Apoptotic and autophagic pathways with relevant small‐molecule compounds,in cancer stem cells

Accumulating evidence demonstrates existence of cancer stem cells (CSCs), which are suspected of contributing to cancer cell self‐renewal capacity and resistance to radiation and/or chemotherapy. Including evasion of apoptosis and autophagic cell death, CSCs have revealed abilities to resist cell death, making them appealing targets for cancer therapy. Recently, molecular mechanisms of apoptosis and of autophagy in CSCs have been gradually explored, comparing them in stem cells and in cancer cells; distinct expression of these systems in CSCs may elucidate how these cells exert their capacity of unlimited self‐renewal and hierarchical differentiation. Due to their proposed ability to drive tumour initiation and progression, CSCs may be considered to be potentially useful pharmacological targets. Further, multiple compounds have been verified as triggering apoptosis and/or autophagy, suppressing tumour growth, thus providing new strategies for cancer therapy. In this review, we summarized regulation of apoptosis and autophagy in CSCs to elucidate how key proteins participate in control of survival and death; in addition, currently well‐studied compounds that target CSC apoptosis and autophagy are selectively presented. With increasing attention to CSCs in cancer therapy, researchers are now trying to find responses to unsolved questions as unambiguous as possible, which may provide novel insight into future anti‐cancer regimes.     

Multi-environment mapping and meta-analysis of 100-seed weight in soybean

100-Seed weight (100-SW) of soybean is an important but complicated quantitative trait to yield. This study was focus on the quantitative trait loci (QTLs) of soybean 100-SW from 2006 to 2010, using recombination inbred lines population that was derived from a cross between Charleston and Dongnong 594. A total of 23 QTLs for 100-SW were detected in the linkage group C2, D1a, F, G and O. Nine QTLs were identified by composite interval mapping including one QTL with the minimum confidence interval (CI) of 1.3?cM, while 14 QTLs by multiple interval mapping. Furthermore, 94 reported QTLs of 100-SW were integrated with our QTL mapping results using BioMercator. As a result, 15 consensus QTLs and their corresponding markers were identified. The minimum CI was reduced to 1.52?cM by the combination of meta-analysis. These findings may merit fine-mapping of these QTL in soybean.     

Identification and characterization of SSRs from soybean (Glycine max) ESTs

Microsatellites, or simple sequence repeats (SSRs), are very useful molecular markers for a number of plant species. We used a new publicly available module (TROLL) to extract microsatellites from the public database of soybean expressed sequence tag (EST) sequences. A total of 12,833 sequences containing di- to penta-type SSRs were identified from 200,516 non-redundant soybean ESTs. On average, one SSR was found per 7.25?kb of EST sequences, with the tri-nucleotide motifs being the most abundant. Primer sequences flanking the SSR motifs were successfully designed for 9,638 soybean ESTs using the software primer3.0 and only 59 pairs of them were found in earlier studies. We synthesized 124 pairs of the primers to determine the polymorphism and heterozygosity among eight genotypes of soybean cultivars, which represented a wide range of the cultivated soybean cultivars. PCR amplification products with anticipated SSRs were obtained with 81 pairs of primers; 36 PCR products appeared to be homozygous and the remaining 45 PCR products appeared to be heterozygous and displayed polymorphism among the eight cultivars. We further analysed the EST sequences containing 45 polymorphic EST-SSR markers using the programs BLASTN and BLASTX. Sequence alignment showed that 29 ESTs have homologous sequences and 15 ESTs could be classified into a Uni-gene cluster with comparatively convincing protein products. Among these 15 ESTs belonging to a Uni-gene cluster, 9 SSRs were located in 3'-UTR, 4 SSRs were located in the intron region and 2 SSRs were located in the CDS region. None of these SSRs was located in the 5'-UTR. These novel SSRs identified in the ESTs of soybean provide useful information for gene mapping and cloning in future studies.     

