Integrative Metabolomic Analysis of Serum and Selected Serum Exosomal microRNA in Metastatic Castration-Resistant Prostate Cancer.

Metastatic castration-resistant prostate cancer (mCRPC) remains a lethal disease due to the absence of effective therapies. A more comprehensive understanding of molecular events, encompassing the dysregulation of microRNAs (miRs) and metabolic reprogramming, holds the potential to unveil precise mechanisms underlying mCRPC. This study aims to assess the expression of selected serum exosomal miRs (miR-15a, miR-16, miR-19a-3p, miR-21, and miR-141a-3p) alongside serum metabolomic profiling and their correlation in patients with mCRPC and benign prostate hyperplasia (BPH). Blood serum samples from mCRPC patients (n = 51) and BPH patients (n = 48) underwent metabolome analysis through 1H-NMR spectroscopy. The expression levels of serum exosomal miRs in mCRPC and BPH patients were evaluated using a quantitative real-time polymerase chain reaction (qRT-PCR). The 1H-NMR metabolomics analysis revealed significant alterations in lactate, acetate, citrate, 3-hydroxybutyrate, and branched-chain amino acids (BCAAs, including valine, leucine, and isoleucine) in mCRPC patients compared to BPH patients. MiR-15a, miR-16, miR-19a-3p, and miR-21 exhibited a downregulation of more than twofold in the mCRPC group. Significant correlations were predominantly observed between lactate, citrate, acetate, and miR-15a, miR-16, miR-19a-3p, and miR-21. The importance of integrating metabolome analysis of serum with selected serum exosomal miRs in mCRPC patients has been confirmed, suggesting their potential utility for distinguishing of mCRPC from BPH.

The driving power of the cell cycle: cyclin-dependent kinases, cyclins and their inhibitors.

The cell cycle covers cell proliferation and growth and is strictly regulated by cyclin-dependent kinase, cyclins and their inhibitors. Cyclin-dependent kinases are serine/threonine kinases that are activated in certain phases of the cell cycle by regulatory subunits, cyclins, with which they form functional heterodimeric complexes. Under physiological conditions, the activation of cyclin-dependent kinases and cyclins is strictly controlled. The formation of these complexes is inhibited, as needed, either specifically or non-specifically, by cyclin-dependent kinase inhibitors. Progression through the cell cycle is a critical process that drives many aspects of cellular function. The cell cycle is a series of events that occurs in a repeating pattern. Each cell cycle consists of two phases, interphase and mitotic phase. Their dysregulation leads to disruption of cell cycle coordination and uncontrollable cell proliferation, which is the main feature of tumorigenesis (Fig. 1, Ref. 69). Keywords: cell cycle, regulation, cyclin­dependent kinases, cyclins, inhibitors.

Effect of hyperhomocysteinemia on rat cardiac sarcoplasmic reticulum.

Increased concentration of plasma homocysteine (Hcy) is an independent risk factor of cardiovascular disease, yet the mechanism by which hyperhomocysteinemia (HHcy) causes cardiac dysfunction is largely unknown. The aim of present study was to investigate the contribution of sarcoplasmic reticulum to impaired cardiac contractile function in HHCy. HHcy-induced by subcutaneous injection of Hcy (0.45 µmol/g of body weight) twice a day for a period of 2 weeks resulted in significant decrease in developed left ventricular pressure and maximum rate of ventricular relaxation. Our results show that abundances of SR Ca2+-handling proteins, Ca2+-ATPase (SERCA2), calsequestrin and histidine-rich calcium-binding protein are significantly reduced while the content of phospholamban is unchanged. Moreover, we found that increased PLN:SERCA2 ratio results in the inhibition of SERCA2 activity at low free Ca2+ concentrations. We further discovered that HHcy is not associated with increased oxidative stress in SR. Taken together, these findings suggest that disturbances in SR Ca2+ handling, caused by altered protein contents but not oxidative damage, may contribute to impaired cardiac contractility in HHcy.

The ubiquitous expression of pyruvate carboxylase among human prostate tumors.

