Pravastatin induces cell cycle arrest and decreased production of VEGF and bFGF in multiple myeloma cell line.

Multiple myeloma (MM) is a B cell bone marrow neoplasia characterized by inflammation with an intense secretion of growth factors that promote tumor growth, cell survival, migration and invasion. The aim of this study was to evaluate the effects of pravastatin, a drug used to reduce cholesterol, in a MM cell line.Cell cycle and viability were determinate by Trypan Blue and Propidium Iodide. IL6, VEGF, bFGF and TGFß were quantified by ELISA and qRT-PCR including here de HMG CoA reductase. It was observed reduction of cell viability, increase of cells in G0/G1 phase of the cell cycle and reducing the factors VEGF and bFGF without influence on 3-Methyl-Glutaryl Coenzyme A reductase expression.The results demonstrated that pravastatin induces cell cycle arrest in G0/G1 and decreased production of growth factors in Multiple Myeloma cell line.

Pravastatin induces cell cycle arrest and decreased production of VEGF and bFGF in multiple myeloma cell line / Pravastatina induz parada no ciclo celular e diminuição na produção de VEGF e bFGF em linhagem de Mieloma Multiplo

Abstract Multiple myeloma (MM) is a B cell bone marrow neoplasia characterized by inflammation with an intense secretion of growth factors that promote tumor growth, cell survival, migration and invasion. The aim of this study was to evaluate the effects of pravastatin, a drug used to reduce cholesterol, in a MM cell line.Cell cycle and viability were determinate by Trypan Blue and Propidium Iodide. IL6, VEGF, bFGF and TGFβ were quantified by ELISA and qRT-PCR including here de HMG CoA reductase. It was observed reduction of cell viability, increase of cells in G0/G1 phase of the cell cycle and reducing the factors VEGF and bFGF without influence on 3-Methyl-Glutaryl Coenzyme A reductase expression.The results demonstrated that pravastatin induces cell cycle arrest in G0/G1 and decreased production of growth factors in Multiple Myeloma cell line.

Resumo O Mieloma Múltiplo é uma neoplasia de linfócitos B da medula óssea, caracterizada por inflamação com uma intensa secreção de fatores de crescimento que promovem o aumento do volume do tumor, sobrevivência celular, migração e invasão. O objetivo deste estudo foi avaliar os efeitos da pravastatina, uma droga usada para reduzir o colesterol, em um linhagem de MM. O ciclo celular e viabilidade foram determinadas por Trypan Blue e iodeto de propídio. IL6, VEGF, bFGF e TGF foram quantificadas por ELISA e qRT-PCR, incluindo aqui de HMG CoA redutase. Observou-se a redução da viabilidade das células, aumento de células na fase G0/G1 do ciclo celular e redução no VEGF e bFGF, sem influência na expressão da enzima 3-Metil-Glutaril Coenzima A redutase. Os resultados demonstraram que a pravastatina induz parada no ciclo celular em G0/G1 e diminuição da produção de fatores de crescimento em várias linhas de células de Mieloma.

Chromosomal organization of repetitive DNA in Sorubim lima (Teleostei; Pimelodidae).

Interspaced repetitive DNA elements and segmental duplications have been extensively analyzed in fishes through physical chromosome mapping methods, providing a better comprehension of the structure and organization of the genome of this group. In order to contribute to this scenario, a sequence integration study of different classes of repetitive DNA with high resolution physical chromosome mapping was performed in Sorubim lima. Fluorescence in situ hybridization (FISH) and fiber-FISH with probes for 18S and 5S rRNA genes, TTAGGGn sequence and non-LTR retrotransposon family members Rex1, Rex3 and Rex6 showed that non-LTR elements may be dispersed in the chromosome set with relative concentration in heterochromatic regions, as shown by Rex1, or may even intercalate in 45S rDNA and the telomeric sequence, as found for Rex3 and Rex6. These results reinforce the presence of preferential regions of retroelement accumulation and contribute to a better understanding of the genomic organization of some repetitive DNA classes in fishes.

Swim training restores glucagon-like peptide-1 insulinotropic action in pancreatic islets from monosodium glutamate-obese rats.

AIMS: Glucagon-like peptide-1 (GLP-1) is an important modulator of insulin secretion by endocrine pancreas. In the present study, we investigated the effect of swim training on GLP-1 insulinotropic action in pancreatic islets from monosodium glutamate (MSG)-obese rats. METHODS: Obesity was induced by neonatal MSG administration. MSG-obese and control (CON) exercised rats swam for 30 min (3 times week(-1) ) for 10 weeks. Pancreatic islets were isolated by colagenase technique and incubated with low (5.6 mM) or high (16.7 mM) glucose concentrations in the presence or absence of GLP-1 (10 nM). In addition, GLP-1 gene expression in ileum was quantified in fasting and glucose conditions. RESULTS: Exercise reduced obesity and hyperinsulinemia in MSG-obese rats. Swim training also inhibited glucose-induced insulin secretion in islets from both groups. Islets from MSG-obese rats maintained GLP-1 insulinotropic response in low glucose concentration. In contrast, in the presence of high glucose concentration, GLP-1 insulinotropic action was absent in islets from MSG-obese rats. Islets from MSG-exercised rats showed reduced GLP-1 insulinotropic action in the presence of low glucose. However, in high glucose concentration swim training restored GLP-1 insulinotropic response in islets from MSG-obese rats. In all groups, glucose intake increased GLP-1 immunoreactivity and gene expression in ileum cells in relation to fasting conditions. Swim training reduced these parameters only in ileum cells from CON-exercised rats. Neither MSG treatment nor exercise affected GLP-1 expression in the ileum. CONCLUSIONS: Exercise avoids insulin hypersecretion restoring GLP-1's insulinotropic action in pancreatic islets from MSG-obese rats.

