Chemical and Biological Strategies for Profiling Protein-Protein Interactions in Living Cells.

Protein-protein interactions (PPIs) play critical roles in almost all cellular signal transduction events. Characterization of PPIs without interfering with the functions of intact cells is very important for basic biology study and drug developments. However, the ability to profile PPIs especially those weak/transient interactions in their native states remains quite challenging. To this end, many endeavors are being made in developing new methods with high efficiency and strong operability. By coupling with advanced fluorescent microscopy and mass spectroscopy techniques, these strategies not only allow us to visualize the subcellular locations and monitor the functions of protein of interest (POI) in real time, but also enable the profiling and identification of potential unknown interacting partners in high-throughput manner, which greatly facilitates the elucidation of molecular mechanisms underlying numerous pathophysiological processes. In this review, we will summarize the typical methods for PPIs identification in living cells and their principles, advantages and limitations will also be discussed in detail.

[Retracted] miR­218 suppresses tumor growth and enhances the chemosensitivity of esophageal squamous cell carcinoma to cisplatin.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the western blotting data shown in Fig. 6 and the tumor images shown in Fig. 7A were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they agreed with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in Oncology Reports 33: 981­989, 2015; DOI: 10.3892/or.2014.3657].

A review of the phytochemistry and pharmacological activities of Ephedra herb.

Ephedra herb is a traditional Chinese medicine with a long history. Conventionally, it was used as a folk phytomedicine in many ancient medical books and traditional prescriptions. Up to date, a variety of specific ingredients have been found in Ephedra herb, mainly including alkaloids, flavonoids, tannins, polysaccharides, organic acids, volatile oils, and many other active compounds. These components from Ephedra herb account for its use as the accurate treatment of cold, cough, cardiovascular and immune system disease, cancer, microbial infection, and other diseases. Moreover, with the fast development of novel chemistry and medicine technology, new chemical constituents and pharmacological effects of Ephedra herb are increasingly identified, demonstrating their great potential for various diseases treatment. Therefore, further detailed understanding and investigation of this ancient herb will offer new opportunities to develop novel therapeutics. This study systematically reviews its progress of phytochemistry, traditional and modern pharmacology based on research data that have been reported, aiming at providing useful insight for commercial exploitation, further study and precision medication of Ephedra herb in future.

[Autotoxic effect of ginsenoside extrats on growth of American ginseng in different medium].

Ginsenosides are the abundant secondary metabolites in American ginseng (Panax quinquefolium), it could be released into soil through root exudation and decomposition during plant growth. This study determined ginsenoside contents in American ginseng cultivated soil by HPLC. Three ginsenosides, Rb1, Rb2 and Rd, were detected in the rhizosphere soil of 3-4 years old American ginseng cultivated in Huairou District, Beijing, and their contents were 0.80-3.19 mg x kg(-1). Correspondingly, the contents of the three ginsenosides in soil solution were 4-16 mg x L(-1) at field water-holding capacity of 20%. According to the field soil test data, we designed the concentration of ginsenosides for bioassays (0.2-125 mg x L(-1) in solution or 0.2-125 mg x kg(-1) in soil). The results showed that radicle lengths of American ginseng were reduced by 6%-23% in solution containing 0.2-125 mg x L(-1) ginsenoside extract, and a significant difference was observed at concentration of 125 mg x L(-1) (P < 0.05). The shoot lengths of American ginseng were not significantly inhibited by 0.2-125 mg x L(-1) ginsenosides extractions. After 20 days of growth in nutrient solution amended with 25 mg x L(-1) ginsenosides extraction, plant height of 3-year-old American ginseng seedling was decreased by 28% compared to the control, and the biomass of aerial parts was also reduced by 50% (P < 0.05). However, the growth of newly-grown fibrous root was not significantly inhibited. Comparatively, when American ginseng embryos were cultivated into sterile or non-sterile soil, neither radicle lengths nor shoot lengths were significantly affected by 0.2-125 mg x kg(-1) ginsenoside extracts. In conclusion, ginsenosides showed autotoxic effect on growth of American ginseng radicle and adult seedling, however, this effect was weakened in field soil.

miR-218 suppresses tumor growth and enhances the chemosensitivity of esophageal squamous cell carcinoma to cisplatin.

A growing body of evidence suggests that microRNA-218 (miR-218) acts as a tumor suppressor and is involved in tumor progression, development and metastasis and confers sensitivity to certain chemotherapeutic drugs in several types of cancer. However, our knowledge concerning the exact roles played by miR-218 in esophageal squamous cell carcinoma (ESCC) and the underlying molecular mechanisms remain relatively unclear. Thus, the aims of this study were to detect the expression of miR-218 in human ESCC tissues and explore its effects on the biological features and chemosensitivity to cisplatin (CDDP) in an ESCC cell line (Eca109), so as to provide new insights for ESCC treatment. Here, we found increased expression of miR-218 in the ESCC tissues compared with that in the matched non-tumor tissues, and its expression level was correlated with key pathological characteristics including clinical stage, tumor depth and metastasis. We also found that enforced expression of miR-218 significantly decreased cell proliferation, colony formation, migration and invasion, induced cell apoptosis and arrested the cell cycle in the G0/G1 phase, as well as suppressed tumor growth in a nude mouse model. In addition, our results showed that miR-218 mimics increased the sensitivity to the antitumor effect of CDDP in the human Eca109 cells. Importantly, this study also showed that miR-218 regulated the expression of phosphorylated PI3K, AKT and mTOR, which may contribute to suppressed tumor growth of ESCC and enhanced sensitivity of ESCC cells. These findings suggest that miR-218 is a potential therapeutic agent for the treatment of ESCC.

Facile synthesis of peptidyl salicylaldehyde esters and its use in cyclic peptide synthesis.

An efficient solid phase synthetic protocol for salicylaldehyde ester peptides is reported. With a Ser or Thr at the N-terminus, these salicylaldehyde ester peptides can be easily converted to Ser/Thr containing cyclic peptides.