Effects of lycopene on protein expression in human primary prostatic epithelial cells

Orchestration of miRNA Patterns by Testosterone and Dietary Tomato Carotenoids during Early Prostate Carcinogenesis in TRAMP Mice

BACKGROUND

The integrative effects of prostate cancer risk factors, such as diet and endocrine status, on cancer-associated miRNA expression are poorly defined.

OBJECTIVES

This study aimed to define the influence of androgens and diet (tomato and lycopene) on prostatic miRNA expression during early carcinogenesis in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model.

METHODS

Wild type (WT) and TRAMP mice were fed control, tomato-containing, or lycopene-containing diets from 4 to 10 weeks of age. Mice underwent either sham (intact) or castration surgery at 8 wk, and half of the castrated mice received testosterone (2.5 mg/kg body weight/d) at 9 wk. Mice were killed at 10 wk, and dorsolateral prostate expression of 602 miRNAs was assessed.

RESULTS

We detected expression of 88 miRNAs (15% of 602), all of which were present in the TRAMP, in comparison with 49 miRNAs being detectable (8%) in WT. Expression of 61 miRNAs differed by TRAMP genotype, with the majority upregulated in TRAMP. Of the 61 miRNAs, 42 were responsive to androgen status. Diet affected 41% of the miRNAs, which differed by genotype (25/61) and 48% of the androgen-sensitive miRNAs (20/42), indicating overlapping genetic and dietary influences on prostate miRNAs. Tomato and lycopene feeding influenced miRNAs previously associated with the regulation of androgen (miR-145 and let-7), MAPK (miR-106a, 204, 145/143, and 200b/c), and p53 signaling (miR-125 and miR-98) pathways.

CONCLUSIONS

Expression of miRNAs in early prostate carcinogenesis is sensitive to genetic, endocrine, and diet drivers, suggesting novel mechanisms by which tomato and lycopene feeding modulate early prostate carcinogenesis.

Multifaceted Effects of Lycopene: A Boulevard to the Multitarget-Based Treatment for Cancer

Lycopene is a pigment belonging to the group of carotenoids and it is among the most carefully studied antioxidants found especially in fruit and vegetables. As a carotenoid, lycopene exerts beneficial effects on human health by protecting lipids, proteins, and DNA from damage by oxidation. Lycopene is a powerful oxygen inactivator in the singlet state. This is suggestive of the fact that lycopene harbors comparatively stronger antioxidant properties over other carotenoids normally present in plasma. Lycopene is also reported to hinder cancer cell proliferation. The uncontrolled, rapid division of cells is a characteristic of the metabolism of cancer cells. Evidently, lycopene causes a delay in the progression of the cell cycle, which explains its antitumor activity. Furthermore, lycopene can block cell transformation by reducing the loss of contact inhibition of cancer cells. This paper collects recent studies of scientific evidence that show the multiple beneficial properties of lycopene, which acts with different molecular and cellular mechanisms.

Recent Progress in Discovering the Role of Carotenoids and Their Metabolites in Prostatic Physiology and Pathology with a Focus on Prostate Cancer-A Review-Part I: Molecular Mechanisms of Carotenoid Action

Among the vast variety of plant-derived phytochemicals, the group of carotenoids has continuously been investigated in order to optimize their potential application in the area of dietary intervention and medicine. One organ which has been especially targeted in many of these studies and clinical trials is the human prostate. Without doubt, carotenoids (and their endogenous derivatives—retinoids and other apo-carotenoids) are involved in intra- and intercellular signaling, cell growth and differentiation of prostate tissue. Due to the accumulation of new data on the role of different carotenoids such as lycopene (LC) and β-carotene (BC) in prostatic physiology and pathology, the present review aims to cover the past ten years of research in this area. Data from experimental studies are presented in the first part of the review, while epidemiological studies are disclosed and discussed in the second part. The objective of this compilation is to emphasize the present state of knowledge regarding the most potent molecular targets of carotenoids and their main metabolites, as well as to propose promising carotenoid agents for the prevention and treatment of prostatic diseases.

