Metastasis-associated protein 1-mediated antitumor and anticancer activity of dietary stilbenes for prostate cancer chemoprevention and therapy

The feedback loop between MTA1 and MTA3/TRIM21 modulates stemness of breast cancer in response to estrogen

The metastasis-associated protein (MTA) family plays a crucial role in the development of breast cancer, a common malignancy with a high incidence rate among women. However, the mechanism by which each member of the MTA family contributes to breast cancer progression is poorly understood. In this study, we aimed to investigate the roles of MTA1, MTA3, and tripartite motif-containing 21 (TRIM21) in the proliferation, invasion, epithelial-mesenchymal transition (EMT), and stem cell-like properties of breast cancer cells in vivo and in vitro. The molecular mechanisms of the feedback loop between MTA1 and MTA3/TRIM21 regulated by estrogen were explored using Chromatin immunoprecipitation (ChIP), luciferase reporter, immunoprecipitation (IP), and ubiquitination assays. These findings demonstrated that MTA1 acts as a driver to promote the progression of breast cancer by repressing the transcription of tumor suppressor genes, including TRIM21 and MTA3. Conversely, MTA3 inhibited MTA1 transcription and TRIM21 regulated MTA1 protein stability in breast cancer. Estrogen disrupted the balance between MTA1 and MTA3, as well as between MTA1 and TRIM21, thereby affecting stemness and the EMT processes in breast cancer. These findings suggest that MTA1 plays a vital role in stem cell fate and the hierarchical regulatory network of EMT through negative feedback loops with MTA3 or TRIM21 in response to estrogen, supporting MTA1, MTA3, and TRIM21 as potential prognostic biomarkers and MTA1 as a treatment target for future breast cancer therapies.

The Therapeutic Efficacy and Mechanism of Action of Gnetin C, a Natural Compound from the Melinjo Plant, in a Preclinical Mouse Model of Advanced Prostate Cancer

The metastasis-associated protein 1/protein kinase B (MTA1/AKT) signaling pathway has been shown to cooperate in promoting prostate tumor growth. Targeted interception strategies by plant-based polyphenols, specifically stilbenes, have shown great promise against MTA1-mediated prostate cancer progression. In this study, we employed a prostate-specific transgenic mouse model with MTA1 overexpression on the background of phosphatase and tensin homolog (Pten) null (R26MTA1; Ptenf/f) and PC3M prostate cancer cells which recapitulate altered molecular pathways in advanced prostate cancer. Mechanistically, the MTA1 knockdown or pharmacological inhibition of MTA1 by gnetin C (dimer resveratrol) in cultured PC3M cells resulted in the marked inactivation of mammalian target of rapamycin (mTOR) signaling. In vivo, mice tolerated a daily intraperitoneal treatment of gnetin C (7 mg/kg bw) for 12 weeks without any sign of toxicity. Treatment with gnetin C markedly reduced cell proliferation and angiogenesis and promoted apoptosis in mice with advanced prostate cancer. Further, in addition to decreasing MTA1 levels in prostate epithelial cells, gnetin C significantly reduced mTOR signaling activity in prostate tissues, including the activity of mTOR-target proteins: p70 ribosomal protein S6 kinase (S6K) and eukaryotic translational initiation factor 4E (elF4E)-binding protein 1 (4EBP1). Collectively, these findings established gnetin C as a new natural compound with anticancer properties against MTA1/AKT/mTOR-activated prostate cancer, with potential as monotherapy and as a possible adjunct to clinically approved mTOR pathway inhibitors in the future.

Metastasis-associated protein 1 participates in regulating luminal acidification of the epididymis via repressing estrogen receptor alpha transcription

BACKGROUND

As a component of the nucleosome remodeling and deacetylating (NuRD) complex, metastasis-associated protein 1 (MTA1) has been reported to be abundant in male reproductive system and might participate in spermatogenesis and sperm maturation, whereas the precise functional role of MTA1 in these processes is still undetermined.

