Defining a vitamin A5/X specific deficiency - vitamin A5/X as a critical dietary factor for mental health.

A healthy and balanced diet is an important factor to assure a good functioning of the central and peripheral nervous system. Retinoid X receptor (RXR)-mediated signaling was identified as an important mechanism of transmitting major diet-dependent physiological and nutritional signaling such as the control of myelination and dopamine signalling. Recently, vitamin A5/X, mainly present in vegetables as provitamin A5/X, was identified as a new concept of a vitamin which functions as the nutritional precursor for enabling RXR-mediated signaling. The active form of vitamin A5/X, 9-cis-13,14-dehydroretinoic acid (9CDHRA), induces RXR-activation, thereby acting as the central switch for enabling various heterodimer-RXR-signaling cascades involving various partner heterodimers like the fatty acid and eicosanoid receptors/peroxisome proliferator-activated receptors (PPARs), the cholesterol receptors/liver X receptors (LXRs), the vitamin D receptor (VDR), and the vitamin A(1) receptors/retinoic acid receptors (RARs). Thus, nutritional supply of vitamin A5/X might be a general nutritional-dependent switch for enabling this large cascade of hormonal signaling pathways and thus appears important to guarantee an overall organism homeostasis. RXR-mediated signaling was shown to be dependent on vitamin A5/X with direct effects for beneficial physiological and neuro-protective functions mediated systemically or directly in the brain. In summary, through control of dopamine signaling, amyloid ß-clearance, neuro-protection and neuro-inflammation, the vitamin A5/X - RXR - RAR - vitamin A(1)-signaling might be "one of" or even "the" critical factor(s) necessary for good mental health, healthy brain aging, as well as for preventing drug addiction and prevention of a large array of nervous system diseases. Likewise, vitamin A5/X - RXR - non-RAR-dependent signaling relevant for myelination/re-myelination and phagocytosis/brain cleanup will contribute to such regulations too. In this review we discuss the basic scientific background, logical connections and nutritional/pharmacological expert recommendations for the nervous system especially considering the ageing brain.

Exploring the role of PI3K/AKT/mTOR inhibitors in hormone-related cancers: A focus on breast and prostate cancer.

Breast cancer (BC) and prostate cancer (PC) are at the top of the list when it comes to the most common types of cancers worldwide. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway is important, in that it strongly influences the development and progression of these tumors. Previous studies have emphasized the key role of inhibitors of the PIK3/AKT/mTOR signaling pathway in the treatment of BC and PC, and it remains to be a crucial method of treatment. In this review, the inhibitors of these signaling pathways are compared, as well as their effectiveness in therapy and potential as therapeutic agents. The use of these inhibitors as polytherapy is evaluated, especially with the use of hormonal therapy, which has shown promising results.

Dual targeting of melanoma translation by MNK/eIF4E and PI3K/mTOR inhibitors.

Melanoma is relatively resistant to chemotherapy, and no targeted therapies are fully effective. The most common mutations in melanoma result in hyperactivation of the mitogen-activated protein kinase (MAPK) and PI3K/AKT/ mTOR pathways responsible for initiating and controlling oncogenic protein translation. This makes both the signaling pathways potentially important therapeutic targets in melanoma. Our studies were carried out on human melanoma cell lines WM793 and 1205 LU with similar genomic alteration (BRAFV600E and PTEN loss). We used a highly specific PI3K/mTOR inhibitor, dactolisib (NVP-BEZ235), and Mnk inhibitor - CGP57380 alone and in combination. Here, we explore the mechanism of action of these drugs alone and in combination, as well as their effect on the viability and invasiveness of melanoma cells. Although when used independently, both drugs suppressed cell proliferation and migration, their combination has additional antitumor effects. We demonstrate that simultaneous inhibition of both pathways may prevent possible drug resistance.

The Potential of Congo Red Supplied Aggregates of Multitargeted Tyrosine Kinase Inhibitor (Sorafenib, BAY-43-9006) in Enhancing Therapeutic Impact on Bladder Cancer.

