Epigallocatechin-3-O-gallate up-regulates microRNA-let-7b expression by activating 67-kDa laminin receptor signaling in melanoma cells

Protein phosphatase 2A modulation and connection with miRNAs and natural products

Protein phosphatase 2A (PP2A), a heterotrimeric holoenzyme (scaffolding, catalytic, and regulatory subunits), regulates dephosphorylation for more than half of serine/threonine phosphosites and exhibits diverse cellular functions. Although several studies on natural products and miRNAs have emphasized their impacts on PP2A regulation, their connections lack systemic organization. Moreover, only part of the PP2A family has been investigated. This review focuses on the PP2A-modulating effects of natural products and miRNAs' interactions with potential PP2A targets in cancer and non-cancer cells. PP2A-modulating natural products and miRNAs were retrieved through a literature search. Utilizing the miRDB database, potential PP2A targets of these PP2A-modulating miRNAs for the whole set (17 members) of the PP2A family were retrieved. Finally, PP2A-modulating natural products and miRNAs were linked via a literature search. This review provides systemic directions for assessing natural products and miRNAs relating to the PP2A-modulating functions in cancer and disease treatments.

EGCG Disrupts the LIN28B/Let-7 Interaction and Reduces Neuroblastoma Aggressiveness

Neuroblastoma (NB) is the most commonly diagnosed extracranial solid tumor in children, accounting for 15% of all childhood cancer deaths. Although the 5-year survival rate of patients with a high-risk disease has increased in recent decades, NB remains a challenge in pediatric oncology, and the identification of novel potential therapeutic targets and agents is an urgent clinical need. The RNA-binding protein LIN28B has been identified as an oncogene in NB and is associated with a poor prognosis. Given that LIN28B acts by negatively regulating the biogenesis of the tumor suppressor let-7 miRNAs, we reasoned that selective interference with the LIN28B/let-7 miRNA interaction would increase let-7 miRNA levels, ultimately leading to reduced NB aggressiveness. Here, we selected (-)-epigallocatechin 3-gallate (EGCG) out of 4959 molecules screened as the molecule with the best inhibitory activity on LIN28B/let-7 miRNA interaction and showed that treatment with PLC/PLGA-PEG nanoparticles containing EGCG (EGCG-NPs) led to an increase in mature let-7 miRNAs and a consequent inhibition of NB cell growth. In addition, EGCG-NP pretreatment reduced the tumorigenic potential of NB cells in vivo. These experiments suggest that the LIN28B/let-7 miRNA axis is a good therapeutic target in NB and that EGCG, which can interfere with this interaction, deserves further preclinical evaluation.

Regulatory effect of Epigallocatechin-3-O-gallate on circular RNA expression in mouse liver

There are few studies on the connection between food components and circular RNA (circRNA), a type of noncoding RNA that is significant for living organisms. (-)-Epigallocatechin-3-O-gallate (EGCG) has been reported to have various biological effects, and elucidation of the molecular mechanism is important for clarifying the functionality of EGCG. In the current study, we looked at how EGCG regulates the expression of circRNA in the liver, which expresses a lot of circRNAs. Mice were given EGCG (10 mg/kg b.w.) orally for one week before circRNA microarray testing was done on their livers. The microarray analysis revealed that mice treated with EGCG had altered expression of 35 circRNAs in their livers. To clarify the function of mmu_circRNA_011775, one of the circRNAs upregulated by EGCG, mouse liver cells after the mmu_circRNA_011775 expression vector was transfected into NMuLi cells, next-generation sequencing (NGS) was used to analyze the gene expression. NGS analysis shows that the expression of the genes responsible for liver fibrosis and inflammation. Gene ontology (GO) analysis showed that mmu_circRNA_011775 changed the meaning of GO terms associated with the cardiovascular system. In the microarray, EGCG altered 35 genes expression. Among them, pre-ribosomal RNA-derived circRNA mmu_circRNA_011775 regulated the expression of various genes related to liver fibrosis and cardiovascular system.

Regulation of gene expression by modulating microRNAs through Epigallocatechin-3-gallate in cancer

Cancer is an intricate ailment that has a higher death rate globally and is characterized by aberrant cell proliferation and metastasis in nature. Since the beginning of healthcare, natural products, especially those derived from plants, have been utilized to support human health. Green tea contains an essential catechin called epigallocatechin gallate, which has anti-proliferative, anti-mutagenic, anti-inflammatory, and antioxidative properties. The anticancer properties of EGCG have been extensively studied using pre-clinical cell culture and animal model systems. Dysregulated miRNA may be a biomarker since it influences the different characteristics of cancer like upholding proliferative signaling, cell death, invasiveness, metastasis, and angiogenesis. EGCG either elevates or lowers the expression of dysregulated miRNAs in cancer. Nonetheless, due to its anticancer properties, greater attention has been paid towards the development of efficient strategies for utilizing EGCG in cancer chemotherapy. This review summarizes the modifying effect of EGCG on miRNAs in cancer after briefly discussing the anticancer mechanisms of EGCG and the function of miRNAs in cancer.

Dietary Epigenetic Modulators: Unravelling the Still-Controversial Benefits of miRNAs in Nutrition and Disease

In the context of nutrient-driven epigenetic alterations, food-derived miRNAs can be absorbed into the circulatory system and organs of recipients, especially humans, and potentially contribute to modulating health and diseases. Evidence suggests that food uptake, by carrying exogenous miRNAs (xenomiRNAs), regulates the individual miRNA profile, modifying the redox homeostasis and inflammatory conditions underlying pathological processes, such as type 2 diabetes mellitus, insulin resistance, metabolic syndrome, and cancer. The capacity of diet to control miRNA levels and the comprehension of the unique characteristics of dietary miRNAs in terms of gene expression regulation show important perspectives as a strategy to control disease susceptibility via epigenetic modifications and refine the clinical outcomes. However, the absorption, stability, availability, and epigenetic roles of dietary miRNAs are intriguing and currently the subject of intense debate; additionally, there is restricted knowledge of their physiological and potential side effects. Within this framework, we provided up-to-date and comprehensive knowledge on dietary miRNAs' potential, discussing the latest advances and controversial issues related to the role of miRNAs in human health and disease as modulators of chronic syndromes.

The anti-cancer effect of epigallocatechin-3-O-gallate against multiple myeloma cells is potentiated by 5,7-dimethoxyflavone

(-)-Epigallocatechin-3-O-gallate (EGCG) is one of the major components of green tea polyphenol. Previous studies have shown that EGCG induces cancer-specific cell death in vitro and in vivo without causing severe side effects. However, the anti-cancer effect of EGCG alone is limited. 5,7-dimethoxyflavone (5,7-DMF), one of the principal functional components of black ginger (Kaempferia parviflora), also exerts anti-cancer effects. Here, we show that 5,7-DMF synergistically enhances the anti-cancer effect of EGCG in multiple myeloma cells by potentiating EGCG-induced intracellular cyclic guanosine monophosphate (cGMP) production. Moreover, the combination of EGCG and 5,7-DMF induces apoptotic cell death in multiple myeloma cells, and this is accompanied by activation of the cGMP/acid sphingomyelinase (ASM)/cleaved caspase-3 pathway. In conclusion, we have shown that 5,7-DMF enhances the anti-cancer effect of EGCG by upregulating cGMP in multiple myeloma cells.