OBJECTIVE

To investigate the effect and potential function of MTA1 in male fertility.

MATERIALS AND METHODS

Mta1 knockout mice (Mta1-/- ) were employed to detect their reproductive phenotype. The pH value of Mta1-/- epididymal luminal fluid was measured, and the potential mechanism of MTA1 involved in regulating luminal acidification was detected in vivo and in vitro. A vasectomy model with abnormal pH of epididymal lumen was established to further detect the effect of MTA1 on epididymal luminal microenvironment.

RESULTS

Mta1-/- mice were fertile without any detectable defects in spermatogenesis or sperm motility while the deficiency of MTA1 could acidify the initial segment of epididymis to a certain extent. MTA1 could interact with estrogen receptor alpha (ERα) and inhibit the transcription of ERα target gene, hydrogen exchanger 3 (NHE3), and ultimately affect the epididymal luminal milieu. After vasectomy, the Mta1-/- mice presented a more acidic epididymal lumen which was closer to the normal state compared to the wild-type model.

DISCUSSION AND CONCLUSION

MTA1 is dispensable for male fertility in mice, but plays a potentially important function in regulating luminal acidification of the epididymis.

Stilbenes: a promising small molecule modulator for epigenetic regulation in human diseases

Stilbenes are characterized by a vinyl group connecting two benzene rings to form the basic parent nucleus. Hydrogen atoms on different positions of the benzene rings can be substituted with hydroQxyl groups. These unique structural features confer anti-inflammatory, antibacterial, antiviral, antioxidant, anticancer, cardiovascular protective, and neuroprotective pharmacological effects upon these compounds. Numerous small molecule compounds have demonstrated these pharmacological activities in recent years, including Resveratrol, and Pterostilbene, etc. Tamoxifen and Raloxifene are FDA-approved commonly prescribed synthetic stilbene derivatives. The emphasis is on the potential of these small molecules and their structural derivatives as epigenetic regulators in various diseases. Stilbenes have been shown to modulate epigenetic marks, such as DNA methylation and histone modification, which can alter gene expression patterns and contribute to disease development. This review will discuss the mechanisms by which stilbenes regulate epigenetic marks in various diseases, as well as clinical trials, with a focus on the potential of small molecule and their derivatives such as Resveratrol, Pterostilbene, and Tamoxifen.

Molecular Efficacy of Gnetin C as Dual-Targeted Therapy for Castrate-Resistant Prostate Cancer

SCOPE

Resistance of castrate-resistant prostate cancer (CRPC) to enzalutamide (Enz) involves the expression of constitutively active androgen receptor splice variant (AR-V7). In addition to altered AR pathways, CRPC is characterized by "non-AR-driven" signaling, which includes an overexpression of metastasis-associated protein 1 (MTA1). Combining natural compounds with anticancer drugs may enhance drug effectiveness while reducing adverse effects. In this study, the in vitro and in vivo anticancer effects of Gnetin C (GnC) alone and in combination with Enz against CRPC are examined.

METHODS AND RESULTS

The effects of GnC alone and in combination with Enz are assessed by cell viability, clonogenic survival, cell migration, and AR and MTA1 expression using 22Rv1 cells. The tumor growth in vivo is assessed by bioluminescent imaging, western blots, RT-PCR, and IHC. GnC alone and in combined treatment inhibit cell viability, clonogenic survival and migration, and AR and MTA1 expression in 22Rv1 cells. The underlying AR- and MTA1-targeted anticancer mechanisms of treatments in vivo involve inhibition of proliferation and angiogenesis, and induction of apoptosis.

CONCLUSION

The findings demonstrate that GnC alone and GnC combined with Enz effectively inhibits AR- and MTA1-promoted tumor-progression in advanced CRPC, which indicates its potential as a novel therapeutic approach for CRPC.

