Phytoestrogens and risk of prostate cancer: an updated meta-analysis of epidemiologic studies

Equol: a metabolite of gut microbiota with potential antitumor effects

An increasing number of studies have shown that the consumption of soybeans and soybeans products is beneficial to human health, and the biological activity of soy products may be attributed to the presence of Soy Isoflavones (SI) in soybeans. In the intestinal tracts of humans and animals, certain specific bacteria can metabolize soy isoflavones into equol. Equol has a similar chemical structure to endogenous estradiol in the human body, which can bind with estrogen receptors and exert weak estrogen effects. Therefore, equol plays an important role in the occurrence and development of a variety of hormone-dependent malignancies such as breast cancer and prostate cancer. Despite the numerous health benefits of equol for humans, only 30-50% of the population can metabolize soy isoflavones into equol, with individual variation in gut microbiota being the main reason. This article provides an overview of the relevant gut microbiota involved in the synthesis of equol and its anti-tumor effects in various types of cancer. It also summarizes the molecular mechanisms underlying its anti-tumor properties, aiming to provide a more reliable theoretical basis for the rational utilization of equol in the field of cancer treatment.

Dietary Flavonoids Consumption and Health: An Umbrella Review

SCOPE

The current evidence between dietary flavonoids consumption and multiple health outcomes is inadequate and inconclusive. To summarize and evaluate the evidence for dietary flavonoids consumption and multiple health outcomes, an umbrella review of meta-analyses and systematic reviews is conducted.

METHODS AND RESULTS

PubMed, Ovid-EMBASE, and the Cochrane Database of Systematic Reviews are searched up to January 2024. The study includes a total of 32 articles containing 24 unique health outcomes in this umbrella review. Meta-analyses are recalculated by using a random effects model. Separate analyses are performed based on the kind of different flavonoid subclasses. The study finds some unique associations such as flavonol and gastric cancer, isoflavone and uterine fibroids and endometrial cancer, total flavonoids consumption and lung cancer, ovarian cancer, and prostate cancer. Overall, the study confirms the negative associations between dietary flavonoids consumption and type 2 diabetes mellitus, cardiovascular diseases, breast cancer, colorectal cancer, lung cancer, and mortality, while positive associations are observed for prostate cancer and uterine fibroids.

CONCLUSION

Although dietary flavonoids are significantly associated with many outcomes, firm generalizable conclusions about their beneficial or harmful effects cannot be drawn because of the low certainty of evidence for most of outcomes. More well-designed primary studies are needed.

Endocrine Disruptors and Estrogens in Human Prostatic Tissue

Endocrine disruptors (EDs) are ubiquitous substances both in the environment and everyday products that interfere with the hormonal system. Growing evidence demonstrates their adverse effects on the organism, including the reproductive system and the prostate, owing to their (anti)estrogenic or antiandrogenic effects. Since EDs can interact with steroid hormone actions on-site, understanding the levels of intraprostatic EDs in conjunction with steroids may hold particular significance. The aim of this study was to develop and validate a method for determining estrogens, various groups of EDs (bisphenols, parabens, oxybenzone and nonylphenol) and phytoestrogens in their unconjugated and conjugated forms in prostate tissue by liquid chromatography-tandem mass spectrometry, and subsequently analyze 20 human prostate tissue samples. The method enabled 20 compounds to be analyzed: estrogens (estrone, estradiol, estriol), bisphenols (bisphenol A- BPA, BPS, BPF, BPAF, BPAP, BPZ, BPP), parabens (methyl-, ethyl-, propyl-, butyl-, benzyl- paraben), oxybenzone, nonylphenol and phytoestrogens (daidzein, genistein, equol) with LLOQs between 0.017-2.86 pg/mg of tissue. The most frequently detected EDs in prostate tissues were propylparaben (conjugated and unconjugated forms in 100 % of tissues), methylparaben (unconjugated in 45 % and conjugated in 100 %), ethylparaben (unconjugated in 25 % and conjugated in 100 % BPA (unconjugated in 35 % and conjugated in 60 % and oxybenzone (both forms in 45 % To the best of our knowledge, this is the first study detecting EDs, phytoestrogens and estriol conjugate (E3C) in the prostate. E3C was the most abundant estrogen in prostatic tissue. This highlights the need for further explorations into estrogen metabolism within the prostate.

The What and Who of Dietary Lignans in Human Health: Special Attention to Estrogen Effects and Safety Evaluation

Lignans are a group of phenolic compounds found in plant-based diets. The human body can obtain lignans through diet, which are then metabolized into enterolignans. The enterolignans have been linked to several health benefits, including anticancer, anti-inflammatory, antioxidant effects, and estrogen effects. This review explores the relationship between the estrogenic effects of lignans and health. This review not only considers the estrogen-like activity of lignans but also discusses the safe dosage of lignans at different life stages. In addition, this review also identified other types of bioactive compounds that can act synergistically with lignans to promote health. Studies have shown that lignan administration during pregnancy and lactation reduces the risk of breast cancer in offspring. Further studies are needed to investigate the estrogenic safety effects of lignan on pregnant women and children. Whether lignans combine with other nutrients in complex food substrates to produce synergistic effects remains to be investigated. This review provides a basis for future studies on the safe dose of lignan and recommended dietary intake of lignan. We believe that the acquired as discussed here has implications for developing dietary therapies that can promote host nutrition and modulate estrogenic diseases.

