DNA Methylation and Flavonoids in Genitourinary Cancers

Epigallocatechin Gallate for the Treatment of Benign and Malignant Gynecological Diseases-Focus on Epigenetic Mechanisms

The most common malignant gynecologic diseases are cervical, uterine, ovarian, vaginal, and vulvar cancer. Among them, ovarian cancer causes more deaths than any other cancer of the female reproductive system. A great number of women suffer from endometriosis, uterine fibroids (UFs), adenomyosis, dysmenorrhea, and polycystic ovary syndrome (PCOS), which are widespread benign health problems causing troublesome and painful symptoms and significantly impairing the quality of life of affected women, and they are some of the main causes of infertility. In addition to the available surgical and pharmacological options, the effects of supporting standard treatment with naturally occurring compounds, mainly polyphenols, are being studied. Catechins are responsible for the majority of potential health benefits attributed to green tea consumption. Epigallocatechin gallate (EGCG) is considered a non-toxic, natural compound with potential anticancer properties. Antioxidant action is its most common function, but attention is also drawn to its participation in cell division inhibition, apoptosis stimulation and epigenetic regulation. In this narrative review, we describe the role of EGCG consumption in preventing the development of benign reproductive disorders such as UF, endometriosis, and PCOS, as well as malignant gynecologic conditions. We discuss possible epigenetic mechanisms that may be related to the action of EGCG.

Dietary Plant Metabolites Induced Epigenetic Modification as a Novel Strategy for the Management of Prostate Cancer

Prostate cancer is a widespread malignancy among men, with a substantial global impact on morbidity and mortality. Despite advances in conventional therapies, the need for innovative and less toxic treatments remains a priority. Emerging evidence suggests that dietary plant metabolites possess epigenetic-modifying properties, making them attractive candidates for prostate cancer treatment. The present work reviews the epigenetic effects of dietary plant metabolites in the context of prostate cancer therapy. We first outline the key epigenetic mechanisms involved in prostate cancer pathogenesis, including histone modifications, DNA methylation, and miRNA or Long Noncoding RNA (lncRNA) dysregulation. Next, we delve into the vast array of dietary plant metabolites that have demonstrated promising anti-cancer effects through epigenetic regulation. Resveratrol, minerals, isothiocyanates, curcumin, tea polyphenols, soy isoflavones and phytoestrogens, garlic compounds, anthocyanins, lycopene, and indoles are among the most extensively studied compounds. These plant-derived bioactive compounds have been shown to influence DNA methylation patterns, histone modifications, and microRNA expression, thereby altering the gene expression allied with prostate cancer progression, cell proliferation, and apoptosis. We also explore preclinical and clinical studies investigating the efficacy of dietary plant metabolites as standalone treatments or in combination with traditional treatments for people with prostate cancer. The present work highlights the potential of dietary plant metabolites as epigenetic modulators to treat prostate cancer. Continued research in this field may pave the way for personalized and precision medicine approaches, moving us closer to the goal of improved prostate cancer management.

Hypermethylated ITGA8 Facilitate Bladder Cancer Cell Proliferation and Metastasis

DNA methylation plays a vital role during the development of tumorigenesis. The purpose of this study is to identify candidate DNA methylation drivers during progression of bladder cancer (BLCA). The methylation spectrum in bladder cancer tissues was detected by CHARM analysis, and methylated ITGA8 was selected for further study due to its low expression. Methylation levels in BLCA tissues and cells were detected with methylated-specific PCR (MSP), while mRNA expression and methylation of ITGA8 were detected by qRT-PCR and MSP. After treatment with 5-Aza-dC (DNA methylation inhibitor), the proliferation, migration, and invasion abilities of BLCA cells were determined by MTT, wound healing, and transwell assays, respectively. Flow cytometric analysis was performed to evaluate any variance in the cell cycle. In addition, the effect of demethylated ITGA8 on BLCA tumor growth was verified with an in vivo xenograft tumor model. Based on the methylation profiling of BLCA, ITGA8 was identified to be hypermethylated. ITGA8 methylation levels in BLCA tissues and cells were upregulated, and 5-Aza-dC significantly suppressed ITGA8 methylation levels and increased ITGA8 mRNA expression. Furthermore, after treatment with 5-Aza-dC, the propagation, migration, and invasiveness of the cancer cells were inhibited, and more cancer cells were arrested at the G0/G1 phase. In vivo assays further demonstrated that 5-Aza-dC could impede BLCA tumor growth by repressing methylation levels of ITGA8 and increasing ITGA8 mRNA expression. Hypermethylated ITGA8 facilitated BLCA progression, and 5-Aza-dC treatment inhibited BLCA cell propagation and metastasis by decreasing methylation levels of ITGA8 and inducing cell cycle arrest.

