Exon skipping restores dystrophin expression, but fails to prevent disease progression in later stage dystrophic dko mice

Antisense therapy with both chemistries of phosphorodiamidate morpholino oligomers (PMOs) and 2'-O-methyl phosphorothioate has demonstrated the capability to induce dystrophin expression in Duchenne muscular dystrophy (DMD) patients in phase II-III clinical trials with benefit in muscle functions. However, potential of the therapy for DMD at different stages of the disease progression is not understood. In this study, we examined the effect of peptide-conjugated PMO (PPMO)-mediated exon skipping on disease progression of utrophin-dystrophin-deficient mice (dko) of four age groups (21-29, 30-39, 40-49 and 50+ days), representing diseases from early stage to advanced stage with severe kyphosis. Biweekly intravenous (i.v.) administration of the PPMO restored the dystrophin expression in nearly 100% skeletal muscle fibers in all age groups. This was associated with the restoration of dystrophin-associated proteins including functional glycosylated dystroglycan and neuronal nitric synthase. However, therapeutic outcomes clearly depended on severity of the disease at the time the treatment started. The PPMO treatment alleviated the disease pathology and significantly prolonged the life span of the mice receiving treatment at younger age with mild phenotype. However, restoration of high levels of dystrophin expression failed to prevent disease progression to the mice receiving treatment when disease was already at advanced stage. The results could be critical for design of clinical trials with antisense therapy to DMD.

Meta-analysis of the differentially expressed breast cancer-related microRNA expression profiles

MicroRNAs (miRNAs), as non-coding RNA molecules, play an important role in regulating gene expression in cancer development. Meta-analysis was used to screen overlapping differentially expressed miRNAs (DEmiRNAs) in three studies. The miRanda was used to identify target genes related to overlapping DEmiRNAs. These Gene Ontology (GO) and Encyclopaedia of Genes and Genomes (KEGG) database were applied to further predict the function of these target genes. As a result, we obtained seven overlapping miRNAs and six significantly over-represented GO terms closely related to breast cancer. After KEGG pathways analysis, a total of seven key target genes were involved in the Wnt signalling pathway (p = 0.0002). Our findings from this study suggest that the altered levels of miRNAs might have great potential to serve as novel, non-invasive biomarkers for early detection of breast cancer.

Establishment of reference panel for human platelet antigen genotyping

BACKGROUND AND OBJECTIVES

Human platelet antigens (HPAs) are platelet-specific alloantigens associated with polymorphisms of platelet surface glycoproteins (GPs), and they can induce alloantibodies when individuals lacking a particular polymorphism are exposed to them via pregnancy or transfusion. Immune responses to HPAs are involved in the pathogenesis of several clinical syndromes. HPA genotyping is therefore important for clinical diagnosis and laboratory research. This study aims to establish a reference panel for HPA genotyping.

MATERIALS AND METHODS

Genomic DNA extracted from human blood was used as the template for amplifying HPA (1a-5a and 15a) gene fragments using specific primers. The amplified products were cloned into pGM-T vectors, which were transformed into competent TOP10 cells. After clone screening and amplification, the plasmids were extracted and sequenced. Next, the gene fragments HPA-1b-5b and 15b were obtained by site-directed mutagenesis using the corresponding HPA-1a-5a and 15a plasmids as template DNA.

RESULTS

We successfully constructed reference plasmids for HPA genotyping with HPA-1a-5a, 15a, HPA-1b-5b and 15b. The DNA sequences were consistent with those published in GenBank.

CONCLUSION

Obtaining reference DNA for low-frequency HPAs is very difficult, and the successful construction of reference plasmids for the six HPA systems may solve this problem. Establishment of this panel has laid the foundation for future research on HPA genotyping.

Partial least squares based gene expression analysis in estrogen receptor positive and negative breast tumors

BACKGROUND

Breast cancer is categorized into two broad groups: estrogen receptor positive (ER+) and ER negative (ER-) groups. Previous study proposed that under trastuzumab-based neoadjuvant chemotherapy, tumor initiating cell (TIC) featured ER- tumors response better than ER+ tumors. Exploration of the molecular difference of these two groups may help developing new therapeutic strategies, especially for ER- patients.