2022 Update on Prostate Cancer Epidemiology and Risk Factors-A Systematic Review

CONTEXT

Prostate cancer (PCa) is one of the most common cancers worldwide. Understanding the epidemiology and risk factors of the disease is paramount to improve primary and secondary prevention strategies.

OBJECTIVE

To systematically review and summarize the current evidence on the descriptive epidemiology, large screening studies, diagnostic techniques, and risk factors of PCa.

EVIDENCE ACQUISITION

PCa incidence and mortality rates for 2020 were obtained from the GLOBOCAN database of the International Agency for Research on Cancer. A systematic search was performed in July 2022 using PubMed/MEDLINE and EMBASE biomedical databases. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and was registered in PROSPERO (CRD42022359728).

EVIDENCE SYNTHESIS

Globally, PCa is the second most common cancer, with the highest incidence in North and South America, Europe, Australia, and the Caribbean. Risk factors include age, family history, and genetic predisposition. Additional factors may include smoking, diet, physical activity, specific medications, and occupational factors. As PCa screening has become more accepted, newer approaches such as magnetic resonance imaging (MRI) and biomarkers have been implemented to identify patients who are likely to harbor significant tumors. Limitations of this review include the evidence being derived from meta-analyses of mostly retrospective studies.

CONCLUSIONS

PCa remains the second most common cancer among men worldwide. PCa screening is gaining acceptance and will likely reduce PCa mortality at the cost of overdiagnosis and overtreatment. Increasing use of MRI and biomarkers for the detection of PCa may mitigate some of the negative consequences of screening.

PATIENT SUMMARY

Prostate cancer (PCa) remains the second most common cancer among men, and screening for PCa is likely to increase in the future. Improved diagnostic techniques can help reduce the number of men who need to be diagnosed and treated to save one life. Avoidable risk factors for PCa may include factors such as smoking, diet, physical activity, specific medications, and certain occupations.

Effects on Serum Hormone Concentrations after a Dietary Phytoestrogen Intervention in Patients with Prostate Cancer: A Randomized Controlled Trial

Phytoestrogens have been suggested to have an anti-proliferative role in prostate cancer, potentially by acting through estrogen receptor beta (ERβ) and modulating several hormones. We primarily aimed to investigate the effect of a phytoestrogen intervention on hormone concentrations in blood depending on the ERβ genotype. Patients with low and intermediate-risk prostate cancer, scheduled for radical prostatectomy, were randomized to an intervention group provided with soybeans and flaxseeds (∼200 mg phytoestrogens/d) added to their diet until their surgery, or a control group that was not provided with any food items. Both groups received official dietary recommendations. Blood samples were collected at baseline and endpoint and blood concentrations of different hormones and phytoestrogens were analyzed. The phytoestrogen-rich diet did not affect serum concentrations of testosterone, insulin-like growth factor 1, or sex hormone-binding globulin (SHBG). However, we found a trend of decreased risk of increased serum concentration of estradiol in the intervention group compared to the control group but only in a specific genotype of ERβ (p = 0.058). In conclusion, a high daily intake of phytoestrogen-rich foods has no major effect on hormone concentrations but may lower the concentration of estradiol in patients with prostate cancer with a specific genetic upset of ERβ.

Genistein and coumestrol reduce MCF-7 breast cancer cell viability and inhibit markers of preferential metastasis, bone matrix attachment and tumor-induced osteoclastogenesis

The propensity of breast cancer to preferentially metastasize to the skeleton is well known. Once established in bone metastatic breast cancers have a poor prognosis due to their ability to promote extensive bone loss which augments tumor burden. Unfortunately, current anti-resorptive therapies for skeletal metastasis are typically prescribed after secondary tumors have formed and are palliative in nature. One group of compounds with the potential to reduce both tumor burden and osteolysis are phytoestrogens (PE), but the mechanisms mediating a beneficial effect are unclear. Therefore, the current study examined the effect of genistein and coumestrol alone or in combination on breast cancer cell number, expression of mediators of preferential skeletal metastasis, bone matrix attachment and tumor-induced osteoclast formation. Results showed that genistein and coumestrol significantly reduced viable cell number in an estrogen receptor dependent manner (p < 0.05), whereas combinations of PE had no effect. In addition, genistein and coumestrol significantly reduced expression of genes driving epithelial to mesenchymal transition (snail), bone attachment (CXCR4 and integrin αV) and osteolysis (PTHrP and TNF-α). In keeping with this genistein and coumestrol significantly suppressed attachment of breast cancer cells to bone matrix and inhibited tumor and RANKL-induced osteoclast formation. Our data suggests that phytoestrogens not only decrease breast cancer cell viability but also antagonize essential tumor bone interactions that establish and drive the progression of skeletal metastasis.