Bladder cancer is a common malignancy associated with high recurrence rates and potential progression to invasive forms. Sorafenib, a multi-targeted tyrosine kinase inhibitor, has shown promise in anti-cancer therapy, but its cytotoxicity to normal cells and aggregation in solution limits its clinical application. To address these challenges, we investigated the formation of supramolecular aggregates of sorafenib with Congo red (CR), a bis-azo dye known for its supramolecular interaction. We analyzed different mole ratios of CR-sorafenib aggregates and evaluated their effects on bladder cancer cells of varying levels of malignancy. In addition, we also evaluated the effect of the test compounds on normal uroepithelial cells. Our results demonstrated that sorafenib inhibits the proliferation of bladder cancer cells and induces apoptosis in a dose-dependent manner. However, high concentrations of sorafenib also showed cytotoxicity to normal uroepithelial cells. In contrast, the CR-BAY aggregates exhibited reduced cytotoxicity to normal cells while maintaining anti-cancer activity. The aggregates inhibited cancer cell migration and invasion, suggesting their potential for metastasis prevention. Dynamic light scattering and UV-VIS measurements confirmed the formation of stable co-aggregates with distinctive spectral properties. These CR-sorafenib aggregates may provide a promising approach to targeted therapy with reduced cytotoxicity and improved stability for drug delivery in bladder cancer treatment. This work shows that the drug-excipient aggregates proposed and described so far, as Congo red-sorafenib, can be a real step forward in anti-cancer therapies.

Clindamycin-Loaded Halloysite Nanotubes as the Antibacterial Component of Composite Hydrogel for Bone Repair.

A new drug delivery system consisting of clindamycin phosphate entrapped in acid-etched halloysite nanotubes was successfully prepared and characterized. It was then used as an antibacterial component of the multicomponent hydrogel designed as a material for bone regeneration. First, halloysite (HNT) was etched and clindamycin phosphate (CP) was entrapped in both raw and modified nanotubes, resulting in HNT-CP and EHNT-CP systems. They were characterized using SEM, TEM, TGA and FTIR; the entrapment efficiency and release of CP from both systems were also studied. EHNT-CP was then used as an antibacterial component of the two hydrogels composed of alginate, collagen and ß-TCP. The hydrogels were prepared using different crosslinking procedures but had the same composition. The morphology, porosity, degradation rate, CP release profile, cytocompatibility, antibacterial activity and ability to induce biomineralization were studied for both materials. The hydrogel obtained by a chemical crosslinking with EDC followed by the physical crosslinking with calcium ions had better properties and was shown to have potential as a bone repair material.

The role of cyclins in the development and progression of prostate cancer.

The role of cyclins in hormone-dependent neoplasms is crucial in the development of the disease that is resistant to first-line therapy, as the example of breast cancer shows. However, in prostate cancer, cyclins are studied to a lesser extent. There are some well-described molecular pathways, including cyclins A1 and D1 signaling, however the role of other cyclins, e.g., D2, D3, E, and H, still requires further investigation. Recent studies indicate that cyclins regulate various cellular processes, not only the cell cycle. Furthermore, they remain in cross-talk with many other signaling pathways, e.g., MAPK/ERK, PI3K/Akt, and Notch. The androgen signaling axis, which is pivotal in prostate cancer progression, interferes with cyclin pathways at many levels. This article summarizes current knowledge on the influence of cyclins on prostate cancer progression by describing interactions between the androgen receptor and cyclins, as well as mechanisms underlying the development of resistance to currently used therapies.

Steroid Receptors in Breast Cancer: Understanding of Molecular Function as a Basis for Effective Therapy Development.

Breast cancer remains one of the most important health problems worldwide. The family of steroid receptors (SRs), which comprise estrogen (ER), progesterone (PR), androgen (AR), glucocorticoid (GR) and mineralocorticoid (MR) receptors, along with a receptor for a secosteroid-vitamin D, play a crucial role in the pathogenesis of the disease. They function predominantly as nuclear receptors to regulate gene expression, however, their full spectrum of action reaches far beyond this basic mechanism. SRs are involved in a vast variety of interactions with other proteins, including extensive crosstalk with each other. How they affect the biology of a breast cell depends on such factors as post-translational modifications, expression of coregulators, or which SR isoform is predominantly synthesized in a given cellular context. Although ER has been successfully utilized as a breast cancer therapy target for years, research on therapeutic application of other SRs is still ongoing. Designing effective hormone therapies requires thorough understanding of the molecular function of the SRs. Over the past decades, huge amount of data was obtained in multiple studies exploring this field, therefore in this review we attempt to summarize the current knowledge in a comprehensive way.

Synthetic Retinoids as Potential Therapeutics in Prostate Cancer-An Update of the Last Decade of Research: A Review.

