Identification of nucleolus-localized PTEN and its function in regulating ribosome biogenesis

The tumor suppressor PTEN is a lipid phosphatase that is found mutated in different types of human cancers. PTEN suppresses cell proliferation by inhibiting the PI3K-Akt signaling pathway at the cell membrane. However, PTEN is also demonstrated to localize in the cell nucleus where it exhibits tumor suppressive activity via a different, unknown mechanism. In this study we report that PTEN also localizes to the nucleolus and that nucleolar PTEN plays an important role in regulating nucleolar homeostasis and maintaining nucleolar morphology. Overexpression of nuclear PTEN in PTEN null cells inhibits Akt phosphorylation and reduces cell size. Knockdown of PTEN in PTEN positive cells leads to nucleolar morphologic changes and an increase in the proportion of cells with a greater number of nucleoli. In addition, knockdown of PTEN in PTEN positive cells increased ribosome biogenesis. These findings expand current understanding of function and relevance of nuclear localized PTEN and provide a foundation for the development of novel therapies targeting PTEN.     

Quercetin Potentiates the Antitumor Activity of Rituximab in Diffuse Large B-Cell Lymphoma by Inhibiting STAT3 Pathway

STAT3 pathway plays an important role in the growth of diffuse large B-cell lymphoma (DLBCL) cells. Here we investigated the antitumor activity of Quercetin, a flavonoid compound, in combination with rituximab in DLBCL cell lines in vitro. We found that Quercetin synergistically enhanced rituximab-induced growth inhibition and apoptosis in DLBCL cell lines. Moreover, we found Quercetin exerted inhibitory activity against STAT3 pathway and downregulated the expression of survival genes. These results suggest that combining the Quercetin with rituximab may present an attractive and potentially effective way for the treatment of DLBCL.     

Expression of GroES TB antigen in tobacco and potato

As the world races towards a plant-based bioeconomy, plants known to be ideal and economical bioreactors are being harnessed for the production of recombinant proteins. The major immunodominant 10 kDa GroES TB antigen (Chaperonin 10) gene from Mycobacterium tuberculosis was selected for expression in plants as a putative tuberculosis (TB) subunit vaccine candidate. Two crops, tobacco and potato, were engineered by stable plant transformation for expression of the 10 kDa GroES TB antigen using non-viral binary vectors. The integration of the GroES TB gene into the genomes of tobacco and potato was confirmed by PCR and Southern blotting. The expression of the GroES TB antigen in tobacco was 0.04–1.2 % of the total soluble protein (TSP). However, the expression of the same TB antigen in the Indian potato cv. Kufri bahar was comparatively low (0.033 % of TSP). The recombinant GroES plant derived protein was characterised and confirmed by MALDI-TOF–TOF and ELISA. This is the first report of the expression of the 10 kDa chaperonin in tobacco and potato.     

Progression of O6-methylguanine-DNA methyltransferase and temozolomide resistance in cancer research

Temozolomide (TMZ) is an alkylating agent that is widely used in chemotherapy for cancer. A key mechanism of resistance to TMZ is the overexpression of O⁶-methylguanine-DNA methyltransferase (MGMT). MGMT specifically repairs the DNA O⁶-methylation damage induced by TMZ and irreversibly inactivates TMZ. Regulation of MGMT expression and research regarding the mechanism of TMZ resistance will help rationalize the clinical use of TMZ. In this review, we provide an overview of recent advances in the field, with particular emphasis on MGMT structure, function, expression regulation, and the association between MGMT and resistance to TMZ.     

A Systems Biology Approach to Study the Biology Characteristics of Esophageal Squamous Cell Carcinoma by Integrating microRNA and Messenger RNA Expression Profiling

Esophageal squamous cell carcinoma (ESCC) is one of the most malignant tumors. The aim of this study was to investigate the biology characteristics of ESCC by analyzing microRNA and mRNA expression profile. We used BRB-array tools to analyze the deregulated microRNA and mRNA between esophageal squamous cell carcinomas and paired normal adjacent tissues. We used miRTrail and protein–protein interaction methods to explore the related pathways and networks of deregulated microRNA and mRNA. By combining the results of pathways and networks, we found that the deregulated microRNA and their deregulated target mRNA are enriched in the following pathways: DNA replication, cell cycle, ECM-receptor interaction, focal adhesion, mismatch repair, and pathways in cancer. The results showed that many deregulated microRNAs and mRNAs may play a vital role in the pathogenesis of ESCC, and the systems biology approach is very helpful to explore molecular mechanism of ESCC.     