Interplay between Lignans and Gut Microbiota: Nutritional, Functional and Methodological Aspects

Lignans are non-flavonoid polyphenols present in a wide range of foods frequently consumed in the Western world, such as seeds, vegetables and fruits, and beverages such as coffee, tea and wine. In particular, the human gut microbiota (GM) can convert dietary lignans into biologically active compounds, especially enterolignans (i.e., enterolactone and enterodiol), which play anti-inflammatory and anti-oxidant roles, act as estrogen receptor activators and modulate gene expression and/or enzyme activity. Interestingly, recent evidence documenting those dietary interventions involving foods enriched in lignans have shown beneficial and protective effects on various human pathologies, including colorectal and breast cancer and cardiovascular diseases. However, considering that more factors (e.g., diet, food transit time and intestinal redox state) can modulate the lignans bioactivation by GM, there are usually remarkable inter-individual differences in urine, fecal and blood concentrations of enterolignans; hence, precise and validated analytical methods, especially gas/liquid chromatography coupled to mass spectrometry, are needed for their accurate quantification. Therefore, this review aims to summarize the beneficial roles of enterolignans, their interaction with GM and the new methodological approaches developed for their evaluation in different biological samples, since they could be considered future promising nutraceuticals for the prevention of human chronic disorders.

The effect of a phytoestrogen intervention and impact of genetic factors on tumor proliferation markers among Swedish patients with prostate cancer: study protocol for the randomized controlled PRODICA trial

BACKGROUND

A high intake of phytoestrogens, found in soy, rye, and seeds, is associated with a reduced risk of a prostate cancer diagnosis. Previously, we found that the overall decreased risk of prostate cancer diagnosis in males with a high intake of phytoestrogens was strongly modified by a nucleotide sequence variant in the estrogen receptor-beta (ERβ) gene. However, we do not know if phytoestrogens can inhibit the growth of prostate cancer in males with established diseases. If there is an inhibition or a delay, there is reason to believe that different variants of the ERβ gene will modify the effect. Therefore, we designed an intervention study to investigate the effect of the addition of foods high in phytoestrogens and their interaction with the ERβ genotype on prostate tumor proliferation in patients with prostate cancer.

METHOD

The PRODICA trial is a randomized ongoing intervention study in patients with low- and intermediate-risk prostate cancer with a Gleason score < 8, prostate-specific antigen (PSA) < 20, and scheduled for radical prostatectomy. The study is conducted at Sahlgrenska University Hospital in Gothenburg, Sweden. The intervention consists of a daily intake of soybeans and flaxseeds (~ 200 mg of phytoestrogens) until the surgery, approximately 6 weeks. The aim is to recruit 200 participants. The primary outcome is the difference in the proliferation marker Ki-67 between the intervention and the control groups. The genotype of ERβ will be investigated as an effect-modifying factor. Secondary outcomes include, e.g., concentrations of PSA and steroid hormones in the blood.

DISCUSSION

The results of the PRODICA trial will contribute important information on the relevance of increasing the intake of phytoestrogens in patients with prostate cancer who want to make dietary changes to improve the prognosis of their cancer. If genetic factors turn out to influence the effect of the intervention diet, dietary advice can be given to patients who most likely benefit from it. Dietary interventions are cost-effective, non-invasive, and result in few mild side effects. Lastly, the project will provide basic pathophysiological insights which could be relevant to the development of treatment strategies for patients with prostate cancer.

TRIAL REGISTRATION

CLINICALTRIALS

gov NCT02759380. Registered on 3 May 2016.

Obesity, the other pandemic: linking diet and carcinogenesis by epigenetic mechanisms

Both obesity and cancer are complex medical conditions that are considered public health problems. The influence of obesity on the predisposition to develop various types of cancer has been observed in a wide variety of studies. Due to their importance as public health problems, and the close relationship between both conditions, it is important to be able to understand and associate them mechanistically. In this review article, we intend to go a little further, by finding relationships between lifestyle, which can lead a person to develop obesity, and how it influences at the cellular and molecular level, affecting gene expression to favor signaling pathways or transcriptional programs involved in cancer. We describe how products of metabolism and intermediate metabolism can affect chromatin structure, participating in the regulation (or dysregulation) of gene expression, and we show an analysis of genes that are responsive to diets high in sugar and fat, and how their epigenetic landscape is altered.

Effects of glutamate and aspartate on prostate cancer and breast cancer: a Mendelian randomization study

Background

Respectively, prostate cancer (PCa) and breast cancer (BC) are the second most and most commonly diagnosed cancer in men and women, and they account for a majority of cancer-related deaths world-wide. Cancer cells typically exhibit much-facilitated growth that necessitates upregulated glycolysis and augmented amino acid metabolism, that of glutamine and aspartate in particular, which is tightly coupled with an increased flux of the tricarboxylic acid (TCA) cycle. Epidemiological studies have exploited metabolomics to explore the etiology and found potentially effective biomarkers for early detection or progression of prostate and breast cancers. However, large randomized controlled trials (RCTs) to establish causal associations between amino acid metabolism and prostate and breast cancers have not been reported.

Objective

Utilizing two-sample Mendelian randomization (MR), we aimed to estimate how genetically predicted glutamate and aspartate levels could impact upon prostate and breast cancers development.