Carotenoids in Cancer Apoptosis-The Road from Bench to Bedside and Back

An incidence and mortality of cancer are rapidly growing worldwide, especially due to heterogeneous character of the disease that is associated with irreversible impairment of cellular homeostasis and function. Targeting apoptosis, one of cancer hallmarks, represents a potent cancer treatment strategy. Carotenoids are phytochemicals represented by carotenes, xanthophylls, and derived compounds such as apocarotenoids that demonstrate a broad spectrum of anti-cancer effects involving pro-apoptotic signaling through extrinsic and intrinsic pathways. As demonstrated in preclinical oncology research, the apoptotic modulation is performed at post-genomic levels. Further, carotenoids demonstrate additive/synergistic action in combination with conventional oncostatic agents. In addition, a sensitization of tumor cells to anti-cancer conventional treatment can be achieved by carotenoids. The disadvantage of anti-cancer application of carotenoids is associated with their low solubility and, therefore, poor bioavailability. However, this deficiency can be improved by using nanotechnological approaches, solid dispersions, microemulsions or biofortification that significantly increase the anti-cancer and pro-apoptotic efficacy of carotenoids. Only limited number of studies dealing with apoptotic potential of carotenoids has been published in clinical sphere. Pro-apoptotic effects of carotenoids should be beneficial for individuals at high risk of cancer development. The article considers the utility of carotenoids in the framework of 3P medicine.

Role of Mass Spectrometry in Establishing Safety and Efficacy of Botanical Dietary Supplements

As in drug discovery and development, mass spectrometry has become essential at all stages for establishing the safety and efficacy of botanical dietary supplements. Applications of mass spectrometry to the development of botanical dietary supplements include preclinical studies of the mechanisms of action (e.g., proteomic target identification and validation); identification of active natural products using high resolution tandem mass spectrometry; chemical standardization using UHPLC-MS/MS; and studies of metabolism, absorption and toxicity of active compounds using high resolution and UHPLC-MS/MS. Clinical applications of mass spectrometry include evaluation of the potential for drug-botanical interactions; investigation of the pharmacokinetics of active compounds; and quantitative analysis of biomarkers of efficacy during Phase I and II and clinical trials of safety and efficacy of botanical dietary supplements.

Heat Shock Proteins (HSPs): A Novel Target for Cancer Metastasis Prevention

Background:

Heat shock proteins (HSPs) are predominant molecular chaperones which are actively involved in the protein folding; which is essential in protecting the structure and functioning of proteins during various stress conditions. Though HSPs have important physiological roles, they have been well known for their roles in various pathogenic conditions such as carcinogenesis; however, limited literature has consolidated its potential as an anti-metastatic drug target.

Objectives:

The present review outlines the role of different HSPs on cancer progression and metastasis; possible role of HSP inhibitors as anti-neoplastic agents is also discussed.

Methods:

The data were collected from PubMed/Medline and other reputed journal databases. The literature that was too old and had no significant role to the review was then omitted.

Results:

Despite their strong physiological functions, HSPs are considered as good markers for cancer prognosis and diagnosis. They have control over survival, proliferation and progression events of cancer including drug resistance, metastasis, and angiogenesis. Since, neoplastic cells are more dependent on HSPs for survival and proliferation, the selectivity and specificity of HSP-targeted cancer drugs remain high. This has made various HSPs potential clinical and experimental targets for cancer prevention. An array of HSP inhibitors has been in trials and many others are in experimental conditions as anticancer and anti-metastatic agents. Several natural products are also being investigated for their efficacy for anticancer and anti-metastatic agents by modulating HSPs.

Conclusion:

Apart from their role as an anticancer drug target, HSPs have shown to be promising targets for the prevention of cancer progression. Extensive studies are required for the use of these molecules as anti-metastatic agents. Further studies in this line may yield specific and effective antimetastatic agents.

Can Lycopene Impact the Androgen Axis in Prostate Cancer?: A Systematic Review of Cell Culture and Animal Studies

First-line therapy for advanced or metastatic prostate cancer (PCa) involves the removal of tumor-promoting androgens by androgen deprivation therapy (ADT), resulting in transient tumor regression. Recurrent disease is attributed to tumor adaptation to survive, despite lower circulating androgen concentrations, making the blockage of downstream androgen signaling a chemotherapeutic goal for PCa. Dietary intake of tomato and its predominant carotenoid, lycopene, reduce the risk for PCa, and preclinical studies have shown promising results that tomato and lycopene can inhibit androgen signaling in normal prostate tissue. The goal of this systematic review was to evaluate whether mechanistic evidence exists to support the hypothesis that tomato or lycopene interact with the androgen axis in PCa. Eighteen studies (n = 5 in vivo; n = 13 in vitro) were included in the final review. A formal meta-analysis was not feasible due to variability of the data; however, the overall estimated directions of effect for the compared studies were visually represented by albatross plots. All studies demonstrated either null or, more commonly, inhibitory effects of tomato or lycopene treatment on androgen-related outcomes. Strong mechanistic evidence was unable to be ascertained, but tomato and lycopene treatment appears to down-regulate androgen metabolism and signaling in PCa.

