Design and synthesis of diarylamines and diarylethers as cytotoxic antitumor agents

Based on a shared structural core of diarylamine in several known anticancer drugs as well as a new cytotoxic hit 6-chloro-2-(4-cyanophenyl)amino-3-nitropyridine (7), 30 diarylamines and diarylethers were designed, synthesized, and evaluated for cytotoxic activity against A549, KB, KB-vin, and DU145 human tumor cell lines (HTCL). Four new leads 11e, 12, 13a, and 13b were discovered with GI(50) values ranging from 0.33 to 3.45μM. Preliminary SAR results revealed that a diarylamine or diarylether could serve as an active structural core, meta-chloro and ortho-nitro groups on the A-ring (either pyridine or phenyl ring) were necessary and crucial for cytotoxic activity, and the para-substituents on the other phenyl ring (B-ring) were related to inhibitory selectivity for different tumor cells. In an investigation of potential biological targets of the new leads, high thoughput kinase screening discovered that new leads 11e, 12 and 13b especially inhibit Mer tyrosine kinase, a proto-oncogene associated with munerous tumor types, with IC(50) values of 2.2-3.0μM. Therefore, these findings provide a good starting point to optimize a new class of compounds as potential anticancer agents, particularly targeting Mer tyrosine kinase.     

The Interactions of Glutathione-Capped CdTe Quantum Dots with Trypsin

Due to their unique fluorescent properties, quantum dots present a great potential for biolabelling applications; however, the toxic interactions of quantum dots with biopolymers are little known. The toxic interactions of glutathione-capped CdTe quantum dots with trypsin were studied in this paper using synchronous fluorescence spectroscopy, fluorescence emission spectra, and UV–vis absorption spectra. The interaction between CdTe quantum dots and trypsin resulted in structure changes of trypsin and inhibited trypsin's activity. Fluorescence emission spectra revealed that the quenching mechanism of trypsin by CdTe quantum dots was a static quenching process. The binding constant and the number of binding sites at 288 and 298 K were calculated to be 1.98 × 10⁶ L mol⁻¹ and 1.37, and 6.43 × 10⁴ L mol⁻¹ and 1.09, respectively. Hydrogen bonds and van der Waals' forces played major roles in this process.     

UV-B-induced DNA damage and repair pathways in polar Pseudogymnoascus sp. from the Arctic and Antarctic regions and their effects on growth,pigmentation and conidiogenesis

Solar radiation regulates most biological activities on Earth. Prolonged exposure to solar UV radiation can cause deleterious effects by inducing two major types of DNA damage, namely, cyclobutane pyrimidine dimers (CPDs) and pyrimidine 6-4 pyrimidone photoproducts. These lesions may be repaired by the photoreactivation (Phr) and nucleotide excision repair (NER) pathways; however, the principal UV-induced DNA repair pathway is not known in the fungal genus Pseudogymnoascus. In this study, we demonstrated that an unweighted UV-B dosage of 1.6 kJ m⁻² d⁻¹ significantly reduced fungal growth rates (by between 22% and 35%) and inhibited conidia production in a 10 d exposure. The comparison of two DNA repair conditions, light or dark, which respectively induced photoreactivation (Phr) and NER, showed that the UV-B-induced CPDs were repaired significantly more rapidly in light than in dark conditions. The expression levels of two DNA repair genes, RAD2 and PHR1 (encoding a protein in NER and Phr respectively), demonstrated that NER rather than Phr was primarily activated for repairing UV-B-induced DNA damage in these Pseudogymnoascus strains. In contrast, Phr was inhibited after exposure to UV-B radiation, suggesting that PHR1 may have other functional roles. We present the first study to examine the capability of the Arctic and Antarctic Pseudogymnoascus sp. to perform photoreactivation and/or NER via RT-qPCR approaches, and also clarify the effects of light on UV-B-induced DNA damage repair in vivo by quantifying cyclobutene pyrimidine dimers and pyrimidine 6-4 pyrimidone photoproducts. Physiological response data, including relative growth rate, pigmentation and conidia production in these Pseudogymnoascus isolates exposed to UV-B radiation are also presented.     