Nutrient-Mediated Perception and Signalling in Human Metabolism: A Perspective of Nutrigenomics

The interaction between selective nutrients and linked genes involving a specific organ reveals the genetic make-up of an individual in response to a particular nutrient. The interaction of genes with food opens opportunities for the addition of bioactive compounds for specific populations comprising identical genotypes. The slight difference in the genetic blueprints of humans is advantageous in determining the effect of nutrients and their metabolism in the body. The basic knowledge of emerging nutrigenomics and nutrigenetics can be applied to optimize health, prevention, and treatment of diseases. In addition, nutrient-mediated pathways detecting the cellular concentration of nutrients such as sugars, amino acids, lipids, and metabolites are integrated and coordinated at the organismal level via hormone signals. This review deals with the interaction of nutrients with various aspects of nutrigenetics and nutrigenomics along with pathways involved in nutrient sensing and regulation, which can provide a detailed understanding of this new leading edge in nutrition research and its potential application to dietetic practice.

Chrysin Modulates Aberrant Epigenetic Variations and Hampers Migratory Behavior of Human Cervical (HeLa) Cells

Purpose: Plant-derived phytochemicals have shown epigenetic modulatory effect in different types of cancer by reversing the pattern of DNA methylation and chromatin modulation, thereby restoring the function of silenced tumor-suppressor genes. In the present study, attempts have been made to explore chrysin-mediated epigenetic alterations in HeLa cells. Methods: Colony formation and migration assays followed by methylation-specific PCR for examining the methylation status of CpG promoters of various tumor-suppressor genes (TSGs) and the expression of these TSGs at the transcript and protein levels were performed. Furthermore, global DNA methylation; biochemical activities of DNA methyltransferases (DNMTs), histone methyl transferases (HMTs), histone deacetylases (HDACs), and histone acetyl transferases (HATs) along with the expression analysis of chromatin-modifying enzymes; and H3 and H4 histone modification marks analyses were performed after chrysin treatment. Results: The experimental analyses revealed that chrysin treatment encourages cytostatic behavior as well as inhibits the migration capacity of HeLa cells in a time- and dose-dependent manner. Chrysin reduces the methylation of various tumor-suppressor genes, leading to their reactivation at mRNA and protein levels. The expression levels of various chromatin-modifying enzymes viz DNMTs, HMTs, HDACs, and HATS were found to be decreased, and H3 and H4 histone modification marks were modulated too. Also, reduced global DNA methylation was observed following the treatment of chrysin. Conclusion: This study concludes that chrysin can be used as a potential epigenetic modifier for cancer treatment and warrants for further experimental validation.

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.

Methylation as a key regulator of Tau aggregation and neuronal health in Alzheimer's disease

Neurodegenerative diseases like Alzheimer's, Parkinson's and Huntington's disease involves abnormal aggregation and accumulation of toxic proteins aggregates. Post-translational modifications (PTMs) of the causative proteins play an important role in the etiology of disease as they could either slow down or accelerate the disease progression. Alzheimer disease is associated with the aggregation and accumulation of two major protein aggregates-intracellular neurofibrillary tangles made up of microtubule-associated protein Tau and extracellular Amyloid-β plaques. Post-translational modifications are important for the regulation of Tau`s function but an imbalance in PTMs may lead to abnormal Tau function and aggregation. Tau methylation is one of the important PTM of Tau in its physiological state. However, the methylation signature on Tau lysine changes once it acquires pathological aggregated form. Tau methylation can compete with other PTMs such as acetylation and ubiquitination. The state of PTM at these sites determines the fate of Tau protein in terms of its function and stability. The global methylation in neurons, microglia and astrocytes are involved in multiple cellular functions involving their role in epigenetic regulation of gene expression via DNA methylation. Here, we have discussed the effect of methylation on Tau function in a site-specific manner and their cross-talk with other lysine modifications. We have also elaborated the role of methylation in epigenetic aspects and neurodegenerative conditions associated with the imbalance in methylation metabolism affecting global methylation state of cells. Video abstract.