Pyruvate carboxylase (PC) is a mitochondrial enzyme catalyzing the ATP-dependent reaction of pyruvate prolongation with bicarbonate ion to oxaloacetate. The synthesis of oxaloacetate by PC, an intermediate of the Krebs cycle, is recently recognized as a significant anaplerotic reaction that supports the biosynthetic capability, growth, aggressiveness, and even viability of several cancer cell types. PC expression was confirmed in several types of cancer cells and tumors. To evaluate the possibility that prostate tumor-forming cells are also exploiting the anaplerotic role of PC, we applied immunoblotting analysis to estimate its presence. Our results revealed that PC is present among the lysate proteins derived from prostate cancer and benign prostatic hyperplasia samples. The expression of PC in cells of prostate tumors and benign prostatic hyperplasia supposes that PC could facilitate the formation of oxaloacetate in situ and enhance the autonomy of their biosynthetic metabolism from the availability of extracellular substrates by increasing the cellular anaplerotic capability (Tab. 1, Fig. 1, Ref. 30). Keywords: pyruvate carboxylase, prostate cancer, cancer metabolism, anaplerosis.

Differential profiling of prostate tumors versus benign prostatic tissues by using a 2DE-MALDI-TOF-based proteomic approach.

Oncoproteomic technologies offer a complementary approach to the understanding of cancer proteins' function and the translation of molecular knowledge into clinical practice. Our aim was to compare the proteomic profiles of prostate tumors versus benign prostatic hyperplasia (BPH) tissues in order to identify modulated proteins as the potential biomarkers for prostate cancer. Proteins extracted from twenty prostate cancer tissue specimens and ten BPH tissues were analyzed by two-dimensional electrophoresis (2-DE) coupled with MALDI-TOF mass spectrometry. Western blot and quantitative real-time PCR (RT-PCR) were performed to confirm the different amounts of protein biomarkers revealed by 2DE combined with MALDI mass spectrometry. We found 42 spots whose expression in the prostate was altered more than 1.5-fold compared with BPH tissue (p<0.05). These spots represented ten different proteins that were identified by a database search after mass spectrometry: they comprised proteins involved in the regulation of actin dynamics, the cytoskeleton, and cell motility (ACTG2, ACTA2, TPM1, DES, VIM, FLNA, and TAGLN), heat shock protein-27 (Hsp27), and proteins with other functions (TR and RANBP3). Subsequent western blot and RT-PCR assays for DES, VIM, TAGLN, and Hsp27 in prostate tumor tissues and BPH tissues confirmed the observations obtained by proteomic analysis. The cytoskeletal and cytoskeleton-associated proteins identified by this approach might be useful molecular targets for prostate cancer diagnostics and may contribute to novel therapies for prostate cancer.

Homocysteine and Mitochondria in Cardiovascular and Cerebrovascular Systems.

Elevated concentration of homocysteine (Hcy) in the blood plasma, hyperhomocysteinemia (HHcy), has been implicated in various disorders, including cardiovascular and neurodegenerative diseases. Accumulating evidence indicates that pathophysiology of these diseases is linked with mitochondrial dysfunction. In this review, we discuss the current knowledge concerning the effects of HHcy on mitochondrial homeostasis, including energy metabolism, mitochondrial apoptotic pathway, and mitochondrial dynamics. The recent studies suggest that the interaction between Hcy and mitochondria is complex, and reactive oxygen species (ROS) are possible mediators of Hcy effects. We focus on mechanisms contributing to HHcy-associated oxidative stress, such as sources of ROS generation and alterations in antioxidant defense resulting from altered gene expression and post-translational modifications of proteins. Moreover, we discuss some recent findings suggesting that HHcy may have beneficial effects on mitochondrial ROS homeostasis and antioxidant defense. A better understanding of complex mechanisms through which Hcy affects mitochondrial functions could contribute to the development of more specific therapeutic strategies targeted at HHcy-associated disorders.

The role of CYP17A1 in prostate cancer development: structure, function, mechanism of action, genetic variations and its inhibition.

Androgens play an important role during the development of both normal prostate epithelium and prostate cancer and variants of genes involved in androgen metabolism may be related to an increased risk of prostate disease. Cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) is a key regulatory enzyme in the steroidogenic pathway; it catalyses both 17α-hydroxylase and 17,20-lyase activities and is essential for the production of both androgens and glucocorticoids. In this review, we focus on the structure and enzymatic activity of CYP17A1 and the mechanism of modulation of CYP17A1 activities. We discuss the relationship between common genetic variations in CYP17A1 gene and prostate cancer risk and the main effects of these variations on the prediction of susceptibility and clinical outcomes of prostate cancer patients. The mechanism of action, the efficacy and the clinical potential of CYP17A1 inhibitors in prostate cancer are also summarized.