Methods

Single nucleotide polymorphisms (SNPs) as instrumental variables (IVs), associated with the serum levels of glutamate and aspartate were extracted from the publicly available genome-wide association studies (GWASs), which were conducted to associate genetic variations with blood metabolite levels using comprehensive metabolite profiling in 1,960 adults; and the glutamate and aspartate we have chosen were two of 644 metabolites. The summary statistics for the largest and latest GWAS datasets for prostate cancer (61,106 controls and 79,148 cases) were from the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) consortium, and datasets for breast cancer (113,789 controls and 133,384 cases) were from Breast Cancer Association Consortium (BCAC). The study was performed through two-sample MR method.

Results

Causal estimates were expressed as odds ratios (OR) and 95% confidence interval (CI) per standard deviation increment in serum level of aspartate or glutamate. Aspartate was positively associated with prostate cancer (Effect = 1.043; 95% confidence interval, 1.003 to 1.084; P = 0.034) and breast cancer (Effect = 1.033; 95% confidence interval, 1.004 to 1.063; P = 0.028); however, glutamate was neither associated with prostate cancer nor with breast cancer. The potential causal associations were robust to the sensitivity analysis.

Conclusions

Our study found that the level of serum aspartate could serve as a risk factor that contributed to the development of prostate and breast cancers. Efforts on a detailed description of the underlying biochemical mechanisms would be extremely valuable in early assessment and/or diagnosis, and strategizing clinical intervention, of both cancers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08442-7.

Life Cycle Environmental Impacts and Health Effects of Protein-Rich Food as Meat Alternatives: A Review

The food sector is responsible for a considerable impact on the environment in most environmental contexts: the food supply chain causes greenhouse gas emissions, water consumption, reduction in cultivable land, and other environmental impacts. Thus, a change in food supply is required to reduce the environmental impacts caused by the food supply chain and to meet the increasing demand for sufficient and qualitative nutrition. Large herds of livestock are inappropriate to achieve these goals due to the relevant impact of meat supply chain on the environment, e.g., the land used to grow feed for animals is eight times more than that for human nutrition. The search for meat alternatives, especially for the intake of critical nutrients such as protein, is a consequent step. In the above context, this paper summarizes the health aspects of protein-rich food alternatives to meat and carries out a literature review on the life-cycle environmental impacts of this alternative food.

Fatty Acid Metabolism Reprogramming in Advanced Prostate Cancer

Prostate cancer (PCa) is a carcinoma in which fatty acids are abundant. Fatty acid metabolism is rewired during PCa development. Although PCa can be treated with hormone therapy, after prolonged treatment, castration-resistant prostate cancer can develop and can lead to increased mortality. Changes to fatty acid metabolism occur systemically and locally in prostate cancer patients, and understanding these changes may lead to individualized treatments, especially in advanced, castration-resistant prostate cancers. The fatty acid metabolic changes are not merely reflective of oncogenic activity, but in many cases, these represent a critical factor in cancer initiation and development. In this review, we analyzed the literature regarding systemic changes to fatty acid metabolism in PCa patients and how these changes relate to obesity, diet, circulating metabolites, and peri-prostatic adipose tissue. We also analyzed cellular fatty acid metabolism in prostate cancer, including fatty acid uptake, de novo lipogenesis, fatty acid elongation, and oxidation. This review broadens our view of fatty acid switches in PCa and presents potential candidates for PCa treatment and diagnosis.

Therapeutic Potential of Isoflavones with an Emphasis on Daidzein

Daidzein is a phytoestrogen isoflavone found in soybeans and other legumes. The chemical composition of daidzein is analogous to mammalian estrogens, and it could be useful with a dual-directional purpose by substituting/hindering with estrogen and estrogen receptor (ER) complex. Hence, daidzein puts forth shielding effects against a great number of diseases, especially those associated with the control of estrogen, such as breast cancer, diabetes, osteoporosis, and cardiovascular disease. However, daidzein also has other ER-independent biological activities, such as oxidative damage reduction acting as an antioxidant, immune regulator as an anti-inflammatory agent, and apoptosis regulation, directly linked to its potential anticancer effects. In this sense, the present review is aimed at providing a deepen analysis of daidzein pharmacodynamics and its implications in human health, from its best-known effects alleviating postmenopausal symptoms to its potential anticancer and antiaging properties.

Scientific Evidence Supporting the Beneficial Effects of Isoflavones on Human Health

Isoflavones are phenolic compounds with a chemical structure similar to that of estradiol. They are present in several vegetables, mainly in legumes such as soy, white and red clover, alfalfa and beans. The most significant food source of isoflavones in humans is soy-derived products. Isoflavones could be used as an alternative therapy for pathologies dependent on hormonal disorders such as breast and prostate cancer, cardiovascular diseases, as well as to minimize menopausal symptoms. According to the results gathered in the present review, it can be stated that there is scientific evidence showing the beneficial effect of isoflavones on bone health and thus in the prevention and treatment of osteoporosis on postmenopausal women, although the results do not seem entirely conclusive as there are discrepancies among the studies, probably related to their experimental designs. For this reason, the results should be interpreted with caution, and more randomized clinical trials are required. By contrast, it seems that soy isoflavones do not lead to a meaningful protective effect on cardiovascular risk. Regarding cancer, scientific evidence suggests that isoflavones could be useful in reducing the risk of suffering some types of cancer, such as breast and endometrial cancer, but further studies are needed to confirm these results. Finally, isoflavones could be useful in reducing hot flushes associated with menopause. However, a limitation in this field is that there is still a great heterogeneity among studies. Lastly, with regard to isoflavone consumption safety, it seems that they are safe and that the most common adverse effect is mild and occurs at the gastrointestinal level.