MATERIALS AND METHODS

With gene expression profile from the Gene Expression Omnibus (GEO) database, we performed partial least squares (PLS) based analysis, which is more sensitive than common variance/regression analysis.

RESULTS

We acquired 512 differentially expressed genes. Four pathways were found to be enriched with differentially expressed genes, involving immune system, metabolism and genetic information processing process. Network analysis identified five hub genes with degrees higher than 10, including APP, ESR1, SMAD3, HDAC2, and PRKAA1.

CONCLUSIONS

Our findings provide new understanding for the molecular difference between TIC featured ER- and ER+ breast tumors with the hope offer supports for therapeutic studies.

Gene expression profiling of gastric cancer

OBJECTIVES

Gastric cancer is the second leading cause of cancer-related death worldwide. Gene expression profile facilitates the identification of molecular mechanism of gastric cancer. Previous studies mainly focused on differentially expressed genes (DEGs) without considering MicroRNAs (miRNAs) and transcription factors (TFs). Here we aim to elaborate the mechanism of gastric cancer on transcription level with microarray data from the gene expression omnibus (GEO) database.

MATERIALS AND METHODS

We firstly identified DEGs between gastric cancer and normal tissues. Then the DEGs were mapped in KEGG pathway and gene ontology database to conduct functional categories enrichment analysis. MiRNAs and TFs enriched with target DEGs were also identified.

RESULTS

A total of 977 DEGs were selected, including 492 down regulated and 485 overexpressed genes in gastric cancer tissue. Functional analysis revealed cell cycle, metabolism and ECM related biological processes as the significant items. Eight miRNAs and 20 TFs enriched with target DEGs were detected, including one novel miRNA (miR-557) and four novel TFs (SPI1, NFIC, SPIB and THAP1), which have not been reported to be related to gastric cancer before. All of them might contribute to the pathogenesis since they are all related to other cancers and their target genes have been reported to play important roles in gastric tumorigenesis.

CONCLUSIONS

Our results may facilitate further therapeutic studies of gastric cancer.

Pluronic-PEI copolymers enhance exon-skipping of 2'-O-methyl phosphorothioate oligonucleotide in cell culture and dystrophic mdx mice

A series of small-size polyethylenimine (PEI)-conjugated pluronic polycarbamates (PCMs) have been investigated for the ability to modulate the delivery of 2'-O-methyl phosphorothioate RNA (2'-OMePS) in vitro and in dystrophic mdx mice. The PCMs retain strong binding capacity to negatively charged oligomer as demonstrated by agarose gel retardation assay, with the formation of condensed polymer/oligomer complexes at a wide-range weight ratio from 1:1 to 20:1. The condensed polymer/oligomer complexes form 100-300 nm nanoparticles. Exon-skipping effect of 2'-OMePS was dramatically enhanced with the use of the most effective PCMs in comparison with 2'-OMePS alone in both cell culture and in vivo, respectively. More importantly, the effective PCMs, especially those composed of moderate size (2k-5kDa) and intermediate hydrophilic-lipophilic balance (7-23) of pluronics, enhanced exon-skipping of 2'-OMePS with low toxicity as compared with Lipofectamine-2000 in vitro or PEI 25k in vivo. The variability of individual PCM for delivery of antisense oligomer and plasmid DNA indicate the complexity of interaction between polymer and their cargos. Our data demonstrate the potential of PCMs to mediate delivery of modified antisense oligonucleotides to the muscle for treating muscular dystrophy or other appropriate myodegenerative diseases.

