Deregulation of Beclin 1 in patients with tobacco-related oral squamous cell carcinoma

Autophagy is a physiologically regulated and evolutionary conserved process that plays a critical role in degradation of cytoplasmic proteins and other macromolecules within the lysosomes. Beclin-1, the mammalian orthologue of yeast Atg6, is an important mediator of autophagy that has been studied in many human cancers. However, the expression of Beclin-1 has not yet been investigated in oral cancer. We for the first time investigated the expression of Beclin-1 in serum and tissues and correlated it with the clinic-pathological features of oral cancer patients. m-RNA expression of Beclin-1 was evaluated in tumor and normal areas of surgical specimens from 10 oral cancer patients by real-time PCR. Approximately, 8-fold lower expression (p<0.001) of Beclin-1 mRNA was observed in tumor tissue as compared to the normal tissue. Serum levels of Beclin-1 were evaluated by SPR and ELISA. No significant difference was observed in serum Beclin-1 levels in patients as compared to healthy subjects, similarly no correlation was found between serum levels and clinic-pathological parameters such as stage, lymph node involvement and tumor size. Our results demonstrate that down-regulation of Beclin-1 may play an important role in the development and progression of oral cancer possibly by dysregulation of autophagy in tumor cells.     

Promoter-independent regulation of vimentin expression in mammary epithelial cells by val(12)ras and TGFbeta

The 1,029 series of mammary epithelial cell lines (D6, GP+E, r3 and r3T) are progressively more transformed: the latter two by val(12)ras. These cell lines respond to TGFbeta by undergoing early events of epithelial-mesenchymal transition (EMT), including morphological changes and redistribution of E-cadherin. Tumors formed by r3T cells in the choroid of the eye express vimentin, a late marker of EMT, possibly in response to TGFbeta. In vitro, vimentin expression is induced in all the cell lines by TGFbeta treatment, whereas cytokeratin expression is only slightly affected. Surprisingly, ras transformation results in a 10-fold suppression of vimentin expression. Neither suppression of vimentin by ras transformation nor induction by TGFbeta is mediated by the vimentin promoter in r3T cells. In transient transfection assays, several human vimentin promoter constructs are more active in the low-expressing r3T cell line than in the vimentin-expressing mesenchymal cell line NIH3T3. In the r3T cells, there is no effect of TGFbeta treatment for 9 days on the activity of either promoter. Azacytidine treatment does not affect vimentin expression in either NIH3T3 or r3T, suggesting that promoter methylation is not the mechanism of suppression by ras. Finally, the half-life of the vimentin mRNA is similar in both the r3T cells and NIH3T3 cells. We conclude that the suppression of vimentin expression by ras, and the relief of this suppression by TGFbeta, occurs in a promoter-independent fashion, possibly through sequences in the first or second intron.     

Functional relevance and health benefits of soymilk fermented by lactic acid bacteria

The growing interest of consumers towards nutritionally enriched, and health promoting foods, provoke interest in the eventual development of fermented functional foods. Soymilk is a growing trend that can serve as a low-cost non-dairy alternative with improved functional and nutritional properties. Soymilk acts as a good nutrition media for the growth and proliferation of the micro-organism as well as for their bioactivities. The bioactive compounds produced by fermentation of soymilk with lactic acid bacteria (LAB) exhibit enhanced nutritional values, and several improved health benefits including antihypertensive, antioxidant, antidiabetic, anticancer and hypocholesterolaemic effects. The fermented soymilk is acquiring a significant position in the functional food industry due to its increased techno-functional qualities as well as ensuring the survivability of probiotic bacteria producing diverse metabolites. This review covers the important benefits conferred by the consumption of soymilk fermented by LAB producing bioactive compounds. It provides a holistic approach to obtain existing knowledge on the biofunctional attributes of fermented soymilk, with a focus on the functionality of soymilk fermented by LAB.     

Scrape cell-block technique for fine needle aspiration cytology smears

An inconclusive diagnosis on fine needle aspiration cytology (FNAC) may be due to poor spreading and presence of thick tissue fragments despite aspiration of adequate material. Repeat aspiration may not be possible especially when aspirates of deep seated organs have been obtained by image guided techniques. We have resorted to a 'scrape cell-block' (SCB) technique in such cases. In this technique the cellular material on the slides which had already been fixed and stained, was carefully removed by scraping following destaining and then processed as a cell block. SCB interpretation was then compared with the smear diagnosis and histological diagnosis, wherever available. A total of 27 cases were studied. In 12 cases SCB slides added information to the FNAC smears. In 14 cases SCB did not offer any additional information. SCB was inconclusive in one case. Final histological correlation was available in eight cases and the SCB diagnosis was confirmed in six cases, whereas in two cases SCB failed to identify the tumour. Immunocytochemistry (ICC) was done in one case. SCB is a useful technique to make the best use of the available material when reaspiration is difficult.     

