TGFβ mediated LINC00273 upregulation sponges mir200a-3p and promotes invasion and metastasis by activating ZEB1

Transforming growth factor β (TGFβ) is a prominent cytokine that promotes tumor progression by activating epithelial-to-mesenchymal transition (EMT). This study indicated that TGFβ exerted metastasis by inducing zinc finger E-box binding homeobox 1 (ZEB1) and a long noncoding RNA, LINC00273, expressions in A549 cells. Knocking down LINC00273 diminished TGFβ induced ZEB1 expression as well as metastasis. Mechanistically, LINC00273 acted as a molecular sponge of microRNA (miR)-200a-3p which liberate ZEB1 to perform its prometastatic functions. LINC00273 knockdown and miR200a3p mimic transfection of A549 cells were used for validating the link between TGFβ and LINC00273 induced metastasis. RNA pulldown and luciferase assay were performed to establish mir200a-3p-LINC00273 interaction. High expressions of LINC00273, TGFβ, and ZEB1 with concurrent low miR200a-3p expression had been verified in vivo and in patient samples. Overall, LINC00273 promoted TGFβ-induced lung cancer EMT through miR-200a-3p/ZEB1 feedback loop and may serve as a potential target for therapeutic intervention in lung cancer metastasis.     

Effect of cholesterol in various liposomal compositions on the in vivo toxicity, therapeutic efficacy, and tissue distribution of amphotericin B

The effect of cholesterol in neutral, positively and negatively charged liposomes on the toxicity, therapeutic efficacy, and alteration in the tissue distribution pattern of amphotericin B (Amp-B) in normal and infected mice was studied. It was observed that inclusion of cholesterol (CHOL) into egg phosphatidylcholine (EPC) liposomes increased the LD50 of Amp-B from 5.3 to 8.5 mg/kg body weight. In the case of phosphatidylserine (PS) liposomes as well as stearylamine (SA) liposomes, cholesterol incorporation had no effect in altering the toxicity of the drug. The survival pattern of animals with all types of liposomal formulation of Amp-B was similar. The tissue distribution studies indicated that in the case of normal mice, cholesterol inclusion in all types of liposomes increased the organ concentration of the drug in various tissues. In infected animals, the concentration of Amp-B in all organs was increased when cholesterol was included in EPC and EPC/PS liposomes. The organ concentration of Amp-B in lung and liver after 1 h of injection was the same in the case of EPC/SA and EPC/SA/CHOL liposomes. Considering the observations on toxicity, therapeutic efficacy, and tissue distribution, it was suggested that cholesterol had a beneficial therapeutic effect on neutral EPC liposomes.     

Antixenosis,tolerance and genetic analysis of some rice landraces for resistance to Nilaparvata lugens (Stål.)

Twenty-six rice landraces from West Bengal, India were evaluated for antixenosis and tolerance against brown planthopper (BPH) biotype 4 at the Bidhan Chandra Krishi Viswavidyalaya (BCKV), West Bengal. High levels of resistance were observed in six landraces, namely Badshabhog, Gamra, Haldichuri, Janglijata, Kalabhat and Khara. These phenotypically resistant rice landraces including Ptb33 exhibited lowest feeding rate, fecundity, nymphal and adult preference, survival, plant dry weight loss per mg of BPH dry weight produced (PDWL), and higher functional plant loss index (FPLI), more days to wilt and unhatched eggs compared with the susceptible check Swarna. All the landraces were classified into four major clusters at 10 unit distance by the scale of similarity during genetic diversity analysis through 21 gene-linked SSR markers of BPH resistance. Some phenotypically resistant landraces were gathered under the major cluster I indicating their analogous genetic history, while some were grouped with susceptible landraces exhibiting their genetic variation. The resistant landraces can be used as potential donors in the breeding programme for the development of rice varieties with resistance to BPH.     

