DR30318, a novel tri-specific T cell engager for Claudin 18.2 positive cancers immunotherapy.

BACKGROUND: Claudin 18.2 (CLDN18.2) is a highly anticipated target for solid tumor therapy, especially in advanced gastric carcinoma and pancreatic carcinoma. The T cell engager targeting CLDN18.2 represents a compelling strategy for enhancing anti-cancer efficacy. METHODS: Based on the in-house screened anti-CLDN18.2 VHH, we have developed a novel tri-specific T cell engager targeting CLDN18.2 for gastric and pancreatic cancer immunotherapy. This tri-specific antibody was designed with binding to CLDN18.2, human serum albumin (HSA) and CD3 on T cells. RESULTS: The DR30318 demonstrated binding affinity to CLDN18.2, HSA and CD3, and exhibited T cell-dependent cellular cytotoxicity (TDCC) activity in vitro. Pharmacokinetic analysis revealed a half-life of 22.2-28.6 h in rodents and 41.8 h in cynomolgus monkeys, respectively. The administration of DR30318 resulted in a slight increase in the levels of IL-6 and C-reactive protein (CRP) in cynomolgus monkeys. Furthermore, after incubation with human PBMCs and CLDN18.2 expressing cells, DR30318 induced TDCC activity and the production of interleukin-6 (IL-6) and interferon-gamma (IFN-γ). Notably, DR30318 demonstrated significant tumor suppression effects on gastric cancer xenograft models NUGC4/hCLDN18.2 and pancreatic cancer xenograft model BxPC3/hCLDN18.2 without affecting the body weight of mice.

An innovative antibody fusion protein targeting PD-L1, VEGF and TGF-ß with enhanced antitumor efficacies.

Immunosuppressive pathways in the tumor microenvironment (TME) are inextricably linked to tumor progression. Mono-therapeutics of immune checkpoint inhibitors (ICIs, e.g. antibodies against programmed cell death protein-1/programmed cell death ligand-1, PD-1/PD-L1) is prone to immune escape while combination therapeutics tends to cause high toxicity and side effects. Therefore, using multi-functional molecules to target multiple pathways simultaneously is becoming a new strategy for cancer therapies. Here, we developed a trifunctional fusion protein, DR30206, composed of Bevacizumab (an antibody against VEGF), and a variable domain of heavy chain of heavy chain antibody (VHH) against PD-L1 and the extracellular domain (ECD) protein of TGF-ß receptor II (TGF-ß RII), which are fused to the N- and C-terminus of Bevacizumab, respectively. The original intention of DR30206 design was to enhance the immune responses pairs by targeting PD-L1 while inhibiting VEGF and TGF-ß in the TME. Our data demonstrated that DR30206 exhibits high antigen-binding affinities and efficient blocking capabilities, the principal drivers of efficacy in antibody therapy. Furthermore, the capability of eliciting antibody-dependent cellular cytotoxicity (ADCC) and mixed lymphocyte reaction (MLR) provides a greater possibility to enhance the immune response. Finally, in vivo experiments showed that the antitumor activity of DR30206 was superior to those of monoclonal antibody of PD-L1 or VEGF, PD-L1 and TGF-ß bispecific antibody or the combination inhibition of PD-L1 and VEGF. Our findings suggest there is a great potential for DR30206 to become a therapeutic for the treatment of multiple cancer types, especially lung cancer, colon adenocarcinoma and breast carcinoma.

Serotonin 2A Receptor (5-HT2AR) Agonists: Psychedelics and Non-Hallucinogenic Analogues as Emerging Antidepressants.

Psychedelics make up a group of psychoactive compounds that induce hallucinogenic effects by activating the serotonin 2A receptor (5-HT2AR). Clinical trials have demonstrated the traditional psychedelic substances like psilocybin as a class of rapid-acting and long-lasting antidepressants. However, there is a pressing need for rationally designed 5-HT2AR agonists that possess optimal pharmacological profiles in order to fully reveal the therapeutic potential of these agonists and identify safer drug candidates devoid of hallucinogenic effects. This Perspective provides an overview of the structure-activity relationships of existing 5-HT2AR agonists based on their chemical classifications and discusses recent advancements in understanding their molecular pharmacology at a structural level. The encouraging clinical outcomes of psychedelics in depression treatment have sparked drug discovery endeavors aimed at developing novel 5-HT2AR agonists with improved subtype selectivity and signaling bias properties, which could serve as safer and potentially nonhallucinogenic antidepressants. These efforts can be significantly expedited through the utilization of structure-based methods and functional selectivity-directed screening.

