also exhibit inherent abilities to prevent carcinogenesis, inhibit the proliferation of neoplastic cells, and reduce the risks of recurrence in patients in remission. This review will focus on the specific activities of blueberry derivatives in cancer cells across many different forms of cancer. Ultimately, such research could be helpful in the development of new strategies to treat cancer.

Mechanistic Study of Bakuchiol-Induced Anti-breast Cancer Stem Cell and in Vivo Anti-metastasis Effects

Cancer stem cells are involved in cancer establishment, progression, and resistance to current treatments. We demonstrated the in vitro and in vivo anti-breast cancer effect of bakuchiol in a previous study. However, the ability of bakuchiol to target breast cancer stem cells (BCSCs) and inhibit breast cancer metastasis remains unknown. In the current study, we used the cell surface markers CD44 and CD24 to distinguish BCSCs from MCF-7 cells. Bakuchiol inhibited mammosphere formation and aldehyde dehydrogenase activity in BCSCs. Moreover, bakuchiol induced apoptosis and suppressed the mitochondrial membrane potential of BCSCs. Bakuchiol upregulated the expression levels of pro-apoptotic genes, BNIP3 and DAPK2. Bakuchiol induced oxidative stress and altered lipogenesis in BCSCs. In zebrafish xenografts, bakuchiol inhibited breast cancer cell metastasis in vivo. In addition, bakuchiol altered the expression levels of metastasis-related genes through upregulating CK18 and downregulating Notch3, FASN, TGFBR1, and ACVR1B. Our study provides evidence for the anti-breast cancer potential of bakuchiol.

Pomegranate Extract Alters Breast Cancer Stem Cell Properties in Association with Inhibition of Epithelial-to-Mesenchymal Transition

Cancer stem cells (CSCs) have become an important target population in cancer therapy and prevention due to their ability to self-renew, initiate tumors, and resist therapy. We examined whether pomegranate extract (PE) alters characteristics of breast CSCs. Ability to grow as mammospheres is a hallmark of breast CSCs. PE inhibited mammosphere formation in two different cell lines, neoplastic mammary epithelial HMLER and breast cancer Hs578T. In addition, mammosphere-derived cells from PE treatment groups showed reduced mammosphere formation for at least two serial passages. These data indicate that PE inhibits CSC's ability to self-renew. In addition, incubation of mammospheres with PE reversed them into adherent cultures, indicating promotion of CSC differentiation. Epithelial-to-mesenchymal transition (EMT) is a key program in generating CSCs and maintaining their characteristics. Thus, we examined the effect of PE on EMT. PE reduced cell migration, a major feature of the EMT phenotype. In addition, PE downregulated genes involved in EMT, including the EMT-inducing transcription factor Twist family basic helix-loop-helix transcription factor 1 (TWIST1). This suggests that PE suppresses CSC characteristics in part due to inhibition of EMT. The ability of PE to suppress CSCs can be exploited in the prevention of breast cancer.

DNA Methylation Targets Influenced by Bisphenol A and/or Genistein Are Associated with Survival Outcomes in Breast Cancer Patients

Early postnatal exposures to Bisphenol A (BPA) and genistein (GEN) have been reported to predispose for and against mammary cancer, respectively, in adult rats. Since the changes in cancer susceptibility occurs in the absence of the original chemical exposure, we have investigated the potential of epigenetics to account for these changes. DNA methylation studies reveal that prepubertal BPA exposure alters signaling pathways that contribute to carcinogenesis. Prepubertal exposure to GEN and BPA + GEN revealed pathways involved in maintenance of cellular function, indicating that the presence of GEN either reduces or counters some of the alterations caused by the carcinogenic properties of BPA. We subsequently evaluated the potential of epigenetic changes in the rat mammary tissues to predict survival in breast cancer patients via the Cancer Genomic Atlas (TCGA). We identified 12 genes that showed strong predictive values for long-term survival in estrogen receptor positive patients. Importantly, two genes associated with improved long term survival, HPSE and RPS9, were identified to be hypomethylated in mammary glands of rats exposed prepuberally to GEN or to GEN + BPA respectively, reinforcing the suggested cancer suppressive properties of GEN.

Blueberries inhibit cyclooxygenase-1 and cyclooxygenase-2 activity in human epithelial ovarian cancer

Ovarian cancer (OC) is the sixth and eighth leading cause of cancer mortality among women in developed and developing countries, respectively. Medical therapy is the main method for the treatment of OC. However, drug toxicity and the marked side effects of chemotherapy limit the usage and therapeutic results of the treatments. Therefore, the identification of multi-target agents with few side effects and high effectiveness is required. Traditional Chinese medicine has been used clinically to treat various types of cancer for thousands of years and is considered to possess multiple components and agents, which exert efficient therapeutic functions with few side effects. Although blueberries have previously been used to treat various types of cancer, the effect on OC and precise molecular mechanism of function of the fruit remains unknown. Cyclooxygenase (COX)-1 and COX-2 have been reported to be the biomarkers of OC. Blueberries may affect the progression of OC by affecting COX levels. To investigate the issue, COX-1 and COX-2 were overexpressed or silenced in ovarian cancer SKOV3 cells. The effect of blueberries on SKOV3 cell viability was determined by an MTT assay. Furthermore, a mouse model for OC was established. The results indicated that blueberries inhibited the proliferation of OC cells by downregulating the levels of COX-1 and COX-2. Blueberry (400 mg daily) consumption reduced tumor size significantly in mice with OC compared with the control without blueberry treatment (P<0.05). The results suggest that blueberries should be used to develop a potential non-pharmaceutical therapy for OC.