Is There Such a Thing as "Anti-Nutrients"? A Narrative Review of Perceived Problematic Plant Compounds

Plant-based diets are associated with reduced risk of lifestyle-induced chronic diseases. The thousands of phytochemicals they contain are implicated in cellular-based mechanisms to promote antioxidant defense and reduce inflammation. While recommendations encourage the intake of fruits and vegetables, most people fall short of their target daily intake. Despite the need to increase plant-food consumption, there have been some concerns raised about whether they are beneficial because of the various ‘anti-nutrient’ compounds they contain. Some of these anti-nutrients that have been called into question included lectins, oxalates, goitrogens, phytoestrogens, phytates, and tannins. As a result, there may be select individuals with specific health conditions who elect to decrease their plant food intake despite potential benefits. The purpose of this narrative review is to examine the science of these ‘anti-nutrients’ and weigh the evidence of whether these compounds pose an actual health threat.

Drinking Refined Deep-Sea Water Improves the Gut Ecosystem with Beneficial Effects on Intestinal Health in Humans: A Randomized Double-Blind Controlled Trial

World health trends are focusing on a balanced food and beverage intake for healthy life. Refined deep-sea water (RDSW), obtained from deep-sea water collected offshore in Muroto (Japan), is mineral-rich drinking water. We previously reported that drinking RDSW improves human gut health. Here, we analyzed the effect of drinking RDSW on the gut ecosystem to understand this effect. This was a randomized double-blind controlled trial. Ninety-eight healthy adults were divided into two groups: RDSW or mineral water (control). The participants consumed 1 L of either water type daily for 12 weeks. A self-administered questionnaire and stool and urine samples were collected through the intervention. The following were determined: fecal biomarkers of secretory immunoglobulin A (sIgA), five putrefactive products, and nine short-chain-fatty-acids (SCFAs) as the primary outcomes; and three urinary isoflavones and the questionnaire as secondary outcomes. In post-intervention in the RDSW group, we found increased concentrations of five SCFAs and decreased concentrations of phenol and sIgA (p < 0.05). The multiple logistic analysis demonstrated that RDSW significantly affected two biomarkers (acetic and 3-methylbutanoic acids) of the five SCFAs mentioned above (p < 0.05). Similarly, the concentrations of urinary isoflavones tended to increase in post-intervention in the RDSW group. Constipation was significantly alleviated in the RDSW group (94%) compared with the control group (60%). Drinking RDSW improves the intestinal environment, increasing fecal SCFAs and urinary isoflavones, which leads to broad beneficial effects in human.

Syringaresinol as a novel androgen receptor antagonist against wild and mutant androgen receptors for the treatment of castration-resistant prostate cancer: molecular docking, in-vitro and molecular dynamics study

Phytoestrogens are dietary estrogens having similar structure as of estrogen. Some of these phytoestrogens are androgen receptor (AR) antagonists and exhibit preventive role in the prostate cancer. However, in androgen-independent prostate cancer (AIPC) the ARs were mutated (T877A, W741L, F876L, etc.) and these mutant ARs convert the antagonist to agonist. Our aim in this study is to find phytoestrogens that could function as an antagonist with wild and mutant ARs. The phytoestrogens were analyzed for binding affinity with wild and mutant ARs in agonist and antagonist conformations. The point mutations were carried out using Chimera. The antagonist AR conformation was modeled using Modeller. We hypothesize that the compounds having binding affinity with agonist AR conformation could not function as a full or pure antagonist. Most of the phytoestrogens have binding affinity with agonist AR conformation contradicting previous results. For example, genistein which is a widely studied isoflavone has known AR antagonist property. However, in our study, it had good binding affinity with agonist AR conformation. Hence, to confirm our hypothesis, we tested genistein in LNCaP (T877A mutant AR) cells by qPCR studies. The genistein functioned as an antagonist only in the presence of an androgen indicting a partial agonist type of activity. The in-vitro results supported our docking hypothesis. We applied this principle and found syringaresinol could function as an antagonist with wild and mutated ARs. Further, we carried out molecular dynamics for the hit molecule to confirm its antagonist binding mode with mutant AR.Communicated by Ramaswamy H. Sarma.