Design and Synthesis of Novel GPR139 Agonists with Therapeutic Effects in Mouse Models of Social Interaction and Cognitive Impairment.

The GPR139 receptor is an orphan G-protein-coupled receptor (GPCR) mainly found in the central nervous system and is a potential therapeutic target for the treatment of schizophrenia and drug addiction. Guided by the reported structure of GPR139, we conducted medicinal chemistry optimizations of TAK-041, the GPR139 agonist in clinical trials. New compounds with three different core structures were designed and synthesized, and their activity at GPR139 was evaluated. Among them, compounds 15a (EC50 = 31.4 nM) and 20a (EC50 = 24.7 nM) showed potent agonist activity at GPR139 and good pharmacokinetic properties. In murine schizophrenia models, both compounds rescued the social interaction deficits observed in BALB/c mice. Compound 20a also alleviated cognitive deficits in mice with a pharmacologically induced model of schizophrenia. These findings further demonstrated the potential of GPR139 agonists in alleviating the negative symptoms and cognitive deficits of schizophrenia. Compound 20a is worth further evaluation as an antischizophrenia drug candidate.

Design and Synthesis of Triazole-Containing HDAC Inhibitors That Induce Antitumor Effects and Immune Response.

Histone deacetylase (HDAC) is an epigenetic antitumor drug target, but most existing HDAC inhibitors show limited antitumor activity and their use is often accompanied by serious adverse effects. To overcome these problems, we designed and synthesized a series of triazole-containing compounds as novel HDAC inhibitors. Among them, compound 19h exhibited potent and selective inhibition of HDAC1, with good antiproliferative activity in vitro and an excellent pharmacokinetic profile. Compound 19h significantly inhibited the growth of human tumor xenografts in nude mice and murine tumor growth in immune-competent mice bearing MC38 colon cancer. In the MC38 model, 19h increased the ratio of splenic CD4+ T effector cells and promoted complete tumor regression in 5/6 animals when combined with the mPD-1 antibody. These results suggested that selective class I HDAC inhibitors exert direct tumor growth inhibition and indirect immune cell-mediated antitumor effects and are synergistic with immune checkpoint inhibitors.

Comparative Analysis of the Phenolic Profile of Lycium barbarum L. Fruits from Different Regions in China.

Lycium barbarum L. (LB) fruits have high nutritive values and therapeutic effects. The aim of this study was to comprehensively evaluate the differences in phenolic composition of LB fruits from different geographical regions. Different methods of characterization and statistical analysis of data showed that different geographic sources of China could be significantly separated from each other. The highest total phenolic compound (TPC) content was observed in LB fruits from Ningxia (LBN), followed by those from Gansu (LBG) and Qinghai (LBQ). The Fourier transform infrared (FTIR) spectra of LB fruits revealed that LBQ had a peak at 2972 cm-1 whereas there was no similar peak in LBG and LBQ. A new HPLC method was established for the simultaneous determination of 8 phenolic compounds by quantitative analysis of multiple components by a single marker (QAMS), including 4 phenolic acids (chlorogenic acid, caffeic acid, 4-hydroxycinnamic acid, and ferulic acid), 1 coumarin (scopoletin), and 3 flavonoids (kaempferol-3-O-rutinoside, rutin, and narcissoside). It was showed that rutin was the most dominant phenolic compound in LBQ, although the average content of 4 phenolic acids was also high in LBQ, and scopoletin was the richest in LBG. UHPLC-Q-TOF-MS was used to qualitatively analyze the phenolics, which showed LBN was abundant in phenolic acids, LBQ was rich in flavonoids, and coumarins were the most plentiful in LBG. In conclusion, this study can provide references for the quality control and evaluation of phenolics in LB fruits and their by-products.