Liquiritigenin decreases tumorigenesis by inhibiting DNMT activity and increasing BRCA1 transcriptional activity in triple-negative breast cancer

As a selective estrogen receptor β agonist, the natural flavonoid liquiritigenin reportedly inhibits invasiveness of breast cancer cells, but its specific role and mechanism remain largely unclear. In this study, cells from the triple negative breast cancer lines MDA-MB-231 and BT549 were incubated with different concentrations of liquiritigenin. The results indicated that low concentrations had no significant cytotoxic effect, whereas high concentrations decreased viability of both MDA-MB-231 and BT549 cells. Liquiritigenin treatment also resulted in increased apoptosis and enhanced Caspase3 activity. After liquiritigenin treatment, we observed decreased invasive and migratory capacities of cells, as well as upregulated E-cadherin and downregulated N-cadherin, vimentin, and MMP9. Interestingly, liquiritigenin increased the mRNA and protein expression of breast cancer 1 (BRCA1). It also increased p21 and growth arrest and DNA-damage-inducible 45 alpha (GADD45A) levels, accompanied by decreased cellular DNA methyltransferase (DNMT) activity and downregulation of DNMT1, DNMT3a, and DNMT3b. These findings suggest that liquiritigenin can inhibit malignant behavior of triple negative breast cancer cells by inhibiting DNMT activity and increasing BRCA1 expression and its transcriptional activity. Liquiritigenin thus may be a promising candidate for the treatment of breast cancer.

Caffeic acid and chlorogenic acid cytotoxicity, genotoxicity and impact on global DNA methylation in human leukemic cell lines

Dietary phenolic compounds such as caffeic and chlorogenic acid exert an antiproliferative effect and modulate the gene-specific DNA methylation status in human breast tumor cells, but it remains unclear whether they interfere with global DNA methylation in human leukemia cells. We examined whether caffeic and chlorogenic acid (1-250 µM) exert antitumor action in human promyelocytic leukemia cells (HL-60) and human acute T-cell leukemia cells (Jurkat). Caffeic and chlorogenic acid did not reduce cell viability in the two cell lines, as assessed using the neutral red uptake and MTT assays. These phenolic acids (1-100 μM) neither induced DNA damage (comet assay) nor increased the micronuclei frequency (micronucleus assay) in HL-60 and Jurkat cells, indicating that they were not genotoxic or mutagenic. Analysis of global DNA methylation levels using a 5-mC DNA ELISA kit revealed that chlorogenic acid at a non-cytotoxic concentration (100 μM) induced global DNA hypomethylation in Jurkat cells, but not in HL-60 cells, suggesting that it exerts a cell-specific effect. Caffeic acid did not change global DNA methylation. As other phenolic compounds, chlorogenic acid probably modulates DNA methylation by targeting DNA methyltransferases. The hypomethylating action of chlorogenic acid can be beneficial against hematological malignances whose pathogenic processes involve impairment of DNA methylation.

Flavonoids as Epigenetic Modulators for Prostate Cancer Prevention

Prostate cancer (PCa) is a multifactorial disease with an unclear etiology. Due to its high prevalence, long latency, and slow progression, PCa is an ideal target for chemoprevention strategies. Many research studies have highlighted the positive effects of natural flavonoids on chronic diseases, including PCa. Different classes of dietary flavonoids exhibit anti-oxidative, anti-inflammatory, anti-mutagenic, anti-aging, cardioprotective, anti-viral/bacterial and anti-carcinogenic properties. We overviewed the most recent evidence of the antitumoral effects exerted by dietary flavonoids, with a special focus on their epigenetic action in PCa. Epigenetic alterations have been identified as key initiating events in several kinds of cancer. Many dietary flavonoids have been found to reverse DNA aberrations that promote neoplastic transformation, particularly for PCa. The epigenetic targets of the actions of flavonoids include oncogenes and tumor suppressor genes, indirectly controlled through the regulation of epigenetic enzymes such as DNA methyltransferase (DNMT), histone acetyltransferase (HAT), and histone deacetylase (HDAC). In addition, flavonoids were found capable of restoring miRNA and lncRNA expression that is altered during diseases. The optimization of the use of flavonoids as natural epigenetic modulators for chemoprevention and as a possible treatment of PCa and other kinds of cancers could represent a promising and valid strategy to inhibit carcinogenesis and fight cancer.

