CD10+GPR77+ Cancer-Associated Fibroblasts Promote Cancer Formation and Chemoresistance by Sustaining Cancer Stemness

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Homeologous plastid DNA transformation in tobacco is mediated by multiple recombination events.

Efficient plastid transformation has been achieved in Nicotiana tabacum using cloned plastid DNA of Solanum nigrum carrying mutations conferring spectinomycin and streptomycin resistance. The use of the incompletely homologous (homeologous) Solanum plastid DNA as donor resulted in a Nicotiana plastid transformation frequency comparable with that of other experiments where completely homologous plastid DNA was introduced. Physical mapping and nucleotide sequence analysis of the targeted plastid DNA region in the transformants demonstrated efficient site-specific integration of the 7.8-kb Solanum plastid DNA and the exclusion of the vector DNA. The integration of the cloned Solanum plastid DNA into the Nicotiana plastid genome involved multiple recombination events as revealed by the presence of discontinuous tracts of Solanum-specific sequences that were interspersed between Nicotiana-specific markers. Marked position effects resulted in very frequent cointegration of the nonselected peripheral donor markers located adjacent to the vector DNA. Data presented here on the efficiency and features of homeologous plastid DNA recombination are consistent with the existence of an active RecA-mediated, but a diminished mismatch, recombination/repair system in higher-plant plastids.     

Studies on Chemical Constituents of Fritillaria yuminensis

Six compounds were isolated from the bulbs of Fritillaria yuminensis X. Z. Duan. They were elucidated as 5α, 14α-cevanine-3α-hydroxy-6-one ( Ⅰ ), 5α, 14α-cevanine-3-one-6β-O-β-D-glucoside ( Ⅱ ), imperialine ( Ⅲ ), delavinone ( Ⅳ ), tortifolisine ( Ⅴ ) and adenosine( Ⅵ ) by means of spectral analysis and chemical reaction. They all were firstly isolated from this plant. Among them, compound Ⅰ and Ⅱ, named yubeinine and yubeiside respectively, were new compounds.     

miR‐495 sensitizes MDR cancer cells to the combination of doxorubicin and taxol by inhibiting MDR1 expression

MDR1 is highly expressed in MDR A2780DX5 ovarian cancer cells, MDR SGC7901R gastric cancer cells and recurrent tumours. It pumps cytoplasmic agents out of cells, leading to decreased drug accumulation in cells and making cancer cells susceptible to multidrug resistance. Here, we identified that miR‐495 was predicted to target ABCB1, which encodes protein MDR1. To reduce the drug efflux and reverse MDR in cancer cells, we overexpressed a miR‐495 mimic in SGC7901R and A2780DX cells and in transplanted MDR ovarian tumours in vivo. The results indicated that the expression of MDR1 in the above cells or tumours was suppressed and that subsequently the drug accumulation in the MDR cells was decreased, cell death was increased, and tumour growth was inhibited after treatment with taxol‐doxorubicin, demonstrating increased drug sensitivity. This study suggests that pre‐treatment with miR‐495 before chemotherapy could improve the curative effect on MDR1‐based MDR cancer.     

Testosterone and bioavailable testosterone help to distinguish between mild Cushing's syndrome and polycystic ovarian syndrome

Women with Cushing's syndrome (CS) and polycystic ovarian syndrome (PCOS) may present with similar symptoms. Subjects with mild CS lack clinical stigmata of classical CS and often have normal laboratory tests measuring hypercortisolism. Thus, distinguishing mild CS from PCOS may be difficult. We hypothesized that either total testosterone (TT) or bioavailable testosterone (BT) levels or the calculation of the free androgen index (FAI) would be low in patients with mild CS and elevated in patients with PCOS, and could help differentiate the two conditions. TT, BT, and FAI were measured in a group of 20 patients of reproductive age with mild CS and 20 PCOS patients matched for age and BMI. We used receiver operator characteristic (ROC) curves to assess the sensitivity and specificity of these measurements for the diagnosis of CS. TT (p<0.0001), BT (p=0.02), and FAI (p=0.003) were significantly elevated in PCOS patients compared to mild CS patients. Sex hormone-binding globulin was similar in both groups. The optimal cut-point for TT was 1.39 nmol/L, yielding a sensitivity of 95% and a specificity of 70%. The cut-point for BT was 0.24 nmol/L, resulting in a sensitivity of 75% and a specificity of 80%. The cut-point for FAI was 5.7, with a sensitivity of 88% and a specificity of 60%. We conclude that TT levels may be useful to discriminate between mild CS and PCOS. In patients with signs and symptoms consistent with CS and PCOS, a TT level of <1.39 nmol/L warrants a workup for CS.     