GPX1 Localizes to the Nucleus in Prostate Epithelium and its Levels are not Associated with Prostate Cancer Recurrence

Glutathione peroxidase 1 (GPX1) is an extensively studied selenium-dependent protein that reduces hydrogen and lipid peroxides to water. Because of its antioxidant function and its responsiveness to dietary intakes of selenium, an essential trace element whose levels are inversely associated with prostate cancer risk, GPX1 levels were assessed in a prostate cancer tissue microarray, comparing cases of recurrent prostate cancer following prostatectomy to non-recurrent controls. While GPX1 is generally considered as a protein that resides in both the cytoplasm and mitochondria, we detected strong nuclear staining by immunofluorescence using GPX1-specific antibodies. Nuclear localization of GPX1 was also observed in both primary prostate epithelial cells and the immortalized prostate-derived cell line RWPE-1, but not in LNCaP or PC3 prostate tumor-derived cell lines. Quantification of GPX1 levels in the entire cell, the cytoplasm, and the nucleus did not indicate any association of either its levels or subcellular distribution with prostate cancer recurrence. While GPX1 levels may not have an impact on survival among men with prostate cancer, the data indicates that this extensively characterized protein may have a novel function in the nucleus of prostate epithelial cells.

Correlations of SELENOF and SELENOP genotypes with serum selenium levels and prostate cancer

BACKGROUND

Selenium status is inversely associated with the incidence of prostate cancer. However, supplementation trials have not indicated a benefit of selenium supplementation in reducing cancer risk. Polymorphisms in the gene encoding selenoprotein 15 (SELENOF) are associated with cancer incidence/mortality and present disproportionately in African Americans. Relationships among the genotype of selenoproteins implicated in increased cancer risk, selenium status, and race with prostate cancer were investigated.

METHODS

Tissue microarrays were used to assess SELENOF levels and cellular location in prostatic tissue. Sera and DNA from participants of the Chicago-based Adiposity Study Cohort were used to quantify selenium levels and genotype frequencies of the genes for SELENOF and the selenium-carrier protein selenoprotein P (SELENOP). Logistic regression models for dichotomous patient outcomes and regression models for continuous outcome were employed to identify both clinical, genetic, and biochemical characteristics that are associated with these outcomes.

RESULTS

SELENOF is dramatically reduced in prostate cancer and lower in tumors derived from African American men as compared to tumors obtained from Caucasians. Differing frequency of SELENOF polymorphisms and lower selenium levels were observed in African Americans as compared to Caucasians. SELENOF genotypes were associated with higher histological tumor grade. A polymorphism in SELENOP was associated with recurrence and higher serum PSA.

CONCLUSIONS

These results indicate an interaction between selenium status and selenoprotein genotypes that may contribute to the disparity in prostate cancer incidence and outcome experienced by African Americans.

Proteomic response of inflammatory stimulated intestinal epithelial cells to in vitro digested plums and cabbages rich in carotenoids and polyphenols

Due to their anti-oxidant and anti-inflammatory potential, polyphenol and carotenoid-rich plant foods have been suggested as promising phytochemicals in the prevention of or as adjuvants regarding inflammatory bowel diseases (IBD). In the present study, we investigated whether plum (Italian Plum, Prunus cocomilla), or cabbage (Kale, Brassica oleracea var. sabellica), selected for their high phytochemical content, are able to reduce inflammation in cellular models of the intestinal epithelium, employing proteomic methods. For this purpose, plum/cabbage (carotenoid content: 1.9 mg per 100 g resp. 13 mg per 100 g; polyphenol content: 83 mg per 100 g resp. 27 mg per 100 g) were gastro-intestinally digested, and aliquots exposed (18 h) to either a monoculture (Caco-2) or a triple culture (Caco-2/HT-29-MTX (90 : 10, v/v) with THP-1 like macrophages), stimulated (with LPS, TNF-α, and IL-1β) to induce inflammation. Cells (Caco-2, Caco-2/HT-29-MTX, and THP-1) were then harvested separately, and proteomic analyses of total cell extracts were carried out by 2D-DIGE. In the monoculture, 68 protein-spots were significantly (p < 0.05, expression ratio >1.5) differentially regulated due to the Kale and Italian plum digesta, and in the co-culture 206 protein-spots, compared to digesta without plum/cabbage. These belonged to 27 (monoculture) and 76 (coculture) uniquely identified proteins, suggesting the coculture to be a more sensitive model. Proteins included antioxidant enzymes such as catalase, superoxide dismutase and glutathione-S-transferases. Only 3 proteins were differentially regulated in the THP-1 cells, perhaps as these were only indirectly exposed. The results show promise regarding some aspects related to IBD complications, however, employing phytochemical-rich food items should be further investigated in in vivo trials.