Regulation of immune complex formation and signalling by FERONIA, a busy goddess in plant-microbe interactions.

Being sessile in soil, plant cells rely on cell-surface receptors to sense and transduce environmental stimulus signals into intracellular responses. FERONIA (FER), a Catharanthus roseus receptor-like kinase 1-like protein, has emerged as a versatile regulator of plant growth, development, and stress responses. In recent years, accumulating studies have witnessed rapid advances in dissecting the mechanisms underlying the interaction between FER and its partners in response to pathogen invasion, particularly regulation of immune complex formation and signalling. Moreover, hormonal signalling, rhizosphere microbiota and other constituents are also extensively involved in these processes.

Design, synthesis and biological evaluation of novel osimertinib derivatives as reversible EGFR kinase inhibitors.

A series of osimertinib derivatives without acrylamide groups were synthesized and their inhibitory rates against L858R/T790M/C797S mutated EGFR kinase and antiproliferation activities against non-small cell lung cancer cell lines (A549, H1975) were evaluated. The preferred compounds were selected and their in vitro inhibitory activities against various EGFR kinases (wild-type, L858R/T790M, L858R/T790M/C797S) and c-Met kinase were tested. Compound 9h showed remarkable inhibitory activity against the wild type (IC50 = 29 nM), L858R/T790M mutant type (IC50 = 10 nM) and L858R/T790M/C797S mutant type (IC50 = 242 nM) as reversible EGFR kinase inhibitor, which was selected to further perform the AO/EB staining assays, cell cycle distribution assays and wound-healing assays on A549 and/or H1975 cell lines. The results showed dose-dependent activities of the induction of cell apoptosis, G1/G0-phase arrestation and inhibition of migration. Compound 22a showed remarkable inhibitory activity against the L858R/T790M/C797S mutant EGFR kinase (IC50 = 137 nM), which was nearly three times compared to osimertinib (IC50 = 410 nM). It's worth noting that 22a exhibited excellent kinase selectivity against the L858R/T790M/C797S mutant EGFR kinase rather than the wild-type, which reached 5.4 times and far more than the 0.012 times of osimertinib. Additionally, molecular docking analyses were performed to explain the action modes between the compounds and the corresponding EGFR kinases. In conclusion, compounds 9h and 22a have been demonstrated as promising candidates and worth further study.

Dual-acting antitumor agents targeting the A2A adenosine receptor and histone deacetylases: Design and synthesis of 4-(furan-2-yl)-1H-pyrazolo[3,4-d]pyrimidin-6-amine derivatives.

Based on its inhibition by antagonists, the A2A adenosine receptor (A2AAR) has attracted attention as an anti-tumor drug target; however, in preclinical models and clinical trials, A2AAR antagonists have so far shown only limited efficacy as standalone therapies. The design of dual-acting compounds, targeting the A2AAR and histone deacetylases (HDACs), is used here as an approach to the discovery of novel and more potent antitumor agents. Based on the core structures of the A2AAR antagonists V-2006 and CPI-444, novel 4-(furan-2-yl)-1H-pyrazolo[3,4-d]pyrimidin-6-amine derivatives were designed as such dual-acting compounds. The binding affinities for A2AAR of all the new compounds were tested, and their HDAC inhibitory activity was evaluated. Compounds with balanced A2AAR antagonism and HDAC inhibition were tested for their in vitro anti-proliferative activity and pharmacokinetic properties. One of the compounds, 14c (4-(2-(6-Amino-4-(furan-2-yl)-1H-pyrazolo[3,4-d]pyrimidin-1-yl)ethyl)-N-(2-amino-phenyl)benzamide) showed an overall favorable pharmacokinetic profile; in the mouse MC38 xenograft model, it showed potent anti-tumor effects with inhibition rates of 44% (90 mg/kg, po, bid) and 85% (60 mg/kg, ip, bid), respectively.

Development and comparison of three 89Zr-labeled anti-CLDN18.2 antibodies to noninvasively evaluate CLDN18.2 expression in gastric cancer: a preclinical study.