Phenolic Acid Profiling, Antioxidant, and Anti-Inflammatory Activities, and miRNA Regulation in the Polyphenols of 16 Blueberry Samples from China

To investigate the anti-atherosclerosis related mechanism of blueberries, the phenolic acids (PAs) content, antioxidant and anti-inflammatory activities, as well as the microRNA (miRNA) regulation of polyphenol fractions in blueberry samples from China were studied. Sixteen batches of blueberries including 14 commercialized cultivars (Reka, Patriot, Brigitta, Bluecrop, Berkeley, Duke, Darrow, Northland, Northblue, Northcountry, Bluesource, Southgood, O’Neal, and Misty) were used in this study. Seven PAs in the polyphenol fractions from 16 blueberry samples in China were quantified by high performance liquid chromatography/tandem mass spectrometry (HPLC/MS²). The antioxidant activities of blueberry polyphenols were tested by (1,1-diphenyl-2-picrylhydrazyl [DPPH]) assay. The anti-inflammatory (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) activities of the polyphenol fractions of the blueberries were investigated by using lipopolysaccharide (LPS) induced RAW 264.7 macrophages. The correlation analysis showed that the antioxidant (1,1-diphenyl-2-picrylhydrazyl [DPPH]) and anti-inflammatory (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) activities of the polyphenol fractions of the blueberries were in accordance with their PA contents. Although the polyphenol-enriched fractions of blueberries could inhibit the microRNAs (miRNAs) (miR-21, miR-146a, and miR-125b) to different extents, no significant contribution from the PAs was observed. The inhibition of these miRNAs could mostly be attributed to the other compounds present in the polyphenol-enriched fraction of the blueberries. This is the first study to evaluate the PAs content, antioxidant and anti-inflammatory activities, and miRNA regulation of Chinese blueberries.

Short-term early exposure to lapatinib confers lifelong protection from mammary tumor development in MMTV-erbB-2 transgenic mice

BACKGROUND

Although chemopreventative agents targeting the estrogen/estrogen receptor (ER) pathway have been effective for ER⁺ breast cancers, prevention of hormone receptor-negative breast cancers, such as Her2/erbB-2⁺ breast cancers, remains a significant issue. Previous studies have demonstrated that administration of EGFR/erbB-2-targeting lapatinib to MMTV-erbB-2 transgenic mice inhibited mammary tumor development. The prevention, however, was achieved by prolonged high dose exposure. The tolerance to high dose/long-term drug administration may hinder its potential in clinical settings. Therefore, we aimed to test a novel, short-term chemopreventative strategy using lapatinib during the premalignant risk window in MMTV-erbB-2 mice.

METHODS

We initially treated cultured cells with lapatinib to explore the anti-proliferative effects of lapatinib in vitro. We used a syngeneic tumor graft model to begin exploring the in vivo anti-tumorigenic effects of lapatinib in MMTV-erbB-2 mice. Then, we tested the efficacy of brief exposure to lapatinib (100 mg/kg/day for 8 weeks), beginning at 16 weeks of age, in the prevention of mammary tumor development in MMTV-erbB-2 mice.

RESULTS

In the syngeneic tumor transplant model, we determined that lapatinib significantly inhibited tumor cell proliferation. Furthermore, we demonstrated that short-term lapatinib exposure resulted in life-long protective effects, as supported by increased tumor latency in lapatinib-treated mice compared to the control mice. We further established that delayed tumor development in the treated mice was preceded by decreased BrdU nuclear incorporation and inhibited mammary morphogenesis. Molecular analysis indicated that lapatinib inhibited phosphorylation and expression of EGFR, erbB-3, erbB-2, Akt1, and Erk1/2 in premalignant mammary tissues. Also, lapatinib drastically inhibited the phosphorylation and expression of ERα and the transcription of ER target genes in premalignant mammary tissues. We also determined that lapatinib suppressed the stemness of breast cancer cell lines, as evidenced by decreased tumorsphere formation and ALDH⁺ cell populations.

CONCLUSIONS

Taken together, these data demonstrate that brief treatment with EGFR/erbB-2-targeting agents before the onset of tumors may provide lifelong protection from mammary tumors, through the concurrent inhibition of erbB-2 and ER signaling pathways and consequential reprogramming. Our findings support further clinical testing to explore the benefit of shorter lapatinib exposure in the prevention of erbB-2-mediated carcinogenesis.