Resveratrol attenuates efavirenz-induced hepatic steatosis and hypercholesterolemia in mice by inhibiting pregnane X receptor activation and decreasing inflammation

Efavirenz (EFV), a widely prescribed antiviral medication, has been implicated in dyslipidemia and can activate the pregnane X receptor (PXR), leading to hepatic steatosis and hypercholesterolemia in mice. Resveratrol (RES) can ameliorate hepatic steatosis and functions as a partial PXR agonist, capable of mitigating PXR expression induced by other PXR agonists. Therefore, we hypothesized that RES could attenuate EFV-induced hepatic steatosis and hypercholesterolemia by downregulating PXR expression and suppressing inflammatory cytokine production. Here, we conducted an in vivo study involving 6-week-old male mice, which were divided into 4 groups for a 7-day intervention: control (carrier solution), EFV (80 mg/kg), RES (50 mg/kg), and RES + EFV groups. Serum and hepatic tissue samples were collected to assess cholesterol and triglyceride concentrations. Hepatic lipid accumulation was evaluated through hematoxylin-eosin and oil red O staining. Polymerase chain reaction and western blot were performed to quantify hepatic inflammatory factors, lipogenic gene, and PXR expression. Our results indicated that hepatic lipid droplet accumulation was reduced in the RES + EFV group compared with the EFV group. Similarly, the expressions of hepatic inflammatory factors were attenuated in the RES + EFV group relative to the EFV group. Furthermore, RES counteracted the upregulation of hepatic lipid-metabolizing enzymes induced by EFV at both the transcriptional and protein levels. Importantly, PXR expression was downregulated in the RES + EFV group compared with the EFV group. Conclusively, our findings suggest that RES effectively mitigates EFV-induced hepatic steatosis and hypercholesterolemia by inhibiting PXR activation and decreasing inflammation.

MTA1, a Novel ATP Synthase Complex Modulator, Enhances Colon Cancer Liver Metastasis by Driving Mitochondrial Metabolism Reprogramming

Liver metastasis is the most fatal event of colon cancer patients. Warburg effect has been long challenged by the fact of upregulated oxidative phosphorylation (OXPHOS), while its mechanism remains unclear. Here, metastasis-associated antigen 1 (MTA1) is identified as a newly identified adenosine triphosphate (ATP) synthase modulator by interacting with ATP synthase F1 subunit alpha (ATP5A), facilitates colon cancer liver metastasis by driving mitochondrial bioenergetic metabolism reprogramming, enhancing OXPHOS; therefore, modulating ATP synthase activity and downstream mTOR pathways. High-throughput screening of an anticancer drug shows MTA1 knockout increases the sensitivity of colon cancer to mitochondrial bioenergetic metabolism-targeted drugs and mTOR inhibitors. Inhibiting ATP5A enhances the sensitivity of liver-metastasized colon cancer to sirolimus in an MTA1-dependent manner. The therapeutic effects are verified in xenograft models and clinical cases. This research identifies a new modulator of mitochondrial bioenergetic reprogramming in cancer metastasis and reveals a new mechanism on upregulating mitochondrial OXPHOS as the reversal of Warburg effect in cancer metastasis is orchestrated.

Effect of Selenium and Lycopene on Radiation Sensitivity in Prostate Cancer Patients Relative to Controls

Almost half of prostate cancer (PC) patients receive radiation therapy as primary curative treatment. In spite of advances in our understanding of both nutrition and the genomics of prostate cancer, studies on the effects of nutrients on the radiation sensitivity of PC patients are lacking. We tested the hypothesis that low plasma levels of selenium and lycopene have detrimental effects on ionising radiation-induced DNA damage in prostate cancer patients relative to healthy individuals. The present study was performed in 106 PC patients and 132 age-matched controls. We found that the radiation-induced micronucleus (MN) and nuclear buds (NBuds) frequencies were significantly higher in PC patients with low selenium (p = 0.008 and p = 0.0006 respectively) or low lycopene (p = 0.007 and p = 0.0006 respectively) levels compared to the controls. The frequency of NBuds was significantly higher (p < 0.0001) in PC patients who had low levels of both selenium and lycopene compared to (i) controls with low levels of both selenium and lycopene and (ii) PC patients with high levels of both selenium and lycopene (p = 0.0001). Our results support the hypothesis that low selenium and lycopene levels increase the sensitivity to radiation-induced DNA damage and suggest that nutrition-based treatment strategies are important to minimise the DNA-damaging effects in PC patients receiving radiotherapy.