Comparison of pulsed and continuous electromagnetic field generated by WPT system on human dermal and neural cells.

In recent decades, we have seen significant technical progress in the modern world, leading to the widespread use of telecommunications systems, electrical appliances, and wireless technologies. These devices generate electromagnetic radiation (EMR) and electromagnetic fields (EMF) most often in the extremely low frequency or radio-frequency range. Therefore, they were included in the group of environmental risk factors that affect the human body and health on a daily basis. In this study, we tested the effect of exposure EMF generated by a new prototype wireless charging system on four human cell lines (normal cell lines-HDFa, NHA; tumor cell lines-SH-SY5Y, T98G). We tested different operating parameters of the wireless power transfer (WPT) device (87-207 kHz, 1.01-1.05 kW, 1.3-1.7 mT) at different exposure times (pulsed 6 × 10 min; continuous 1 × 60 min). We observed the effect of EMF on cell morphology and cytoskeletal changes, cell viability and mitotic activity, cytotoxicity, genotoxicity, and oxidative stress. The results of our study did not show any negative effect of the generated EMF on either normal cells or tumor cell lines. However, in order to be able to estimate the risk, further population and epidemiological studies are needed, which would reveal the clinical consequences of EMF impact.

The association between estrogen receptor alpha polymorphisms and the risk of prostate cancer in Slovak population.

The aim of our study was to evaluate the effect of two polymorphisms in the estrogen receptor alpha, PvuII and XbaI, on the development of prostate cancer within Slovak population, as well as their correlation with selected clinical characteristics. The study was performed using 311 prostate cancer patients and 256 healthy male controls. Both polymorphisms were significantly associated with higher risk of prostate cancer development. At the same time, the CC genotype of PvuII polymorphism (OR = 1.98; 95% CI 0.94-4.21; p = 0.05) and the AG genotype of XbaI polymorphism (OR = 1.74; 95% CI 1.0-3.02; p = 0.04) significantly contributed to the development of low-grade carcinoma, while the AG and GG genotypes of the XbaI polymorphism contributed mainly to the development of high-grade prostate cancer (OR = 1.83; 95% CI 1.12-3.01; p = 0.01 and OR = 2.13; 95% CI 1.06-4.19; p = 0.03, respectively). Similarly, the AG and GG genotypes of XbaI polymorphism showed significant association with prostate cancer in patients with serum PSA level ≥10 ng/ml. Both polymorphisms were found at the same time to be more frequent in patients diagnosed before the age of 60. We conclude on the basis of these results that PvuII and XbaI polymorphisms of estrogen receptor alpha might be associated with prostate cancer risk within Slovak population. Although this is a pilot study and, as such, more detailed investigations are needed to confirm the role of these polymorphisms in prostate cancer development and progression within said Slovak population, our results might still provide a valuable basis for further research with larger patient groups.

Polymorphisms in the gene encoding CYP1A2 influence prostate cancer risk and progression.

The role of the cytochrome P450 1A2 (CYP1A2) rs2472299, rs2470890 and rs11072508 polymorphisms in prostate cancer risk, disease progression and tumour development remains unclear. The potential associations of these three CYP1A2 polymorphisms and haplotypes with prostate cancer susceptibility and its clinicopathological characteristics were therefore investigated. The present case-control study consisted of 522 patients with prostate cancer and 554 healthy controls. High-resolution melting analysis was used to determine the CYP1A2 polymorphisms. No significant association in prostate cancer risk was seen for CYP1A2 rs2472299 and rs11072508. However, a significantly decreased risk of prostate cancer was found for CYP1A2 rs2470890 [odds ratio (OR), 0.67; P=0.02] in the recessive model. After analysis of the associations of clinical status and these three CYP1A2 polymorphisms, the CYP1A2 rs2470890 and rs11072508 polymorphisms showed a positive association with a higher Gleason score (rs2470890 OR, 1.36, P=0.04 in the allelic model; rs11072508 OR, 1.37, P=0.04 in the allelic model and OR, 1.60, P=0.03 in the dominant model). All three polymorphisms showed a significant positive association with pathological T stage in the additive, allelic and dominant genetic models (P<0.05). Haplotype analysis revealed that the most common haplotypes 'GTT' and 'ACC' were significantly associated with pathological T stages 3 and 4 (OR, 0.62; P=0.02 and OR, 1.54; P=0.03, respectively). A significant association was found between the 'GTT' haplotype and the Gleason score (OR, 0.71; P=0.03). In conclusion, these CYP1A2 polymorphisms and haplotypes have the potential to predict prostate cancer disease progression.

