Association of EGF, IGFBP-3 and TP53 Gene Polymorphisms with Major Depressive Disorder in Slovak Population.

BACKGROUND: Major depressive disorder (MDD) is a main public health concern worldwide. Despite extensive investigations, the exact mechanisms responsible for MDD have not been identified. Epidermal growth factor (EGF) and insulin growth factor binding protein-3 (IGFBP-3) are involved in brain function. Tumour suppressor protein p53 is widely involved in neuronal death in response to different forms of acute insults and neurological disorders. The present study focuses on the possible associations of the single-nucleotide polymorphisms (SNP) of EGF A61G (rs4444903), IGFBP-3 C32G (rs2854746) and TP53 G72C (rs1042522) genes with MDD risk in the Slovak population. METHODS: The present case-control association study was carried out in 111 confirmed MDD patients and 207 healthy subjects. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism methods. RESULTS: Logistic regression analysis showed no association between SNPs of selected genes and MDD risk in the Slovak population. However, the stratification of individuals by gender revealed that males carrying IGFBP-3 G alleles (G32G or GG) had marginally increased risk for developing MDD as compared to CC homozygous males (p=0.09). In women, inverse association was observed between SNP rs1042522 and MDD risk (p=0.04 for recessive model). CONCLUSION: Our results suggest the protective effect of minor allele 72C of TP53 gene towards MDD. The disruption of mechanisms involved in cell survival and death regulation may be involved in pathophysiology of MDD.

The Molecular and Cellular Effect of Homocysteine Metabolism Imbalance on Human Health.

Homocysteine (Hcy) is a sulfur-containing non-proteinogenic amino acid derived in methionine metabolism. The increased level of Hcy in plasma, hyperhomocysteinemia, is considered to be an independent risk factor for cardio and cerebrovascular diseases. However, it is still not clear if Hcy is a marker or a causative agent of diseases. More and more research data suggest that Hcy is an important indicator for overall health status. This review represents the current understanding of molecular mechanism of Hcy metabolism and its link to hyperhomocysteinemia-related pathologies in humans. The aberrant Hcy metabolism could lead to the redox imbalance and oxidative stress resulting in elevated protein, nucleic acid and carbohydrate oxidation and lipoperoxidation, products known to be involved in cytotoxicity. Additionally, we examine the role of Hcy in thiolation of proteins, which results in their molecular and functional modifications. We also highlight the relationship between the imbalance in Hcy metabolism and pathogenesis of diseases, such as cardiovascular diseases, neurological and psychiatric disorders, chronic kidney disease, bone tissue damages, gastrointestinal disorders, cancer, and congenital defects.

Fruit peel polyphenols demonstrate substantial anti-tumour effects in the model of breast cancer.

PURPOSE: Fruit and vegetable intake is inversely correlated with cancer; thus, it is proposed that an extract of phytochemicals as present in whole fruits, vegetables, or grains may have anti-carcinogenic properties. Thus, the anti-tumour effects of fruit peel polyphenols (Flavin7) in the chemoprevention of N-methyl-N-nitrosourea-induced mammary carcinogenesis in female rats were evaluated. METHODS: Lyophilized substance of Flavin7 (F7) was administered at two concentrations of 0.3 and 3 % through diet. The experiment was terminated 14 weeks after carcinogen administration, and mammary tumours were removed and prepared for histopathological and immunohistochemical analysis. In addition, using an in vitro cytotoxicity assay, apoptosis and proliferation after F7 treatment in human breast adenocarcinoma (MCF-7) cells were performed. RESULTS: High-dose F7 suppressed tumour frequency by 58 % (P < 0.001), tumour incidence by 24 % (P < 0.05), and lengthened latency by 8 days (P > 0.05) in comparison with the control rats, whereas lower dose of F7 was less effective. Histopathological analysis of tumours showed significant decrease in the ratio of high-/low-grade carcinomas after high-dose F7 treatment. Immunohistochemical analysis of rat carcinoma cells in vivo found a significant increase in caspase-3 expression and significant decrease in Bcl-2, Ki67, and VEGFR-2 expression in the high-dose group. Both doses demonstrated significant positive effects on plasma lipid metabolism in rats. F7 significantly decreased survival of MCF-7 cells in vitro in MTT assay by dose- and time-dependent manner compared to control. F7 prevented cell cycle progression by significant enrichment in G1 cell populations. Incubation with F7 showed significant increase in the percentage of annexin V-/PI-positive MCF-7 cells and DNA fragmentation. CONCLUSIONS: Our results reveal a substantial tumour-suppressive effect of F7 in the breast cancer model. We propose that the effects of phytochemicals present in this fruit extract are responsible for observed potent anti-cancer activities.