Perylene ligand wrapping G-quadruplex DNA for label-free fluorescence potassium recognition

A perylene ligand, N,N-bis-(1-aminopropyl-3-propylimidazol salt)-3,4,9,10-perylene tetracarboxylic acid diimide ligand (PDI), which consisted of π-conjugated perylene moiety and hydrophilic side chains with positively charged imidazole rings, was used to wrap G-quadruplex for fluorescence turn-on K(+) recognition. Electrostatic attraction between PDI's positively charged imidazole rings and DNA's negatively charged phosphate backbones enabled PDI to accumulate on DNA. Upon trapping K(+), these G-rich DNA sequences transitioned to G-quadruplex. Subsequently, PDI ligands wrapped G-quadruplex, in which the flat aromatic core of PDI ligand interacted with G-quartet through π-π stacking and the side chains were positioned in grooves through electrostatic interactions. Consequently, the interaction mode change and conformational transition from PDI stacked G-sequence to PDI wrapped G-quadruplex led to PDI fluorescence enhancement, which was readily monitored as the detection signal. This strategy excluded the sequence tagging step and exhibited high selectivity and sensitivity towards K(+) ion with the linear detection range of 10-150nM. Besides, PDI ligands may hold diagnostic and therapeutic application potentials to human telomere and cancer cells.     

A novel porcine circovirus type 2a strain, 10JS-2, with eleven-nucleotide insertions in the origin of genome replication

Here, we report a novel porcine circovirus type 2a (PCV2a) strain with 11 nucleotides (nt) inserted in the origin of genome replication (Ori). This is the first report of a PCV2a strain with nucleotide insertion in Ori. Our study will help further epidemiological studies and extend our knowledge of evolutionary characteristics of PCV2.     

Identification of new autoantigens for primary biliary cirrhosis using human proteome microarrays

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown etiology and is considered to be an autoimmune disease. Autoantibodies are important tools for accurate diagnosis of PBC. Here, we employed serum profiling analysis using a human proteome microarray composed of about 17,000 full-length unique proteins and identified 23 proteins that correlated with PBC. To validate these results, we fabricated a PBC-focused microarray with 21 of these newly identified candidates and nine additional known PBC antigens. By screening the PBC microarrays with additional cohorts of 191 PBC patients and 321 controls (43 autoimmune hepatitis, 55 hepatitis B virus, 31 hepatitis C virus, 48 rheumatoid arthritis, 45 systematic lupus erythematosus, 49 systemic sclerosis, and 50 healthy), six proteins were confirmed as novel PBC autoantigens with high sensitivities and specificities, including hexokinase-1 (isoforms I and II), Kelch-like protein 7, Kelch-like protein 12, zinc finger and BTB domain-containing protein 2, and eukaryotic translation initiation factor 2C, subunit 1. To facilitate clinical diagnosis, we developed ELISA for Kelch-like protein 12 and zinc finger and BTB domain-containing protein 2 and tested large cohorts (297 PBC and 637 control sera) to confirm the sensitivities and specificities observed in the microarray-based assays. In conclusion, our research showed that a strategy using high content protein microarray combined with a smaller but more focused protein microarray can effectively identify and validate novel PBC-specific autoantigens and has the capacity to be translated to clinical diagnosis by means of an ELISA-based method.     

Haemodynamics-driven developmental pruning of brain vasculature in zebrafish

The brain blood vasculature consists of a highly ramified vessel network that is tailored to meet its physiological functions. How the brain vasculature is formed has long been fascinating biologists. Here we report that the developing vasculature in the zebrafish midbrain undergoes not only angiogenesis but also extensive vessel pruning, which is driven by changes in blood flow. This pruning process shapes the initial exuberant interconnected meshwork into a simplified architecture. Using in vivo long-term serial confocal imaging of the same zebrafish larvae during 1.5-7.5 d post-fertilization, we found that the early formed midbrain vasculature consisted of many vessel loops and higher order segments. Vessel pruning occurred preferentially at loop-forming segments via a process mainly involving lateral migration of endothelial cells (ECs) from pruned to unpruned segments rather than EC apoptosis, leading to gradual reduction in the vasculature complexity with development. Compared to unpruned ones, pruned segments exhibited a low and variable blood flow, which further decreased irreversibly prior to the onset of pruning. Local blockade of blood flow with micro-bead obstruction led to vessel pruning, whereas increasing blood flow by noradrenergic elevation of heartbeat impeded the pruning process. Furthermore, the occurrence of vessel pruning could be largely predicted by haemodynamics-based numerical simulation of vasculature refinement. Thus, changes of blood flow drive vessel pruning via lateral migration of ECs, leading to the simplification of the vasculature and possibly efficient routing of blood flow in the developing brain.