Resveratrol in breast cancer treatment: from cellular effects to molecular mechanisms of action

Resveratrol triggers autophagy-related apoptosis to inhibit the progression of colorectal cancer via inhibition of FOXQ1

Colorectal cancer (CRC) is a significant health problem with elevated mortality rates, prompting intense exploration of its complex molecular mechanisms and innovative therapeutic avenues. Resveratrol (RSV), recognised for its anticancer effects through SIRT1 activation, is a promising candidate for CRC treatment. This study focuses on elucidating RSV's role in CRC progression, particularly its effect on autophagy-related apoptosis. Using bioinformatics, protein imprinting and immunohistochemistry, we established a direct correlation between FOXQ1 and adverse CRC prognosis. Comprehensive in vitro experiments confirmed RSV's ability to promote autophagy-related apoptosis in CRC cells. Plasmids for SIRT1 modulation were used to investigate underlying mechanisms. Molecular docking, glutathione-S-transferase pull-down experiments and immunoprecipitation highlighted RSV's direct activation of SIRT1, resulting in the inhibition of FOXQ1 expression. Downstream interventions identified ATG16L as a crucial autophagic target. In vivo and in vitro studies validated RSV's potential for CRC therapy through the SIRT1/FOXQ1/ATG16L pathway. This study establishes RSV's capacity to enhance autophagy-related cell apoptosis in CRC, positioning RSV as a prospective therapeutic agent for CRC within the SIRT1/FOXQ1/ATG16L pathway.

Epigenetic Effects of Resveratrol on Oncogenic Signaling in Breast Cancer

The crosstalk between oncogenic signaling pathways plays a crucial role in driving cancer development. We previously demonstrated that dietary polyphenols, specifically resveratrol (RSV) and other stilbenoids, epigenetically target oncogenes for silencing via DNA hypermethylation in breast cancer. In the present study, we identify signal transduction regulators among RSV-hypermethylated targets and investigate the functional role of RSV-mediated DNA hypermethylation in the regulation of Hedgehog and Wnt signaling. Non-invasive ER-positive MCF-7 and highly invasive triple-negative MCF10CA1a human breast cancer cell lines were used as experimental models. Upon 9-day exposure to 15 µM RSV, pyrosequencing and qRT-PCR were performed to assess DNA methylation and expression of GLI2 and WNT4, which are upstream regulators of the Hedgehog and Wnt pathways, respectively. Our results showed that RSV led to a DNA methylation increase within GLI2 and WNT4 enhancers, which was accompanied by decreases in gene expression. Consistently, we observed the downregulation of genes downstream of the Hedgehog and Wnt signaling, including common targets shared by both pathways, CCND1 and CYR61. Further analysis using chromatin immunoprecipitation identified increased H3K27 trimethylation and decreased H3K9 and H3K27 acetylation, along with abolishing OCT1 transcription factor binding. Those changes indicate a transcriptionally silent chromatin state at GLI2 and WNT4 enhancers. The inhibition of the Wnt signal transduction was confirmed using a phospho-antibody array that demonstrated suppression of positive and stimulation of negative Wnt regulators. In conclusion, our results provide scientific evidence for dietary polyphenols as epigenetics-modulating agents that act to re-methylate and silence oncogenes, reducing the oncogenic signal transduction. Targeting such an action could be an effective strategy in breast cancer prevention and/or adjuvant therapy.

Nutraceuticals known to promote hair growth do not interfere with the inhibitory action of tamoxifen in MCF7, T47D and BT483 breast cancer cell lines

BACKGROUND

Hair loss/thinning is a common side effect of tamoxifen in estrogen receptor (ER) positive breast cancer therapy. Some nutraceuticals known to promote hair growth are avoided during breast cancer therapy for fear of phytoestrogenic activity. However, not all botanical ingredients have similarities to estrogens, and in fact, no information exists as to the true interaction of these ingredients with tamoxifen. Therefore, this study sought to ascertain the effect of nutraceuticals (+/- estrogen/tamoxifen), on proliferation of breast cancer cells and the relative expression of ERα/β.