PLS3 predicts poor prognosis in pancreatic cancer and promotes cancer cell proliferation via PI3K/AKT signaling

Plastin-3 plays a key role in cancer cell proliferation and invasion, but its prognostic value in pancreatic cancer (PACA) remains poorly defined. In this study, we show that PLS3 messenger RNA is overexpressed in PACA tissue compared with normal tissue. We accumulated 207 cases of PACA specimens to perform immunohistochemical analysis and demonstrated that PLS3 levels correlate with T-classification (p < .001) and pathology (p < .001). Furthermore, overall survival rates (p < .001) in tumors with high PLS3 expression were poor, as assessed through Kaplan–Meier survival analysis. PLS3 was found to be an independent prognostic factor for PACA through multivariate Cox regression analysis. Moreover, we found that PLS3 enhances the proliferation and invasion of tumor cells as assessed through Cell Counting Kit-8, wounding healing assays, and Transwell assays. The upregulation of PLS3 also led to enhanced phosphatidylinositol-3 kinase/protein kinase B signaling in PACA cells. These data suggest that PLS3 is a biomarker to estimate PACA progression and represents a molecular target for PACA therapy.     

Trace detection of picloram using an electrochemical immunosensor based on three-dimensional gold nanoclusters

Picloram, a herbicide widely used for broadleaf weed control, is persistent and mobile in soil and water with adverse health and environmental effects. It is important to develop a sensitive method for accurate detection of trace picloram in the environment. In this article, a type of ordered three-dimensional (3D) gold (Au) nanoclusters obtained by two-step electrodeposition using the spatial obstruction/direction of the polycarbonate membrane is reported. Bovine serum albumin (BSA)-picloram was immobilized on the 3D Au nanoclusters by self-assembly, and then competitive immunoreaction with picloram antibody and target picloram was executed. The horseradish peroxidase (HRP)-labeled secondary antibody was applied for enzyme-amplified amperometric measurement. The electrodeposited Au nanoclusters built direct electrical contact and immobilization interface with protein molecules without postmodification and positioning. Under the optimal conditions, the linear range for picloram determination was 0.001-10 μg/ml with a correlation coefficient of 0.996. The detection and quantification limits were 5.0 × 10⁻⁴ and 0.0021 μg/ml, respectively. Picloram concentrations in peach and excess sludge supernatant extracts were tested by the proposed immunosensor, which exhibited good precision, sensitivity, selectivity, and storage stability.     

Genetic Analyses of the Internal Transcribed Spacer Sequences Suggest Introgression and Duplication in the Medicinal Mushroom Agaricus subrufescens

The internal transcribed spacer (ITS) region of the nuclear ribosomal RNA gene cluster is widely used in fungal taxonomy and phylogeographic studies. The medicinal and edible mushroom Agaricus subrufescens has a worldwide distribution with a high level of polymorphism in the ITS region. A previous analysis suggested notable ITS sequence heterogeneity within the wild French isolate CA487. The objective of this study was to investigate the pattern and potential mechanism of ITS sequence heterogeneity within this strain. Using PCR, cloning, and sequencing, we identified three types of ITS sequences, A, B, and C with a balanced distribution, which differed from each other at 13 polymorphic positions. The phylogenetic comparisons with samples from different continents revealed that the type C sequence was similar to those found in Oceanian and Asian specimens of A. subrufescens while types A and B sequences were close to those found in the Americas or in Europe. We further investigated the inheritance of these three ITS sequence types by analyzing their distribution among single-spore isolates from CA487. In this analysis, three co-dominant markers were used firstly to distinguish the homokaryotic offspring from the heterokaryotic offspring. The homokaryotic offspring were then analyzed for their ITS types. Our genetic analyses revealed that types A and B were two alleles segregating at one locus ITSI, while type C was not allelic with types A and B but was located at another unlinked locus ITSII. Furthermore, type C was present in only one of the two constitutive haploid nuclei (n) of the heterokaryotic (n+n) parent CA487. These data suggest that there was a relatively recent introduction of the type C sequence and a duplication of the ITS locus in this strain. Whether other genes were also transferred and duplicated and their impacts on genome structure and stability remain to be investigated.     

Long noncoding RNA LINC01234 promoted cell proliferation and invasion via miR-1284/TRAF6 axis in colorectal cancer