Friction measurement on free standing plates using atomic force microscopy

A method is introduced to measure friction on small, free standing objects, specifically microfabricated silicon plates, based on atomic force microscopy (AFM). An AFM tip is brought into contact with the plate resting on a substrate. The substrate is displaced laterally and, provided the AFM tip does not slide over the plate, the twisting of the AFM cantilever is used to measure the friction of the underlying plate-substrate interface. The method can measure nano-Newton to micro-Newton forces (both friction and applied load) and provides a means to measure friction of macroscopic structures at low load.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

Electroplated CoPt magnets for actuation of stiff cantilevers

A cantilever has been microfabricated for use in non-contact Atomic Force Microscopy (AFM) using a very thick magnetic film to actuate the cantilever motion. The thick magnetic block is deposited electrochemically over a defined area of the cantilever. This cantilever is particularly suitable for driving stiff AFM cantilevers in a liquid environment. Clean mechanical resonances are easily observed. Examples are given of a hard (CoPt) magnet of dimension 29 × 21 × 6 μm(3) electroplated on Silicon cantilevers of stiffness ~22 N/m, giving a static displacement of ~0.2 nm in an applied field of 10(-3) T.

Regulatory T cell expression of CLA or α(4)β(7) and skin or gut acute GVHD outcomes

Regulatory T cells (Tregs) are a suppressive subset of CD4(+) T lymphocytes implicated in the prevention of acute GVHD (aGVHD) after allo-SCT (ASCT). To determine whether increased frequency of Tregs with a skin-homing (cutaneous lymphocyte Ag, CLA(+)) or a gut-homing (α(4)β(7)(+)) phenotype is associated with reduced risk of skin or gut aGVHD, respectively, we quantified circulating CLA(+) or α(4)β(7)(+) on Tregs at the time of neutrophil engraftment in 43 patients undergoing ASCT. Increased CLA(+) Tregs at engraftment was associated with the prevention of skin aGVHD (2.6 vs 1.7%; P=0.038 (no skin aGVHD vs skin aGVHD)), and increased frequencies of CLA(+) and α(4)β(7)(+) Tregs were negatively correlated with severity of skin aGVHD (odds ratio (OR), 0.67; 95% confidence interval (CI), 0.46-0.98; P=0.041) or gut aGVHD (OR, 0.93; 95% CI, 0.88-0.99; P=0.031), respectively. This initial report suggests that Treg tissue-homing subsets help to regulate organ-specific risk and severity of aGVHD after human ASCT. These results need to be validated in a larger, multicenter cohort.

WAY-318068: a novel, potent and selective noradrenaline re-uptake inhibitor with activity in rodent models of pain and depression

BACKGROUND AND PURPOSE

Antidepressants, which raise the CNS concentrations of 5-HT and noradrenaline, are frequently used in the treatment of chronic pain; however, it is not known if increasing CNS noradrenaline levels alone is sufficient for efficacy, in part resulting from a lack of small molecules with sufficient selectivity.

EXPERIMENTAL APPROACH

In this report, we present the in vitro pharmacological and in vivo pharmacokinetic and pharmacological properties of the novel, orally available and CNS penetrant inhibitor of the noradrenaline transporter (NET), WAY-318068 (1-[(1S,2R)-1-(3,5-difluorophenyl)-2-hydroxy-3-(methylamino)propyl]-7-fluoro-3,3-dimethyl-1,3-dihydro-2H-indol-2-one).

KEY RESULTS

WAY-318068 is a potent and effective inhibitor of the NET with a K(i) of 8.7 nM in a binding assay, and an IC(50) of 6.8 nM in an assay of transporter function, without significant binding to the dopamine transporter. Furthermore, the compound has only weak activity at the 5-HT transporter, leading to a functional selectivity of greater than 2500-fold. It is orally bioavailable with substantial quantities of the compound found in the CNS after oral dosing. As measured by microdialysis in rats, the compound causes a robust and significant increase in cortical noradrenaline levels without affecting 5-HT. WAY-318068 was effective in models of acute, visceral, inflammatory, osteoarthritic, neuropathic, diabetic and bone cancer pain, as well as in traditional models of depression at doses that do not cause motor deficits.

CONCLUSIONS AND IMPLICATIONS

Collectively, the present results support the conclusion that selectively increasing CNS levels of noradrenaline is sufficient for efficacy in models of depression and pain.