METHODS

Kelp, Astaxanthin, Saw Palmetto, Tocotrienols, Maca, Horsetail, Resveratrol, Curcumin and Ashwagandha were assessed on proliferation of MCF7, T47D and BT483 breast cancer cell lines +/- 17β-estradiol and tamoxifen. Each extract was analysed by high performance liquid chromatography (HPLC) prior to use. Cellular ERα and ERβ expression was assessed by qRT-PCR and western blot. Changes in the cellular localisation of ERα:ERβ and their ratio following incubation with the nutraceuticals was confirmed by immunocytochemistry.

RESULTS

Estradiol stimulated DNA synthesis in three different breast cancer cell lines: MCF7, T47D and BT483, which was inhibited by tamoxifen; this was mirrored by a specific ERa agonist in T47D and BT483 cells. Overall, nutraceuticals did not interfere with tamoxifen inhibition of estrogen; some even induced further inhibition when combined with tamoxifen. The ERα:ERβ ratio was higher at mRNA and protein level in all cell lines. However, incubation with nutraceuticals induced a shift to higher ERβ expression and a localization of ERs around the nuclear periphery.

CONCLUSIONS

As ERα is the key driver of estrogen-dependent breast cancer, if nutraceuticals have a higher affinity for ERβ they may offer a protective effect, particularly if they synergize and augment the actions of tamoxifen. Since ERβ is the predominant ER in the hair follicle, further studies confirming whether nutraceuticals can shift the ratio towards ERβ in hair follicle cells would support a role for them in hair growth. Although more research is needed to assess safety and efficacy, this promising data suggests the potential of nutraceuticals as adjuvant therapy for hair loss in breast cancer patients receiving endocrine therapy.

The potential therapeutic effect of melatonin in oxaliplatin combination therapy against chemoresistant colorectal cancer cells

BACKGROUND

Oxaliplatin is one of the main therapeutics in colorectal cancer (CRC) chemotherapy. However, in light of multidrug resistance (MDR) phenotype development, the efficacy of oxaliplatin has decreased. This study aimed to assess the potential therapeutic effect of melatonin in oxaliplatin combination therapy for drug-resistant colorectal cancer cells.

METHODS AND RESULTS

Initially, the oxaliplatin-resistant cell line was created of LS174T (LS174T/DR) by using the oxaliplatin IC50 concentration and resting cycles. MTT assays and flow cytometry were applied for assessing cell viability and apoptotic cells. The mRNA expression level of Bax, Bcl2, MT1, MT2, and ABCB1 as well as protein levels of ABCB1, Bcl2, BAX were measured by the qRT-PCR and western blot techniques respectively. P-gp activity was assessed by Rho123 staining. The IC50 concentration of oxaliplatin in resistant cells was increased from 500.7 ± 0.2 nM to 7119 ± 0.1 nM. Bcl2, MT1, MT2, and ABCB1 mRNA plus protein expression levels of Bcl2 and ABCB1 were significantly reduced in resistant cells, along with a marked increase in Bax mRNA and protein levels compared to parental cells. Rho 123 staining revealed a marked reduction in P-gp activities in the combination-treated group compared to the oxaliplatin-treated group.

CONCLUSIONS

The results of cytotoxicity assays, MTT, and flow cytometry revealed that the combination of melatonin and oxaliplatin exerts synergistic effects on induction of oxaliplatin's cytotoxicity in CRC. Our research suggests that combining the treatments of melatonin and oxaliplatin may be considered as a new approach to overcoming oxaliplatin resistance in CRC patients.

Identification of anti-gastric cancer effects and molecular mechanisms of resveratrol: From network pharmacology and bioinformatics to experimental validation

BACKGROUND

Gastric cancer (GC) is one of the most aggressive malignancies with limited therapeutic options and a poor prognosis. Resveratrol, a non-flavonoid polyphenolic compound found in a variety of Chinese medicinal materials, has shown excellent anti-GC effect. However, its exact mechanisms of action in GC have not been clarified.

AIM

To identify the effects of resveratrol on GC progression and explore the related molecular mechanisms.

METHODS

Action targets of resveratrol and GC-related targets were screened from public databases. The overlapping targets between the two were confirmed using a Venn diagram, and a "Resveratrol-Target-GC" network was constructed using Cytoscape software version 3.9.1. The protein-protein interaction (PPI) network was constructed using STRING database and core targets were identified by PPI network analysis. The Database for Annotation, Visualization and Integrated Discovery database was used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. A "Target-Pathway" network was created by using Cytoscape 3.9.1. The RNA and protein expression levels of core target genes were observed using the Cancer Genome Atlas and the Human Protein Atlas databases. DriverDBv3 and Timer2.0 databases were used for survival and immune infiltration analysis. Subsequently, the findings were further verified by molecular docking technology and in vitro experiments.