Gnetin C Intercepts MTA1-Associated Neoplastic Progression in Prostate Cancer

Nutritional chemoprevention is particularly suitable for prostate cancer. Gnetin C, a resveratrol dimer found abundantly in the melinjo plant (Gnetum gnemon), may possess more potent biological properties compared to other stilbenes. We examined the effects of gnetin C in a high-risk premalignant transgenic mouse model overexpressing tumor-promoting metastasis-associated protein 1 (MTA1) on the background of Pten heterozygosity (R26^MTA1; Pten^+/f; Pb-Cre⁺). Mice were fed diets supplemented with the following compounds: pterostilbene (70 mg/kg diet); gnetin C, high dose (70 mg/kg diet); and gnetin C, low dose (35 mg/kg diet). Prostate tissues were isolated after 17 weeks and examined for histopathology and molecular markers. Serum was analyzed for cytokine expression. Gnetin C-supplemented diets substantially delayed the progression of preneoplastic lesions compared to other groups. Prostate tissues from gnetin C-fed mice showed favorable histopathology, with decreased severity and number of prostatic intraepithelial neoplasia (PIN) foci, reduced proliferation, and angiogenesis. A decreased level of MTA1, concurrent with the trend of increasing phosphatase and tensin homolog expression and reduced interleukin 2 (IL-2) levels in sera, were also detected in gnetin C-fed mice. Importantly, gnetin C did not exert any visible toxicity in mice. Our findings demonstrate that a gnetin C-supplemented diet effectively blocks MTA1-promoted tumor progression activity in high-risk premalignant prostate cancer, which indicates its potential as a novel form of nutritional interception for prostate cancer chemoprevention.

A new antioxidant made from a pterostilbene functionalized graphene nanocomposite as an efficient treatment for dry eye disease

Dry eye disease is a common condition that affects the eyes. It is caused by problems with the tear film and the tear dynamics. Dry eye can be caused by an increase in the amount of reactive oxygen species (ROS) in the corneal epithelium. The treatment for dry eye typically focuses on relieving the uncomfortable symptoms by using eye drops such as artificial tears, antibiotics, and by using anti-inflammatory/immunosuppressive agents such as cyclosporine, and lifitegrast. However, the recovery of patients with dry eye can take several years particularly if the symptoms are severe. This is because the present treatment approaches for dry eye are not based on its cause, e.g., the oxidative stress arising from the rapid increase in ROS. This work describes a new type of antioxidant made from pterostilbene (PS) and carboxyl-chitosan modified graphene (CG). The use of a hydrophilic two-dimensional CG nanosheet to improve the properties of PS is reported. Superior enhanced properties including better cellular permeability, long sustained release period (over 30 h), and antioxidant properties, were realized by using PS-CG. A hyperosmotic (HS) damaged human corneal epithelial cell (HCEC) model was used for antioxidant tests. This model has an intracellular ROS level 4 times more than that of a control group. The ROS content was declined efficiently to the same amount as normal cells in the PS-CG treated HS group. There was a significant decline in the content of lactate dehydrogenase (LDH) and the apoptosis rate of HCEC in the PS-CG treated HS group when compared to that seen in the HS model. Real-time polymerase chain reaction (PCR) and western blots (WB) were used to understand the antioxidant mechanism of PS-CG. The results showed that the antioxidant was working by activating the Keap1-Nrf2-ARE signalling pathway. In vivo testing testing using a dry eye mouse model suggested that the PS-CG acted as an efficient antioxidant. More tear production and healthier corneal and conjunctival epithelial cells were achieved when PC-CG was applied to this model. The use of PS-CG could be a new strategy for treating dry eye and other ocular diseases caused by ROS.