Colorectal cancer is one of the most common and leading malignancies globally. Long noncoding RNAs (lncRNAs) function as potentially critical regulator in colorectal cancer. LINC01234, a novel lncRNA in tumor biology, regulates the progression of various tumors. However, the tumorigenic mechanism of LINC01234 in colorectal cancer is still unclear. This study was performed with the aim to prospectively investigate clinical significance, effect, and mechanism of lncRNA LINC01234 in colorectal cancer. First, we found that LINC01234, localized in the cytoplasm, was increased in both colorectal cancer cell lines and tissues. Subsequent functional assays suggested LINC01234 knockdown suppressed cell proliferation, migration, and invasion of colorectal cancer cells, while blocked cell cycle and induced cell apoptosis. Moreover, we identified that miR-1284 was target of LINC01234, we further demonstrated a negative correlation with LINC01234 in colorectal cancer tissues and cells. Furthermore, miR-1284 targeted and suppressed tumor necrosis factor receptor–associated factor 6 (TRAF6). Loss-of-function assay revealed that LINC01234 silencing suppressed colorectal cancer progression through inhibition of miR-1284. In vivo subcutaneous xenotransplanted tumor model indicated LINC01234 knockdown inhibited in vivo tumorigenic ability of colorectal cancer via downregulation of TRAF6. Collectively, this study clarified the biological significance of LINC01234/miR-1284/TRAF6 axis in colorectal cancer progression, providing insights into LINC01234 as novel potential therapeutic target for colorectal cancer therapeutic from bench to clinic.     

3-Pyrroline containing arylacetamides: a novel series of remarkably selective kappa-agonists

A series of 2-(substituted phenyl)-N-methyl-N-[(1S)-1-(substituted alkyl)-2-(1-(3-pyrrolinyl))ethyl]acetamides were synthesized and evaluated as highly selective kappa-agonists with K(i) values in low nanomolar range. 3-Pyrroline incorporated into the basic amino functionality in combination with 2-(methylthio)ethyl substituent on the carbon adjacent to the amide nitrogen remarkably enhanced the kappa-selectivity. 3,4-Dichlorophenyl derivative 1e was found the most potent and selective analgesic in this series with ED(50) value of 0.023 mg/kg.     

生物信息学在发现新基因方面的应用

自生物信息学作为一门交叉学科诞生以来,其在计算机、农业和生命科学等各方面发挥了重要的作用,在后基因组时代,更是成为发现新基因的重要手段。对生物信息学的概况做了回顾与展望,并简述了生物信息学近年在发现新基因方面所取得的成果。     

Periplaneta Americana extract inhibits osteoclastic differentiation in vitro

ObjectivesPeriplaneta americana extract (PAE) is proven to be promising in treating fever, wound healing, liver fibrosis, and cardiovascular disease. However, the role of PAE in skeletal disorders remains unclear. This study investigated whether PAE regulates osteoclastic differentiation in vitro via the culture using RAW264.7 cells and bone marrow derived macrophages (BMDMs).Materials and MethodsRAW264.7 cells and BMDMs were cultured and induced for osteoclastic differentiation supplementing with different concentrations of PAE (0, 0.1, 1, and 10 mg/mL). Cell counting kit‐8 (CCK‐8) assay was used to detect the cytotoxicity and cell proliferation. TRAP staining, actin ring staining, real‐time quantitative PCR (RT‐qPCR), and bone resorption activity test were performed to detect osteoclastic differentiation. RT‐qPCR and enzyme‐linked immunosorbent assay (ELISA) were conducted to assay the expression and secretion of inflammatory factors. RNA sequencing (RNA‐seq) and western blot analysis were carried out to uncover the underlying mechanism.ResultsCCK‐8 results showed that 10 mg/mL and a lower concentration of PAE did not affect cell proliferation. RT‐qPCR analysis verified that PAE down‐regulated the osteoclastic genes Nfatc1, Ctsk, and Acp5 in macrophages. Moreover, PAE restrained the differentiation, formation, and function of osteoclasts. Besides, RT‐qPCR and ELISA assays showed that PAE decreased inflammatory genes expression and reduced the secretion of inflammatory factors, including IL1β, IL6, and TNFα. Subsequent RNA‐seq analysis identified possible genes and signaling pathways of PAE‐mediated osteoclastogenesis suppression.ConclusionsOur study indicates that PAE has inhibitive effects on osteoclastogenesis and may be a potential therapeutic alternative for bone diseases.

Periplaneta americana extract (PAE), the animal medicine material extracted from the insects Periplaneta americana, is proven to possess a variety of pharmacological functions. However, the role of PAE in skeletal disorders remains unclear. In this study, we found that PAE decreased osteoclast genes expression Nfatc1, Ctsk, and Acp5 in macrophages. Besides, PAE restrained the differentiation, formation, and function of osteoclasts. Moreover, PAE suppressed the LPS‐induced inflammation. Subsequent RNA‐seq analysis identified the signaling pathways of PAE‐mediated osteoclastogenesis suppression. Our study indicated that PAE has inhibitive effects on osteoclastic differentiation and may be a potential therapeutic Chinese medicine for bone diseases.