Association of p53 and p21 polymorphisms with prostate cancer.

Cell cycle deregulation is common in human cancer. Alterations of the tumor-suppressor gene p53 and its downstream effector p21 have been indicated in the development of numerous human malignancies. Therefore, we hypothesize that the p53 codon 72 polymorphism, either on its own or in combination with p21 (C98A and C70T) polymorphisms, modifies the risk of prostate cancer within the Slovak population, and no previous studies have investigated these gene-gene interactions in the pathogenesis of prostate cancer in the Slovak population. Polymerase chain reaction-restriction fragment length polymorphism was used to determine the p53 and p21 genotypes in subjects comprising 300 prostate cancer patients and 446 healthy individuals. These 3 polymorphisms individually did not correlate with the prostate cancer risk. Conversely, the interaction between the p53 and p21 polymorphisms significantly decreased the risk of prostate cancer, with the odds ratio (OR) being 0.49 [95% confidence interval (CI), 0.27-0.86; P<0.05] for subjects carrying the p53 codon 72 arginine (Arg)/proline (Pro)+Pro/Pro and p21 C98A CA genotypes compared to the combined reference genotypes p53 codon 72 Arg/Arg and p21 C98A CC. Neither the p53 genotypes nor the p21 genotypes showed statistically significant differences in Gleason score or serum prostate-specific antigen levels (P>0.05). A decreased risk of prostate cancer association with the p21 C98A CA genotype (OR=0.58; 95% CI, 0.36-0.93; P<0.05) in non-smokers compared to the non-smokers with the p21 C98A CC genotype was observed. Smokers carrying the p53 codon 72 Pro/Pro genotype were not at any significant risk of prostate cancer (OR=2.97; 95% CI, 0.51-17.15) compared to the non-smokers with the Arg/Arg genotype. Taken together, to the best of our knowledge this is the first study to show that a combination of the variant genotypes of p53 codon 72 and p21 C98A may modify the prostate cancer risk within the Slovak population.

Vacuole dynamics in the salivary glands of Drosophila melanogaster during prepupal development.

A central function of the Drosophila salivary glands (SGs), historically known for their polytene chromosomes, is to produce and then release during pupariation the secretory glue used to affix a newly formed puparium to a substrate. This essential event in the life history of Drosophila is regulated by the steroid hormone ecdysone in the late-larval period. Ecdysone triggers a cascade of sequential gene activation that leads to glue secretion and initiates the developmentally-regulated programmed cell death (PCD) of the larval salivary glands, which culminates 16 h after puparium formation (APF). We demonstrate here that, even after the larval salivary glands have completed what is perceived to be one of their major biological functions--glue secretion during pupariation--they remain dynamic and physiologically active up until the execution phase of PCD. We have used specific metabolic inhibitors and genetic tools, including mutations or transgenes for shi, Rab5, Rab11, vha55, vha68-2, vha36-1, syx1A, syx4, and Vps35 to characterize the dramatic series of cellular changes occurring in the SG cells between pupariation and 7-8 h APF. Early in the prepupal period, they are remarkably active in endocytosis, forming acidic vacuoles. Midway through the prepupal period, there is abundant late endosomal trafficking and vacuole growth, which is followed later by vacuole neutralization and disappearance via membrane consolidation. This work provides new insights into the function of Drosophila SGs during the early- to mid-prepupal period.

Most frequent molecular and immunohistochemical markers present in selected types of brain tumors.

Tumors of brain tissue and meninges create a heterogeneous group with various biological behavior, therapy management and differing prognosis. Some of these do not require treatment, some can be cured by surgery and some are rapidly fatal despite treatment. Despite huge progress in tumor research, innovations in diagnostic tools and therapy, prognosis remains, in case of malignant tumor types, very serious. There has been an increased understanding of molecular abnormalities occurring in primary brain tumors. Genome-wide analyses of tumors have improved the knowledge in tumor biology. The aim of the research is to explain the oncogenesis features thus leading to the use of new therapeutic modalities in order to prolong survival rate of patients and at the same time providing satisfactory life quality. This article offers a short review of the basic genetic alterations present with some histological types of brain tumors.