Effect of CYP17 and PSA gene polymorphisms on prostate cancer risk and circulating PSA levels in the Slovak population.

Cytochrome P-450c17α (CYP17) and prostate-specific antigen (PSA) genes, which are involved in the androgen metabolism cascade, have been studied as possible candidates for genetic influences on prostate cancer development. Contradictory results prompted us to evaluate the frequencies of polymorphisms in the CYP17 and PSA genes as well as the association between these genetic variants and serum PSA levels in prostate cancer patients and men routinely screened for prostate cancer with PSA in the Slovak male population. The CYP17 and PSA polymorphisms were determined by the PCR-RFLP analysis in 197 Caucasian prostate cancer patients and 256 Caucasian controls. We did not find any association between the CYP17 and PSA genotypes and prostate cancer risk overall, or by grade. Also the total serum PSA levels in the cases with the AG or AA genotype were not significantly higher than in the men with the GG genotype (P > 0.05). Our study did not provide support for the hypothesized relationship between CYP17 and PSA gene polymorphisms and prostate cancer in the Slovak male population.

Role of Genetic Variations in CDK2, CCNE1 and p27KIP1 in Prostate Cancer.

BACKGROUND/AIM: Our aim was to investigate possible influences of genetic variants in genes involved in the G1/S transition [cyclin-dependent kinase-2 (CDK2), cyclin E1 (CCNE1) and cyclin-dependent kinase inhibitor 1B (p27KIP1)] on the expression/activity of their corresponding proteins and to assess the functional impact of these variants on the risk of prostate cancer. MATERIALS AND METHODS: We genotyped 530 cases and 562 healthy controls for two relevant single nucleotide polymorphisms (CDK2 rs2069408 and CCNE1 rs997669) by TaqMan genotyping assay. p27KIP1 rs2066827 polymorphisms were studied by polymerase chain reaction-restriction fragment length polymorphism assay. In addition, the expression of CDK2, CCNE1 and p27KIP1 was evaluated by quantitative real-time-polymerase chain reaction and western blotting in 44 prostate cancer tissues and 31 benign prostatic hyperplasia tissues. RESULTS: No association was found between CDK2 rs2069408, CCNE1 rs997669 or p27KIP1 rs2066827 polymorphisms and an increased risk of prostate cancer development. Higher CDK2 expression was more prevalent in those with rs2069408 GG genotype than in AA carriers (p>0.05). We also noted reduced p27KIP1 protein expression in those with the p27KIP1 G109 allele. No difference was observed for CCNE1 expression in relation to the risky genotype (CC). A significant association was detected between CCNE1 mRNA overexpression and development of higher-grade carcinomas (Gleason score >7, p<0.05). CONCLUSION: Polymorphisms CDK2 rs2069408, CCNE1 rs997669 and p27KIP1 rs2066827 have no significant impact on prostate cancer risk nor on the gene and protein expression of CDK2, CCNE1 and p27KIP1, although high CCNE1 expression was significantly associated with a higher tumour grade in patients with prostate cancer.

Effect of NAT2 gene polymorphism on bladder cancer risk in Slovak population.