Epigallocatechin-3-gallate and cancer: focus on the role of microRNAs

MicroRNAs (miRNAs) are a group of small non-coding RNAs that affect gene expression. The role of miRNAs in different types of cancers has been published and it was shown that several miRNAs are inappropriately expressed in different cancers. Among the mechanisms that can cause this lack of proper expression are epigenetics, chromosomal changes, polymorphisms or defects in processing proteins. Recent research shows that phytochemicals, including epigallocatechin-3-gallate (EGCG), exert important epigenetic-based anticancer effects such as pro-apoptotic or anti proliferative through miRNA gene silencing. Given that EGCG is able to modulate a variety of cancer-related process i.e., angiogenesis, proliferation, metastasis and apoptosis via targeting various miRNAs such as let-7, miR-16, and miR-210. The discovery of new miRNAs and the differences observed in their expression when exposed to EGCG provides evidence that targeting these miRNAs may be beneficial as a form of treatment. In this review, we aim to provide an overview, based on current knowledge, on how phytochemicals, including epigallocatechin-3-gallate, can be considered as potential miRNAs modulator to improve efficacy of current cancer treatments.

Recent insights into the nutritional immunomodulation of cancer-related microRNAs

Cancer is the most common cause of death worldwide, following cardiovascular diseases. Cancer is a multifactorial disease and many reasons such as physical, chemical, biological, and lifestyle-related factors. Nutrition, which is one of the various factors that play a role in the prevention, development, and treatment of many types of cancer, affects the immune system, which is characterized by disproportionate pro-inflammatory signaling in cancer. Studies investigating the molecular mechanisms of this effect have shown that foods rich in bioactive compounds, such as green tea, olive oil, turmeric, and soybean play a significant role in positively changing the expression of miRNAs involved in the regulation of genes associated with oncogenic/tumor-suppressing pathways. In addition to these foods, some diet models may change the expression of specific cancer-related miRNAs in different ways. While Mediterranean diet has been associated with anticancer effects, a high-fat diet, and a methyl-restricted diet are considered to have negative effects. This review aims to discuss the effects of specific foods called "immune foods," diet models, and bioactive components on cancer by changing the expression of miRNAs in the prevention and treatment of cancer.

Tannins in cancer prevention and therapy

Tannins are a heterogenous class of polyphenolic natural products with promising cancer chemopreventive and therapeutic potential. Studies undertaken over the last 30 years have demonstrated their capacity to target many cellular pathways and molecules important in the development of cancer. Recently, new mechanisms that might be important in anti-carcinogenic activity, such as inhibition of epithelial-to-mesenchymal transition, reduction of cancer stem cell creation, and modulation of cancer cells metabolism have been described. Along with the mechanisms underlying the anti-cancer activity of tannins, this review focuses on their possible application as chemosensitizers in adjuvant therapy and countering multidrug resistance. Furthermore, characteristic physicochemical properties of some tannins, particularly tannic acid, are useful in the formation of nanovehicles for anticancer drugs or the isolation of circulating cancer cells. These new potential applications of tannins deserve further studies. Well-designed clinical trials, which are scarce, are needed to assess the therapeutic effects of tannins themselves or as adjuvants in cancer treatment.

Green Tea Epigallocatechin Gallate Inhibits Preadipocyte Growth via the microRNA-let-7a/HMGA2 Signaling Pathway

SCOPE

This study investigates the effect of epigallocatechin gallate (EGCG) on white and beige preadipocyte growth and explores the involvement of the miR-let-7a/HMGA2 pathway.

METHODS AND RESULTS

3T3-L1 and D12 cells are treated with EGCG. The effect of EGCG on cell proliferation and viability is evaluated, as well as microRNA (miRNA)-related signaling pathways. EGCG inhibits 3T3-L1 and D12 preadipocyte growth, upregulates miR-let-7a expression, and downregulates high-mobility group AT-hook 2 (HMGA2) mRNA and protein levels in a time- and dose-dependent manner. In addition, overexpression of miR-let-7a significantly inhibits the growth of 3T3-L1 and D12 cells and decreases HMGA2 mRNA and protein levels. MiR-let-7a inhibitor antagonizes the inhibitory effects of EGCG on the number and viability of 3T3-L1 and D12 cells. Furthermore, miR-let-7a inhibitor reverses the EGCG-induced increase in miR-let-7a expression levels and decrease in HMGA2 mRNA and protein levels. HMGA2 overexpression induces an increase in cell number and viability and antagonizes EGCG-suppressed cell growth and HMGA2 expression in 3T3-L1 and D12 preadipocytes.

CONCLUSION

EGCG inhibits the growth of 3T3-L1 and D12 preadipocytes by modulating the miR-let-7a and HMGA2 pathways.

Epigallocatechin gallate restores the reduction of protein phosphatase 2 A subunit B caused by middle cerebral artery occlusion

BACKGROUND

Epigallocatechin gallate (EGCG) is a flavonoid compound commonly found in green tea. It exhibits antioxidant, anti-inflammatory, and neuroprotective effects in cerebral ischemia. Protein phosphatase 2 A (PP2A) is an important serine/threonine phosphatase enzyme involved in various cellular activities. PP2A subunit B is present abundantly in the brain and plays an important role in the nervous system. We investigated the effect of EGCG on the expression level of PP2A subunit B in cerebral ischemia caused by middle cerebral artery occlusion (MCAO). EGCG (50 mg/kg) or vehicle was injected into the peritoneal cavity prior to MCAO surgery. Neurological behavior tests were performed 24 h after MCAO, and right cerebral cortex tissue was collected. Cerebral ischemia caused serious neurological abnormalities, which were alleviated by EGCG administration. We screened the expression of PP2A subunits containing A, B, and C using reverse-transcription PCR. We confirmed that PP2A subunit B exhibited significant changes in MCAO animals compared to subunits A and C. We continuously examined the expression of PP2A subunit B protein in MCAO animals using Western blot analysis.

RESULTS

EGCG alleviated the reduction of PP2A subunit B protein by MCAO damage. In addition, immunohistochemistry demonstrated a decrease in the number of PP2A subunit B-positive cells in the cerebral cortex, and EGCG attenuated this decrease. Maintenance of PP2A subunit B is important for normal brain function.

CONCLUSION

Therefore, our findings suggest that EGCG exerts neuroprotective effects against cerebral ischemia through modulation of PP2A subunit B expression.

Melanoma Cellular Signaling Transduction Pathways Targeted by Polyphenols Action Mechanisms

Melanoma is the most aggressive type of skin cancer. Although different anti-melanoma treatments are available, their efficacy is still improvable, and the number of deaths continues to increase worldwide. A promising source of antitumor agents could be presented by polyphenols-natural plant-based compounds. Over the past decades, many studies have described multiple anticancer effects of polyphenols in melanoma, presenting their potential interactions with targeted molecules from different signaling pathways. However, to our knowledge, there is no comprehensive review on polyphenols-regulated mechanisms in melanoma cells available in the literature. To fulfill this gap, this article aims to summarize the current knowledge of molecular mechanisms of action regulated by polyphenols involved in melanoma initiation and progression. Here, we focus on in vitro and in vivo effects of polyphenol treatments on tumor-essential cellular pathways, such as cell proliferation, apoptosis, autophagy, inflammation, angiogenesis, and metastasis. Moreover, emerging studies regarding the well-marked role of polyphenols in the regulation of microRNAs (miRNAs), highlighting their contribution to melanoma development, are also epitomized. Finally, we hope this review will provide a firm basis for developing polyphenol-based therapeutic agents in melanoma treatment.