BACKGROUND: Isoform 2 of claudin 18 (CLDN18.2) is overexpressed in gastric cancer and may be a promising imaging target. In this study, we constructed three anti-CLDN18.2 antibodies and compared them in preclinical experiments. METHODS: Screening from anti-CLDN18.2 nanobody library, we constructed three antibodies, anti-CLDN18.2 VHH (recombinant single-chain antibody fused with poly-histidine-tag), anti-CLDN18.2 VHH-ABD (recombinant single-chain antibody fused fused with albumin binding domain), and anti-CLDN18.2 VHH-Fc (recombinant single-chain antibody fused with IgG1-Fc) and radiolabeled with 89Zr. Affinity assay, in vitro stability, immunoactivity, blood pharmacokinetics, in vivo and ex vivo biodistribution study, specificity study, and immunohistochemical analysis were performed to assess these radiotracers. RESULTS: The EC50 were 12.21 nM, 2.48 nM, and 0.14 nM for anti-CLDN18.2 VHH, anti-CLDN18.2 VHH-ABD, and anti-CLDN18.2 VHH-Fc, respectively. 89Zr-anti-CLDN18.2 VHH demonstrated the lowest tumor uptake in PET imaging. Both 89Zr-anti-CLDN18.2 VHH-ABD and 89Zr-anti-CLDN18.2 VHH-Fc demonstrated high tumor accumulation, with highest ID%/g of 25.78 ± 5.60 at 24 h post-injection with 89Zr-anti-CLDN18.2 VHH-ABD and 49.43 ± 9.86 at 72 h post-injection with 89Zr-anti-CLDN18.2 VHH-Fc. The specificity of 89Zr-anti-CLDN18.2 VHH-Fc targeting CLDN18.2 was further confirmed by blocking study. The ex vivo biodistribution results were consistent with in vivo biodistribution data. For 89Zr-anti-CLDN18.2 VHH-ABD, tumor uptake was 21.46 ± 1.78 ID%/g at 12 h and 13.73 ± 2.22 ID%/g at 108 h. For 89Zr-anti-CLDN18.2 VHH-Fc, the tumor accumulation was 25.28 ± 3.83 ID%/g at 12 h and 40.13 ± 9.50 ID%/g at 108 h. Immunohistochemistry of the xenograft tissue revealed high and homogenous CLDN18.2 expression in CO-SNU620 tumor. CONCLUSION: Both anti-CLDN18.2 VHH-ABD and anti-CLDN18.2 VHH-Fc can be efficiently and stably radiolabeled with 89Zr for noninvasive imaging and quantification of CLDN18.2 expression in gastric cancer, of which 89Zr-anti-CLDN18.2 VHH-ABD seems to be the optimal choice balancing tumor uptake and liver background. They can provide essential information to select patients who are likely to benefit from CLDN18.2-targeted treatment.

Component Analysis and Anti-Colorectal Cancer Mechanism via AKT/mTOR Signalling Pathway of Sanghuangporus vaninii Extracts.

Sanghuangporus vaninii (Ljub.) L.W. Zhou & Y.C. Dai (SV) is a major cultivar of Sanghuang, which is well known as an excellent anti-tumour drug and reaches the mainstream market in China. Water, 60% ethanol and 95% ethanol were used to extract the drug, and three kinds of polar extracts were obtained separately. Compared with water extracts and 95% ethanol extracts, the 60% ethanol extract had the highest flavonoid content, and its polysaccharide content was greater than that in the 95% ethanol extract and lower than that in the water extract. Its essential components were phenolics whose majority were phenolic acids, flavonoids and phenylpropanoids. This extract has better inhibition effects on the proliferation of SW480 human colon cancer cells, inducing cell apoptosis and blocking G2/M period cells. It can significantly inhibit gene expression and reduce the activation of the AKT/mTOR signalling pathway. The anti-cancer activity of the 60% ethanol extract is satisfactory and may be a result of the combined effects of polysaccharides and flavonoids. The data suggest that the 60% ethanol extract can be used as an adjuvant for chemotherapy and as a potential anti-cancer agent with broad development prospects.

DNA Repair Genes Are Associated with Subtype Classification, Prognosis, and Immune Infiltration in Uveal Melanoma.