N-acetyltransferase 2 (NAT2) is phase II enzyme with major roles in catalyzing the detoxification of aromatic amines, which are known risk factors for bladder cancer, and are ubiquitously present in the environment. We assessed the association between common polymorphisms in NAT2 gene and the risk of bladder cancer in 90 Slovak patients and 274 ethnicity-matched healthy controls. Effect modifications by smoking, age and gender were also evaluated. Overall, NAT2 slow acetylation was associated with significantly increased risk of bladder cancer (OR = 1.90; 95% CI, 1.15-3.16). In stratified analyses by age and gender, the elevated risk conferred by slow acetylator genotype was evident in older individuals (OR = 3.55; 95% CI, 1.77-7.35) and males (OR = 4.65; 95% CI, 1.68-16.10), with further increasing in NAT2*5B/*6A genotype carriers. Smoking was confirmed to be important risk factor, moreover, the risk was markedly increased in smokers with NAT2 slow acetylator genotype, and NAT2*5B/*6A carriers especially. In summary, these findings are consistent with previous literature suggesting that individual susceptibility to bladder cancer may be modulated by NAT2 polymorphisms, particularly in interaction with relevant environmental exposures such as smoking.

Association between estrogen receptor ß polymorphisms and prostate cancer in a Slovak population.

Sex steroid hormones have important roles in the function of the prostate; however, they may also serve as factors in the initiation and progression of carcinogenesis. Estrogens, acting through estrogen receptors, may significantly affect prostate cancer development and progression. The main aim of the present study was to analyze the association between the rs3020449, rs4986938 and rs1256049 polymorphisms in the promoter region of the estrogen receptor ß (ESR2) gene and prostate cancer risk in the Slovak population. A total of 510 patients with prostate cancer and 184 healthy men were included in the present study. No association between the rs4986938 and rs1256049 polymorphisms and prostate cancer development and progression was revealed; however, there was a statistically significant association between the rs3020449 GG genotype [odds ratio (OR), 2.35; P=0.002] and the G allele (OR, 1.42; P=0.005) and a higher risk of prostate cancer development. The rs3020449 GG genotype was significantly associated with a higher risk of development of carcinoma with a Gleason score >7 (OR, 2.66; P=0.005), as well as with the development of carcinoma with pT3/pT4 (OR, 2.28; P=0.02). According to the results from the present study, the rs3020449 polymorphism, in the promoter region of ESR2, may be considered to have a role in the development and progression of prostate cancer in the Slovak population.

Association of MDM2 T309G (rs2279744) Polymorphism and Expression Changes With Risk of Prostate Cancer in the Slovak Population.

BACKGROUND/AIM: The aim of this study was to evaluate the relationship between MDM2 T309G polymorphism and prostate cancer risk in the Slovak population and the association of this polymorphism with MDM2 expression and clinicopathological features. MATERIALS AND METHODS: The MDM2 T309G polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 506 prostate cancer patients and 592 controls. Quantitative real-time (RT)-PCR and western blot analysis were applied to examine MDM2 expression in 47 prostate cancer tissues and 43 benign prostatic hyperplasia (BPH) tissues. RESULTS: A decreased risk of prostate cancer in men carrying the GG genotype in comparison with the TT genotype was found. A decrease in the relative MDM2 mRNA and protein levels was found in prostate cancer tissues among patients with the MDM2 GG genotype. CONCLUSION: There is a potentially protective effect of the MDM2 GG genotype on the risk of prostate cancer in the Slovak male population.

Influence of pyridoxylidene aminoguanidine on biomarkers of the oxidative stress and selected metabolic parameters of rats with diabetes mellitus.

Oxidative damage is considered to play an important role in the pathogenesis of several diseases, such as diabetes mellitus (DM), atherosclerosis, cardiovascular complications and chronic renal failure. DM is associated with the oxidative stress and formation of advanced glycation end products (AGEs). Different drugs inhibit oxidative stress and formation of advanced glycation end products. Aminoguanidine (AG) has been proposed as a drug of potential benefit in prophylaxis of the complications of DM. Recent reports show a pro-oxidant activity of AG. Therefore we examined the effect of structural analogue of AG, its Schiff base with pyridoxal-pyridoxylidene aminoguanidine (PAG) on the level of selected markers of oxidative stress. We found that PAG decreased total damage to DNA in controls as well as in diabetic group of rats. However, we also found that PAG supplementation increases susceptibility of lipoproteins to oxidation and formation of conjugated dienes in both, diabetic as well as control animals. Its administration to diabetic rats decreases antioxidant capacity of plasma. Therefore, it is necessary to search for other structural modifications of AG that would combine its higher anti-diabetic activity with less toxicity.

Androgen receptor and soy isoflavones in prostate cancer.