Resveratrol up-regulates ATP2A3 gene expression in breast cancer cell lines through epigenetic mechanisms

Resveratrol (RSV) is a phytoestrogen which has been related to chemoprevention of several types of cancer. In this work, we show up to a 6-fold increased expression of ATP2A3 gene induced by RSV that triggers apoptosis and changes of intracellular Ca²⁺ management in MCF-7 and MDA-MB-231 breast cancer cell lines. We explored epigenetic mechanisms for that RSV-induced ATP2A3 up-regulation. The results indicate that RSV-induced ATP2A3 up-regulation correlates with about 50% of reduced HDAC activity and reduced nuclear HDAC2 expression and occupancy on ATP2A3 promoter, increasing the global acetylation of histone H3 and the enrichment of histone mark H3K27Ac on the proximal promoter of the ATP2A3 gene in MDA-MB-231 cells. We also quantified HAT activity, finding that it can be boosted with RSV treatment; however, pharmacological inhibition of p300, one of the main HATs, did not have significant effects in RSV-mediated ATP2A3 gene expression. Additionally, DNMT activity was also reduced in cells treated with RSV, as well as the expression of Methyl-DNA binding proteins MeCP2 and MBD2. However, analysis of the methylation pattern of ATP2A3 gene promoter showed un-methylated promoter in both cell lines. Taken together, the results of this work help to explain, at the molecular level, how ATP2A3 gene is regulated in breast cancer cells, and the benefits of RSV intake observed in epidemiological data, studies with animals, and in vitro models.

Genistein treatment duration effects biomarkers of cell motility in human prostate

BACKGROUND

Long term dietary consumption of genistein by Chinese men is associated with decreased PCa metastasis and mortality. Short term treatment of US men with prostate cancer (PCa) with genistein decreases MMP-2 in prostate tissue. MEK4 regulates MMP-2 expression, drives PCa metastasis, and genistein inhibits MEK4, decreases MMP-2 expression and dietary dosing inhibits human PCa metastasis in mice. This study examines short- versus long-term treatment effects of genistein in humans and in vitro.

METHODS AND FINDINGS

US men with localized PCa were treated on a phase II trial with genistein (N = 14) versus not (N = 14) for one month prior to radical prostatectomy. Prostate epithelial cells were removed from fresh frozen tissue by laser capture microdissection, and the expression of 12,000 genes profiled. Genistein significantly altered the expression of four genes, three had established links to cancer cell motility and metastasis. Of these three, one was a non-coding transcript, and the other two were BASP1 and HCF2. Genistein increased BASP1 expression in humans, and its engineered over expression and knockdown demonstrated that it suppressed cell invasion in all six human prostate cell lines examined. Genistein decreased HCF2 expression in humans, and it was shown to increase cell invasion in all cell lines examined. The expression of MMP-2, MEK4 and BASP1 was then measured in formalin fixed prostate tissue from N = 38 Chinese men living in China and N = 41 US men living in the US, both cohorts with localized PCa. MMP-2 was 52% higher in Chinese compared to US tissue (P < 0.0001), MEK4 was 48% lower (P < 0.0001), and BASP1 was unaltered. Treatment of PC3 human PCa cells in vitro for up to 8 weeks demonstrated that short term genistein treatment decreased MMP-2, while long term treatment increased it, both changes being significant (P<0.05) compared to untreated control cells. Long term genistein-treated cells retained their responsiveness to genistein's anti-motility effect.

CONCLUSIONS

Genistein inhibits pathways in human prostate that drive transformation to a lethal high motility phenotype. Long term treatment induces compensatory changes in biomarkers of efficacy. The current strategy of using such biomarkers after short term intervention as go/no-go determinants in early phase chemoprevention trials should be carefully examined.

Adherence to Mediterranean diet and prostate cancer risk in Sicily: population-based case-control study

Prostate cancer (PCa) is the second most frequently diagnosed cancer and the sixth leading cause of death from cancer worldwide. Countries following a Mediterranean-type dietary pattern, has been reported to have lower PCa incidence and mortality compared with other European regions. A population-based case-control study has been conducted from January 2015 to December 2016 in a single institution of the municipality of Catania, southern Italy. A total of 118 PCa and 238 population-based controls were collected. Controls had significantly higher adherence to the Mediterranean diet, which was evident for several subgroups (including age groups, overweight and obese men, current smokers, alcohol intake, low and medium physical activity levels). PCa cases were found to consume lower amount of vegetables (223 g/d vs. 261 g/d; p = 0.001), legumes (34.26 g/d vs. 53.55 g/d; p = 0.003), and fish (47.75 g/d vs. 58.3 g/d) than controls; other differences emerged were related to alcohol intake (12.37 g/d vs 5.07 g/d; p < 0.01), cereals (254.06 g/d vs.235.94 g/d; p < 0.001), dairy (196 g/d vs. 166 g/d; p < 0.001), and meat consumption (98.09 g/d vs. 70.15 g/d; p < 0.001). However, no statistically significant differences between cases and controls were found regarding fruit, legumes, and olive oil consumption. The Mediterranean diet score was inversely associated with lower likelihood of having PCa in a linear manner (odds ratio [OR]: 0.86 [95% CI 0.77-0.96]). Specifically, individuals in the highest group of adherence had 78% less likelihood of have PCa and 14% less likelihood for each point increase of the score. The model adjusted for total polyphenol intake showed still a significant inverse association between adherence to the Mediterranean diet and PCa, but the relation was no more linear and not significant for one-point increase of the score (OR: 0.88 [95% CI 0.77-1.01]). In our cohorts of Italian men, we observed that high adherence to the Mediterranean diet was inversely associated with likelihood of having PCa cancer.