RESULTS

A total of 378 resveratrol action targets and 2154 GC disease targets were obtained from public databases, and 181 intersection targets between the two were screened by Venn diagram. The top 20 core targets were identified by PPI network analysis of the overlapping targets. GO function analysis mainly involved protein binding, identical protein binding, cytoplasm, nucleus, negative regulation of apoptotic process and response to xenobiotic stimulus. KEGG enrichment analysis suggested that the involved signaling pathways mainly included PI3K-AKT signaling pathway, MAPK signaling pathway, IL-17 signaling pathway, TNF signaling pathway, ErbB signaling pathway, etc. FBJ murine osteosarcoma viral oncogene homolog (FOS) and matrix metallopeptidase 9 (MMP9) were selected by differential expression analysis, and they were closely associated with immune infiltration. Molecular docking results showed that resveratrol docked well with these two targets. Resveratrol treatment arrested the cell cycle at the S phase, induced apoptosis, and weakened viability, migration and invasion in a dose-dependent manner. Furthermore, resveratrol could exhibit anti-GC effect by regulating FOS and MMP9 expression.

CONCLUSION

The anti-GC effects of resveratrol are related to the inhibition of cell proliferation, migration, invasion and induction of cell cycle arrest and apoptosis by targeting FOS and MMP9.

CYP1-Activation and Anticancer Properties of Synthetic Methoxylated Resveratrol Analogues

Naturally occurring stilbenoids, such as the (E)-stilbenoid resveratrol and the (Z)-stilbenoid combretastatin A4, have been considered as promising lead compounds for the development of anticancer drugs. The antitumour properties of stilbenoids are known to be modulated by cytochrome P450 enzymes CYP1A1 and CYP1B1, which contribute to extrahepatic phase I xenobiotic and drug metabolism. Thirty-four methyl ether analogues of resveratrol were synthesised, and their anticancer properties were assessed, using the MTT cell proliferation assay on a panel of human breast cell lines. Breast tumour cell lines that express CYP1 were significantly more strongly affected by the resveratrol analogues than the cell lines that did not have CYP1 activity. Metabolism studies using isolated CYP1 enzymes provided further evidence that (E)-stilbenoids can be substrates for these enzymes. Structures of metabolic products were confirmed by comparison with synthetic standards and LC-MS co-elution studies. The most promising stilbenoid was (E)-4,3',4',5'-tetramethoxystilbene (DMU212). The compound itself showed low to moderate cytotoxicity, but upon CYP1-catalysed dealkylation, some highly cytotoxic metabolites were formed. Thus, DMU212 selectively affects proliferation of cells that express CYP1 enzymes.

The activation of SIRT1 by resveratrol reduces breast cancer metastasis to lung through inhibiting neutrophil extracellular traps

Neutrophil extracellular traps (NETs) play a crucial role in breast cancer metastasis. However, the therapeutic target of NETs in breast cancer metastasis is still unknown. Using a natural metabolite library and single-cell sequencing data analysis, we identified resveratrol (RES), a polyphenolic natural phytoalexin, and agonist of silent information regulator-1 (SIRT1) that suppressed NETs formation after cathepsin C (CTSC) treatment. In vivo, RES significantly hindered breast cancer metastasis in a murine orthotopic 4T1 breast cancer model. Serum levels of myeloperoxidase-DNA and neutrophil elastase-DNA in mouse breast cancer model were significantly lower after RES treatment. Correspondingly, the tumour infiltrated CD8+T cells in the lungs increased after the treatment. Mechanistically, RES targets SIRT1 in neutrophils and significantly inhibits the citrullination of histones H3, which is essential for chromatin decondensation and NETs formation. Furthermore, we identified that the NETs were suppressed by RES in bone marrow neutrophils after CTSC treatment, while specific deficiency of SIRT1 in neutrophils promoted NETs formation and breast cancer to lung metastasis. Thus, our results revealed that RES could be potentially identified as a viable therapeutic drug to prevent neutrophil cell death and breast cancer metastasis.