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. DNA repair genes play a vital role in cancer development. However, there has been very little research about DNA repair genes in UM. This study aimed to evaluate the importance of DNA repair genes and established a signature for predicting prognosis and immune features of UM. In this study, we mined TCGA database through bioinformatics analysis, and the intersect was taken between DNA repair genes and prognosis related genes and yielded 52 genes. We divided 80 UM patients into C1 and C2 subtypes. GSEA results indicated that abundant cancer-promoting functions and signaling pathways were activated in C2 subtype and the proportion of SNVs was higher in C2 than in C1 which suggested a worse prognosis. We built a six DNA repair genes model including ITPA, CETN2, CCNO, POLR2J, POLD1, and POLA1 by LASSO regression to predict prognosis of UM patients and utilized the median value of risk scores as the cutoff point to differentiate high risk and low risk group. The survival analyses and the receiver operating characteristic (ROC) curves in the validation group and entire data set confirmed the accuracy of this model. We also constructed a nomogram based on age and risk scores to evaluate the relationship between risk scores and clinical outcome. The calibration curve of the overall survival (OS) indicated that the performance of this model is steady and robust. Finally, the enrichment analysis showed that there were complex regulatory mechanisms in UM patients. The immune infiltration analysis indicated that the immune infiltration in C2 in the high risk group was different from that in the low risk group. Our findings indicated that the DNA repair genes may be related to UM prognosis and provide new insight into the underlying mechanisms.

Probing membrane protein interactions and signaling molecule homeostasis in plants by Förster resonance energy transfer analysis.

Membrane proteins have key functions in signal transduction, transport, and metabolism. Therefore, deciphering the interactions between membrane proteins provides crucial information on signal transduction and the spatiotemporal organization of protein complexes. However, detecting the interactions and behaviors of membrane proteins in their native environments remains difficult. Förster resonance energy transfer (FRET) is a powerful tool for quantifying the dynamic interactions and assembly of membrane proteins without disrupting their local environment, supplying nanometer-scale spatial information and nanosecond-scale temporal information. In this review, we briefly introduce the basic principles of FRET and assess the current state of progress in the development of new FRET techniques (such as FRET-FLIM, homo-FRET, and smFRET) for the analysis of plant membrane proteins. We also describe the various FRET-based biosensors used to quantify the homeostasis of signaling molecules and the active state of kinases. Furthermore, we summarize recent applications of these advanced FRET sensors in probing membrane protein interactions, stoichiometry, and protein clustering, which have shed light on the complex biological functions of membrane proteins in living plant cells.

Design, synthesis and biological evaluation of novel N-(3-amino-4-methoxyphenyl)acrylamide derivatives as selective EGFRL858R/T790M kinase inhibitors.

On the basis of N-(3-amino-4-methoxyphenyl)acrylamide scaffold, a series of novel compounds containing 3-substitutional-1-methyl-1H-indole, 2-substitutional pyrrole or thiophene moieties were synthesized and their in vitro antiproliferation activities against A549 and H1975 cell lines were evaluated. The results indicated that most of the compounds showed moderate to excellent antitumor activities. Especially, compounds 9a (A549 IC50 = 1.96 µM, H1975 IC50 = 0.095 µM), 17i (A549 IC50 = 4.17 µM, H1975 IC50 = 0.052 µM), 17j (A549 IC50 = 1.67 µM, H1975 IC50 = 0.061 µM) exhibited comparable antitumor activities and selectivity ratios compared to the positive control osimertinib (A549 IC50 = 2.91 µM, H1975 IC50 = 0.064 µM). In vitro inhibitory activities against EGFR kinases containing different mutations were also tested. Compound 17i showed remarkable inhibitory activity (with IC50 value of 1.7 nM) to EGFRL858R/T790M kinase and selectivity (22-folds compared to EGFRWT kinase). Furthermore, acridine orange/ethidium bromide (AO/EB) staining assay, cell apoptosis assay, cell cycle distribution assay and wound-healing assay of the compounds 9a and 17i were performed on H1975 cell line. The results showed dose-dependent activities of the induction of apoptosis, G0/G1-phase arrestation and inhibition of migration, which were similar to the positive control osimertinib. Additionally, molecular docking analysis was performed to seek the possible binding mode between the selected compounds (9a, 17i-17j) and EGFRL858R/T790M kinase. The results demonstrated that compound 17i is a promising candidate and worth further study.