Prediagnosis plasma concentrations of enterolactone and survival after colorectal cancer: the Danish Diet, Cancer and Health cohort

The association between lifestyle and survival after colorectal cancer has received limited attention. The female sex hormone, oestrogen, has been associated with lower colorectal cancer risk and mortality after colorectal cancer. Phyto-oestrogens are plant compounds with structure similar to oestrogen, and the main sources in Western populations are plant lignans. We investigated the association between the main lignan metabolite, enterolactone and survival after colorectal cancer among participants in the Danish Diet, Cancer and Health cohort. Prediagnosis plasma samples and lifestyle data, and clinical data from time of diagnosis from 416 women and 537 men diagnosed with colorectal cancer were used. Enterolactone was measured in plasma using a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. Participants were followed from date of diagnosis until death or end of follow-up. During this time, 210 women and 325 men died (170 women and 215 men died due to colorectal cancer). The Cox proportional hazards model was used to estimate hazard ratios (HR) and 95 % CI. Enterolactone concentrations were associated with lower colorectal cancer-specific mortality among women (HRper doubling: 0·88, 95 % CI 0·80, 0·97, P=0·0123). For men, on the contrary, enterolactone concentrations were associated with higher colorectal cancer-specific mortality (HRper doubling: 1·10, 95 % CI 1·01, 1·21, P=0·0379). The use of antibiotics affects enterolactone production, and the associations between higher enterolactone and lower colorectal cancer-specific mortality were more pronounced among women who did not use antibiotics (analysis on a subset). Our results suggest that enterolactone is associated with lower risk of mortality among women, but the opposite association was found among men.

Association between dietary phytoestrogens intakes and prostate cancer risk in Sicily

OBJECTIVE

In this study we aimed to investigate the association between dietary phytoestrogen consumption and prostate cancer in a sample of southern Italian individuals.

METHODS

A population-based case-control study on the association between prostate cancer and dietary factors was conducted from January 2015 to December 2016 in a single institution of the municipality of Catania, southern Italy (Registration number: 41/2015). A total of 118 histopathological-verified prostate cancer (PCa) cases and a total of 222 controls were collected. Dietary data was collected by using two food frequency questionnaires.

RESULTS

Patients with PCa consumed significantly higher levels of phytoestrogens. Multivariate logistic regression showed that lignans (Q[quartile]4 vs. Q1, OR [odds ratio] = 4.72; p < .05) and specifically, lariciresinol (Q4 vs. Q1, OR = 4.60; p < .05), pinoresinol (Q4 vs. Q1, OR = 5.62; p < .05), matairesinol (Q4 vs. Q1, OR = 3.63; p < .05), secoisolariciresinol (Q4 vs. Q1, OR = 4.10; p < .05) were associated with increased risk of PCa. Furthermore, we found that isoflavones (Q3 vs. Q1, OR = 0.28; p < .05) and specifically, genistein (Q4 vs. Q1, OR = 0.40; p < .05) were associated with reduced risk of PCa.

CONCLUSION

We found of an inverse association between dietary isoflavone intake and PCa, while a positive association was found with lignans intake.

Daidzein induces choriocarcinoma cell apoptosis in a dose-dependent manner via the mitochondrial apoptotic pathway

Choriocarcinoma is a malignant gestational trophoblastic disease and relapse or drug resistance occurs in ~25% of gestational trophoblastic tumors. Cell apoptosis serves a role in the progression from hydatidiform mole to persistent gestational trophoblastic disease. It has been demonstrated that daidzein [7‑hydroxy‑3‑(4‑hydroxyphenyl)‑4H‑chromen‑4‑one] may induce apoptosis in a number of cancer types via the mitochondrial apoptotic pathway by altering the B‑cell lymphoma (Bcl)‑2/Bcl‑2 associated X, apoptosis regulator (Bax) ratio, and activating the caspase cascade. Daidzein also serves a role in regulation of production of human chorionic gonadotropin in trophoblast cells and inhibition of cell proliferation. However, few reports have been published regarding the effect of daidzein on apoptosis in choriocarcinoma. Therefore, in the present study, JAR and JEG‑3 human gestational choriocarcinoma cells were used to investigate the effect of daidzein on apoptosis of choriocarcinoma cells. Treatment with daidzein for 48 h reduced cell viability in a dose‑dependent manner. The percentages of early and late apoptotic cells also increased following treatment with daidzein in a dose‑dependent manner, with the number of late apoptotic cells increasing more prominently. Furthermore, treatment with daidzein led to apoptosis‑associated alterations in nuclear morphology of JAR and JEG-3 cells. Expression levels of cleaved poly(ADP‑ribose) polymerase, cleaved caspase‑3 and cleaved caspase‑9 increased following treatment with daidzein, whereas the Bcl‑2/Bax ratio decreased in a dose‑dependent manner. In conclusion, the results of the present study demonstrate that daidzein may induce apoptosis of choriocarcinoma cells in a dose‑dependent manner via the mitochondrial apoptotic pathway.