Molecular Mechanisms Underlying the Link between Diet and DNA Methylation

DNA methylation is a vital modification process in the control of genetic information, which contributes to the epigenetics by regulating gene expression without changing the DNA sequence. Abnormal DNA methylation—both hypomethylation and hypermethylation—has been associated with improper gene expression, leading to several disorders. Two types of risk factors can alter the epigenetic regulation of methylation pathways: genetic factors and modifiable factors. Nutrition is one of the strongest modifiable factors, which plays a direct role in DNA methylation pathways. Large numbers of studies have investigated the effects of nutrition on DNA methylation pathways, but relatively few have focused on the biochemical mechanisms. Understanding the biological mechanisms is essential for clarifying how nutrients function in epigenetics. It is believed that nutrition affects the epigenetic regulations of DNA methylation in several possible epigenetic pathways: mainly, by altering the substrates and cofactors that are necessary for proper DNA methylation; additionally, by changing the activity of enzymes regulating the one-carbon cycle; and, lastly, through there being an epigenetic role in several possible mechanisms related to DNA demethylation activity. The aim of this article is to review the potential underlying biochemical mechanisms that are related to diet modifications in DNA methylation and demethylation.

The co-administration of proanthocyanidins and an obesogenic diet prevents the increase in intestinal permeability and metabolic endotoxemia derived to the diet

The consumption of Westernized diets leads to hyperphagia and obesity, as well as intestinal alterations. In the present study, we evaluated the effect of the administration of a grape seed proanthocyanidin extract (GSPE) at different time points on the modulation of intestinal barrier function (intestinal permeability and metabolic endotoxemia), in rats with high-fat/high-carbohydrate diet-induced obesity. Animals were fed a cafeteria diet (CAF) supplemented with a preventive (PRE-CAF) or simultaneously intermittent (SIT-CAF) GSPE treatment (500 mg/kg bw). Changes in the plasma levels of an orally administered marker of intestinal permeability (ovalbumin, OVA), lipopolysaccharide (LPS) and tumor necrosis factor-α (TNF-α) were analyzed after animals were fed the obesogenic diet for 8, 12 and 17 weeks. In addition, ex vivo variations in transepithelial electrical resistance (TEER), the expression of tight junction (TJ) genes and the activity of myeloperoxidase (MPO) in the small and large intestines were monitored at the end of the experiment. The CAF diet increased OVA, LPS, MPO and TNF-α levels, accompanied by decreased TEER values in the small and large intestines. Interestingly, both GSPE treatments prevented these detrimental effects of the CAF diet, being the SIT-CAF group the most effective after 17 weeks of diet intervention. For the first time, this study provides evidence of the ameliorative effect of a proanthocyanidin extract, administered before or together with an obesogenic diet, on barrier dysfunction, as measured by intestinal permeability and metabolic endotoxemia.

SETD6 regulates NF-κB signaling in urothelial cell survival: Implications for bladder cancer

Non-muscle invasive bladder cancer has a high recurrence rate of 45-70%, progressing to muscle invasive disease in about 15% of those patients over a 5-year period. Administration of the mycobacterium, Bacillus Calmette-Guerin (BCG) that induces local inflammation resulting in tumor remission in responsive patients is frequently used for treatment. BCG-treated patients with NF-κB del/del genotype have an increased risk of recurrence suggesting an important role of NF-κB in bladder cancer. Since protein methyltransferases play critical roles in modulating chromatin structure and gene expression, we screened a focused array of epigenetic modification genes to identify differential expression between normal urothelial and bladder cancer cells. We found and validated high expression of the SET-domain-containing protein methyltransferase, SETD6. SETD6 monomethylates NF-κB-p65 at lysine 310. Our results show that primary urothelial cells and normal bladder tissue have nearly undetectable message and protein level of SETD6 that increases in transformed urothelial cells and is further increased in bladder cancer cells and tissues. Overexpression of SETD6 in transformed urothelial cells increased cell survival and colony formation while knockdown in cancer cells decreased both parameters. Luciferase reporter assays showed that SETD6 induced the canonical NF-κB signaling pathway. Further, the use of catalytic SETD6 and IκBα mutant shows that SETD6 positively regulates survival by affecting p65 message, protein level and its function as determined by increased expression of NF-κB target genes. Our findings suggest that SETD6 plays an important role in NF-κB regulation and may have an important role in NF-κB-mediated local inflammatory response following BCG treatment.

