Specific aspects of researching the oncogenesis and metastatasing potential of laringeal squamous cell carcinoma

Malignant tumor metastasizing, comprised of several consecutive steps beginning with local cancer cell invasion, is a key factor which compromises the prognosis of cancer patients and is responsible for 90% of the lethal outcome. 2/3 of our diagnosed patients show with locally advanced process and/or metastatic disease (stage III/IV).Researching key molecular and cellular mechanisms tied to development and metastasizing of laryngeal squamous cell carcinoma is of clinical importance to developing and using molecular target therapy.Based on popular literature studies the emphasize was put on the following genes: TP53, CDKN2A – accentuating on exons 1,2,3, and PIK3CA – exons 9, 20, as primarily connected to the higher mutation potential of laryngeal squamous cell carcinoma.Researching the genetic similarity between carcinoma and metastasis could potentially help understanding the genotype and mutation potential of Head and Neck squamous cell carcinomas. The practical potential use of this knowledge is the developing of predictive markers and better therapeutic algorithms for diagnosed patients. ---------------------------------------------------------------------- Туморното метастазиране, включващо няколко последователни стъпки, започвайки от инвазия на раковите клетки в околните тъкани, е ключовият фактор, който компрометира прогнозата на раково болните пациенти и отговаря за 90% от смъртността. 2/3 от диагностицираните пациенти са с локално авансирал процес и/ или метастатична болест (стадий III или IV).Проучването на молекулярни и клетъчни механизми, водещи до формирането и метастазирането на плоскоклетъчния карцином от ларингеален произход, би било от клинична полза за разработването на молекулярна таргетна терапия.На базата на обширен литературен обзор акцентът е поставен върху следните гени – TP53, CDKN2A – exons 1,2,3 and PIK3CA – exons 9, 20, като потенциални отговорници за повишаване метастатичния потенциал на плосколетъчния карцином от ларингеален произход.Изследването на генетично сродство между карцином и метастаза би имало теоретичен принос към опознаването на генотипа и мутационния статус на плоскоклетъчните карциноми на глава и шия, чийто практически потенциал се изразява като прогностична стойност за преживяемостта на онкоболните и подобряване на терапевтичния алгоритъм при диагностицирани пациенти

Changes in gene expression of EGFR and LAD1 in patients with metastatic squamous cell laryngeal carcinoma

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INFLUENCE OF PIRACETAM ON ERYTHROPOIESIS IN RATS

The effects of piracetam (2 x 200 mg/kg b. w.) injected intraperitoneally for three days on erythropoiesis and some functional characteristics of erythrocytes were studied in Wistar rats. A significant increase of reticulocytes in relative (by 122,03 %, p < 0,01) and in absolute counts (by 109,29 %, p < 0,01), an increase of 59Fе incorporation in newly-formed erythrocytes (by 13,80 %) and a significant rise of erythroblasts as followed: total counts (by 59,39 %, p < 0,01), proerythroblasts (by 52,87 %, p < 0,05), and orthochromatic erythroblasts (by 54,25 %, p< 0,01) were observed in the piracetamtreated rats. It was accepted that piracetam stimulated erythroid proliferation and differentiation. Erythroid deformability enhanced by 14,69 % (p < 0,01) but spontaneous haemolysis of erythrocytes reduced by 16,95 % (p < 0,025). Thus it could be suggested that piracetam, along with its stimulatory effect on erythropoiesis, improves some of the most important functional characteristics of erythrocytes such as deformability and oxidative resistance

Structure of the complete, membrane-assembled COPII coat reveals a complex interaction network

COPII mediates Endoplasmic Reticulum to Golgi trafficking of thousands of cargoes. Five essential proteins assemble into a two-layer architecture, with the inner layer thought to regulate coat assembly and cargo recruitment, and the outer coat forming cages assumed to scaffold membrane curvature. Here we visualise the complete, membrane-assembled COPII coat by cryo-electron tomography and subtomogram averaging, revealing the full network of interactions within and between coat layers. We demonstrate the physiological importance of these interactions using genetic and biochemical approaches. Mutagenesis reveals that the inner coat alone can provide membrane remodelling function, with organisational input from the outer coat. These functional roles for the inner and outer coats significantly move away from the current paradigm, which posits membrane curvature derives primarily from the outer coat. We suggest these interactions collectively contribute to coat organisation and membrane curvature, providing a structural framework to understand regulatory mechanisms of COPII trafficking and secretion

Structure of the complete, membrane-assembled COPII coat reveals a complex interaction network