Green Tea in Reproductive Cancers: Could Treatment Be as Simple?

Green tea originates from the tea plant Camellia sinensis and is one of the most widely consumed beverages worldwide. Green tea polyphenols, commonly known as catechins, are the major bioactive ingredients and account for green tea's unique health benefits. Epigallocatechin-3-gallate (EGCG), is the most potent catechin derivative and has been widely studied for its pro- and anti-oxidative effects. This review summarizes the chemical and chemopreventive properties of green tea in the context of female reproductive cancers. A comprehensive search of PubMed and Google Scholar up to December 2022 was conducted. All original and review articles related to green tea or EGCG, and gynecological cancers published in English were included. The findings of several in vitro, in vivo, and epidemiological studies examining the effect of green tea on reproductive cancers, including ovarian, cervical, endometrial, and vulvar cancers, are presented. Studies have shown that this compound targets specific receptors and intracellular signaling pathways involved in cancer pathogenesis. The potential benefits of using green tea in the treatment of reproductive cancers, alone or in conjunction with chemotherapeutic agents, are examined, shedding light on new therapeutic strategies for the management of female reproductive cancers.

(-)‑Epigallocatechin‑3‑O‑gallate upregulates the expression levels of miR‑6757‑3p, a suppressor of fibrosis‑related gene expression, in extracellular vesicles derived from human umbilical vein endothelial cells

As pulmonary fibrosis (PF), a severe interstitial pulmonary disease, has such a poor prognosis, the development of prevention and treatment methods is imperative. (-)-Epigallocatechin-3-O-gallate (EGCG), one of the major catechins in green tea, exerts an antifibrotic effect, although its mechanism remains unclear. Recently, it has been reported that microRNAs (miRNAs or miRs) transported by extracellular vesicles (EVs) from vascular endothelial cells (VECs) are involved in PF. In the present study, the effects of EGCG on the expression of miRNAs in EVs derived from human umbilical vein endothelial cells (HUVECs) were assessed and miRNAs with antifibrotic activity were identified. miRNA microarray analysis revealed that EGCG modulated the expression levels of 31 miRNAs (a total of 27 miRNAs were upregulated, and 4 miRNAs were downregulated.) in EVs from HUVECs. Furthermore, TargetScan analysis indicated that miR-6757-3p in particular, which exhibited the highest degree of change, may target transforming growth factor-β (TGF-β) receptor 1 (TGFBR1). To evaluate the effects of miR-6757-3p on TGFBR1 expression, human fetal lung fibroblasts (HFL-1) were transfected with an miR-6757-3p mimic. The results demonstrated that the miR-6757-3p mimic downregulated the expression of TGFBR1 as well the expression levels of fibrosis-related genes including fibronectin and α-smooth muscle actin in TGF-β-treated HFL-1 cells. In summary, EGCG upregulated the expression levels of miR-6757-3p, which may target TGFBR1 and downregulate fibrosis-related genes, in EVs derived from VECs.

Quercetin up-regulates the expression of tumor-suppressive microRNAs in human cervical cancer

Quercetin, a flavonol present in many vegetables and fruits, has been identified as a chemoprevention agent in several cancer models. However, the molecular mechanism of quercetin's anticancer activity is not entirely understood. MicroRNAs (miRNAs), small noncoding RNAs, have been reported to play key roles in various biological processes by regulating their target genes. We hypothesized that quercetin can exert an anticancer effect through the regulation of miRNAs. To test this hypothesis, we investigated the effects of quercetin on the expression of tumor-suppressive miRNAs in cervical cancer. Quercetin up-regulated the in vivo and in vitro expression of tumor-suppressive miRNAs miR-26b, miR-126, and miR-320a. Quercetin suppressed the level of β-catenin, encoded by catenin beta 1 (CTNNB1), by up-regulating miR-320a in HeLa cells. Moreover, quercetin increased the expression of mir-26b, mir-126, and mir-320a precursors in HeLa cells. The results from this study show that quercetin has the potential to prevent cervical cancer by regulating the expression of tumor-suppressive miRNAs.

Contribution of Non-Coding RNAs to Anticancer Effects of Dietary Polyphenols: Chlorogenic Acid, Curcumin, Epigallocatechin-3-Gallate, Genistein, Quercetin and Resveratrol

Growing evidence has been accumulated to show the anticancer effects of daily consumption of polyphenols. These dietary polyphenols include chlorogenic acid, curcumin, epigallocatechin-3-O-gallate, genistein, quercetin, and resveratrol. These polyphenols have similar chemical and biological properties in that they can act as antioxidants and exert the anticancer effects via cell signaling pathways involving their reactive oxygen species (ROS)-scavenging activity. These polyphenols may also act as pro-oxidants under certain conditions, especially at high concentrations. Epigenetic modifications, including dysregulation of noncoding RNAs (ncRNAs) such as microRNAs, long noncoding RNAs, and circular RNAs are now known to be involved in the anticancer effects of polyphenols. These polyphenols can modulate the expression/activity of the component molecules in ROS-scavenger-triggered anticancer pathways (RSTAPs) by increasing the expression of tumor-suppressive ncRNAs and decreasing the expression of oncogenic ncRNAs in general. Multiple ncRNAs are similarly modulated by multiple polyphenols. Many of the targets of ncRNAs affected by these polyphenols are components of RSTAPs. Therefore, ncRNA modulation may enhance the anticancer effects of polyphenols via RSTAPs in an additive or synergistic manner, although other mechanisms may be operating as well.

Role of epigallocatechin-3- gallate in the regulation of known and novel microRNAs in breast carcinoma cells

Breast cancer comprises 30% of all cancer cases among the world’s women population. MicroRNAs are small, endogenous, non-coding RNAs that regulate cell proliferating and apoptotic pathways by modulating expressions of related genes. Phytochemicals like epigallocatechin-3-gallate (EGCG) are known to have a chemotherapeutic effect on cancer often through the regulation of microRNAs. The aim is to find out the key known and novel miRNAs, which are controlled by EGCG in breast cancer cell line MDA-MB-231. Next-generation sequencing (NGS) revealed 1,258 known and 330 novel miRNAs from untreated and 83 μM EGCG (IC50 value of EGCG) treated cells. EGCG modulated 873 known and 47 novel miRNAs in the control vs. treated sample. The hypothesis of EGCG being a great modulator of miRNAs that significantly control important cancer-causing pathways has been established by analyzing with Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein Analysis Through Evolutionary Relationships (PANTHER) database. Validation of known and novel miRNA expression differences in untreated vs. treated cells was done using qPCR. From this study, a few notable miRNAs were distinguished that can be used as diagnostics as well as prognostic markers for breast cancer.

Efficacy of green tea extract on PC3 prostate cancer cells through upregulation of miR-195 expression and suppression of epithelial to mesenchymal transition

OBJECTIVE

To evaluate anticancer efficacy of green tea extract (GTE) on PC3 prostate cancer cells.

METHODS

By using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot methods, the expression of miR-195 and the epithelial to mesenchymal transition (EMT) markers such as E-cadherin and vimentin was analyzed.