Circulating MicroRNA Biomarkers for Glioma and Predicting Response to Therapy

The need for glioma biomarkers with improved sensitivity and specificity has sparked research into short non-coding RNA known as microRNA (miRNA). Altered miRNA biogenesis and expression in glioma plays a vital role in important signaling pathways associated with a range of tumor characteristics including gliomagenesis, invasion, and malignancy. This review will discuss current research into the role of miRNA in glioma and altered miRNA expression in biofluids as candidate biomarkers with a particular focus on glioblastoma, the most malignant form of glioma. The isolation and characterization of miRNA using cellular and molecular biology techniques from the circulation of glioma patients could potentially be used for improved diagnosis, prognosis, and treatment decisions. We aim to highlight the links between research into miRNA function, their use as biomarkers, and how these biomarkers can be used to predict response to therapy. Furthermore, increased understanding of miRNA in glioma biology through biomarker research has led to the development of miRNA therapeutics which could restore normal miRNA expression and function and improve the prognosis of glioma patients. A panel of important miRNA biomarkers for glioma in various biofluids discovered to date has been summarized here. There is still a need, however, to standardize techniques for biomarker characterization to bring us closer to clinically relevant miRNA-based diagnostic and therapeutic signatures. A clinically validated biomarker panel has potential to improve time to diagnosis, predicting response to treatment and ultimately the prognosis of glioma patients.     

Expression of microRNA-1, microRNA-133a and Hand2 protein in cultured embryonic rat cardiomyocytes

In this study, we investigated the expression of the pathway, SRF–microRNA-1/microRNA-133a–Hand2, in the Wistar rat embryonic ventricular cardiomyocytes under conventional monolayer culture. The morphological observation of the cultured cardiomyocytes and the mRNA expression levels of three vital constituent proteins, MLC-2v, N-cadherin, and connexin43, demonstrated the immaturity of these cultured cells, which was featured by less myofibril density, immature sarcomeric structure, and significantly lower mRNA expression of the three constituent proteins than those in neonatal ventricular samples. More importantly, results in this study suggest that the change of SRF–microRNA-1/microRNA-133a–Hand2 pathway results into the attenuation of the Hand2 repression in cultured cardiomyocytes. These outcomes are valuable to understand the cellular state as embryonic cardiomyocytes to be in vitro model and might be useful for the assessment of engineered cardiac tissue and cardiac differentiation of stem cells.     

Primary alveolar macrophages exposed to diesel particulate matter increase RAGE expression and activate RAGE signaling

Receptors for advanced glycation end-products (RAGE) are members of the immunoglobulin superfamily of cell-surface receptors implicated in mechanisms of pulmonary inflammation. In the current study, we test the hypothesis that RAGE mediates inflammation in primary alveolar macrophages (AMs) exposed to diesel particulate matter (DPM). Quantitative RT-PCR and immunoblotting revealed that RAGE was up-regulated in Raw264.7 cells, an immortalized murine macrophage cell line and primary AMs exposed to DPM for 2 h. Because DPM increased RAGE expression, we exposed Raw264.7 cells and primary AMs isolated from RAGE null and wild-type (WT) mice to DPM prior to the assessment of inflammatory signaling intermediates. DPM led to the activation of Rat sarcoma GTPase (Ras), p38 MAPK and NF-κB in WT AMs and, when compared to WT AMs, these intermediates were diminished in DPM-exposed AMs isolated from RAGE null mice. Furthermore, cytokines implicated in inflammation, including IL-4, IL-12, IL-13 and TNFα, were all significantly decreased in DPM-exposed RAGE null AMs compared to similarly exposed WT AMs. These results demonstrate that diesel-induced inflammatory responses by primary AMs are mediated, at least in part, via RAGE signaling mechanisms. Further work may show that RAGE signaling in both alveolar epithelial cells and resident macrophages is a potential target in the treatment of inflammatory lung diseases exacerbated by environmental pollution.     

Insights into resistome and stress responses genes in Bubalus bubalis rumen through metagenomic analysis

Buffalo rumen microbiota experience variety of diets and represents a huge reservoir of mobilome, resistome and stress responses. However, knowledge of metagenomic responses to such conditions is still rudimentary. We analyzed the metagenomes of buffalo rumen in the liquid and solid phase of the rumen biomaterial from river buffalo adapted to varying proportion of concentrate to green or dry roughages, using high-throughput sequencing to know the occurrence of antibiotics resistance genes, genetic exchange between bacterial population and environmental reservoirs. A total of 3914.94 MB data were generated from all three treatments group. The data were analysed with Metagenome rapid annotation system tools. At phyla level, Bacteroidetes were dominant in all the treatments followed by Firmicutes. Genes coding for functional responses to stress (oxidative stress and heat shock proteins) and resistome genes (resistance to antibiotics and toxic compounds, phages, transposable elements and pathogenicity islands) were prevalent in similar proportion in liquid and solid fraction of rumen metagenomes. The fluoroquinolone resistance, MDR efflux pumps and Methicillin resistance genes were broadly distributed across 11, 9, and 14 bacterial classes, respectively. Bacteria responsible for phages replication and prophages and phage packaging and rlt-like streptococcal phage genes were mostly assigned to phyla Bacteroides, Firmicutes and proteaobacteria. Also, more reads matching the sigma B genes were identified in the buffalo rumen. This study underscores the presence of diverse mechanisms of adaptation to different diet, antibiotics and other stresses in buffalo rumen, reflecting the proportional representation of major bacterial groups.     