Molecular mechanisms of resveratrol as chemo and radiosensitizer in cancer

One of the primary diseases that cause death worldwide is cancer. Cancer cells can be intrinsically resistant or acquire resistance to therapies and drugs used for cancer treatment through multiple mechanisms of action that favor cell survival and proliferation, becoming one of the leading causes of treatment failure against cancer. A promising strategy to overcome chemoresistance and radioresistance is the co-administration of anticancer agents and natural compounds with anticancer properties, such as the polyphenolic compound resveratrol (RSV). RSV has been reported to be able to sensitize cancer cells to chemotherapeutic agents and radiotherapy, promoting cancer cell death. This review describes the reported molecular mechanisms by which RSV sensitizes tumor cells to radiotherapy and chemotherapy treatment.

Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.

Citrus Carotenoid Extracts Exert Anticancer Effects through Anti-Proliferation, Oxidative Stress, and Mitochondrial-Dependent Apoptosis in MCF-7 Cells

Citrus is a globally popular fruit crop that contains bioactive compounds with numerous health benefits. Carotenoids are one of the main bioactive compounds present in citrus pulp. They possess exceptional antioxidant and anticancer properties, making them potentially effective in the prevention and treatment of breast cancer. Different citrus species, identified as ZMPG, DFGJ, NFMJ, XY, and ZHQC, were studied for their antioxidant activity and anticancer activity. XY had the highest total carotenoid content (75.30 µg/g FW), and ZHQC (ZH) had the lowest carotenoid content (19.74 µg/g FW). The composition of NFMJ, ZMPG, and DFHJ consisted of the most abundant number of carotenoids, while XY only had three types. The antioxidant capacity of the carotenoid extracts was evaluated, and ZH and DFHJ were identified as good sources of antioxidants. XY and ZH significantly inhibited cell proliferation, migration, and arresting cells during the G0/G1 phase. XY and ZH enhanced the accumulation of reactive oxygen species (ROS); reduced mitochondrial membrane potential (MMP); reduced the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and peroxidase (POD); decreased glutathione (GSH) levels; and increased the malonaldehyde (MDA) content. Apoptosis occurred through the mitochondrial-mediated pathway through the up-regulation of BAX, caspase-3, and caspase-9 and the down-regulation of Bcl-2. In this study, the carotenoid-rich extracts of citrus pulp were found to induce oxidative stress through their pro-oxidant potential and regulate cell apoptosis in MCF-7 cancer cells. These results indicate that citrus carotenoids act as pro-oxidants and have the potential to be utilized for the development of anti-breast cancer products.

Phytochemical and biological characterization of aqueous extract of Vassobia breviflora on proliferation and viability of melanoma cells: involvement of purinergic pathway

Vassobia breviflora belongs to the Solanaceae family, possessing biological activity against tumor cells and is a promising alternative for therapy. The aim of this investigation was to determine the phytochemical properties V. breviflora using ESI-ToF-MS. The cytotoxic effects of this extract were examined in B16-F10 melanoma cells and the relationship if any to purinergic signaling was involved. The antioxidant activity of total phenols, (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) was analyzed, as well as production of reactive oxygen species (ROS) and nitric oxide (NO) was determined. Genotoxicity was assessed by DNA damage assay. Subsequently, the structural bioactive compounds were docked against purinoceptors P2X7 and P2Y1 receptors. The bioactive compounds found in V. breviflora were N-methyl-(2S,4 R)-trans-4-hydroxy-L-proline, calystegine B, 12-O-benzoyl- tenacigenin A and bungoside B. In vitro cytotoxicity was demonstrated at concentration ranges of 0.1-10 mg/ml, and plasmid DNA breaks only at the concentration of 10 mg/ml. V. breviflora extracts affected hydrolysis by ectoenzymes, such as ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) and ectoadenosine deaminase (E-ADA) which control levels of degradation and formation of nucleosides and nucleotides. In the presence of substrates ATP, ADP, AMP and adenosine, the activities of E-NTPDase, 5´-NT or E-ADA were significantly modulated by V. breviflora. N-methyl-(2S,4 R)-trans-4-hydroxy-L-proline presented higher binding affinity (according to receptor-ligand complex estimated binding affinity as evidenced by ∆G values) to bind to both P2X7 and P2Y1purinergic receptors.Our results suggest a putative interaction of V. breviflora bioactive compounds with growth inhibitory potential in B16-F10 melanoma and suggest that may be considered as promising compounds in melanoma and cancer treatment.