COPII mediates Endoplasmic Reticulum to Golgi trafficking of thousands of cargoes. Five essential proteins assemble into a two-layer architecture, with the inner layer thought to regulate coat assembly and cargo recruitment, and the outer coat forming cages assumed to scaffold membrane curvature. Here we visualise the complete, membrane-assembled COPII coat by cryo-electron tomography and subtomogram averaging, revealing the full network of interactions within and between coat layers. We demonstrate the physiological importance of these interactions using genetic and biochemical approaches. Mutagenesis reveals that the inner coat alone can provide membrane remodelling function, with organisational input from the outer coat. These functional roles for the inner and outer coats significantly move away from the current paradigm, which posits membrane curvature derives primarily from the outer coat. We suggest these interactions collectively contribute to coat organisation and membrane curvature, providing a structural framework to understand regulatory mechanisms of COPII trafficking and secretion

Characterizing benthic macroinvertebrate and algal biological condition gradient models for California wadeable Streams, USA

The Biological Condition Gradient (BCG) is a conceptual model that describes changes in aquatic communities under increasing levels of anthropogenic stress. The BCG helps decision-makers connect narrative water quality goals (e.g., maintenance of natural structure and function) to quantitative measures of ecological condition by linking index thresholds based on statistical distributions (e.g., percentiles of reference distributions) to expert descriptions of changes in biological condition along disturbance gradients. As a result, the BCG may be more meaningful to managers and the public than indices alone. To develop a BCG model, biological response to stress is divided into 6 levels of condition, represented as changes in biological structure (abundance and diversity of pollution sensitive versus tolerant taxa) and function. We developed benthic macroinvertebrate (BMI) and algal BCG models for California perennial wadeable streams to support interpretation of percentiles of reference-based thresholds for bioassessment indices (i.e., the California Stream Condition Index [CSCI] for BMI and the Algal Stream Condition Index [ASCI] for diatoms and soft-bodied algae). Two panels (one of BMI ecologists and the other of algal ecologists) each calibrated a general BCG model to California wadeable streams by first assigning taxa to specific tolerance and sensitivity attributes, and then independently assigning test samples (264 BMI and 248 algae samples) to BCG Levels 1–6. Consensus on the assignments was developed within each assemblage panel using a modified Delphi method. Panels then developed detailed narratives of changes in BMI and algal taxa that correspond to the 6 BCG levels. Consensus among experts was high, with 81% and 82% expert agreement within 0.5 units of assigned BCG level for BMIs and algae, respectively. According to both BCG models, the 10th percentiles index scores at reference sites corresponded to a BCG Level 3, suggesting that this type of threshold would protect against moderate changes in structure and function while allowing loss of some sensitive taxa. The BCG provides a framework to interpret changes in aquatic biological condition along a gradient of stress. The resulting relationship between index scores and BCG levels and narratives can help decision-makers select thresholds and communicate how these values protect aquatic life use goals

Escherichia coli Frameshift Mutation Rate Depends on the Chromosomal Context but Not on the GATC Content Near the Mutation Site

Different studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent manner, being almost nonfunctional when GATC sequences are located at 1 kb or more from the mutation site. Interestingly, we found that in E. coli genomic DNA the mismatch repair system can efficiently function even if the nearest GATC sequence is located more than 2 kb away from the mutation site. The results presented in this work show that even though frameshift mutations can be efficiently generated and/or repaired anywhere in the genome, these processes can be modulated by the chromosomal context that surrounds the mutation site

DNA methylation and methyl-CpG binding proteins: developmental requirements and function

DNA methylation is a major epigenetic modification in the genomes of higher eukaryotes. In vertebrates, DNA methylation occurs predominantly on the CpG dinucleotide, and approximately 60% to 90% of these dinucleotides are modified. Distinct DNA methylation patterns, which can vary between different tissues and developmental stages, exist on specific loci. Sites of DNA methylation are occupied by various proteins, including methyl-CpG binding domain (MBD) proteins which recruit the enzymatic machinery to establish silent chromatin. Mutations in the MBD family member MeCP2 are the cause of Rett syndrome, a severe neurodevelopmental disorder, whereas other MBDs are known to bind sites of hypermethylation in human cancer cell lines. Here, we review the advances in our understanding of the function of DNA methylation, DNA methyltransferases, and methyl-CpG binding proteins in vertebrate embryonic development. MBDs function in transcriptional repression and long-range interactions in chromatin and also appear to play a role in genomic stability, neural signaling, and transcriptional activation. DNA methylation makes an essential and versatile epigenetic contribution to genome integrity and function