Cancer Prevention and Treatment by Wholistic Nutrition

Cancer is traditionally considered a genetic disease. It starts with a gene mutation, often caused by environmental carcinogens that are enzymatically activated to metabolites that covalently bind to DNA. If these now-damaged carcinogen-DNA adducts are not repaired before the cell replicates, they result in a mutation, which is inherited by daughter cells and their subsequent progeny. Still more mutations are added that are thought to advance cellular independence, metastasis, and drug resistance, among other characteristics typically observed for advanced cancer. The stages of initiation, promotion and progression of cancer by mutations infer irreversibility because back mutations are exceedingly rare. Thus, treatment protocols typically are designed to remove or kill cancer cells by surgery, chemotherapy, immunotherapy and/or radiotherapy. However, empirical evidence has existed to show a fundamentally different treatment option. For example, the promotion of cancer growth and development in laboratory animals initiated by a powerful mutagen/carcinogen can be repetitively turned on and off by non-mutagenic mechanisms, even completely, by modifying the consumption of protein at relevant levels of intake. Similar but less substantiated evidence also exists for other nutrients and other cancer types. This suggests that ultimate cancer development is primarily a nutrition-responsive disease rather than a genetic disease, with the understanding that nutrition is a comprehensive, wholistic biological effect that reflects the natural contents of nutrients and related substances in whole, intact food. This perspective sharply contrasts with the contemporary inference that nutrition is the summation of individual nutrients acting independently. The spelling of 'holism' with the 'w' is meant to emphasize the empirical basis for this function. The proposition that wholistic nutrition controls and even reverses disease development suggests that cancer may be treated by nutritional intervention.

A Phase II Randomized Trial of Lycopene-Rich Tomato Extract Among Men with High-Grade Prostatic Intraepithelial Neoplasia

A diverse body of evidence suggests that lycopene might inhibit prostate cancer development. We conducted a 6-mo repeat biopsy randomized trial among men with high-grade prostatic intraepithelial neoplasia (HGPIN). Here we report results for serum lycopene, prostate specific antigen (PSA) and insulin-like growth factor (IGF) proteins, histopathological review, and tissue markers for proliferation [minichromosome maintenance protein 2 (MCM-2)] and cell cycle inhibition (p27). Participants consumed placebo or tomato extract capsules containing 30 mg/day lycopene. Pre- and posttreatment biopsies were immunostained and digitally scored. Serum lycopene was determined by LC-MS-MS. In secondary analyses, pathologists blindly reviewed each biopsy to score histological features. Fifty-eight men completed the trial. Serum lycopene increased 0.55 μmol/L with treatment and declined 0.29 μmol/L with placebo. We observed no meaningful differences in PSA, IGF-1, or IGF binding protein 3 concentrations between groups, nor any differences in expression of MCM-2 or p27 in epithelial nuclei. Prevalences of cancer, HGPIN, atrophy, or inflammation posttreatment were similar; however, more extensive atrophy and less extensive HGPIN was more common in the lycopene group. Despite large differences in serum lycopene following intervention, no treatment effects were apparent on either the serum or benign tissue endpoints. Larger studies are warranted to determine whether changes observed in extent of HGPIN and focal atrophy can be replicated.

Dietary lycopene intake and risk of prostate cancer defined by ERG protein expression

BACKGROUND

There is limited evidence that supports etiologically distinct molecular subtypes of prostate cancer, the identification of which may improve prevention. Given their antioxidant properties, we hypothesized that lycopene and tomato sauce may be especially protective against diseases harboring the common gene fusion transmembrane protease, serine 2 (TMPRSS2):v-ets avian erythroblastosis virus E26 oncogene homolog (ERG).

OBJECTIVE

We aimed to examine associations between estimated lycopene and tomato sauce intake and the risk of prostate cancer defined by ERG protein expression subtype.

