Long non‐coding RNAs in melanoma

Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non‐coding RNAs remain unclear. Long non‐coding RNAs (lncRNAs) are a group of endogenous non‐protein‐coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY‐IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment.     

Protective effect of bixin on carbon tetrachloride-induced hepatotoxicity in rats

Background

The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl₄) in rats.

Results

The animals were divided into four groups with six rats in each group. CCl₄ (0.125 mL kg^-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg^-1 body wt.) was given by gavage 7 days before the CCl₄ injection. Bixin prevented the liver damage caused by CCl₄, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl₄ by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.

Conclusion

Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl₄ is related to the antioxidant activity of the compound.     

Thermostability of DNA and its connection with the glassing process

Using differential scanning calorimetry, the thermal denaturation of calf thymus DNA with different content of water (from 12 to 92%) was investigated. Dependences of melting temperature and enthalpy on the biopolymer hydration degree were established. Within the range of water concentrations from 92 to 50% the values of thermodynamic parameters of denaturation were obtained being in good agreement with the published data. Besides, a calorimetric manifestation of renaturation process at different cooling conditions after denaturation was studied. Special attention was paid to thermal properties of denatured and native DNA in the samples containing only the bound water. The temperature dependence of heat capacity in the denatured samples, which have completely lost their renaturation ability due to the proper thermal treatment, demonstrated a characteristic jump of thermal capacity. The value of this jump has been determined to be equal to 1.0 cal/g. degree C, related to dry weight, and almost not dependent on humidity. Temperature position of the jump (Tg) depends on the content of water which serves as a plasticizer. It is shown that the observed anomaly demonstrates all the properties characteristic of vitrification process in synthetic polymers and proteins. General similarity of thermal properties of the samples of native DNA, containing only the bound water, with those of denatured DNA also indicates a transition from the glassy into the rabber-like state. A possibility of existence of both native and denatured DNA in the glassy state at room temperature for the samples with low humidity (about 25%) has been demonstrated experimentally. It can be suggested that the formation of glassy state at dehydration of native DNA ensures its thermostability and the ability of restoration of its functional properties at a subsequent dehydration.     

Phosphorylation and biosynthesis of high molecular weight proteins of tumor nuclear matrix

INTRODUCTIONAsearlyasin1948wehavefr8CtionatedisolatednucleifromnormalandtumorcellsbyextractionwithiMNaCIanddilutealkali[1].Thenuclearresiduewasthenstudiedmorethoroughly[2,3].Lateron,sillillarproteinousnuclearresidueswereisolatedbyotherworkers[46]andasstud…     

Algorithms and software for support of gene identification experiments

MOTIVATION: Gene annotation is the final goal of gene prediction algorithms. However, these algorithms frequently make mistakes and therefore the use of gene predictions for sequence annotation is hardly possible. As a result, biologists are forced to conduct time-consuming gene identification experiments by designing appropriate PCR primers to test cDNA libraries or applying RT-PCR, exon trapping/amplification, or other techniques. This process frequently amounts to 'guessing' PCR primers on top of unreliable gene predictions and frequently leads to wasting of experimental efforts. RESULTS: The present paper proposes a simple and reliable algorithm for experimental gene identification which bypasses the unreliable gene prediction step. Studies of the performance of the algorithm on a sample of human genes indicate that an experimental protocol based on the algorithm's predictions achieves an accurate gene identification with relatively few PCR primers. Predictions of PCR primers may be used for exon amplification in preliminary mutation analysis during an attempt to identify a gene responsible for a disease. We propose a simple approach to find a short region from a genomic sequence that with high probability overlaps with some exon of the gene. The algorithm is enhanced to find one or more segments that are probably contained in the translated region of the gene and can be used as PCR primers to select appropriate clones in cDNA libraries by selective amplification. The algorithm is further extended to locate a set of PCR primers that uniformly cover all translated regions and can be used for RT-PCR and further sequencing of (unknown) mRNA.      

A new species of Mesocoelium (Digenea: Mesocoeliidae) found in Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia

Mesocoelium lanfrediaesp. nov. (Digenea: Mesocoeliidae) inhabits the small intestine of Rhinella marina (Amphibia: Bufonidae) and is described here, with illustrations provided by light, scanning electron microscopy and molecular approachs. M. lanfrediae sp. nov. presents the typical characteristics of the genus, but is morphometrically and morphologically different from the species described previously. The main diagnostic characteristics of M. lanfrediae sp. nov. are (i) seven pairs of regularly-distributed spherical papillae on the oral sucker, (ii) ventral sucker outlined by four pairs of papillae distributed in a uniform pattern and interspersed with numerous spines, which are larger at the posterior margin and (iii) small, rounded tegumentary papillae around the opening of the oral sucker, which are morphologically different from those of the oral sucker itself, some of which are randomly disposed in the ventrolateral tegumentary region of the anterior third of the body. Addionally, based on SSU rDNA, a phylogenetic analysis including Brachycoeliidae and Mesocoeliidae taxa available on GenBank established the close relationship between M. lanfrediae sp. nov. and Mesocoelium sp.     

Calorimetric study of the formation and melting of thermotropic gel in solutions of globular proteins

Scanning calorimetry has been used for studying lysozyme water solutions of different buffer molarity (mu = 0.5 divided by 1.0) and concentrations (c = 1.5 divided by 25%) at pH 2.0. It is shown that an additional high temperature maximum (HTM) can be observed on the heating curves for lysozyme solutions during irreversible denaturation. Calorimetric and rheological studies under identical heating conditions have shown that aggregation of protein during denaturation leads to the formation of the thermotropic gel. Further increase of temperature brings up the melting of this gel which results in the appearance of HTM on thermograms. Slow cooling of lysozyme gel melt leads to its reconstruction which results in the appearance of exothermic maximum on the corresponding thermograms.