RESULTS

Based on the results of 2D and 3D cell culture models, the inhibition of EMT and up regulation of miR-195 expression were detected.

CONCLUSIONS

Our findings will be helpful to design anti-tumor regimens with natural product original, and more studies will be required to identify the related mechanisms involving anticancer activities of green tea miRNAs.

Circulating miRNA profiles in mice plasma following flavonoid intake

BACKGROUND

Polyphenols, including flavonoids, have been the focus of numerous studies that have revealed diverse health benefits. MicroRNAs (miRNAs) constitute a class of small non-coding RNAs that function as posttranscriptional regulators of gene expression. miRNAs can be detected in the blood and these so-called circulating miRNAs are potential biomarkers of various diseases. This study aimed to explore circulating miRNAs in plasma as a means to predict the biological effects of functional food ingredients.

METHODS AND RESULTS

We used miRNA microarray analysis to compare plasma miRNA levels in mice orally administered three flavonoids (daidzein, quercetin, and delphinidin). Several miRNAs were differentially expressed in plasma from mice in each treatment group compared with the vehicle-treated group. The plasma levels of miR-25-5p, miR-146b-5p, and miR-501-3p were increased in the flavonoid-treated and the plasma levels of miR-148b-3p, miR-669e-5p, and miR-3962 were decreased.

CONCLUSIONS

Our findings suggested that flavonoids alter miRNA expression in plasma and identified promising plasma miRNAs for assessing the functionality of flavonoids.

Green tea epigallocatechin gallate suppresses 3T3-L1 cell growth via microRNA-143/MAPK7 pathways

Green tea epigallocatechin gallate (EGCG) and microRNA (miRNA) molecules modulate obesity. Nevertheless, it is still unknown whether EGCG modulates fat cell growth via miRNA-related signaling. In this study, white preadipocytes were used to examine whether the antimitogenic effect of EGCG on fat cells is regulated by the miR-143/MAPK7 pathway. We showed that EGCG upregulated the levels of miR-143, but not miR-155, in 3T3-L1 preadipocytes. Moreover, EGCG downregulated MAPK7 mRNA and protein levels time- and dose-dependently. MAPK7 expression increased during 3T3-L1 cell proliferation. miR-143 overexpression in the absence of EGCG mimicked the effects of EGCG to suppress preadipocyte growth and MAPK7 expression, whereas knockdown of miR-143 antagonized the EGCG-altered levels of miR-143, MAPK7, and pERK1/2 and reversed the EGCG-inhibited cell growth. These findings suggest that EGCG inhibits 3T3-L1 cell growth via miR-143/MAPK7 pathway.

Suppression of colonic oxidative stress caused by chronic ethanol administration and attenuation of ethanol-induced colitis and gut leakiness by oral administration of sesaminol in mice

Chronic consumption of excess ethanol is one of the major risk factors for colorectal cancer (CRC), and the pathogenesis of ethanol-related CRC (ER-CRC) involves ethanol-induced oxidative-stress and inflammation in the colon and rectum, as well as gut leakiness. In this study, we hypothesised that oral administration of sesaminol, a sesame lignan, lowers the risk of ER-CRC because we found that it is a strong antioxidant with very low prooxidant activity. This hypothesis was examined using a mouse model, in which 2.0% v/v ethanol was administered ad libitum for 2 weeks with or without oral gavage with sesaminol (2.5 mg per day). Oral sesaminol administration suppressed the ethanol-induced colonic lesions and the ethanol-induced elevation of the colonic levels of oxidative stress markers (8-hydroxy-2'-deoxyguanosine, malondialdehyde, and 4-hydroxyalkenals). It consistently suppressed the chronic ethanol-induced expressions of cytochrome P450-2E1 and inducible nitric oxide synthase and upregulated heme oxygenase-1 expression, probably via the nuclear factor erythroid-derived 2-like 2 pathway in the mouse colon. Oral sesaminol administration also suppressed the chronic ethanol-induced elevation of colonic inflammation marker levels, such as those of tumour necrosis factor-α, interleukin-6, and monocyte chemoattractant protein-1, probably via the nuclear factor-kappa B pathway. Moreover, it prevented the chronic ethanol-induced gut leakiness by restoring tight junction proteins, giving rise to lower plasma endotoxin levels compared with those of ethanol-administered mice. All of these results suggest that dietary supplementation of sesaminol may lower the risk of ER-CRC by suppressing each of the above-mentioned steps in ER-CRC pathogenesis.

67-kDa Laminin Receptor-Mediated Cellular Sensing System of Green Tea Polyphenol EGCG and Functional Food Pairing

The body is equipped with a “food factor-sensing system” that senses food factors, such as polyphenols, sulfur-containing compounds, and vitamins, taken into the body, and plays an essential role in manifesting their physiological effects. For example, (–)-epigallocatechin-3-O-gallate (EGCG), the representative catechin in green tea (Camellia sinensi L.), exerts various effects, including anti-cancer, anti-inflammatory, and anti-allergic effects, when sensed by the cell surficial protein 67-kDa laminin receptor (67LR). Here, we focus on three representative effects of EGCG and provide their specific signaling mechanisms, the 67LR-mediated EGCG-sensing systems. Various components present in foods, such as eriodictyol, hesperetin, sulfide, vitamin A, and fatty acids, have been found to act on the food factor-sensing system and affect the functionality of other foods/food factors, such as green tea extract, EGCG, or its O-methylated derivative at different experimental levels, i.e., in vitro, animal models, and/or clinical trials. These phenomena are observed by increasing or decreasing the activity or expression of EGCG-sensing-related molecules. Such functional interaction between food factors is called “functional food pairing”. In this review, we introduce examples of functional food pairings using EGCG.

Omics Technology for the Promotion of Nutraceuticals and Functional Foods

The influence of nutrition and environment on human health has been known for ages. Phytonutrients (7,000 flavonoids and phenolic compounds; 600 carotenoids) and pro-health nutrients—nutraceuticals positively add to human health and may prevent disorders such as cancer, diabetes, obesity, cardiovascular diseases, and dementia. Plant-derived bioactive metabolites have acquired an imperative function in human diet and nutrition. Natural phytochemicals affect genome expression (nutrigenomics and transcriptomics) and signaling pathways and act as epigenetic modulators of the epigenome (nutri epigenomics). Transcriptomics, proteomics, epigenomics, miRNomics, and metabolomics are some of the main platforms of complete omics analyses, finding use in functional food and nutraceuticals. Now the recent advancement in the integrated omics approach, which is an amalgamation of multiple omics platforms, is practiced comprehensively to comprehend food functionality in food science.

