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A series of novel benzimidazole derivatives were designed and synthesised based on the structures of reported oral available ALK inhibitor and HDAC inhibitor, pracinostat. In enzymatic assays, compound , containing a 2-acyliminobenzimidazole moiety and hydroxamic acid side chain, could inhibit both ALK and HDAC6 (IC = 16 nM and 1.03 µM, respectively). Compound also inhibited various ALK mutants known to be involved in crizotinib resistance, including mutant L1196M (IC , 4.9 nM). Moreover, inhibited the proliferation of several cancer cell lines, including ALK-addicted H2228 cells. To evaluate its potential for treating cancers , was used in a human A549 xenograft model with BALB/c nude mice. At 20 mg/kg, inhibited tumour growth by 85% yet had a negligible effect on mean body weight. These results suggest a attracting route for the further research and optimisation of dual ALK/HDAC inhibitors.

Large numbers of cells are generally required for quantitative global proteome profiling due to surface adsorption losses associated with sample processing. Such bulk measurement obscures important cell-to-cell variability (cell heterogeneity) and makes proteomic profiling impossible for rare cell populations (e.g., circulating tumor cells (CTCs)). Here we report a surfactant-assisted one-pot sample preparation coupled with mass spectrometry (MS) method termed SOP-MS for label-free global single-cell proteomics. SOP-MS capitalizes on the combination of a MS-compatible nonionic surfactant, n-Dodecyl-β-D-maltoside, and hydrophobic surface-based low-bind tubes or multi-well plates for ‘all-in-one’ one-pot sample preparation. This ‘all-in-one’ method including elimination of all sample transfer steps maximally reduces surface adsorption losses for effective processing of single cells, thus improving detection sensitivity for single-cell proteomics. This method allows convenient label-free quantification of hundreds of proteins from single human cells and ~1200 proteins from small tissue sections (close to ~20 cells). When applied to a patient CTC-derived xenograft (PCDX) model at the single-cell resolution, SOP-MS can reveal distinct protein signatures between primary tumor cells and early metastatic lung cells, which are related to the selection pressure of anti-tumor immunity during breast cancer metastasis. The approach paves the way for routine, precise, quantitative single-cell proteomics.Tsai, Zhang, Scholten et al. develop a surfactant- assisted one-pot sample preparation coupled with mass spectrometry method (SOP-MS) for label-free global single-cell proteomics. This method allows researchers to measure hundreds of proteins from single human cells, suggesting its utility for quantitative single-cell proteomics.

The enigmatic histone deacetylase 6 (HDAC6) is one of a kind among its family. Recent reports revealed that HDAC6 CD1 exhibits E3 ligase activity. Inspired by these researches, we attempted to develop drugs targeting HDAC6 novel mechanism. Herein, we report a palladium catalysed transformation and purification method for hydroxamic acid dimers, and series of HDAC6 inhibitor-based dimer showing outstanding biological activities and capability of inducing auto-degradation. Our proof-of-concept was highlighted with 2-amino benzamide-based HDAC6 inhibitor dimers that exhibit great HDAC6 inhibition activity (3.9-15.4 nM), good HDAC1/6 selectivity (95-577), and excellent cytotoxicity against human hormone-resistant prostate cancer (HRPC) PC-3 and non-small cell lung cancer (NSCLC) A549 cell lines (5.9-11.3 and 6.6-17.9 μM, respectively) while simultaneously inducing HDAC6 degradation. These dimers not only induce apoptosis and autophagy but also interfere with kinetochore attachment by the detection of BUBR1 phosphorylation at S670.