Androgens and androgen receptor (AR) play a critical role not only in normal prostate development, but also in prostate cancer. For that reason, androgen deprivation therapy (ADT) is the primary treatment for prostate cancer. However, the majority of patients develop castration-resistant prostate cancer, which eventually leads to mortality. Novel therapeutic approaches, including dietary changes, have been explored. Soy isoflavones have become a focus of interest because of their positive health benefits on numerous diseases, particularly hormone-related cancers, including prostate and breast cancers. An important strategy for the prevention and/or treatment of prostate cancer might thus be the action of soy isoflavones on the AR signaling pathway. The current review article provides a detailed overview of the anticancer potential of soy isoflavones (genistein, daidzein and glycitein), as mediated by their effect on AR.

Tyrosine nitration of mitochondrial proteins during myocardial ischemia and reperfusion.

Myocardial ischemia reperfusion is associated with mitochondrial dysfunction and increased formation of reactive oxygen/nitrogen species. The main purpose of this study was to assess the role of tyrosine nitration of mitochondrial proteins in postischemic contractile dysfunction known as myocardial stunning. Isolated Langendorff-perfused rat hearts were subjected to 20-min global ischemia followed by 30-min reperfusion. The reperfused hearts showed marked decline in left ventricular developed pressure, maximal rate of contraction (+dP/dt), and maximal rate of relaxation (-dP/dt). Immunofluorescence and ELISA assays demonstrated enhanced protein tyrosine nitration in reperfused hearts. Using two-dimensional gel electrophoresis and MALDI-TOF/TOF mass spectrometry, eight mitochondrial proteins were identified to be nitrated after ischemia reperfusion. These proteins are crucial in mitochondrial electron transport, fatty acid oxidation, tricarboxylic acid cycle, ATP synthesis, and control of high-energy phosphates. The proteome data also indicated reduced abundance in several of nitrated proteins. The results suggest that these changes may contribute to inhibition of aconitase activity but are unlikely to affect electron transport chain activity. Whether tyrosine nitration of mitochondrial proteins can be considered the contributing factor of postischemic contractile dysfunction remains to be explored.

Associations Between Gene Polymorphisms of Vascular Endothelial Growth Factor and Prostate Cancer.

BACKGROUND/AIM: The aim of this study was to evaluate the association between selected polymorphisms of the vascular endothelial growth factor gene (rs699947, rs144854329, rs833061, rs2010963, rs3025039) and the risk of prostate cancer development and progression. MATERIALS AND METHODS: The present study included 446 patients with prostate cancer and 241 healthy men. Genotyping was performed by polymerase-chain reaction-restriction fragment length polymorphism analysis. RESULTS: No significant association between the individual polymorphisms studied and the risk of prostate cancer development was detected. A statistically significantly increased risk of prostate cancer development associated with the presence of 9 or 10 risky alleles was found considering the whole group of patients, as well as in patients with low-grade carcinomas (Gleason score <7). CONCLUSION: Individual polymorphisms of VEGF do not appear to contribute to prostate cancer. However, a combination of risky alleles of the studied polymorphisms significantly increases the risk of prostate cancer in Slovak patients.

The Role of Interleukin-6 Polymorphism (rs1800795) in Prostate Cancer Development and Progression.

BACKGROUND/AIM: Interleukin-6 is an important modulator of inflammation, which is one of the factors involved in prostate cancer. The aim of the study was to evaluate the possible association of the IL-6 -174 polymorphism (rs1800795) with the risk of prostate cancer development and progression. MATERIALS AND METHODS: The study population consisted of 446 prostate cancer patients, 377 benign prostatic hyperplasia (BHP) patients and 276 healthy men. Genotyping was performed by PCR-RFLP analysis. IL-6 plasma levels were measured by the ELISA method. RESULTS: The GC genotype (OR=0.61, p=0.005) and C allele (OR=0.8, p=0.04) of the IL-6 -174 polymorphism were significantly associated with prostate cancer. No genotype was associated with BHP. IL-6 plasma levels were significantly increased in prostate cancer patients compared to both healthy men (p=0.02) and BHP patients (p=0.008). No significant differences were observed in IL-6 plasma levels in connection with IL-6 -174 genotypes. CONCLUSION: The IL-6 -174 polymorphism was significantly associated with prostate cancer in Slovak patients.