Inhibitory Mechanism of Combined Hydroxychavicol With Epigallocatechin-3-Gallate Against Glioma Cancer Cell Lines: A Transcriptomic Analysis

Emerging reports have shown therapeutic potential of hydroxychavicol (HC) and epigallocatechin-3-gallate (EGCG) against cancer cells, however high concentrations are required to achieve the anticancer activity. We reported the synergy of low combination doses of EGCG+HC in glioma cell lines 1321N1, SW1783, and LN18 by assessing the effects of EGCG+HC through functional assays. Using high throughput RNA sequencing, the molecular mechanisms of EGCG+HC against glioma cell lines were revealed. EGCG/HC alone inhibited the proliferation of glioma cell lines, with IC50 values ranging from 82 to 302 µg/ml and 75 to 119 µg/ml, respectively. Sub-effective concentrations of combined EGCG+HC enhanced the suppression of glioma cell growth, with SW1783 showing strong synergism with a combination index (CI) of 0.55 and LN18 showing a CI of 0.51. A moderate synergistic interaction of EGCG+HC was detected in 1321N1 cells, with a CI value of 0.88. Exposure of 1321N1, SW1783, and LN18 cells to EGCG+HC for 24 h induces cell death, with caspase-3 activation rates of 52%, 57%, and 9.4%, respectively. However, the dose for SW1783 is cytotoxic to normal cells, thus this dose was excluded from other tests. EGCG+HC induced cell cycle arrest at S phase and reduced 1321N1 and LN18 cell migration and invasion. Combined EGCG+HC amplified its anticancer effect by downregulating the axon guidance process and metabolic pathways, while simultaneously interfering with endoplasmic reticulum unfolded protein response pathway. Furthermore, EGCG+HC exerted its apoptotic effect through the alteration of mitochondrial genes such as MT-CO3 and MT-RNR2 in 1321N1 and LN18 cells respectively. EGCG+HC dynamically altered DYNLL1 alternative splicing expression in 1321N1 and DLD splicing expression in LN18 cell lines. Our work indicated the pleiotropic effects of EGCG+HC treatment, as well as particular target genes that might be investigated for future glioma cancer therapeutic development.

Involvement of microRNA modifications in anticancer effects of major polyphenols from green tea, coffee, wine, and curry

Epidemiological studies have shown that consumption of green tea, coffee, wine, and curry may contribute to a reduced risk of various cancers. However, there are some cancer site-specific differences in their effects; for example, the consumption of tea or wine may reduce bladder cancer risk, whereas coffee consumption may increase the risk. Animal and cell-based experiments have been used to elucidate the anticancer mechanisms of these compounds, with reactive oxygen species (ROS)-based mechanisms emerging as likely candidates. Chlorogenic acid (CGA), curcumin (CUR), epigallocatechin gallate (EGCG), and resveratrol (RSV) can act as antioxidants that activate AMP-activated protein kinase (AMPK) to downregulate ROS, and as prooxidants to generate ROS, leading to the downregulation of NF-κB. Polyphenols can modulate miRNA (miR) expression, with these dietary polyphenols shown to downregulate tumor-promoting miR-21. CUR, EGCG, and RSV can upregulate tumor-suppressing miR-16, 34a, 145, and 200c, but downregulate tumor-promoting miR-25a. CGA, EGCG, and RSV downregulate tumor-suppressing miR-20a, 93, and 106b. The effects of miRs may combine with ROS-mediated pathways, enhancing the anticancer effects of these polyphenols. More precise analysis is needed to determine how the different modulations of miRs by polyphenols relate to the cancer site-specific differences found in epidemiological studies related to the consumption of foods containing these polyphenols.

Dietary flavonoid narirutin as a prospective antagonist of oncogenic pri/pre-microRNAs

MicroRNAs (miRNAs) are involved in cancer progression via translational degradation in a sequence-specific manner of the 3'-untranslated region (3'UTR) of messenger RNA (mRNA). The involvement of miRNA in the biological progression of various cancer types is considered to be a potential target. Primary miRNA (pri-miRNA) and precursor-miRNA (pre-miRNA) synthesize the miRNA by dicer-catalyzed processes thus targeting pri/pre-miRNA by phytochemicals is amongst the appropriate approaches for anticancer therapies. Flavonoids category of phytochemicals is well-known for its chemotherapeutic and chemopreventive potential against multiple cancer types. However, the molecular interactions of flavonoids with miRNAs are not reported so far. Thus, this study aims to identify the promising flavonoids as the antagonist of miRNAs (pre-miR21, pri-miR-208a, pri-miR-378a, pri-miR320b, pri-miR-300, pri-miR-19b, and pre-miR-20b) using molecular docking simulations studies. Among the tested flavonoids, narirutin showed highest binding energy (-11.7 kcal/mol) against pri-miR19b followed by pri-miR-378a (-11.4 kcal/mol) >  pri-miR320b (-11.2 kcal/mol) =  pri-miR-300 (-11.2 kcal/mol) >  pri-miR-208a (-9.0 kcal/mol) >  pre-miR-20b (- 8.3 kcal/mol). The molecular dynamic simulation experiment confirmed that narirutin destabilizes the tertiary structure of pri-miRNA in comparison to apo-RNA. The finding indicates that narirutin binding with pre-miRNA causes disruption of pri-RNA structure that creates a loss of DICER-pre-miRNA interactions by hindering the pre-miRNA synthesis, thereby affecting miRNA processing. Further pharmacokinetics and toxicity prediction revealed that it is non-carcinogenic, non-mutagenic, and does not inhibit the CYPs activity. Thus, narirutin could be a possible antagonist of oncogenic miRNAs, therefore could be useful for miRNA-targeted cancer prevention and treatment.

Phytochemicals mediated modulation of microRNAs and long non-coding RNAs in cancer prevention and therapy

MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are two main categories of noncoding RNAs (ncRNAs) that can influence essential biological functions in various ways, as well as their expression and function are tightly regulated in physiological homeostasis. Additionally, the dysregulation of these ncRNAs seems to be crucial to the pathogenesis of human diseases. The latest findings indicate that ncRNAs execute vital roles in cancer initiation and progression, and the cancer phenotype can be reversed by modulating their expression. Available scientific discoveries suggest that phytochemicals such as polyphenols, alkaloids, terpenoids, and organosulfur compounds can significantly modulate multiple cancer-associated miRNAs and lncRNAs, thereby inhibiting cancer initiation and development. However, despite promising outcomes of experimental research, only a few clinical trials are currently being conducted to evaluate the therapeutic effectiveness of these compounds. Nevertheless, understanding phytochemical-mediated ncRNA regulation in cancer and the underlying molecular mechanisms on tumor pathophysiology can aid in the development of novel therapeutic strategies to combat this deadly disease.

Soy isoflavone metabolite equol inhibits cancer cell proliferation in a PAP associated domain containing 5-dependent and an estrogen receptor-independent manner

Isoflavone is a species of polyphenol found mainly in soy and soy products. Many studies have demonstrated its estrogen receptor (ER)-dependent action. Equol is an intestinal metabolite of a major soy isoflavone daidzein. We aimed to elucidate the mechanism for ER-independent actions of equol. Equol has been shown to inhibit proliferation of HeLa human cervical cancer cells and mouse melanoma B16 cells in an ER-independent manner. Using functional genetic screening, PAP associated domain containing 5 (PAPD5), which is a non-canonical poly(A) polymerase, was identified as an essential molecule in the ER-independent action. While peroral administration of equol inhibited tumor growth of control B16 cells subcutaneously inoculated in mice, it had little effect on the growth of PAPD5-ablated B16 cells. Intriguingly, equol progressed tumor growth of the PAPD5-ablated human breast cancer MCF-7 cells, which have high ERα expression. Equol has been found to induce polyadenylation of snoRNAs in a PAPD5-depdendent manner. Furthermore, peroral equol administration increased microRNA miR-320a expression in tumors. Together, these results suggest that equol may have a dual effect on ER-positive cancer cells, acting with, antiproliferative activity through PAPD5 and exhibiting proliferative activity via ERα and the former could be associated with miR-320a.