Prostate cancer (PC) is the second most common tumor in males. The search for appropriate therapeutic options against advanced PC has been in process for several decades. Especially after cessation of the effectiveness of hormonal therapy (i.e., emergence of castration-resistant PC), PC management options have become scarce and the prognosis is poor. To overcome this stage of disease, an array of natural and synthetic substances underwent investigation. An interesting and promising class of compounds constitutes the derivatives of natural retinoids. Synthesized on the basis of the structure of retinoic acid, they present unique and remarkable properties that warrant their investigation as antitumor drugs. However, there is no up-to-date compilation that consecutively summarizes the current state of knowledge about synthetic retinoids with regard to PC. Therefore, in this review, we present the results of the experimental studies on synthetic retinoids conducted within the last decade. Our primary aim is to highlight the molecular targets of these compounds and to identify their potential promise in the treatment of PC.

Specific Binding of Novel SPION-Based System Bearing Anti-N-Cadherin Antibodies to Prostate Tumor Cells.

PURPOSE: Epithelial-mesenchymal (EMT) transition plays an important role in metastasis and is accompanied by an upregulation of N-cadherin expression. A new nanoparticulate system (SPION/CCh/N-cad) based on superparamagnetic iron oxide nanoparticles, stabilized with a cationic derivative of chitosan and surface-modified with anti-N-cadherin antibody, was synthetized for the effective capture of N-cadherin expressing circulating tumor cells (CTC). METHODS: The morphology, physicochemical, and magnetic properties of the system were evaluated using dynamic light scattering (DLS), fluorescence spectroscopy, Mössbauer spectroscopy, magnetometry, and fluorescence spectroscopy. Atomic force microscopy (AFM), confocal microscopy and flow cytometry were used to study the interaction of our nanoparticulate system with N-cadherin expressed in prostate cancer cell lines (PC-3 and DU 145). A purpose-built cuvette was used in the cancer cell capture experiments. RESULTS: The obtained nanoparticles were a spherical, stable colloid, and exhibited excellent magnetic properties. Biological experiments confirmed that the novel SPION/CCh/N-cad system interacts specifically with N-cadherin present on the cell surface. Preliminary studies on the magnetic capture of PC-3 cells using the obtained nanoparticles were successful. Incubation times as short as 1 minute were sufficient for the synthesized system to effectively bind to the PC-3 cells. CONCLUSION: Results obtained for our system suggest a possibility of using it to capture CTC in the flow conditions.

Mechanistic aspects of carotenoid health benefits - where are we now?

Dietary intake and tissue levels of carotenoids have been associated with a reduced risk of several chronic diseases, including cardiovascular diseases, type 2 diabetes, obesity, brain-related diseases and some types of cancer. However, intervention trials with isolated carotenoid supplements have mostly failed to confirm the postulated health benefits. It has thereby been speculated that dosing, matrix and synergistic effects, as well as underlying health and the individual nutritional status plus genetic background do play a role. It appears that our knowledge on carotenoid-mediated health benefits may still be incomplete, as the underlying mechanisms of action are poorly understood in relation to human relevance. Antioxidant mechanisms - direct or via transcription factors such as NRF2 and NF-κB - and activation of nuclear hormone receptor pathways such as of RAR, RXR or also PPARs, via carotenoid metabolites, are the basic principles which we try to connect with carotenoid-transmitted health benefits as exemplified with described common diseases including obesity/diabetes and cancer. Depending on the targeted diseases, single or multiple mechanisms of actions may play a role. In this review and position paper, we try to highlight our present knowledge on carotenoid metabolism and mechanisms translatable into health benefits related to several chronic diseases.

Inhibition Effect of Chloroquine and Integrin-Linked Kinase Knockdown on Translation in Melanoma Cells.

The twofold role of autophagy in cancer is often the therapeutic target. Numerous regulatory pathways are shared between autophagy and other molecular processes needed in tumorigenesis, such as translation or survival signaling. Thus, we have assumed that ILK knockdown should promote autophagy, and used together with chloroquine, an autophagy inhibitor, it could generate a better anticancer effect by dysregulation of common signaling pathways. Expression at the protein level was analyzed using Western Blot; siRNA transfection was done for ILK. Analysis of cell signaling pathways was monitored with phospho-specific antibodies. Melanoma cell proliferation was assessed with the crystal violet test, and migration was evaluated by scratch wound healing assays. Autophagy was monitored by the accumulation of its marker, LC3-II. Our data show that ILK knockdown by siRNA suppresses melanoma cell growth by inducing autophagy through AMPK activation, and simultaneously initiates apoptosis. We demonstrated that combinatorial treatment of melanoma cells with CQ and siILK has a stronger antitumor effect than monotherapy with either of these. It generates the synergistic antitumor effects by the decrease of translation of both global and oncogenic proteins synthesis. In our work, we point to the crosstalk between translation and autophagy regulation.