Background The c.G6055A (p.G2019S) mutation in leucine-rich repeat kinase 2 ( LRRK2 ) is the most prevalent genetic cause of Parkinson’s disease (PD). CRISPR/Cas9-mediated genome editing by homology-directed repair (HDR) has been applied to correct the mutation but may create small insertions and deletions (indels) due to double-strand DNA breaks. Adenine base editors (ABEs) could convert targeted A·T to G·C in genomic DNA without double-strand breaks. However, the correction efficiency of ABE in LRRK2 c.G6055A (p.G2019S) mutation remains unknown yet. This study aimed to compare the mutation correction efficiencies and off-target effects between HDR and ABEs in induced pluripotent stem cells (iPSCs) carrying LRRK2 c.G6055A (p.G2019S) mutation. Methods A set of mutation-corrected isogenic lines by editing the LRRK2 c.G6055A (p.G2019S) mutation in a PD patient-derived iPSC line using HDR or ABE were established. The mutation correction efficacies, off-target effects, and indels between HDR and ABE were compared. Comparative transcriptomic and proteomic analyses between the LRRK2 p.G2019S iPSCs and isogenic control cells were performed to identify novel molecular targets involved in LRRK2-parkinsonism pathways. Results ABE had a higher correction rate (13/53 clones, 24.5%) than HDR (3/47 clones, 6.4%). Twenty-seven HDR clones (57.4%), but no ABE clones, had deletions, though 14 ABE clones (26.4%) had off-target mutations. The corrected isogenic iPSC-derived dopaminergic neurons exhibited reduced LRRK2 kinase activity, decreased phospho-α-synuclein expression, and mitigated neurite shrinkage and apoptosis. Comparative transcriptomic and proteomic analysis identified different gene expression patterns in energy metabolism, protein degradation, and peroxisome proliferator-activated receptor pathways between the mutant and isogenic control cells. Conclusions The results of this study envision that ABE could directly correct the pathogenic mutation in iPSCs for reversing disease-related phenotypes in neuropathology and exploring novel pathophysiological targets in PD.

Protein phosphorylation has a major role in controlling the life-cycle and infection stages of bacteria. Proteome-wide occurrence of S/T/Y phosphorylation has been reported for many prokaryotic systems. Previously, we reported the phosphoproteome of Pseudomonas aeruginosa and Pseudomonas putida. In this study, we show the role of S/T phosphorylation of one motility protein, FliC, in regulating multiple surface-associated phenomena of P. aeruginosa PAO1. This is the first report of occurrence of phosphorylation in the flagellar protein, flagellin FliC in its highly conserved N-terminal NDO domain across several Gram negative bacteria. This phosphorylation is likely a well-regulated phenomenon as it is growth phase dependent in planktonic cells. The absence of phosphorylation in the conserved T27 and S28 residues of FliC, interestingly, did not affect swimming motility, but affected the secretome of type 2 secretion system (T2SS) and biofilm formation of PAO1. FliC phosphomutants had increased levels and activities of type 2 secretome proteins. The secretion efficiency of T2SS machinery is associated with flagellin phosphorylation. FliC phosphomutants also formed reduced biofilms at 24 h under static conditions and had delayed biofilm dispersal under dynamic flow conditions, respectively. The levels of type 2 secretome and biofilm formation under static conditions had an inverse correlation. Hence, increase in type 2 secretome levels was accompanied by reduced biofilm formation in the FliC phosphomutants. As T2SS is involved in nutrient acquisition and biofilm dispersal during survival and spread of P. aeruginosa, we propose that FliC phosphorylation has a role in ecological adaptation of this opportunistic environmental pathogen. Altogether, we found a system of phosphorylation that affects key surface related processes such as proteases secretion by T2SS, biofilm formation and dispersal.

Protein phosphorylation can induce signal transduction to change sperm motility patterns during sperm capacitation. However, changes in the phosphorylation of sperm proteins in mice are still incompletely understood. Here, capacitation-related phosphorylation in mouse sperms were firstly investigated by label-free quantitative (LFQ) phosphoproteomics coupled with bioinformatics analysis using ingenuity pathway analysis (IPA) methods such as canonical pathway, upstream regulator, and network analysis. Among 1632 phosphopeptides identified at serine, threonine, and tyrosine residues, 1050 novel phosphosites, corresponding to 402 proteins, were reported. Gene heatmaps for IPA canonical pathways showed a novel role for GSK-3 in GP6 signaling pathways associated with capacitation for 60 min. At the same time, the reduction of the abundant isoform-specific GSK-3α expression was shown by western blot (WB) while the LFQ pY of this isoform slightly decreased and then increased. The combined results from WB and LFQ methods explain the less inhibitory phosphorylation of GSK-3α during capacitation and also support the predicted increases in its activity. In addition, pAKAP4 increased at the Y156 site but decreased at the Y811 site in a capacitated state, even though IPA network analysis and WB analysis for overall pAKAP revealed upregulated trends. The potential roles of GSK-3 and AKAP4 in fertility are discussed.