Influence of the Bioactive Diet Components on the Gene Expression Regulation

Diet bioactive components, in the concept of nutrigenetics and nutrigenomics, consist of food constituents, which can transfer information from the external environment and influence gene expression in the cell and thus the function of the whole organism. It is crucial to regard food not only as the source of energy and basic nutriments, crucial for living and organism development, but also as the factor influencing health/disease, biochemical mechanisms, and activation of biochemical pathways. Bioactive components of the diet regulate gene expression through changes in the chromatin structure (including DNA methylation and histone modification), non-coding RNA, activation of transcription factors by signalling cascades, or direct ligand binding to the nuclear receptors. Analysis of interactions between diet components and human genome structure and gene activity is a modern approach that will help to better understand these relations and will allow designing dietary guidances, which can help maintain good health.

Current insights into epigenetics, noncoding RNA interactome and clinical pharmacokinetics of dietary polyphenols in cancer chemoprevention

Several studies have reported the health-beneficial effects of dietary phytochemicals, namely polyphenols, to prevent various diseases, including cancer. Polyphenols, like (-)-epigallocatechin-3-gallate (EGCG) from green tea, curcumin from turmeric, and ellagic acid from pomegranate are known to act by modulating antioxidant, anti-inflammatory and apoptotic signal transduction pathways in the tumor milieu. The evolving literature underscores the role of epigenetic regulation of genes associated with cancer by these polyphenols, primarily via non-coding RNAs (ncRNAs), such as microRNAs (miRNA) and long noncoding RNA (lncRNA). However, there is little clarity on the exact role(s) played by these ncRNAs and their interactions with other ncRNAs, or with their protein targets, in response to modulation by these dietary polyphenols. Here, we review ncRNA interactions and functional networks of the complex ncRNA interactome with their targets in preclinical studies along with the role of epigenetics as well as key aspects of pharmacokinetics and phytochemistry of dietary polyphenols. We also summarize the current state of clinical trials with these dietary polyphenols. Taken together, this synthetic review provides insights into the molecular aspects underlying the anticancer chemopreventive effects of dietary polyphenols as well as summarizes data on novel biomarkers modulated by these polyphenols for preventive or therapeutic purposes in various types of cancer.

Potential effect of EGCG on the anti-tumor efficacy of metformin in melanoma cells

Metformin, a first-line drug for type 2 diabetes mellitus, has been recognized as a potential anti-tumor agent in recent years. Epigallocatechin-3-gallate (EGCG), as the dominant catechin in green tea, is another promising adjuvant agent for tumor prevention. In the present work, the potential effect of EGCG on the anti-tumor efficacy of metformin in a mouse melanoma cell line (B16F10) was investigated. Results indicated that EGCG and metformin exhibited a synergistic effect on cell viability, migration, and proliferation, as well as signal transducer and activator of transcription 3/nuclear factor-κB (STAT3/NF-κB) pathway signaling and the production of inflammation cytokines. Meanwhile, the combination showed an antagonistic effect on cell apoptosis and oxidative stress levels. The combination of EGCG and metformin also differentially affected the nucleus (synergism) and cytoplasm (antagonism) of B16F10 cells. Our findings provide new insight into the potential effects of EGCG on the anti-tumor efficacy of metformin in melanoma cells.

Green Tea Polyphenol-Sensitive Calcium Signaling in Immune T Cell Function

Polyphenol compounds found in green tea have a great therapeutic potential to influence multiple human diseases including malignancy and inflammation. In this mini review, we describe effects of green tea and the most important component EGCG in malignancy and inflammation. We focus on cellular mechanisms involved in the modification of T cell function by green tea polyphenol EGCG. The case is made that EGCG downregulates calcium channel activity by influencing miRNAs regulating expression of the channel at the post-transcriptional level.

Updated review on green tea polyphenol epigallocatechin-3-gallate as a cancer epigenetic regulator

In-depth insights in cancer biology over the past decades have highlighted the important roles of epigenetic mechanisms in the initiation and progression of tumorigenesis. The cancer epigenome usually experiences multiple alternations, including genome-wide DNA hypomethylation and site-specific DNA hypermethylation, various histone posttranslational modifications, and dysregulation of non-coding RNAs (ncRNAs). These epigenetic changes are plastic and reversible, and could potentially occur in the early stage of carcinogenesis preceding genetic mutation, offering unique opportunities for intervention therapies. Therefore, targeting the cancer epigenome or cancer epigenetic dysregulation with some selected agents (called epi-drugs) represents an evolving and promising strategy for cancer chemoprevention and therapy. Phytochemicals, as a class of pleiotropic molecules, have manifested great potential in modulating different cancer processes through epigenetic machinery, of which green tea polyphenol epigallocatechin-3-gallate (EGCG) is one of the most extensively studied. In this review, we first summarize epigenetic events involved in the pathogenesis of cancer, including DNA/RNA methylations, histone modifications and ncRNAs' dysregulations. We then focus on the recently discovered roles of phytochemicals, with a special emphasis on EGCG, in modulating different cancer processes through regulating epigenetic machinery. We finally discuss limitations of EGCG as an epigenetic modulator for cancer chemoprevention and treatment and offer potential strategies to overcome the shortcomings.

Flavonoid display ability to target microRNAs in cancer pathogenesis

MicroRNAs (miRNAs) are non-coding, conserved, single-stranded nucleotide sequences involved in physiological and developmental processes. Recent evidence suggests an association between miRNAs' deregulation with initiation, promotion, progression, and drug resistance in cancer cells. Besides, miRNAs are known to regulate the epithelial-mesenchymal transition, angiogenesis, autophagy, and senescence in different cancer types. Previous reports proposed that apart from the antioxidant potential, flavonoids play an essential role in miRNAs modulation associated with changes in cancer-related proteins, tumor suppressor genes, and oncogenes. Thus, flavonoids can suppress proliferation, help in the development of drug sensitivity, suppress metastasis and angiogenesis by modulating miRNAs expression. In the present review, we summarize the role of miRNAs in cancer, drug resistance, and the chemopreventive potential of flavonoids mediated by miRNAs. The potential of flavonoids to modulate miRNAs expression in different cancer types demonstrate their selectivity and importance as regulators of carcinogenesis. Flavonoids as chemopreventive agents targeting miRNAs are extensively studied in vitro, in vivo, and pre-clinical studies, but their efficiency in targeting miRNAs in clinical studies is less investigated. The evidence presented in this review highlights the potential of flavonoids in cancer prevention/treatment by regulating miRNAs, although further investigations are required to validate and establish their clinical usefulness.

Anti-Cancer Effects of Green Tea Epigallocatchin-3-Gallate and Coffee Chlorogenic Acid

Tea and coffee are consumed worldwide and epidemiological and clinical studies have shown their health beneficial effects, including anti-cancer effects. Epigallocatechin gallate (EGCG) and chlorogenic acid (CGA) are the major components of green tea polyphenols and coffee polyphenols, respectively, and believed to be responsible for most of these effects. Although a large number of cell-based and animal experiments have provided convincing evidence to support the anti-cancer effects of green tea, coffee, EGCG, and CGA, human studies are still controversial and some studies have suggested even an increased risk for certain types of cancers such as esophageal and gynecological cancers with green tea consumption and bladder and lung cancers with coffee consumption. The reason for these inconsistent results may have been arisen from various confounding factors. Cell-based and animal studies have proposed several mechanisms whereby EGCG and CGA exert their anti-cancer effects. These components appear to share the common mechanisms, among which one related to reactive oxygen species is perhaps the most attractive. Meanwhile, EGCG and CGA have also different target molecules which might explain the site-specific differences of anti-cancer effects found in human studies. Further studies will be necessary to clarify what is the mechanism to cause such differences between green tea and coffee.