Epigallocatechin gallate inhibits the growth and promotes the apoptosis of bladder cancer cells

Epigallocatechin gallate (EGCG) has been revealed to inhibit the proliferation and induce the apoptosis of several types of tumor, in addition to inhibiting DNA methyltransferase activity, leading to CpG demethylation. Tissue factor pathway inhibitor 2 (TFPI-2) expression is downregulated in bladder cancer. The present study revealed that this downregulation was partly due to hypermethylation of the TFPI-2 gene promoter, which was decreased by EGCG treatment. In addition, the present study demonstrated that EGCG could inhibit the viability and invasion, and induce the apoptosis, of bladder cancer T24 cells. Furthermore, western blot analysis and reverse transcription-quantitative polymerase chain reaction analyses demonstrated that EGCG could upregulate the expression of TFPI-2. These results suggest that EGCG inhibits the growth and induces the apoptosis of bladder cancer cells through restoring TFPI-2 expression. Thus, EGCG is a potential therapeutic candidate for the treatment of bladder cancer.

The Anti-Inflammatory Properties of Citrus wilsonii Tanaka Extract in LPS-Induced RAW 264.7 and Primary Mouse Bone Marrow-Derived Dendritic Cells

‘Zhique’ (Citrus wilsonii Tanaka) is a traditional Chinese medicine. Its fruits have been used to treat inflammation-related symptoms, such as cough and sputum, though the underlying mechanism remains poorly understood. The aim of this study was to investigate the anti-inflammatory properties of ‘Zhique’ pulp extract (ZQE) in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages and primary mouse bone marrow-derived dendritic cells (BMDCs). The flavonoid profiles of the ZQE were determined by high performance liquid chromatography. The anti-inflammatory activity was evaluated in LPS-induced inflammatory RAW 264.7 macrophages and BMDCs through enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and Western blot assays. Naringin was a predominant flavonoid occurring in ZQE, followed by eriocitrin, hesperidin, neohesperidin, rhoifolin, naringenin, and poncirin. ZQE exhibited a very low cytotoxicity in LPS-stimulated RAW 264.7 macrophages. Meanwhile, ZQE significantly inhibited the production of prostaglandins E2 and secretion of cyclooxygenase-2 protein in LPS-stimulated RAW 264.7 macrophages, and markedly suppressed the mRNA expression of inflammatory mediators, such as cyclooxygenase-2, tumor necrosis factor alpha, interleukin-1 beta (IL-1β), and IL-6 in LPS-induced RAW 264.7 macrophages and/or primary BMDCs. The ZQE inhibited the inflammatory responses in RAW 264.7 macrophages and BMDCs triggered by LPS. The results suggested that ‘Zhique’ has a high potential as a novel therapeutic agent to treat chronic inflammatory diseases.

Current Concepts of Epigenetics in Testicular Cancer

Testicular germ cell tumors (GCTs) are characterized into seminomas (SGCTs) and non-seminomatous testicular germ cell tumors (NSGCTs). Serum tumor markers (STMs) play an important role in testicular cancer as they provide useful information for diagnosis, staging, and detection of recurrence. Nonetheless, additional tumor markers for early diagnosis and therapeutic options are required to enhance specificity of serological diagnosis of testes cancers. Epigenetics is defined as inherited changes in gene expression that are not encoded in the DNA structure. Epigenetic changes include DNA methylation, histone modifications, and microRNA (miRNA) regulation. It is through the study of epigenetics that diagnostic methods for early detection and novel therapeutic strategies may be established for testicular cancer. We performed a comprehensive review of the English medical literature in PubMed by combining search terms including DNA methylation, histone modifications, microRNA (miRNA) regulation, epigenetics, and testicular cancer. DNA methylation is the most extensively studied epigenetic modification. It consists of the addition of a methyl group to nucleotide bases. It has been reported that SGCT contain reduced levels of DNA methylation compared to NSGCT. MiRNAs are small non-coding RNAs that regulate posttranscriptional gene expression. It has been suggested that miRNAs may play a role in the pathogenesis of GCT. Specific expression patterns have been displayed by various miRNAs in patients with GCT. Histones are proteins intertwined with coiled, double-stranded genomic DNA that form a structure known as a nucleosome. The most widely studied histone modifications include acetylation, methylation, and phosphorylation. Methylation of histone proteins has been found in all types of NSGCT. Epigenetics may offer an additional and effective tool in establishing a diagnosis of GCT of the testes, including prognostic information and perhaps enabling targeted treatment in patients with testicular GCT.