Application of sensitive enzymeimmunoassays for oxytocin and prolactin determination in blood plasma of yaks (Poephagus grunniens L.) during milk let down and cyclicity

Highly sensitive and specific enzymeimmunoassays for oxytocin and prolactin determination in yak plasma using the biotin-streptavidin amplification system and the second antibody coating technique were validated and applied for determining their profiles during milk let down and cyclicity in yaks. Oxytocin EIA was conducted taking duplicate 200 microl of unknown plasma samples and standards per well. The lowest detection limit was 0.2 pg/well, which corresponded to 1pg/ml plasma. Prolactin EIA was carried out directly in 50 microl of yak plasma. The sensitivity of EIA procedure was 5 pg/well prolactin, which corresponded to 0.1 ng/ml plasma. Mean plasma prolactin concentrations although high at estrus were not statistically different (P > 0.05) from the hormone concentrations on other days. Mean plasma prolactin concentrations during non-breeding season were significantly higher (P < 0.001) than that recorded in breeding season. Oxytocin and prolactin profiles were also obtained in two yaks before, during and after milking. A sharp release of oxytocin and prolactin shortly after udder stimulation was observed. High levels of oxytocin and prolactin were maintained during milking, falling sharply thereafter.     

Frequent Long-Range Epigenetic Silencing of Protocadherin Gene Clusters on Chromosome 5q31 in Wilms' Tumor

Wilms'' tumour (WT) is a pediatric tumor of the kidney that arises via failure of the fetal developmental program. The absence of identifiable mutations in the majority of WTs suggests the frequent involvement of epigenetic aberrations in WT. We therefore conducted a genome-wide analysis of promoter hypermethylation in WTs and identified hypermethylation at chromosome 5q31 spanning 800 kilobases (kb) and more than 50 genes. The methylated genes all belong to α-, β-, and γ-protocadherin (PCDH) gene clusters (Human Genome Organization nomenclature PCDHA@, PCDHB@, and PCDHG@, respectively). This demonstrates that long-range epigenetic silencing (LRES) occurs in developmental tumors as well as in adult tumors. Bisulfite polymerase chain reaction analysis showed that PCDH hypermethylation is a frequent event found in all Wilms'' tumor subtypes. Hypermethylation is concordant with reduced PCDH expression in tumors. WT precursor lesions showed no PCDH hypermethylation, suggesting that de novo PCDH hypermethylation occurs during malignant progression. Discrete boundaries of the PCDH domain are delimited by abrupt changes in histone modifications; unmethylated genes flanking the LRES are associated with permissive marks which are absent from methylated genes within the domain. Silenced genes are marked with non-permissive histone 3 lysine 9 dimethylation. Expression analysis of embryonic murine kidney and differentiating rat metanephric mesenchymal cells demonstrates that Pcdh expression is developmentally regulated and that Pcdhg@ genes are expressed in blastemal cells. Importantly, we show that PCDHs negatively regulate canonical Wnt signalling, as short-interfering RNA–induced reduction of PCDHG@ encoded proteins leads to elevated β-catenin protein, increased β-catenin/T-cell factor (TCF) reporter activity, and induction of Wnt target genes. Conversely, over-expression of PCDHs suppresses β-catenin/TCF-reporter activity and also inhibits colony formation and growth of cancer cells in soft agar. Thus PCDHs are candidate tumor suppressors that modulate regulatory pathways critical in development and disease, such as canonical Wnt signaling.     

Life-cycle differentiation in Trypanosoma brucei: molecules and mutants

Differentiation between bloodstream and tsetse midgut procyclic forms during the life cycle of the African trypanosome is an attractive model for the analysis of stage-regulated events. In particular, this transformation occurs synchronously, there are well-defined markers for stage-regulated processes and cell lines with specific defects in differentiation have been identified. This combination of tools, combined with the developing Trypanosoma brucei genome database is allowing its underlying controls to be investigated at the molecular and cytological levels. This paper examines some recent discoveries that illuminate some of the key events during trypanosome life-cycle progression.     

Transport of bacteria in porous media: II. A model for convective Transport and growth

A model is presented for the coupled processes of bacterial growth and convective transport of bacteria has been modeled using a fractional flow approach. The various mechanisms of bacteria retention can be incorporated into the model through selection of an appropriate shape of the fractional flow curve. Permeability reduction due to pore plugging by bacteria was simulated using the effective medium theory. In porous media, the rates of transport and growth of bacteria, the generation of metabolic products, and the consumption of nutrients are strongly coupled processes. Consequently, the set of governing conservation equations form a set of coupled, nonlinear partial differential equations that were solved numerically. Reasonably good agreement between the model and experimental data has been obtained indicating that the physical processes incorporated in the model are adequate. The model has been used to predict the in situ transport and growth of bacteria, nutrient consumption, and metabolite production. It can be particularly useful in simulating laboratory experiments and in scaling microbial-enhanced oil recovery or bioremediation processes to the field. (c) 1994 John Wiley & Sons, Inc.