Targeting the intrinsically disordered architectural High Mobility Group A (HMGA) oncoproteins in breast cancer: learning from the past to design future strategies

INTRODUCTION

Triple-negative breast cancer (TNBC) is the most difficult breast cancer subtype to treat because of its heterogeneity and lack of specific therapeutic targets. High Mobility Group A (HMGA) proteins are chromatin architectural factors that have multiple oncogenic functions in breast cancer, and they represent promising molecular therapeutic targets for this disease.

AREAS COVERED

We offer an overview of the strategies that have been exploited to counteract HMGA oncoprotein activities at the transcriptional and post-transcriptional levels. We also present the possibility of targeting cancer-associated factors that lie downstream of HMGA proteins and discuss the contribution of HMGA proteins to chemoresistance.

EXPERT OPINION

Different strategies have been exploited to counteract HMGA protein activities; these involve interfering with their nucleic acid binding properties and the blocking of HMGA expression. Some approaches have provided promising results. However, some unique characteristics of the HMGA proteins have not been exploited; these include their extensive protein-protein interaction network and their intrinsically disordered status that present the possibility that HMGA proteins could be involved in the formation of proteinaceous membrane-less organelles (PMLO) by liquid-liquid phase separation. These unexplored characteristics could open new pharmacological avenues to counteract the oncogenic contributions of HMGA proteins.

Epigallocatechin-3-Gallate and PEDF 335 Peptide, 67LR Activators, Attenuate Vasogenic Edema, and Astroglial Degeneration Following Status Epilepticus

Non-integrin 67-kDa laminin receptor (67LR) is involved in cell adherence to the basement membrane, and it regulates the interactions between laminin and other receptors. The dysfunction of 67LR leads to serum extravasation via blood-brain barrier (BBB) disruption. Polyphenol (–)-epigallocatechin-3-O-gallate (EGCG) and pigment epithelium-derived factor (PEDF) bind to 67LR and inhibit neovascularization. Therefore, in the present study, we investigated the effects of EGCG and NU335, a PEDF-derive peptide, on BBB integrity and their possible underlying mechanisms against vasogenic edema formation induced by status epilepticus (SE, a prolonged seizure activity). Following SE, both EGCG and NU335 attenuated serum extravasation and astroglial degeneration in the rat piriform cortex (PC). Both EGCG and NU335 reversely regulated phosphatidylinositol 3 kinase (PI3K)/AKT–eNOS (endothelial nitric oxide synthase) mediated BBB permeability and aquaporin 4 (AQP4) expression in endothelial cells and astrocytes through the p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways, respectively. Furthermore, EGCG and NU335 decreased p47Phox (a nicotinamide adenine dinucleotide phosphate oxidase subunit) expression in astrocytes under physiological and post-SE conditions. Therefore, we suggest that EGCG and PEDF derivatives may activate 67LR and its downstream effectors, and they may be considerable anti-vasogenic edema agents.

The green tea polyphenol epigallocatechin-3-gallate attenuates age-associated muscle loss via regulation of miR-486-5p and myostatin

(-)-Epigallocatechin-3-gallate (EGCG), the most abundant catechin component in green tea, has been reported to attenuate age-associated insulin resistance, lipogenesis and loss of muscle mass through restoring Akt activity in skeletal muscle in our previous and present studies. Accumulated data has suggested that polyphenols regulate signaling pathways involved in aging process such as inflammation and oxidative stress via modulation of miRNA expression. Here we found that miRNA-486-5p was significantly decreased in both aged senescence accelerated mouse-prone 8 (SAMP8) mice and late passage C2C12 cells. Thus, we further investigated the regulatory effect of EGCG on miRNA-486-5p expression in age-regulated muscle loss. SAMP8 mice were fed with chow diet containing without or with 0.32% EGCG from aged 32 weeks for 8 weeks. Early passage (<12 passages) and late passage (>30 passages) of C2C12 cells were treated without or with EGCG at concentrations of 50 μM for 24h. Our data showed that EGCG supplementation increased miRNA-486-5p expression in both aged SAMP8 mice and late passage C2C12 cells. EGCG stimulated AKT phosphorylation and inhibited FoxO1a-mediated MuRF1 and Atrogin-1 transcription via up-regulating the expression of miR-486 in skeletal muscle of 40-wk-old SAMP8 mice as well as late passage C2C12 cells. In addition, myostatin expression was increased in late passage C2C12 cells and anti-myostatin treatment upregulated the expression of miR-486-5p. Our results identify a unique mechanism of a dietary constituent of green tea and suggest that use of EGCG or compounds derived from it attenuates age-associated muscle loss via myostatin/miRNAs/ubiquitin-proteasome signaling.

The Protective Effect of Polyphenols for Colorectal Cancer

Colorectal cancer (CRC) is one of the most prevalent cancers that threaten people in many countries. It is a multi-factorial chronic disease caused by a combination of genetic and environmental factors, but it is mainly related to lifestyle factors, including diet. Plentiful plant foods and beverages are abundant in polyphenols with antioxidant, anti-atherosclerotic, anti-inflammatory, and anticancer properties. These compounds participate in host nutrition and disease pathology regulation in different ways. Polyphenolic compounds have been used to prevent and inhibit the development and prognosis of cancer, and examples include green tea polyphenol (-)epigallocatechin-3-O-gallate (EGCG), curcumin, and resveratrol. Of course, there are more known and unknown polyphenol compounds that need to be further explored for their anticancer properties. This article focuses on the fact that polyphenols affect the progression of CRC by controlling intestinal inflammation, epigenetics, and the intestinal microbe in the aspects of prevention, treatment, and prognosis.

Molecular mechanisms of action of epigallocatechin gallate in cancer: Recent trends and advancement

Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is an ester of epigallocatechin and gallic acid. EGCG, abundantly found in tea, is a polyphenolic flavonoid that has the potential to affect human health and disease. EGCG interacts with various recognized cellular targets and inhibits cancer cell proliferation by inducing apoptosis and cell cycle arrest. In addition, scientific evidence has illustrated the promising role of EGCG in inhibiting tumor cell metastasis and angiogenesis. It has also been found that EGCG may reverse drug resistance of cancer cells and could be a promising candidate for synergism studies. The prospective importance of EGCG in cancer treatment is owed to its natural origin, safety, and low cost which presents it as an attractive target for further development of novel cancer therapeutics. A major challenge with EGCG is its low bioavailability which is being targeted for improvement by encapsulating EGCG in nano-sized vehicles for further delivery. However, there are major limitations of the studies on EGCG, including study design, experimental bias, and inconsistent results and reproducibility among different study cohorts. Additionally, it is important to identify specific EGCG pharmacological targets in the tumor-specific signaling pathways for development of novel combined therapeutic treatments with EGCG. The present review highlights the ongoing development to identify cellular and molecular targets of EGCG in cancer. Furthermore, the role of nanotechnology-mediated EGCG combinations and delivery systems will also be discussed.