Association of S19W polymorphism in APOA5 gene and serum lipid levels in patients with type 2 diabetic nephropathy

OBJECTIVES

Type 2 diabetic Mellitus (T2DM) is the most common systemic and endocrine disease in humans, and diabetic nephropathy is one of the most serious complications of this disorder. The polymorphisms in the apolipoprotein A5 (ApoA5) gene are strongly related to hypertriglyceridemia and are considered a predisposing factor for diabetic nephropathy. The current study proposed to examine the association of APOA5-S19W polymorphism with serum lipids levels in patients with type 2 diabetic nephropathy in Mazandaran province.

METHODS

This case-control study was designed to determine the association of APOA5-S19W polymorphism with plasma lipid profile in 161 T2DM patients with nephropathy (DN+), without nephropathy (DN-), and in 58 healthy individuals. Lipid profile values were measured using Pars Azmoun commercial kits. S19W variant, one of the polymorphisms of the APOA5 gene, was determined by PCR-restriction fragment length polymorphism (PCR-RFLP) and Taq1 restriction enzyme.

RESULTS

In comparison between the three groups, DN+ had a higher mean TG than DN- and the control group (p<0.001). The incidence of the G allele in DN+ was not significant compared to groups of DN-. Comparing the relationship between the mean of biochemical variables with CC and CG genotypes showed that the mean level of TG in people with CC genotype was increased compared to people with CG genotype in diabetic patients. However, this increase was not significant (p=0.19).

CONCLUSIONS

There was no association between SNP APOA5 S19W and serum lipids in diabetic patients with and without nephropathy.

Recent Progress in Nanotechnology Improving the Therapeutic Potential of Polyphenols for Cancer

Polyphenols derived from fruits, vegetables, and plants are bioactive compounds potentially beneficial to human health. Notably, compounds such as quercetin, curcumin, epigallocatechin-3-gallate (EGCG), and resveratrol have been highlighted as antiproliferative agents for cancer. Due to their low solubility and limited bioavailability, some alternative nanotechnologies have been applied to encapsulate these compounds, aiming to improve their efficacy against cancer. In this comprehensive review, we evaluate the main nanotechnology approaches to improve the therapeutic potential of polyphenols against cancer using in vitro studies and in vivo preclinical models, highlighting recent advancements in the field. It was found that polymeric nanomaterials, lipid-based nanomaterials, inorganic nanomaterials, and carbon-based nanomaterials are the most used classes of nanocarriers for encapsulating polyphenols. These delivery systems exhibit enhanced antitumor activity and pro-apoptotic effects, particularly against breast, lung, prostate, cervical, and colorectal cancer cells, surpassing the performance of free bioactive compounds. Preclinical trials in xenograft animal models have revealed decreased tumor growth after treatment with polyphenol-loaded delivery systems. Moreover, the interaction of polyphenol co-delivery systems and polyphenol-drug delivery systems is a promising approach to increase anticancer activity and decrease chemotherapy side effects. These innovative approaches hold significant implications for the advancement of clinical cancer research.

Uncovering the mechanism of resveratrol in the treatment of diabetic kidney disease based on network pharmacology, molecular docking, and experimental validation

BACKGROUND

Diabetic kidney disease (DKD) has been the leading cause of chronic kidney disease in developed countries. Evidence of the benefits of resveratrol (RES) for the treatment of DKD is accumulating. However, comprehensive therapeutic targets and underlying mechanisms through which RES exerts its effects against DKD are limited.

METHODS

Drug targets of RES were obtained from Drugbank and SwissTargetPrediction Databases. Disease targets of DKD were obtained from DisGeNET, Genecards, and Therapeutic Target Database. Therapeutic targets for RES against DKD were identified by intersecting the drug targets and disease targets. GO functional enrichment analysis, KEGG pathway analysis, and disease association analysis were performed using the DAVID database and visualized by Cytoscape software. Molecular docking validation of the binding capacity between RES and targets was performed by UCSF Chimera software and SwissDock webserver. The high glucose (HG)-induced podocyte injury model, RT-qPCR, and western blot were used to verify the reliability of the effects of RES on target proteins.