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 ß-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.

Recent Progress in Discovering the Role of Carotenoids and Metabolites in Prostatic Physiology and Pathology-A Review-Part II: Carotenoids in the Human Studies.

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 related to chronic diseases. One organ that 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 apo-carotenoids) are involved in a plethora of 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 (LYC) and ß-carotene (BC), in prostatic physiology and pathology, the present review aimed to cover the past ten years of research in this regard. Data from experimental studies are presented in the first part of the review, while epidemiological studies are disclosed in this second part. The objective of this compilation was to emphasize the present state of knowledge about the most potent molecular targets of carotenoids, as well as to propose promising carotenoid agents for the prevention and possible treatment of prostatic diseases.

Hyaluronic Acid-Silver Nanocomposites and Their Biomedical Applications: A Review.

For the last years scientific community has witnessed a rapid development of novel types of biomaterials, which properties made them applicable in numerous fields of medicine. Although nanosilver, well-known for its antimicrobial, anti-angiogenic, anti-inflammatory and anticancer activities, as well as hyaluronic acid, a natural polysaccharide playing a vital role in the modulation of tissue repair, signal transduction, angiogenesis, cell motility and cancer metastasis, are both thoroughly described in the literature, their complexes are still a novel topic. In this review we introduce the most recent research about the synthesis, properties, and potential applications of HA-nanosilver composites. We also make an attempt to explain the variety of mechanisms involved in their action. Finally, we present biocompatible and biodegradable complexes with bactericidal activity and low cytotoxicity, which properties suggest their suitability for the prophylaxis and therapy of chronic wounds, as well as analgetic therapies, anticancer strategies and the detection of chemical substances and malignant cells. Cited studies reveal that the usage of hyaluronic acid-silver nanocomposites appears to be efficient and safe in clinical practice.

From carotenoid intake to carotenoid blood and tissue concentrations - implications for dietary intake recommendations.

There is uncertainty regarding carotenoid intake recommendations, because positive and negative health effects have been found or are correlated with carotenoid intake and tissue levels (including blood, adipose tissue, and the macula), depending on the type of study (epidemiological vs intervention), the dose (physiological vs supraphysiological) and the matrix (foods vs supplements, isolated or used in combination). All these factors, combined with interindividual response variations (eg, depending on age, sex, disease state, genetic makeup), make the relationship between carotenoid intake and their blood/tissue concentrations often unclear and highly variable. Although blood total carotenoid concentrations <1000 nmol/L have been related to increased chronic disease risk, no dietary reference intakes (DRIs) exist. Although high total plasma/serum carotenoid concentrations of up to 7500 nmol/L are achievable after supplementation, a plateauing effect for higher doses and prolonged intake is apparent. In this review and position paper, the current knowledge on carotenoids in serum/plasma and tissues and their relationship to dietary intake and health status is summarized with the aim of proposing suggestions for a "normal," safe, and desirable range of concentrations that presumably are beneficial for health. Existing recommendations are likewise evaluated and practical dietary suggestions are included.

Dysregulation of Transcription Factor Activity During Formation of Cancer-Associated Fibroblasts.

The reciprocal interactions between cancer cells and the quiescent fibroblasts leading to the activation of cancer-associated fibroblasts (CAFs) serve an important role in cancer progression. Here, we investigated the activation of transcription factors (TFs) in prostate fibroblasts (WPMY cell line) co-cultured with normal prostate or tumorous cells (RWPE1 and RWPE2 cell lines, respectively). After indirect co-cultures, we performed mRNA-seq and predicted TF activity using mRNA expression profiles with the Systems EPigenomics Inference of Regulatory Activity (SEPIRA) package and the GTEx and mRNA-seq data of 483 cultured fibroblasts. The initial differential expression analysis between time points and experimental conditions showed that co-culture with normal epithelial cells mainly promotes an inflammatory response in fibroblasts, whereas with the cancerous epithelial, it stimulates transformation by changing the expression of the genes associated with microfilaments. TF activity analysis revealed only one positively regulated TF in the RWPE1 co-culture alone, while we observed dysregulation of 45 TFs (7 decreased activity and 38 increased activity) uniquely in co-culture with RWPE2. Pathway analysis showed that these 45 dysregulated TFs in fibroblasts co-cultured with RWPE2 cells may be associated with the RUNX1 and PTEN pathways. Moreover, we showed that observed dysregulation could be associated with FER1L4 expression. We conclude that phenotypic changes in fibroblast responses to co-culturing with cancer epithelium result from orchestrated dysregulation of signaling pathways that favor their transformation and motility rather than proinflammatory status. This dysregulation can be observed both at the TF and transcriptome levels.