Soy Consumption and the Risk of Prostate Cancer: An Updated Systematic Review and Meta-Analysis

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men, accounting for 15% of all cancers in men worldwide. Asian populations consume soy foods as part of a regular diet, which may contribute to the lower PCa incidence observed in these countries. This meta-analysis provides a comprehensive updated analysis that builds on previously published meta-analyses, demonstrating that soy foods and their isoflavones (genistein and daidzein) are associated with a lower risk of prostate carcinogenesis. Thirty articles were included for analysis of the potential impacts of soy food intake, isoflavone intake, and circulating isoflavone levels, on both primary and advanced PCa. Total soy food (p < 0.001), genistein (p = 0.008), daidzein (p = 0.018), and unfermented soy food (p < 0.001) intakes were significantly associated with a reduced risk of PCa. Fermented soy food intake, total isoflavone intake, and circulating isoflavones were not associated with PCa risk. Neither soy food intake nor circulating isoflavones were associated with advanced PCa risk, although very few studies currently exist to examine potential associations. Combined, this evidence from observational studies shows a statistically significant association between soy consumption and decreased PCa risk. Further studies are required to support soy consumption as a prophylactic dietary approach to reduce PCa carcinogenesis.

Plasma enterolactone and risk of prostate cancer in middle-aged Swedish men

Purpose

Enterolactone (ENL) is formed in the human gut after consumption of lignans, has estrogenic properties, and has been associated with risk of prostate cancer. We examined the association between plasma ENL levels and prostate cancer in a nested case–control study within the population-based Malmö Diet and Cancer cohort. We also examined the association between plasma ENL and dietary and lifestyle factors.

Methods

The study population consisted of 1010 cases occurring during a mean follow-up of 14.6 years, and 1817 controls matched on age and study entry date. We used national registers (95%) and hospital records (5%) to ascertain cases. Diet was estimated by a modified diet history method. Plasma ENL concentrations were determined by a time-resolved fluoroimmunoassay. Odds ratios were calculated by unconditional logistic regression.

Results

There were no significant associations between plasma ENL and incidence of all prostate cancer (odds ratio 0.99 [95% confidence interval 0.77–1.280] for the highest ENL quintile versus lowest, p for trend 0.66). However, in certain subgroups of men, including men with abdominal obesity (p for interaction = 0.012), we observed associations between high ENL levels and lower odds of high-risk prostate cancer. Plasma ENL was positively associated with consumption of high-fibre bread, fruit, tea, and coffee; with age, and with height, while it was negatively associated with smoking and waist circumference; however, although significant, all associations were rather weak (r ≤ |0.14|).

Conclusion

ENL concentration was not consistently associated with lower prostate cancer risk, although it was weakly associated with a healthy lifestyle.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-017-1530-z) contains supplementary material, which is available to authorized users.

Does soy protein affect circulating levels of unbound IGF-1?

INTRODUCTION

Despite the enormous amount of research that has been conducted on the role of soyfoods in the prevention and treatment of chronic disease, the mechanisms by which soy exerts its physiological effects are not fully understood. The clinical data show that neither soyfoods nor soy protein nor isoflavones affect circulating levels of reproductive hormones in men or women. However, some research suggests that soy protein, but not isoflavones, affects insulin-like growth factor I (IGF-1).

METHODS

Since IGF-1 may have wide-ranging physiological effects, we sought to determine the effect of soy protein on IGF-1 and its major binding protein insulin-like growth factor-binding protein (IGFBP-3). Six clinical studies were identified that compared soy protein with a control protein, albeit only two studies measured IGFBP-3 in addition to IGF-1.

RESULTS

Although the data are difficult to interpret because of the different experimental designs employed, there is some evidence that large amounts of soy protein (>25 g/day) modestly increase IGF-1 levels above levels observed with the control protein.

CONCLUSION

The clinical data suggest that a decision to incorporate soy into the diet should not be based on its possible effects on IGF-1.

Soy and Health Update: Evaluation of the Clinical and Epidemiologic Literature

Soyfoods have long been recognized as sources of high-quality protein and healthful fat, but over the past 25 years these foods have been rigorously investigated for their role in chronic disease prevention and treatment. There is evidence, for example, that they reduce risk of coronary heart disease and breast and prostate cancer. In addition, soy alleviates hot flashes and may favorably affect renal function, alleviate depressive symptoms and improve skin health. Much of the focus on soyfoods is because they are uniquely-rich sources of isoflavones. Isoflavones are classified as both phytoestrogens and selective estrogen receptor modulators. Despite the many proposed benefits, the presence of isoflavones has led to concerns that soy may exert untoward effects in some individuals. However, these concerns are based primarily on animal studies, whereas the human research supports the safety and benefits of soyfoods. In support of safety is the recent conclusion of the European Food Safety Authority that isoflavones do not adversely affect the breast, thyroid or uterus of postmenopausal women. This review covers each of the major research areas involving soy focusing primarily on the clinical and epidemiologic research. Background information on Asian soy intake, isoflavones, and nutrient content is also provided.