GABA Pharmacology: The Search for Analgesics

Decades of research have been devoted to defining the role of GABAergic transmission in nociceptive processing. Much of this work was performed using rigid, orthosteric GABA analogs created by Povl Krogsgaard-Larsen and his associates. A relationship between GABA and pain is suggested by the anatomical distribution of GABA receptors and the ability of some GABA agonists to alter nociceptive responsiveness. Outlined in this report are data supporting this proposition, with particular emphasis on the anatomical localization and function of GABA-containing neurons and the molecular and pharmacological properties of GABA_A and GABA_B receptor subtypes. Reference is made to changes in overall GABAergic tone, GABA receptor expression and activity as a function of the duration and intensity of a painful stimulus or exposure to GABAergic agents. Evidence is presented that the plasticity of this receptor system may be responsible for the variability in the antinociceptive effectiveness of compounds that influence GABA transmission. These findings demonstrate that at least some types of persistent pain are associated with a regionally selective decline in GABAergic tone, highlighting the need for agents that enhance GABA activity in the affected regions without compromising GABA function over the long-term. As subtype selective positive allosteric modulators may accomplish these goals, such compounds might represent a new class of analgesic drugs.     

Implementation of Transportation Distance for Analyzing FLIM and FRET Experiments

Analysis of fluorescence lifetime imaging microscopy (FLIM) and Förster resonance energy transfer (FRET) experiments in living cells is usually based on mean lifetimes computations. However, these mean lifetimes can induce misinterpretations. We propose in this work the implementation of the transportation distance for FLIM and FRET experiments in vivo. This non-fitting indicator, which is easy to compute, reflects the similarity between two distributions and can be used for pixels clustering to improve the estimation of the FRET parameters. We study the robustness and the discriminating power of this transportation distance, both theoretically and numerically. In addition, a comparison study with the largely used mean lifetime differences is performed. We finally demonstrate practically the benefits of the transportation distance over the usual mean lifetime differences for both FLIM and FRET experiments in living cells.     

Transarterial chemoembolization combined with sorafenib for unresectable hepatocellular carcinoma: a systematic review and meta-analysis

Sorafenib in combination with Transarterial chemoembolization (TACE) is increasingly used in patients with unresectable hepatocellular carcinoma (HCC), but the current evidence is still controversial. The aim of this systematic review was to evaluate the effectiveness and safety of TACE plus sorafenib versus TACE alone for unresectable HCC. We searched PubMed, EMBASE and the Cochrane Library for clinical trials comparing TACE plus sorafenib with TACE alone for unresectable HCC. The study outcomes included overall survival (OS), time to progression (TTP), objective response and adverse events (AEs). Six studies including 1,181 patients were included. Meta-analysis of all studies suggested that the combination therapy group had significant longer OS than TACE group [hazard ratio (HR) = 0.64, 95 % confidence interval (CI) = 0.43–0.97], but the pooled HR of randomized controlled trials (RCTs) failed to achieve statistical significance. For TTP, meta-analysis in both RCTs subgroup and retrospective studies subgroup suggested that combination therapy was superior to TACE group. The combination therapy was also associated with better response to treatment (risk ratio = 1.45, 95 % CI = 1.04–2.02) when both RCTs and retrospective studies were pooled. However, the sorafenib associated AEs were more frequent in the combination therapy group. In conclusion, the combination of TACE and sorafenib is likely to improve OS, TTP and response to treatment when compared with TACE monotherapy. The combination group is also associated with more sorafenib-related AEs.     

Pyramiding Bt genes for increasing resistance of cotton to two major lepidopteran pests: Spodoptera litura and Heliothis armigera

To more effectively control two major cotton insects (cotton bollworm and Spodoptera litura) and improve the efficacy of the pest resistance management, novel transgenic plants expressing Bacillus thuringiensis Cry9C gene were generated, and gene stacking strategy was incorporated. Initially, a binary plasmid vector harboring Cry9C gene was introduced into an elite cotton cultivar Simian-3 by Agrobacterium-mediated transformation. Integration and expression of the Cry9C genes in three transgenic lines were confirmed by PCR and RT-PCR. Among these transgenic lines, T0 generation of line 16 (L-16) with normal phenotypes were selected by ELISA assays for its highest expression level of Cry9C. In T1 population of L-16, the expression level of Cry9C ranged from 29 to 45 μg/g fresh leaf. The following insect bioassays demonstrated that transgenic S3-35S::Cry9C cotton plants exhibited moderate toxicity to Heliothis armigera but strong toxicity to S. litura compared with the transgenic plants expressing Cry 1Ac gene. For incorporation of gene staking strategy, Cry9C gene and Cry 2A or Cry 1Ac were pyramided, respectively by sexual crossing. The expression of Cry9C protein in all F1 progenies had a similar level as the parent plants indicating the high heritability of Bt genes in transgenic progenies. Progenies from both Cry9C × Cry 2A and Cry9C × Cry 1Ac exhibited higher resistance to S. litura compared with their parents. Together our data demonstrated that our newly generated transgenic plants represent a reservoir of novel insect-resistant materials in cotton breeding, and the successful incorporation of gene pyramiding technology can provide a new solution of developing multiple resistance management strategies.