Probing the recognition specificity of αVß1 integrin and syndecan-4 using force spectroscopy.

The knowledge on how cells interact with microenvironment is particularly important in understanding the interaction of cancer cells with surrounding stroma, which affects cell migration, adhesion, and metastasis. The main cell surface receptors responsible for the interaction with extracellular matrix (ECM) are integrins, however, they are not the only ones. Integrins are accompanied to other molecules such as syndecans. The role of the latter has not yet been fully established. In our study, we would like to answer the question of whether integrins and syndecans, possessing similar functions, share also similar unbinding properties. By using single molecule force spectroscopy (SMFS), we conducted measurements of the unbinding properties of αVß1 and syndecan-4 in the interaction with vitronectin (VN), which, as each ECM protein, possesses two binding sites specific to integrins and syndecans. The unbinding force and the kinetic off rate constant derived from SMFS describe the stability of single molecular complex. Obtained data show one barrier transition for each complex. The proposed model shows that the unbinding of αVß1 from VN proceeds before the unbinding of SDC-4. However, despite different unbinding kinetics, the access to both receptors is needed for cell growth and proliferation.

Could the kinetin riboside be used to inhibit human prostate cell epithelial-mesenchymal transition?

The epithelial-mesenchymal transition (EMT) is a molecular process connected to higher expression of vimentin and increased activity of transcription factors (Snail, Twist) which restrains E-cadherin. EMT has been linked to prostate cancer metastatic potential, therapy resistance, and poor outcomes. Kinetin riboside (9-(b-dribofuranosyl)-6-furfurylaminopurine, KR) is a naturally occurring cytokinin, which induces apoptosis and shows strong antiproliferative activity against various human cancer cell lines. To establish the effect of KR on human prostate cell lines, expression of, e.g. AR, E-, N-cadherins, Vimentin, Snail, Twist, and MMPs, was analysed at mRNA and protein levels using Western Blot and RT-PCR and/or RQ-PCR techniques. KR inhibited the growth of human prostate cancer cells, but also, to a small extent, of normal cells. This effect depended on the type of the cells and their androgen sensitivity. KR also decreased the level of p-Akt, which takes part in androgen signalling modulation. The antiapoptotic Bcl-2 protein was down-regulated in cancer cell lines, while that of Bax is up-regulated upon KR exposure. KR contributed to re-expression of the E-cadherin as well as to significant changes in cell migration. Taken together, our results indicate for the first time that KR can be proposed as a factor for signalling pathways regulation that participates in the inhibition of development of aggressive forms of prostate cancer, and may alter the approach to therapeutic interventions. We propose KR as a potent inhibitor of EMT in human prostate cells.

Aberrant promoter methylation may be responsible for the control of CD146 (MCAM) gene expression during breast cancer progression.

The CD146 (also known as MCAM, MUC-18, Mel-CAM) was initially reported in 1987, as a protein crucial for the invasiveness of malignant melanoma. Recently, it has been confirmed that CD146 has been involved in progression and poor overall survival of many cancers including breast cancer. Importantly, in independent studies, CD146 was reported to be a trigger of epithelial to mesenchymal transition in breast cancer cells. The goal of our current study was to verify the potential involvement of epigenetic mechanism behind the regulation of CD146 expression in breast cancer cells, as it has been previously reported in prostate cancer. First, we analysed the response of breast cancer cell lines, differing in the initial CD146 mRNA and protein content, to epigenetic modifier, 5-aza-2-deoxycytidine, and subsequently the methylation status of CD146 gene promoter was investigated, using direct bisulfite sequencing. We observed that treatment with demethylating agent led to induction of CD146 expression in all analysed breast cancer cell lines, both at mRNA and protein level, what was accompanied by increased expression of selected mesenchymal markers. Importantly, CD146 gene promoter analysis showed aberrant CpG island methylation in 2 out of 3 studied breast cancer cells lines, indicating epigenetic regulation of CD146 gene expression. In conclusion, our study revealed, for the first time, that aberrant methylation maybe involved in expression control of CD146, a very potent EMT inducer in breast cancer cells. Altogether, the data obtained may provide the basis for novel therapies as well as diagnostic approaches enabling sensitive and very accurate detection of breast cancer cells.