DESIGN

Our study population consisted of a prospective cohort of 46,719 men from the Health Professionals Follow-Up Study. TMPRSS2:ERG was assessed by ERG immunohistochemistry on tumor tissue microarrays constructed from radical prostatectomy specimens. We used multivariable competing risk models to calculate HRs and 95% CIs for the risk of ERG-positive and, separately, ERG-negative disease. We implemented inverse probability weighting to account for evaluating ERG status only in surgically treated cases.

RESULTS

During 23 y of follow-up, 5543 men were diagnosed with prostate cancer, among whom 884 were assayed for ERG (426 ERG-positive). With inclusion of only the latter cases, increasing cumulative average tomato sauce intake was associated with a decreased risk of prostate cancer overall (≥2 servings/wk compared with <1 serving/mo; multivariable HR: 0.70; 95% CI: 0.52, 0.95; P-trend = 0.002). With respect to molecular subtypes, cumulative average tomato sauce intake was associated with a decreased risk of ERG-positive disease (HR: 0.54; 95% CI: 0.37, 0.81; P-trend = 0.004) but not with ERG-negative disease (HR: 0.96; 95% CI: 0.62, 1.50; P-trend = 0.10) (P-heterogeneity = 0.04). Increasing quintiles of lycopene intake were associated with a decreased risk of both subtypes (P-heterogeneity = 0.79). Inverse probability weighting did not materially change the results.

CONCLUSIONS

Our results lend some support to the hypothesis that prostate cancers that harbor TMPRSS2:ERG may be etiologically distinct from fusion-negative cancers. In particular, tomato sauce consumption may play a role in reducing TMPRSS2:ERG-positive disease.

Compartmental and noncompartmental modeling of ¹³C-lycopene absorption, isomerization, and distribution kinetics in healthy adults

BACKGROUND

Lycopene, which is a red carotenoid in tomatoes, has been hypothesized to mediate disease-preventive effects associated with tomato consumption. Lycopene is consumed primarily as the all-trans geometric isomer in foods, whereas human plasma and tissues show greater proportions of cis isomers.

OBJECTIVE

With the use of compartmental modeling and stable isotope technology, we determined whether endogenous all-trans-to-cis-lycopene isomerization or isomeric-bioavailability differences underlie the greater proportion of lycopene cis isomers in human tissues than in tomato foods.

DESIGN

Healthy men (n = 4) and women (n = 4) consumed (13)C-lycopene (10.2 mg; 82% all-trans and 18% cis), and plasma was collected over 28 d. Unlabeled and (13)C-labeled total lycopene and lycopene-isomer plasma concentrations, which were measured with the use of high-performance liquid chromatography-mass spectrometry, were fit to a 7-compartment model.

RESULTS

Subjects absorbed a mean ± SEM of 23% ± 6% of the lycopene. The proportion of plasma cis-(13)C-lycopene isomers increased over time, and all-trans had a shorter half-life than that of cis isomers (5.3 ± 0.3 and 8.8 ± 0.6 d, respectively; P < 0.001) and an earlier time to reach maximal plasma concentration than that of cis isomers (28 ± 7 and 48 ± 9 h, respectively). A compartmental model that allowed for interindividual differences in cis- and all-trans-lycopene bioavailability and endogenous trans-to-cis-lycopene isomerization was predictive of plasma (13)C and unlabeled cis- and all-trans-lycopene concentrations. Although the bioavailability of cis (24.5% ± 6%) and all-trans (23.2% ± 8%) isomers did not differ, endogenous isomerization (0.97 ± 0.25 μmol/d in the fast-turnover tissue lycopene pool) drove tissue and plasma isomeric profiles.

CONCLUSION

(13)C-Lycopene combined with physiologic compartmental modeling provides a strategy for following complex in vivo metabolic processes in humans and reveals that postabsorptive trans-to-cis-lycopene isomerization, and not the differential bioavailability of isomers, drives tissue and plasma enrichment of cis-lycopene. This trial was registered at clinicaltrials.gov as NCT01692340.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

Lycopene Protects against Hypoxia/Reoxygenation Injury by Alleviating ER Stress Induced Apoptosis in Neonatal Mouse Cardiomyocytes