Sanggenol L promotes apoptotic cell death in melanoma skin cancer cells through activation of caspase cascades and apoptosis-inducing factor

Sanggenol L is one component of root bark of Morus alba. The molecular and cellular mechanisms of sanggenol L effects on melanoma cells are not well known. Recently, melanoma is the most common skin cancer with a high mortality rate not only in United States, but also in East Asia. Therefore, safe and effective treatments for melanoma treatment are required. In this study, we investigated whether or not sanggenol L possesses anti-cancer activity in human and mouse melanoma skin cancer cells. Sanggenol L treatment exerted significant cell growth inhibitory effects and inhibited colony formation capacity against B16, SK-MEL-2, and SK-MEL-28 melanoma skin cancer cells, whereas HaCaT human epithelial keratinocyte cells was unaffected by sanggenol L treatment. Sanggenol L treatment resulted in apoptotic cell death in melanoma skin cancer cells, which was characterized by accumulation of apoptotic cells, nuclear condensation, and apoptotic bodies. We also showed that sanggenol L treatment induced caspase-dependent apoptosis (up-regulation of Bax and cleaved-PARP or down-regulation of Bid, Bcl-2, procaspse-3, -8, and -9), induction of caspase-independent apoptosis (up-regulation of AIF and Endo G on cytosol) in melanoma skin cancer cells. These results suggest that sanggenol L induces caspase-dependent and -independent apoptosis in melanoma skin cancer cells.

Procyanidin C1 Inhibits Melanoma Cell Growth by Activating 67-kDa Laminin Receptor Signaling

SCOPE

Procyanidin C1 (PC1) is an epicatechin trimer found mainly in grapes that is reported to provide several health benefits. However, little is known about the molecular mechanisms underlying these benefits. The aim of this study is to demonstrate the molecular mechanisms by which PC1 operates.

METHODS AND RESULTS

A 67-kDa laminin receptor (67LR) is identified as a cell surface receptor of PC1, with a Kd value of 2.8 µm. PC1 induces an inhibitory effect on growth, accompanied by dephosphorylation of the C-kinase potentiated protein phosphatase-1 inhibitor protein of 17 kDa (CPI17) and myosin regulatory light chain (MRLC) proteins, followed by actin cytoskeleton remodeling in melanoma cells. These actions are mediated by protein kinase A (PKA) and protein phosphatase 2A (PP2A) activation once PC1 is bound to 67LR.

CONCLUSION

It is demonstrated that PC1 elicits melanoma cell growth inhibition by activating the 67LR/PKA/PP2A/CPI17/MRLC pathway.

Epigallocatechin gallate (EGCG) suppresses growth and tumorigenicity in breast cancer cells by downregulation of miR-25

The aim of the present study was to investigate the anticancer effects and potential mechanisms of polyphenol epigallocatechin-3-gallate (EGCG) on breast cancer MCF-7 cells in vitro and in vivo. Our results showed that EGCG significantly inhibited MCF-7 cell viability in a time- and dose-dependent manner. Flow cytometry analysis indicated that EGCG induced apoptosis and disrupted cell cycle progression at G2/M phase. Moreover, EGCG inhibited miR-25 expression and increased PARP, pro-caspase-3 and pro-caspase-9 at protein levels. Restoration of miR-25 inhibited EGCG-induced cell apoptosis. Furthermore, EGCG suppressed tumor growth in vivo by downregulating the expression of miR-25 and proteins associated with apoptosis, which was further confirmed by a reduction of Ki-67 and increase of pro-apoptotic PARP expression as determined by immunohistochemistry staining. These findings indicate that EGCG possesses chemopreventive potential in breast cancer which may serve as a promising anticancer agent for clinical applications.

Cyclic-AMP induces Nogo-A receptor NgR1 internalization and inhibits Nogo-A-mediated collapse of growth cone

The promotion of axonal regeneration is required for functional recovery from stroke and various neuronal injuries. However, axonal regeneration is inhibited by diverse axonal growth inhibitors, such as Nogo-A. Nogo-66, a C-terminal domain of Nogo-A, binds to the Nogo-A receptor 1 (NgR1) and induces the collapse of growth cones and inhibits neurite outgrowth. NgR1 is also a receptor for additional axonal growth inhibitors, suggesting it is an important target for the prevention of axonal growth inhibition. By using the indirect immunofluorescence method, we show for the first time that a cell-permeable cAMP analog (dibutyryl-cAMP) induced a rapid decrease in the cell surface expression of NgR1 in Neuroscreen-1 (NS-1) cells. The biotinylation method revealed that cAMP indeed induced internalization of NgR1 within minutes. Other intracellular cAMP-elevating agents, such as forskolin, which directly activates adenylyl cyclase, and rolipram, which inhibits cyclic nucleotide phosphodiesterase, also induced this process. This internalization was found to be reversible and influenced by intracellular levels of cAMP. Using selective activators and inhibitors of protein kinase A (PKA) and the exchange protein directly activated by cAMP (Epac), we found that NgR1 internalization is independent of PKA, but dependent on Epac. The decrease in cell surface expression of NgR1 desensitized NS-1 cells to Nogo-66-induced growth cone collapse. Therefore, it is likely that besides axonal growth inhibitors affecting neurons, neurons themselves also self-regulate their sensitivity to axonal growth inhibitors, as influenced by intracellular cAMP/Epac. This normal cellular regulatory mechanism may be pharmacologically exploited to overcome axonal growth inhibitors, and enhance functional recovery after stroke and neuronal injuries.

Current shreds of evidence on the anticancer role of EGCG in triple negative breast cancer: an update of the current state of knowledge

Triple-Negative Breast Cancer (TNBC), represents a subtype of breast cancer in which the estrogens receptor (ER) negative, the progesterone receptor (PR) negative and the human epidermal growth factor receptor 2 (HER2) negative, are not expressed. Thusly, TNBC does not respond to hormonal therapies or to those targeting the HER2 protein receptors. To overcome this flawed issue, new alternative therapies based on the use of natural substances, as the (-) - epigallocatechin 3-gallate (EGCG), has been proposed. It is largely documented that EGCG, the principal constituent of green tea, has suppressive effects on different types of cancer, including breast cancer, through the regulation of different signaling pathways. Thus, is reasonable to assume that EGCG could be viewed as a therapeutic option for the prevention and the treatment of TNBC. Here, we summarizing these promising results with the scope of turn a light on the potential roles of EGCG in the treatment of TNBC patients.

Chinese Herbal Medicine-Based Cancer Therapy: Novel Anticancer Agents Targeting MicroRNAs to Regulate Tumor Growth and Metastasis

MicroRNAs, small non-coding RNA molecules, have gained a reputation of the most substantial regulators in gene network with the ability to down-regulate their targets. Accumulating evidence shifted insight toward microRNAs regulation as the key element of cancer initiation, development, and aggression. Recent studies have attached the importance of traditional Chinese medicine (TCM) to the treatment of various cancers, and the functional natural compounds have been considered as novel anticancer agents to directly inhibit tumor progression. In more recent decades, a wide range of biologically active components of TCM has gained increasing attention to their applications in the modulation of microRNAs. This review is on the purpose of demonstrating the significance of TCM bioactive ingredients in microRNAs regulation for cancer treatment according to the reports mainly in the recent six years, providing the evidence of efficient Chinese herbal medicine-based therapy and effective pro-diagnosis focusing on microRNAs expression of cancer patients.