Cytoskeletal proteins regulate chromatin access of BR-C transcription factor and Rpd3-Sin3A histone deacetylase complex in Drosophila salivary glands.

At the onset of Drosophila metamorphosis the steroid hormone ecdysone induces a process leading to a rapid degeneration of the larval salivary glands (SGs). Ecdysone acts through the ecdysone receptor heterodimer, which activates primary response genes. In particular these genes include the Broad-Complex (BR-C) gene encoding a set of BTB/POZ-transcription factors, among which the Z1 isoform is critical for SG cell death. The timing of SG disappearance depends upon of p127 (l(2)gl) , a cytoskeletal tumor suppressor that interacts with nonmuscle myosin II heavy chain (nmMHC) encoded by the zipper (zip) gene. Reduced l(2)gl expression delays SG histolysis whereas over-expression accelerates this process without affecting larval and pupal development. However, the mechanism by which l(2)gl controls SG histolysis remains yet unknown. Here we analyze the regulation controlled by p127 (l(2)gl) and nmMHC in the cytoplasm on the association of BR-C Z1 with chromatin and remodeling factors, such as Rpd3, Sin3A, and Smrter. In wild-type SGs these factors bind to chromatin but in l(2)gl SGs they accumulate in the cytoplasm and the cortical nuclear zone (CNZ). Similar chromatin exclusion occurs in SGs of developmentally delayed zip (E(br)) /+ larvae or can be achieved by high levels of nmMHC synthesis. The present data show that p127 (l(2)gl) and nmMHC regulate the access of BR-C Z1, Rpd3, Sin3A, and Smrter to chromatin. As the interaction between p127 (l(2)gl) and nmMHC occurs in the cytoplasm, we propose that these nuclear factors are processed by p127 (l(2)gl) and then released from p127 (l(2)gl) by nmMHC to allow their binding to chromatin. This process may constitute a novel mechanism of gene regulation, which in the absence of p127 (l(2)gl) , or excessive amounts of nmMHC, could lead to a fixed configuration in the pattern of gene expression that prevents further progression of SG differentiation, and programmed cell death (PCD). Such a transcriptional block could play a critical role in the neoplastic transformation of l(2)gl tissues. 

Formulation and numerical simulations of a continuum model of avascular tumor growth.

In this paper we present a continuum mathematical model for a multicellular spheroid that mimics the micro-environment within avascular tumor growth. The model consists of a coupled system of non-linear convection-diffusion-reaction equations. This system is solved using a previously developed conservative Galerkin characteristics method. In the model considered, there are three cell types: the proliferative cells, the quiescent non-dividing cells which stay in the G(0) phase of the cell cycle and the necrotic cells. The model includes viable cell diffusion, diffusion of cellular material and the removal of necrotic cells. We assume that the nutrients diffuse passively and are consumed by the proliferative and quiescent tumor cells depending on the availability of resources (oxygen, glucose, etc.). The numerical simulations are performed using different sets of parameters, including biologically realistic ones, to explore the effects of each of these model parameters on reaching the steady state. The present results, taken together with those reported earlier, indicate that the removal of necrotic cells and the diffusion of cellular material have significant effects on the steady state, reflecting growth saturation, the number of viable cells, and the spheroid size.

Temporal regulation of Drosophila salivary gland degeneration by the Broad-Complex transcription factors.

The destruction of obsolete larval tissues at the onset of insect metamorphosis is a complex process triggered by the steroid hormone ecdysone. Among the genes required for the implementation of salivary gland (SG) degeneration the reduced bristles on palpus (rbp) gene of the Broad-Complex (BR-C) locus plays a critical role. This gene encodes the BR-C Z1 transcription factor and its expression is directly regulated by ecdysone through the ecdysone receptor (EcR/Usp). The BR-C locus encodes four major protein isoforms, including BR-C Z1, Z2, Z3, and Z4. With the exceptions of mutations in BR-C Z1 all mutations affecting the other BR-C isoforms produce pupal lethality. To gain insight into the function of the different BR-C isoforms on the process of SG degeneration, we used transgenes expressing each of the four major BR-C isoform proteins. This study revealed that, depending upon the period of expression relative to the major peak of ecdysone production, BR-C Z1, Z2, and Z4 first inhibited and then stimulated the process of SG degeneration. In contrast, BR-C Z3 exerted all time points an inhibition on SG degeneration.