Endoplasmic reticulum (ER) stress induced apoptosis plays a pivotal role in myocardial ischemia/reperfusion (I/R)-injury. Inhibiting ER stress is a major therapeutic target/strategy in treating cardiovascular diseases. Our previous studies revealed that lycopene exhibits great pharmacological potential in protecting against the I/R-injury in vitro and vivo, but whether attenuation of ER stress (and) or ER stress-induced apoptosis contributes to the effects remains unclear. In the present study, using neonatal mouse cardiomyocytes to establish an in vitro model of hypoxia/reoxygenation (H/R) to mimic myocardium I/R in vivo, we aimed to explore the hypothesis that lycopene could alleviate the ER stress and ER stress-induced apoptosis in H/R-injury. We observed that lycopene alleviated the H/R injury as revealed by improving cell viability and reducing apoptosis, suppressed reactive oxygen species (ROS) generation and improved the phosphorylated AMPK expression, attenuated ER stress as evidenced by decreasing the expression of GRP78, ATF6 mRNA, sXbp-1 mRNA, eIF2α mRNA and eIF2α phosphorylation, alleviated ER stress-induced apoptosis as manifested by reducing CHOP/GADD153 expression, the ratio of Bax/Bcl-2, caspase-12 and caspase-3 activity in H/R-treated cardiomyocytes. Thapsigargin (TG) is a potent ER stress inducer and used to elicit ER stress of cardiomyocytes. Our results showed that lycopene was able to prevent TG-induced ER stress as reflected by attenuating the protein expression of GRP78 and CHOP/GADD153 compared to TG group, significantly improve TG-caused a loss of cell viability and decrease apoptosis in TG-treated cardiomyocytes. These results suggest that the protective effects of lycopene on H/R-injury are, at least in part, through alleviating ER stress and ER stress-induced apoptosis in neonatal mouse cardiomyocytes.

Nutrition, dietary interventions and prostate cancer: the latest evidence

Prostate cancer (PCa) remains a leading cause of mortality in US men and the prevalence continues to rise world-wide especially in countries where men consume a 'Western-style' diet. Epidemiologic, preclinical and clinical studies suggest a potential role for dietary intake on the incidence and progression of PCa. 'This minireview provides an overview of recent published literature with regard to nutrients, dietary factors, dietary patterns and PCa incidence and progression. Low carbohydrates intake, soy protein, omega-3 (w-3) fat, green teas, tomatoes and tomato products and zyflamend showed promise in reducing PCa risk or progression. A higher saturated fat intake and a higher β-carotene status may increase risk. A 'U' shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Despite the inconsistent and inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa is promising. The combination of all the beneficial factors for PCa risk reduction in a healthy dietary pattern may be the best dietary advice. This pattern includes rich fruits and vegetables, reduced refined carbohydrates, total and saturated fats, and reduced cooked meats. Further carefully designed prospective trials are warranted.

Dietary tomato and lycopene impact androgen signaling- and carcinogenesis-related gene expression during early TRAMP prostate carcinogenesis

Consumption of tomato products containing the carotenoid lycopene is associated with a reduced risk of prostate cancer. To identify gene expression patterns associated with early testosterone-driven prostate carcinogenesis, which are impacted by dietary tomato and lycopene, wild-type (WT) and transgenic adenocarcinoma of the mouse prostate (TRAMP) mice were fed control or tomato- or lycopene-containing diets from 4 to 10 weeks of age. Eight-week-old mice underwent sham surgery, castration, or castration followed by testosterone repletion (2.5 mg/kg/d initiated 1 week after castration). Ten-week-old intact TRAMP mice exhibit early multifocal prostatic intraepithelial neoplasia. Of the 200 prostate cancer-related genes measured by quantitative NanoString, 189 are detectable, 164 significantly differ by genotype, 179 by testosterone status, and 30 by diet type (P < 0.05). In TRAMP, expression of Birc5, Mki67, Aurkb, Ccnb2, Foxm1, and Ccne2 is greater compared with WT and is decreased by castration. In parallel, castration reduces Ki67-positive staining (P < 0.0001) compared with intact and testosterone-repleted TRAMP mice. Expression of genes involved in androgen metabolism/signaling pathways is reduced by lycopene feeding (Srd5a1) and by tomato feeding (Srd5a2, Pxn, and Srebf1). In addition, tomato feeding significantly reduced expression of genes associated with stem cell features, Aldh1a and Ly6a, whereas lycopene feeding significantly reduced expression of neuroendocrine differentiation-related genes, Ngfr and Syp. Collectively, these studies demonstrate a profile of testosterone-regulated genes associated with early prostate carcinogenesis that are potential mechanistic targets of dietary tomato components. Future studies on androgen signaling/metabolism, stem cell features, and neuroendocrine differentiation pathways may elucidate the mechanisms by which dietary tomato and lycopene impact prostate cancer risk.