Effect of Pterostilbene, a Natural Derivative of Resveratrol, in the Treatment of Colorectal Cancer through Top1/Tdp1-Mediated DNA Repair Pathway

Topoisomerase 1 (Top1) inhibitor is an effective anticancer drug, but several factors limit its clinical application such as drug inactivation, tyrosyl-DNA phosphodiesterase 1 (Tdp1)-mediated tumor drug resistance, and its toxicity. Our previous study identified pterostilbene (PTE) and resveratrol (RE) to suppress these two proteins by binding to their active center. PTE and RE could inhibit the proliferation of various colorectal cancer cells, induce cell apoptosis, and make cell cycle stay in G2/M phase in vitro. PTE and RE could decrease Top1 and Tdp1 contents and mRNA expression in wild-type, constructed Tdp1 overexpressing CL187, Top1- or Tdp1- silenced CL187 cell lines. PTE exhibited excellent antitumor activity in subcutaneous CL187 transplantation model (TGI = 79.14 ± 2.85%, 200 mg/kg, i.p.) and orthotopic transplantation model (TGI = 76.57 ± 6.34%, 100 mg/kg, i.p.; TGI = 72.79 ± 4.06%, 500 mg/kg, i.g.) without significant toxicity. PTE had no significant inhibitory effect on non-tumor cell proliferation in vitro and would not induce damage to liver, kidney, and other major organs. Overall, PTE and RE can inhibit the activity of Top1 enzyme and inhibit the DNA damage repair pathway mediated by Top1/Tdp1, and can effectively inhibit colorectal cancer development with low toxicity, thus they have great potential to be developed into a new generation of anti-tumor drugs.

Recent trends in extraction of plant bioactives using green technologies: A review

Phenolic compounds from plant sources have significant health-promoting properties and are known to be an integral part of folk and herbal medicines. Consumption of phenolics is known to alleviate the risk of various lifestyle diseases including cancer, cardiovascular, diabetes, and Alzheimer's. In this context, numerous plant crops have been explored and characterized based on phenolic compounds for their use as supplements, nutraceutical, and pharmaceuticals. The present review highlights some important source of bioactive phenolic compounds and novel technologies for their efficient extraction. These techniques include the use of microwave, ultrasound, and supercritical methods. Besides, the review will also highlight the use of response surface methodology (RSM) as a statistical tool for optimizing the recoveries of the phenolic bioactives from plant-based matrices.

Dietary Factors and Prostate Cancer Development, Progression, and Reduction

Due to the constantly increasing number of cases, prostate cancer has become one of the most important health problems of modern societies. This review presents the current knowledge regarding the role of nutrients and foodstuff consumption in the etiology and development of prostate malignancies, including the potential mechanisms of action. The results of several in vivo and in vitro laboratory experiments as well as those reported by the clinical and epidemiological research studies carried out around the world were analyzed. The outcomes of these studies clearly show the influence of both nutrients and food products on the etiology and prevention of prostate cancer. Consumption of certain nutrients (saturated and trans fatty acids) and food products (e.g., processed meat products) leads to the disruption of prostate hormonal regulation, induction of oxidative stress and inflammation, and alteration of growth factor signaling and lipid metabolism, which all contribute to prostate carcinogenesis. On the other hand, a high consumption of vegetables, fruits, fish, and whole grain products exerts protective and/or therapeutic effects. Special bioactive functions are assigned to compounds such as flavonoids, stilbenes, and lycopene. Since the influence of nutrients and dietary pattern is a modifiable risk factor in the development and prevention of prostate cancer, awareness of the beneficial and harmful effects of individual food ingredients is of great importance in the global strategy against prostate cancer.