Development and Characterization of Enteric-Coated Immediate-Release Pellets of Aceclofenac by Extrusion/Spheronization Technique Using κ-Carrageenan as a Pelletizing Agent

In the present study, an attempt was made to prepare immediate-release enteric-coated pellets of aceclofenac, a poorly soluble nonsteroidal anti-inflammatory drug that has a gastrointestinal intolerance as its serious side effect. Formulation of enteric-coated pellets with improved solubility of aceclofenac could address both of these problems. To achieve these goals, pellets were prepared by extrusion–spheronization method using pelletizing agents that can contribute to the faster disintegration and thereby improve the solubility of the drug. Different disintegrants like β-cyclodextrin, kollidon CL, Ac-Di-Sol, and sodium starch glycolate were tried in order to further improve disintegration time. The pellets were characterized for drug content, particle size distribution, flow properties, infrared spectroscopy, surface morphology, disintegration rate, and dissolution profile. The formulations, which showed best disintegration and dissolution profiles, were coated with Eudragit L100-55, an enteric-coated polymer which does not dissolve at gastric pH but dissolves at intestinal pH, releasing the drug immediately in the dissolution medium. The optimized enteric-coated formulation containing 20% κ-carrageenan, lactose, and sodium starch glycolate as a disintegrant did inhibit the release of the drug for 2 h in 0.1 N HCl, whereas 87% of the drug was released within 45 min. The improvement was substantial when it was compared with solubility of pure drug under the same conditions. Thus, dissolution profiles suggested that combination of κ-carrageenan and sodium starch glycolate resulted into fast-disintegrating, immediate-release pellets, overcoming the bioavailability problem of the poorly soluble drug, aceclofenac, and enteric coating of these pellets avoids the exposure of aceclofenac to ulcer-prone areas of the gastrointestinal tract.     

The fragile X syndrome repeats form RNA hairpins that do not activate the interferon-inducible protein kinase, PKR, but are cut by Dicer

We show here that under physiologically reasonable conditions, CGG repeats in RNA readily form hairpins. In contrast to its DNA counterpart that forms a complex mixture of hairpins and tetraplexes, r(CGG)₂₂ forms a single stable hairpin with no evidence for any other folded structure even at low pH. RNA with the sequence (CGG)₉AGG (CGG)₁₂AGG(CGG)₉₇, found in a fragile X syndrome pre-mutation allele, forms a number of different hairpins. The most prominent hairpin forms in the 3′ part of the repeat and involves the 97 uninterrupted CGG repeats. In contrast to the CUG-RNA hairpins formed by myotonic dystrophy type 1 repeats, we found no evidence that CGG-RNA hairpins activate PKR, the interferon-inducible protein kinase that is activated by a wide range of double-stranded RNAs. However, we do show that the CGG-RNA is digested, albeit inefficiently, by the human Dicer enzyme, a step central to the RNA interference effect on gene expression. These data provide clues to the basis of the toxic effect of CGG-RNA that is thought to occur in fragile X pre-mutation carriers. In addition, RNA hairpins may also account for the stalling of the 40S ribosomal subunit that is thought to contribute to the translation deficit in fragile X pre-mutation and full mutation alleles.     

The structure and early evolution of recently arisen gene duplicates in the Caenorhabditis elegans genome

The significance of gene duplication in provisioning raw materials for the evolution of genomic diversity is widely recognized, but the early evolutionary dynamics of duplicate genes remain obscure. To elucidate the structural characteristics of newly arisen gene duplicates at infancy and their subsequent evolutionary properties, we analyzed gene pairs with < or =10% divergence at synonymous sites within the genome of Caenorhabditis elegans. Structural heterogeneity between duplicate copies is present very early in their evolutionary history and is maintained over longer evolutionary timescales, suggesting that duplications across gene boundaries in conjunction with shuffling events have at least as much potential to contribute to long-term evolution as do fully redundant (complete) duplicates. The median duplication span of 1.4 kb falls short of the average gene length in C. elegans (2.5 kb), suggesting that partial gene duplications are frequent. Most gene duplicates reside close to the parent copy at inception, often as tandem inverted loci, and appear to disperse in the genome as they age, as a result of reduced survivorship of duplicates located in proximity to the ancestral copy. We propose that illegitimate recombination events leading to inverted duplications play a disproportionately large role in gene duplication within this genome in comparison with other mechanisms.