Pyridopyrimidine based cannabinoid-1 receptor inverse agonists: Synthesis and biological evaluation

The synthesis, SAR and binding affinities are described for cannabinoid-1 receptor (CB1R) specific inverse agonists based on pyridopyrimidine and heterotricyclic scaffolds. Food intake and pharmacokinetic evaluation of several of these compounds indicate that they are effective orally active modulators of CB1R.     

TOR-mediated autophagy regulates cell death in Drosophila neurodegenerative disease

Target of rapamycin (TOR) signaling is a regulator of cell growth. TOR activity can also enhance cell death, and the TOR inhibitor rapamycin protects cells against proapoptotic stimuli. Autophagy, which can protect against cell death, is negatively regulated by TOR, and disruption of autophagy by mutation of Atg5 or Atg7 can lead to neurodegeneration. However, the implied functional connection between TOR signaling, autophagy, and cell death or degeneration has not been rigorously tested. Using the Drosophila melanogaster visual system, we show in this study that hyperactivation of TOR leads to photoreceptor cell death in an age- and light-dependent manner and that this is because of TOR''s ability to suppress autophagy. We also find that genetically inhibiting TOR or inducing autophagy suppresses cell death in Drosophila models of Huntington''s disease and phospholipase C (norpA)–mediated retinal degeneration. Thus, our data indicate that TOR induces cell death by suppressing autophagy and provide direct genetic evidence that autophagy alleviates cell death in several common types of neurodegenerative disease.     

Versatile Dual Reporter Gene Systems for Investigating Stop Codon Readthrough in Plants

Background

Translation is most often terminated when a ribosome encounters the first in-frame stop codon (UAA, UAG or UGA) in an mRNA. However, many viruses (and some cellular mRNAs) contain “stop” codons that cause a proportion of ribosomes to terminate and others to incorporate an amino acid and continue to synthesize a “readthrough”, or C-terminally extended, protein. This dynamic redefinition of codon meaning is dependent on specific sequence context.

Methodology

We describe two versatile dual reporter systems which facilitate investigation of stop codon readthrough in vivo in intact plants, and identification of the amino acid incorporated at the decoded stop codon. The first is based on the reporter enzymes NAN and GUS for which sensitive fluorogenic and histochemical substrates are available; the second on GST and GFP.

Conclusions

We show that the NAN-GUS system can be used for direct in planta measurements of readthrough efficiency following transient expression of reporter constructs in leaves, and moreover, that the system is sufficiently sensitive to permit measurement of readthrough in stably transformed plants. We further show that the GST-GFP system can be used to affinity purify readthrough products for mass spectrometric analysis and provide the first definitive evidence that tyrosine alone is specified in vivo by a ‘leaky’ UAG codon, and tyrosine and tryptophan, respectively, at decoded UAA, and UGA codons in the Tobacco mosaic virus (TMV) readthrough context.     

Chromosomal Mcm2-7 distribution and the genome replication program in species from yeast to humans

The spatio-temporal program of genome replication across eukaryotes is thought to be driven both by the uneven loading of pre-replication complexes (pre-RCs) across the genome at the onset of S-phase, and by differences in the timing of activation of these complexes during S phase. To determine the degree to which distribution of pre-RC loading alone could account for chromosomal replication patterns, we mapped the binding sites of the Mcm2-7 helicase complex (MCM) in budding yeast, fission yeast, mouse and humans. We observed similar individual MCM double-hexamer (DH) footprints across the species, but notable differences in their distribution: Footprints in budding yeast were more sharply focused compared to the other three organisms, consistent with the relative sequence specificity of replication origins in S. cerevisiae. Nonetheless, with some clear exceptions, most notably the inactive X-chromosome, much of the fluctuation in replication timing along the chromosomes in all four organisms reflected uneven chromosomal distribution of pre-replication complexes.     

Computational resources and tools for antimicrobial peptides

Antimicrobial peptides (AMPs), as evolutionarily conserved components of innate immune system, protect against pathogens including bacteria, fungi, viruses, and parasites. In general, AMPs are relatively small peptides (<10 kDa) with cationic nature and amphipathic structure and have modes of action different from traditional antibiotics. Up to now, there are more than 19 000 AMPs that have been reported, including those isolated from nature sources or by synthesis. They have been considered to be promising substitutes of conventional antibiotics in the quest to address the increasing occurrence of antibiotic resistance. However, most AMPs have modest direct antimicrobial activity, and their mechanisms of action, as well as their structure–activity relationships, are still poorly understood. Computational strategies are invaluable assets to provide insight into the activity of AMPs and thus exploit their potential as a new generation of antimicrobials. This article reviews the advances of AMP databases and computational tools for the prediction and design of new active AMPs. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.