Therapeutic Potential of Gnetin C in Prostate Cancer: A Pre-Clinical Study

Natural stilbenes have gained significant attention in the scientific community owing to their potential anticancer effects against prostate cancer. We recently reported that Gnetin C, a resveratrol (Res) dimer, demonstrated more potent inhibition of metastasis-associated protein 1/v-ets avian erythroblastosis virus E26 oncogene homolog 2 (MTA1/ETS2) axis in prostate cancer cell lines than other stilbenes. In this study, we investigated in vivo antitumor effects of Gnetin C in two doses (50 and 25 mg/kg, i.p.) using PC3M-Luc subcutaneous xenografts and compared these to Res and pterostilbene (Pter). We found that while vehicle-treated mice revealed rapid tumor progression, compounds-treated mice showed noticeable delay in tumor growth. Gnetin C in 50 mg/kg dose demonstrated the most potent tumor inhibitory effects. Gnetin C in 25 mg/kg dose exhibited tumor inhibitory effects comparable with Pter in 50 mg/kg dose. Consistent with the effective antitumor effects, Gnetin C-treated tumors showed reduced mitotic activity and angiogenesis and a significant increase in apoptosis compared to all the other groups. The data suggest that Gnetin C is more potent in slowing tumor progression in prostate cancer xenografts than Res or Pter. Taken together, we demonstrated, for the first time, that Gnetin C is a lead compound among stilbenes for effectively blocking prostate cancer progression in vivo.

Grape Powder Supplementation Attenuates Prostate Neoplasia Associated with Pten Haploinsufficiency in Mice Fed High-Fat Diet

SCOPE

Previous studies have identified potent anticancer activities of polyphenols in preventing prostate cancer. The aim of the current study is to evaluate the chemopreventive potential of grape powder (GP) supplemented diets in genetically predisposed and obesity-provoked prostate cancer.

METHODS AND RESULTS

Prostate-specific Pten heterozygous (Pten+/f ) transgenic mice are fed low- and high-fat diet (LFD and HFD, respectively) supplemented with 10% GP for 33 weeks, ad libitum. Prostate tissues are characterized using immunohistochemistry and western blots, and sera are analyzed by ELISA and qRT-PCR. Pten+/f mice fed LFD and HFD supplemented with 10% GP show favorable histopathology, significant reduction of the proliferative rate of prostate epithelial cells (Ki67), and rescue of PTEN expression. The most potent protective effect of GP supplementation is detected against HFD-induced increase in inflammation (IL-1β; TGF-β1), activation of cell survival pathways (Akt, AR), and angiogenesis (CD31) in Pten+/f mice. Moreover, GP supplementation reduces circulating levels of oncogenic microRNAs (miR-34a; miR-22) in Pten+/f mice. There are no significant changes in body weight and food intake in GP supplemented diet groups.

CONCLUSIONS

GP diet supplementation can be a beneficial chemopreventive strategy for obesity-related inflammation and prostate cancer progression. Monitoring serum miRNAs can facilitate the non-invasive evaluation of chemoprevention efficacy.

Identification and Quantification of Stilbenes (Piceatannol and Resveratrol) in Passiflora edulis By-Products

Recently, studies on the by-products from the food industry, such as passion fruit seeds, have significantly increased, as these can have an added value, due to their properties, such as potential antioxidant activity. This study was conducted to determine the presence of piceatannol and resveratrol in various extracts of passion fruit (Passiflora edulis) seeds from Madeira Island and a commercial passion fruit oil was used as reference. The commercial oil and the extracts that were obtained by traditional Soxhlet method with ethanol and acetone did not reveal the presence of the two stilbenes, piceatannol and resveratrol. However, the extracts that were obtained by the ultrasound method showed significant amounts of piceatannol and resveratrol when compared with the commercial oil. The presence of these compounds indicates that this oil could have potential application in cosmetic and pharmaceutical industries, due to their proven antioxidant and anti-aging properties.