Anticancer Natural Compounds as Epigenetic Modulators of Gene Expression

Accumulating evidence shows that hallmarks of cancer include: "genetic and epigenetic alterations leading to inactivation of cancer suppressors, overexpression of oncogenes, deregulation of intracellular signaling cascades, alterations of cancer cell metabolism, failure to undergo cancer cell death, induction of epithelial to mesenchymal transition, invasiveness, metastasis, deregulation of immune response and changes in cancer microenvironment, which underpin cancer development". Natural compounds as bioactive ingredients isolated from natural sources (plants, fungi, marine life forms) have revolutionized the field of anticancer therapeutics and rapid developments in preclinical studies are encouraging. Natural compounds could affect the epigenetic molecular mechanisms that modulate gene expression, as well as DNA damage and repair mechanisms. The current review will describe the latest achievements in using naturally produced compounds targeting epigenetic regulators and modulators of gene transcription in vitro and in vivo to generate novel anticancer therapeutics.

Epigenetic regulation of active Chinese herbal components for cancer prevention and treatment: A follow-up review

Epigenetic modifications include DNA methylation, histone modification, and other patterns. These processes are associated with carcinogenesis and cancer progression. Thus, epigenetic modification-related enzymes, such as DNA methyltransferases (DNMTs), histone methyltransferases (HMTs), histone demethylases (HDMTs), histone acetyltransferases (HATs), and histone deacetylases (HDACs), as well as some related proteins, including methyl-CpG binding proteins (MBPs) and DNMT1-associated protein (DMAP 1), are considered as potential targets for cancer prevention and therapy. Numerous natural compounds, mainly derived from Chinese herbs and chemically ranging from polyphenols and flavonoids to mineral salts, inhibit the growth and development of various cancers by targeting multiple genetic and epigenetic alterations. This review summarizes the epigenetic mechanisms by which active compounds from Chinese herbs exert their anti-cancer effect. A subset of these compounds, such as curcumin and resveratrol, affect multiple epigenetic processes, including DNMT inhibition, HDAC inactivation, MBP suppression, HAT activation, and microRNA modulation. Other compounds also regulate epigenetic modification processes, but the underlying mechanisms and clear targets remain unknown. Accordingly, further studies are required.

Overview of Oroxylin A: A Promising Flavonoid Compound

Oroxylin A is one of the main active components extracted from Scutellariae radix. It has been proved that oroxylin A possesses a broad spectrum of pharmacological functions, including anti-cancer, antiinflammation, neuroprotective, anti-coagulation and so on. The pharmacological activity of oroxylin A has been studied in vitro and on animal models, which reflected its promising potency in disease treatment. This review aims to recapitulate the pharmacological function and the molecular mechanisms of oroxylin A, as well as its sources, extraction, synthesis and toxicity study. These data confirmed the therapeutic potential of oroxylin A and provided reference for further development. Copyright © 2016 John Wiley & Sons, Ltd.

All-trans retinoic acid and genistein induce cell apoptosis in OVCAR-3 cells by increasing the P14 tumor suppressor gene

In this study, we evaluated the effects of all-trans retinoic acid (ATRA) alone or in combination with genistein (GEN) in p14 tumor suppressor gene and subsequent apoptosis of human ovarian carcinoma cells (OVCAR-3). The cells were treated with ATRA or GEN at concentrations of 50 and 25 μM respectively, either alone or in combination for 24 and 48 h. The cell viability was evaluated using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay. The percentage of cell apoptosis was determined using flow cytometry and p14 gene expression was measured using real time PCR. The MTT results showed that in both ATRA and GEN treated groups, the cell viabilityviability in group treated for 48 h was significantly lower than group treated for 24 h. The flow cytometry results showed that the percentage of apoptotic cells in groups that treated with ATRA and GEN in combination for 24 h and 48 h was significantly more than all other tested groups. The real time results showed that the mRNA level of p14 in cells treated with both drugs for 48 h was significantly higher than all other groups. In conclusion, we confirm that GEN in combination with ATRA is an effective strategy to up regulate the p14 tumor suppressor gene and induce cell apoptosis in OVCAR-3 cell line.

Epigenetic modulation of DNA methylation by nutrition and its mechanisms in animals

It is well known that phenotype of animals may be modified by the nutritional modulations through epigenetic mechanisms. As a key and central component of epigenetic network, DNA methylation is labile in response to nutritional influences. Alterations in DNA methylation profiles can lead to changes in gene expression, resulting in diverse phenotypes with the potential for decreased growth and health. Here, I reviewed the biological process of DNA methylation that results in the addition of methyl groups to DNA; the possible ways including methyl donors, DNA methyltransferase (DNMT) activity and other cofactors, the critical periods including prenatal, postnatal and dietary transition periods, and tissue specific of epigenetic modulation of DNA methylation by nutrition and its mechanisms in animals.