RESULTS

After the intersection of the 86 drug targets and 566 disease targets, 25 therapeutic targets for RES against DKD were obtained. And the target proteins were classified into 6 functional categories. A total of 11 cellular components terms and 27 diseases, and the top 20 enriched biological processes, molecular functions, and KEGG pathways potentially involved in the RES action against DKD were recorded. Molecular docking studies showed that RES had a strong binding affinity toward PPARA, ESR1, SLC2A1, SHBG, AR, AKR1B1, PPARG, IGF1R, RELA, PIK3CA, MMP9, AKT1, INSR, MMP2, TTR, and CYP2C9 domains. The HG-induced podocyte injury model was successfully constructed and validated by RT-qPCR and western blot. RES treatment was able to reverse the abnormal gene expression of PPARA, SHBG, AKR1B1, PPARG, IGF1R, MMP9, AKT1, and INSR.

CONCLUSIONS

RES may target PPARA, SHBG, AKR1B1, PPARG, IGF1R, MMP9, AKT1, and INSR domains to act as a therapeutic agent for DKD. These findings comprehensively reveal the potential therapeutic targets for RES against DKD and provide theoretical bases for the clinical application of RES in the treatment of DKD.

The Role of NQO1 in Ovarian Cancer

Ovarian cancer is one of the most dangerous gynecologic malignancies showing a high fatality rate because of late diagnosis and relapse occurrence due to chemoresistance onset. Several researchers reported that oxidative stress plays a key role in ovarian cancer occurrence, growth and development. The NAD(P)H:quinone oxidoreductase 1 (NQO1) is an antioxidant enzyme that, using NADH or NADPH as substrates to reduce quinones to hydroquinones, avoids the formation of the highly reactive semiquinones, then protecting cells against oxidative stress. In this review, we report evidence from the literature describing the effect of NQO1 on ovarian cancer onset and progression.

Phytoestrogens, novel dietary supplements for breast cancer

While endocrine therapy is considered as an effective way to treat breast cancer, it still faces many challenges, such as drug resistance and individual discrepancy. Therefore, novel preventive and therapeutic modalities are still in great demand to decrease the incidence and mortality rate of breast cancer. Numerous studies suggested that G protein-coupled estrogen receptor (GPER), a membrane estrogen receptor, is a potential target for breast cancer prevention and treatment. It was also shown that not only endogenous estrogens can activate GPERs, but many phytoestrogens can also function as selective estrogen receptor modulators (SERMs) to interact GPERs. In this review, we discussed the possible mechanisms of GPERs pathways and shed a light of developing novel phytoestrogens based dietary supplements against breast cancers.

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.

Increased expression of androgen receptor and PSA genes in LNCaP (prostate cancer) cell line due to high concentrations of EGCG, an active ingredient in green tea

OBJECTIVES

Androgen receptor (AR) play a key role in the onset and progression of prostate cancer. Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound and the active ingredient in green tea, which is involved in modulating gene expression through epigenetic alterations. Previous studies have shown that EGCG at low concentrations reduces the expression of AR and prostate-specific antigen (PSA) in the LNCaP cell line of prostate cancer. In this study, the effect of higher EGCG concentrations on AR and PSA expression in LNCaP prostate cancer cell line was investigated.

METHODS

In this study, LNCaP prostate cancer cell line was used and after MTT test, concentrations of 40, 60 and 80 μg/mL EGCG were used for treatment. Then, the expression of AR and PSA genes was evaluated by RT-PCR. AR protein expression was also assessed by Western blotting.

RESULTS

The present study showed that treatment of LNCaPs cells by EGCG reduces cell proliferation. The IC50 value was 42.7 μg/mL under experimental conditions. It was also observed that EGCG at concentrations of 40 and 80 μg/mL increased the expression of AR and PSA (p<0.05).

CONCLUSIONS

The present study showed that the effect of EGCG on AR expression was different at different concentrations, so that unlike previous studies, higher concentrations of EGCG (80 and 40 μg/mL) increased AR and PSA expression. It seems that due to the toxic effects of EGCG in high concentrations on cancer cells and the possibility of its effect on normal cells, more caution should be exercised in its use.