Objective To investigate the expression of Notch1 protein and its clinicopathologieal characteristics in colorectal carcinomas. Methods The expression and location of Notch1 protein were determined using immunohistochemical S-P method in 30 colorectal carcinomas and 18 normal colorectal tissues. Results The average positive rate of Notch1 protein was 45.5 ± 0. 7% in colorectal carcinomas and 6. 8 ± 0. 9% in normal colorectal tissues. There was significant difference between colorectal carcinomas and normal colorectal tissues (P ＜ 0. 05). The expression of Notchl protein in different age, sex, tumor site, nodal involvement and Dukes stage had no significant difference. The expression of Notch1 protein in different histology grade had significantly statistical difference. Conclusion Notch1 expression was associated with the development of colorectal carcinoma. Notch1 was the potential oncagenic gene. Nothe1 would become the new target of the colorectal tumor therapy in the future.

Objective·To establish various in vitro screening systems for the discovery of peptide inhibitors targeting the interaction between small ubiquitin-like modifier(SUMO)-activating enzyme subunit 1(SAE1)and subunit 2(SAE2),as well as to evaluate their advantages,disadvantages,and applicability to this research.Methods·The DNA fragments encoding human SAE1 and SAE2 were cloned into vector pET-28a,respectively,to generate protein SAE1 and SAE2.Purified proteins were used to establish screening assays,including isothermal calorimetry(ITC),fluorescence polarization(FP),surface plasmon resonance(SPR)and a fluorescence assay based on the SAE enzyme activity.The inhibitory activity of peptide candidates in different screening systems was examined,and their performance in terms of sensitivity,robustness,throughput and cost was evaluated.Results·The dissociation constant(Kd)of in vitro SAE1 and SAE2 interaction was determined to be 0.96 μmol/L by ITC,and PEPT7 was identified as the most potent peptide.However,the tracer of FP,which was derived from PEPT7,was not up to snuff due to its low affinity with SAE2.In the SPR assay,the Kd value(=1.13 μmol/L)of SAE1 and SAE2 interaction was in line with the results from ITC.The SAE enzyme activity-based screening assay revealed that HP1B,the most effective peptide,inhibited SAE with an half-maximal inhibitory concentration(IC50)of 15.72 μmol/L.The affinity of HP1B for SAE1 was determined to be 34.4 μmol/L by SPR.Conclusion·Several common screening systems for protein-protein interation(PPI)inhibitors are established and compared.Among them,ITC does not allow for high-throughput screening and it is difficult to accurately evaluate the low-affinity polypeptides with insignificant binding heat.The feasibility of FP relies heavily on the strong affinity between a tracer peptide and the protein target,making it unsuitable for the screening and optimization of low-affinity peptides.SPR is highly sensitive but the cost is high.The SAE enzyme activity-based assay stands out because it is a combination of high sensitivity,robustness,throughput and acceptable cost.

The recent discovery of activator compounds binding to an allosteric site on the NAD

Ankylosing spondylitis is a chronic immunoinflammatory disease that mainly affects the spine and the sacroiliac joint， the mechanism of which is closely related to signaling pathways， such as osteoprotegerin （OPG）/receptor activator of nuclear factor-κB （RANK）/RANK ligand， mitogen-activated protein kinase （MAPK）， Wnt/β-catenin （β-catenin）， phosphoinositide 3- kinase/protein kinase B/mammalian target of rapamycin （PI3K/Akt/mTOR）. Traditional Chinese medicine has the characteristics of multiple components and targets， and is widely used for the treatment of autoimmune diseases due to its low toxicity， strong specificity， and high efficacy. This review found that monomers and compounds of traditional Chinese medicine can exert anti ankylosing spondylitis effects by intervening in the aforementioned signaling pathways， regulating immune inflammatory responses， and inhibiting biological processes such as bone destruction， ectopic osteogenic differentiation， cell apoptosis， and autophagy.

RAS, a member of the small GTPase family, functions as a binary switch by shifting between inactive GDP-loaded and active GTP-loaded state. RAS gain-of-function mutations are one of the leading causes in human oncogenesis, accounting for ∼19% of the global cancer burden. As a well-recognized target in malignancy, RAS has been intensively studied in the past decades. Despite the sustained efforts, many failures occurred in the earlier exploration and resulted in an 'undruggable' feature of RAS proteins. Phosphorylation at several residues has been recently determined as regulators for wild-type and mutated RAS proteins. Therefore, the development of RAS inhibitors directly targeting the RAS mutants or towards upstream regulatory kinases supplies a novel direction for tackling the anti-RAS difficulties. A better understanding of RAS phosphorylation can contribute to future therapeutic strategies. In this review, we comprehensively summarized the current advances in RAS phosphorylation and provided mechanistic insights into the signaling transduction of associated pathways. Importantly, the preclinical and clinical success in developing anti-RAS drugs targeting the upstream kinases and potential directions of harnessing allostery to target RAS phosphorylation sites were also discussed.

SIRT6 belongs to the conserved NAD⁺-dependent deacetylase superfamily and mediates multiple biological and pathological processes. Targeting SIRT6 by allosteric modulators represents a novel direction for therapeutics, which can overcome the selectivity problem caused by the structural similarity of orthosteric sites among deacetylases. Here, developing a reversed allosteric strategy AlloReverse, we identified a cryptic allosteric site, Pocket Z, which was only induced by the bi-directional allosteric signal triggered upon orthosteric binding of NAD⁺. Based on Pocket Z, we discovered an SIRT6 allosteric inhibitor named JYQ-42. JYQ-42 selectively targets SIRT6 among other histone deacetylases and effectively inhibits SIRT6 deacetylation, with an IC₅₀ of 2.33 μmol/L. JYQ-42 significantly suppresses SIRT6-mediated cancer cell migration and pro-inflammatory cytokine production. JYQ-42, to our knowledge, is the most potent and selective allosteric SIRT6 inhibitor. This study provides a novel strategy for allosteric drug design and will help in the challenging development of therapeutic agents that can selectively bind SIRT6.