Association of cancer metabolism-related proteins with oral carcinogenesis - indications for chemoprevention and metabolic sensitizing of oral squamous cell carcinoma?

Background

Tumor metabolism is a crucial factor for the carcinogenesis of oral squamous cell carcinoma (OSCC).

Methods

Expression of IGF-R1, glycolysis-related proteins (GLUT-1, HK 2, PFK-1, LDHA, TKTL1), mitochondrial enzymes (SDHA, SDHB, ATP synthase) were analyzed in normal oral mucosa (n = 5), oral precursor lesions (simple hyperplasia, n = 11; squamous intraepithelial neoplasia, SIN I-III, n = 35), and OSCC specimen (n = 42) by immunohistochemistry and real-time polymerase chain reaction (qPCR) analysis in OSCC cell lines. Metabolism-related proteins were correlated with proliferation activity (Ki-67) and apoptotic properties (TUNEL assay) in OSCC. Specificity of antibodies was confirmed by western blotting in cancer cell lines.

Results

Expression of IGF-R1, glycolysis-related proteins (GLUT-1, HK 2, LDHA, TKTL1), and mitochondrial enzymes (SDHA, SDHB, ATP synthase) were significantly increased in the carcinogenesis of OSCC. Metabolic active regions of OSCC were strongly correlated with proliferating cancer (Ki-67+) cells without detection of apoptosis (TUNEL assay).

Conclusions

This study provides the first evidence of the expression of IGF-R1, glycolysis-related proteins GLUT-1, HK 2, PFK-1, LDHA, and TKTL1, as well as mitochondrial enzymes SDHA, SDHB, and ATP synthase in the multi-step carcinogenesis of OSCC. Both, hypoxia-related glucose metabolism and mitochondrial oxidative phosphorylation characteristics are associated with the carcinogenesis of OSCC. Acidosis and OXPHOS may drive a metabolic shift towards the pentose phosphate pathway (PPP). Therefore, inhibition of the PPP, glycolysis, and targeted anti-mitochondrial therapies (ROS generation) by natural compounds or synthetic vitamin derivatives may act as sensitizer for apoptosis in cancer cells mediated by adjuvant therapies in OSCC.

Traditional Chinese medicinal formula Si-Wu-Tang prevents oxidative damage by activating Nrf2-mediated detoxifying/antioxidant genes

Background

Induction of Nrf2-mediated detoxifying/antioxidant genes has been recognized as an effective strategy for cancer chemoprevention. Si-Wu-Tang (SWT), comprising the combination of four herbs, Paeoniae, Angelicae, Chuanxiong and Rehmanniae, is one of the most popular traditional oriental medicines for women’s diseases. The purpose of this study is to determine the effects of SWT on Nrf2 pathway in vitro and in vivo and to identify the active component(s).

Results

Cell viability and apoptosis were analyzed in the non-cancerous breast epithelial cell line MCF-10A after H₂O₂ treatment in the presence or absence of SWT using the Sulphorhodamine B assay, Annexin-V/Propidium iodide staining and flow cytometry. SWT strongly reduced H₂O₂ -induced cytotoxicity and apoptosis in MCF-10A cells. Expression of Nrf2 and Nrf2-regulated genes HMOX1 (heme oxygenase 1) and SLC7A11 (xCT) was evaluated by quantitative RT-PCR, Western Blot and immunocytochemistry. SWT strongly induced Nrf2-regulated genes at mRNA and protein levels and increased the nuclear translocation of Nrf2 in MCF-10A cells. The in vivo pharmacodynamic effect of SWT was evaluated in healthy female Sprague–Dawley rats. Short-term oral administration of SWT (1,000 mg/kg per day for six consecutive days) to rats resulted in an increased expression of Nrf2-regulated genes Hmox1 and Slc7A11 in the liver detected by quantitative RT-PCR. Among nine compounds that have been identified previously in the SWT products, z-liguistilide was discovered as the main component responsible for the effect of Nrf2 activation using the antioxidant response element-luciferase reporter gene assay. Z-liguistilide was confirmed with a high potency to induce Nrf2-regulated genes and Nrf2 nuclear translocation.