Colorectal cancer (CRC) is a leading cause of cancer-related deaths, particularly in metastatic cases. Sialic acid, frequently overexpressed in tumors, promotes immune evasion by engaging Siglecs (Sialic acid-binding immunoglobulin-like lectins) on immune cells. Siglec-5 and Siglec-14, expressed on myeloid cells, share ligand-binding domains but have opposing signaling functions. While these paired receptors regulate macrophage immune responses against bacterial infection, their role in the tumor microenvironment remains unclear. We found that Siglec-14 expression in THP-1 macrophages, when exposed to CRC tumor-conditioned medium, induces a protumoral SPP1 + tumor-associated macrophage phenotype, with enrichment of angiogenic pathways. In vivo, Siglec-14-expressing macrophages promoted CRC xenograft growth in mice, and their conditioned medium enhanced angiogenesis in chicken chorioallantoic membranes. We identified LGALS3BP (Lectin galactoside-binding soluble 3 binding protein), a sialylated glycoprotein in CRC tumor-conditioned medium, as a Siglec-14 ligand. Blocking this interaction reduced tumor-associated macrophage polarization and VEGF release. Siglec-14 is absent in some individuals due to a SIGLEC5 / 14 fusion polymorphism. Siglec-14-positive CRC patients exhibited elevated serum LGALS3BP, which correlated with advanced progression and poorer survival. Collectively, these findings establish the LGALS3BP-Siglec-14 axis as a potential therapeutic target, offering a strategy to enhance antitumor immunity in Siglec-14-positive CRC patients.

Melanoma is an aggressive cancer with high lethality. In order to find new anticancer agents, isokotomolide A (Iso A) and secokotomolide A (Sec A) isolated from Cinnamomum kotoense were identified to be potential bioactive agents against human melanoma but without strong antioxidative properties. Cell proliferation assay displayed Iso A and Sec A treated in the normal human skin cells showed high viabilities. It also verified that two of them possess strong antimelanoma effect in concentration-dependent manners, especially on B16F10, A2058, MeWo, and A375 cells. Wound healing assay presented their excellent antimigratory effects. Through 3-N,3-N,6-N,6-N-Tetramethylacridine-3,6-diamine (acridine orange, AO) staining and Western blot, the autophagy induced by treatment was confirmed, including autophagy-related proteins (Atgs). By using annexin V–FITC/PI double-stain, the apoptosis was confirmed, and both components also triggered the cell cycle arrest and DNA damage. We demonstrated the correlations between the mitogen-activated protein kinase (MAPK) pathway and antimelanoma, such as caspase cascade activations. To further evaluate in vivo experiments, the inhibition of tumor cell growth was verified through the histopathological staining in a xenograft model. In this study, it was confirmed that Iso A and Sec A can encourage melanoma cell death via early autophagy and late apoptosis processes.

Regulation of Shp2, a tyrosine phosphatase, critically influences the development of various diseases. Its role in epithelial lumenogenesis is not clear. Here we show that oncogenic Shp2 dephosphorylates Tuba to decrease Cdc42 activation, leading to the abnormal multi-lumen formation of epithelial cells. HDAC6 suppression reverses oncogenic Shp2-induced multiple apical domains and spindle mis-orientation during division in cysts to acquire normal lumenogenesis. Intriguingly, Cdc42 activity is not restored in this rescued process. We present evidence that simultaneous reduction in myosin II and ERK1/2 activity by HDAC6 inhibition is responsible for the reversion. In HER2-positive breast cancer cells, Shp2 also mediates Cdc42 repression, and HDAC6 inhibition or co-suppression of ERK/myosin II promotes normal epithelial lumen phenotype without increasing Cdc42 activity. Our data suggest a mechanism of epithelial disorganization by Shp2 deregulation, and reveal the cellular context where HDAC6 suppression is capable of establishing normal epithelial lumenogenesis independent of Cdc42. Cdc42 activity is important for apical-basal epithelial polarity. Here, the authors show that Shp2 disrupts Cdc42 activation, and by reducing the expression of histone deactylase 6, restores epithelial lumen formation in a cdc42-independent manner.

For decades, major difficulties in analyzing histidine phosphorylation have limited the study of phosphohistidine signaling. Here we report a method revealing widespread and abundant protein histidine phosphorylation in Escherichia coli. We generated an extensive E. coli phosphoproteome data set, in which a remarkably high percentage (∼10%) of phosphorylation sites are phosphohistidine sites. This resource should help enable a better understanding of the biological function of histidine phosphorylation.