Cytogenetic analysis of Lagria villosa (Coleoptera, Tenebrionidae): emphasis on the mechanism of association of the Xy(p) sex chromosomes.

The Xy(p) sex determination mechanism is the system most frequent and ancestral to Coleoptera. Moreover, the presence of argyrophilous material associated with the sex bivalent is described as being responsible for the maintenance and association of these chromosomes. There are no karyotype data available regarding the genus Lagria and no consensus in the literature regarding the argyrophilous material present in the lumen of sex bivalent. Therefore, the aim of this work was to investigate the mechanism of sex chromosome bivalent association in Lagria villosa by analyzing the argyrophilous nature of the material present in the Xy(p) lumen. It was also intended to characterize L. villosa cytogenetically. The analysis of meiotic cells showed 2n = 18 = 16+Xy(p) for males and 2n = 18 = 16+XX in females and the meiotic formula was 2n = 8(II)+Xy(p). The C-banding showed blocks of pericentromeric heterochromatin in all chromosomes except in the y(p) chromosome. In these regions, the use of fluorochromes revealed the presence of heterochromatin containing GC rich DNA sequences. The study of synaptonemal complex showed a gradual increase in the electron-density of the axial elements of the sex chromosomes and their association with strongly electron-dense material. The pepsin pretreatment revealed that the material impregnated by silver is protein.

Population structure and genetic diversity analysis in Gynaikothrips uzeli (Zimerman, 1909) (Thysanoptera: Phlaeothripidae) by RAPD markers.

Thrips are small insects (0.5-3.0 mm) with distinct habits and life histories characterized by haplodiploid sex determination. In general, low levels of genetic diversity have been reported in haplodiploid insects, although most reports focus on the order Hymenoptera. Therefore, we used RAPD markers to evaluate the structure and both inter- and intra-population genetic variability of Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae). Six populations, three from Paraná state, southern Brazil, and three from Bahia, northeastern Brazil, were studied. Similarly to other haplodiploid insects, the genetic diversity of G. uzeli was reduced. This result is putatively related to the haplodiploid sex determination system, which yields little genetic variation, and to ecological traits of the studied species, such as the low dispersal abilities and life mode in leaf galls. All individuals were homogeneously clustered in their respective collection sites, forming two main groups in which populations from similar environments were more closely related. The analyzed populations were highly structured, and the genetic variation was higher among than within populations.

Satellite DNA and chromosomes in Neotropical fishes: methods, applications and perspectives.

Constitutive heterochromatin represents a substantial portion of the eukaryote genome, and it is mainly composed of tandemly repeated DNA sequences, such as satellite DNAs, which are also enriched by other dispersed repeated elements, including transposons. Studies on the organization, structure, composition and in situ localization of satellite DNAs have led to consistent advances in the understanding of the genome evolution of species, with a particular focus on heterochromatic domains, the diversification of heteromorphic sex chromosomes and the origin and maintenance of B chromosomes. Satellite DNAs can be chromosome specific or species specific, or they can characterize different species from a genus, family or even representatives of a given order. In some cases, the presence of these repeated elements in members of a single clade has enabled inferences of a phylogenetic nature. Genomic DNA restriction, using specific enzymes, is the most frequently used method for isolating satellite DNAs. Recent methods such as C(0)t-1 DNA and chromosome microdissection, however, have proven to be efficient alternatives for the study of this class of DNA. Neotropical ichthyofauna is extremely rich and diverse enabling multiple approaches with regard to the differentiation and evolution of the genome. Genome components of some species and genera have been isolated, mapped and correlated with possible functions and structures of the chromosomes. The 5SHindIII-DNA satellite DNA, which is specific to Hoplias malabaricus of the Erythrinidae family, has an exclusively centromeric location. The As51 satellite DNA, which is closely correlated with the genome diversification of some species from the genus Astyanax, has also been used to infer relationships between species. In the Prochilodontidae family, two repetitive DNA sequences were mapped on the chromosomes, and the SATH 1 satellite DNA is associated with the origin of heterochromatic B chromosomes in Prochilodus lineatus. Among species of the genus Characidium and the Parodontidae family, amplifications of satellite DNAs have demonstrated that these sequences are related to the differentiation of heteromorphic sex chromosomes. The possible elimination of satellite DNA units could explain the genome compaction that occurs among some species of Neotropical Tetraodontiformes. These topics are discussed in the present review, showing the importance of satellite DNA analysis in the differentiation and karyotype evolution of Actinopterygii.