Conclusions

Our results demonstrated that SWT and its component z-liguistilide are able to activate the Nrf2 pathway in non-cancerous cells and organs in vitro and in vivo, suggesting that SWT might be an orally effective and nontoxic agent for cancer chemoprevention.

Protective effect of lycopene on cardiac function and myocardial fibrosis after acute myocardial infarction in rats via the modulation of p38 and MMP-9

Extracellular matrix (ECM) plays an important role in maintaining the left ventricular geometry and ventricular function, and the inhibition of ECM remodeling has therapeutic benefits that could alleviate the progression of ventricular remodeling. Recent studies have indicated that lycopene has cardioprotective effects. In this study, a rat myocardial infarction (MI) model was established by left anterior descending coronary artery ligation. After the operation, the rats received lycopene or saline. After 28 days, the rats underwent echocardiography detection and were sacrificed. Myocardial fibrosis was observed by Masson staining. Type I collagen, MMP-9, and MAPK protein expression were detected in the ischemic zone surrounding the MI by western blot. Treatment with lycopene increased the EF from 45.2 ± 3.12 % to 51.1 ± 4.63, and it decreased the LVEDd from 6.52 ± 0.37 mm to 6.18 ± 0.41 mm and the LVESd from 4.29 ± 0.63 to 3.94 ± 0.37 at 28 days post-myocardial infarction. Lycopene attenuated the MI-induced increase in MMP-9 and type I collagen expression, and inhibited p38 activation. Moreover, lycopene decreased the collagen volume fraction in the peri-infarcted zone. The data indicated that lycopene improved the cardiac function and ventricular remodeling by inhibiting p38 activation and MMP-9 expression.

Anticarcinogenic, cardioprotective, and other health benefits of tomato compounds lycopene, α-tomatine, and tomatidine in pure form and in fresh and processed tomatoes

Tomatoes produce the bioactive compounds lycopene and α-tomatine that are reported to have potential health-promoting effects in animals and humans, but our understanding of the roles of these compounds in the diet is incomplete. Our current knowledge gained from the chemistry and analysis of these compounds in fresh and processed tomatoes and from studies on their bioavailability, bioactivity, and mechanisms of action against cancer cells and other beneficial bioactivities including antibiotic, anti-inflammatory, antioxidative, cardiovascular, and immunostimulating effects in cells, animals, and humans is discussed and interpreted here. Areas for future research are also suggested. The collated information and suggested research might contribute to a better understanding of the agronomical, biochemical, chemical, physiological, molecular, and cellular bases of the health-promoting effects and facilitate and guide further studies needed to optimize the use of lycopene and α-tomatine in pure form and in fresh tomatoes and processed tomato products to help prevent or treat human disease.

The potential role of lycopene for the prevention and therapy of prostate cancer: from molecular mechanisms to clinical evidence

Lycopene is a phytochemical that belongs to a group of pigments known as carotenoids. It is red, lipophilic and naturally occurring in many fruits and vegetables, with tomatoes and tomato-based products containing the highest concentrations of bioavailable lycopene. Several epidemiological studies have linked increased lycopene consumption with decreased prostate cancer risk. These findings are supported by in vitro and in vivo experiments showing that lycopene not only enhances the antioxidant response of prostate cells, but that it is even able to inhibit proliferation, induce apoptosis and decrease the metastatic capacity of prostate cancer cells. However, there is still no clearly proven clinical evidence supporting the use of lycopene in the prevention or treatment of prostate cancer, due to the only limited number of published randomized clinical trials and the varying quality of existing studies. The scope of this article is to discuss the potential impact of lycopene on prostate cancer by giving an overview about its molecular mechanisms and clinical effects.

Is lycopene an effective agent for preventing prostate cancer?

The role of lycopene, an open-chain carotenoid found in tomatoes and devoid of retinoid activity, as an anticarcinogenic, chemopreventive agent, especially for use in prostate cancer, is still under active investigation. In this issue, Qui and colleagues show that lycopene induces responses in human prostate epithelial cells that are antiproliferative, antioxidative, and anti-inflammatory, as well as downregulating targets in the androgen receptor signaling pathway. In this perspective, we review aspects of the molecular and cellular biology of lycopene that support its use for prevention of prostate cancer. Whether lycopene itself or its metabolites induce most of its benefits is still uncertain. At present, meta-analysis of clinical studies of lycopene for prevention of prostate cancer in men does not yet support the definitive clinical use of this carotenoid in a preventive setting.