Carbon-silicon switch led to the discovery of novel synthetic cannabinoids with therapeutic effects in a mouse model of multiple sclerosis.

Cannabinoids are widely studied as therapeutic agents for the treatment of various diseases. Among them, THC and CBD are two important phytocannabinoids which have served as structural templates for the design of synthetic analogs. In this study, we designed and synthesized a variety of novel cannabinoids based on the structural backbones of THC and CBD using the carbon-silicon switch strategy. A dimethyl silyl group was introduced as the tail group and two series of novel compounds were designed and synthesized, which showed a wide range of binding affinity for CB1 and CB2 receptors. Among them, compound 15b was identified as a non-selective CB1 and CB2 agonist and 38b as a selective agonist for the CB2 receptor. Preliminary screening showed that both compounds have improved metabolic stability than their carbon analogs and good in vivo pharmacokinetic profiles. Furthermore, both 15b and 38b significantly alleviated the phenotype of experimental autoimmune encephalomyelitis (EAE) in mice.

Discovery of selective HDAC/BRD4 dual inhibitors as epigenetic probes.

According to the binding mode of ABBV-744 with bromodomains and the cape space of HDAC, the novel selective HDAC/BRD4 dual inhibitors were designed and synthesized by the pharmacophore fusion strategy. Evaluating the biomolecular activities through SARs exploration identified three kinds of selective dual inhibitors 41c (HDAC1/BRD4), 43a (pan-HDAC/BRD4) and 43d (HDAC6/BRD4(BD2)), whose target-related cellular activities in MV-4-11 cells were also confirmed. Significantly, the selective dual inhibitor 41c (HDAC1/BRD4) exhibited synergistic effects against MV-4-11 cells, which strongly induced G0/G1 cell cycle arrest and apoptosis, and the first HDAC6/BRD4(BD2) dual inhibitor was found. This study provides support for selective HDAC/BRD4 dual inhibitors as epigenetic probes based on pyrrolopyridone core for the future biological evaluation in different cancer cell lines.

Tumor Immunotherapy Using A2A Adenosine Receptor Antagonists.

The A2A adenosine receptor (A2AAR) plays critical roles in human physiology and pathophysiology, which makes it an important drug target. Previous drug-discovery efforts targeting the A2AAR have been focused on the use of A2AAR antagonists for the treatment of Parkinson's disease. More recently, the A2AAR has attracted additional attention for its roles in immuno-oncology, and a number of A2AAR antagonists are currently used as lead compounds for antitumor drugs in both preclinical models and clinical trials. This review surveys recent advances in the development of A2AAR antagonists for cancer immunotherapy. The therapeutic potential of representative A2AAR antagonists is discussed based on both animal efficacy studies and clinical data.

Design, Synthesis, and Biological Evaluation of the First c-Met/HDAC Inhibitors Based on Pyridazinone Derivatives.

Simultaneous blockade of more than one pathway is considered to be a promising approach to overcome the low efficacy and acquired resistance of cancer therapies. Thus, a novel series of c-Met/HDAC bifunctional inhibitors was designed and synthesized by merging pharmacophores of c-Met and HDAC inhibitors. The most potent compound, 2m, inhibited c-Met kinase and HDAC1, with IC50 values of 0.71 and 38 nM, respectively, and showed efficient antiproliferative activities against both EBC-1 and HCT-116 cells with greater potency than the reference drug Chidamide. Western blot analysis revealed that compound 2m inhibited phosphorylation of c-Met and c-Met downstream signaling proteins and increased expression of Ac-H3 and p21 in EBC-1 cells in a dose-dependent manner. Our study presents novel compounds for the further exploration of dual c-Met/HDAC pathway inhibition achieved with a single molecule.

ProC-TEL: Profiling of Protein C-Termini by Enzymatic Labeling.

Proteins are frequently processed by proteases in cell signaling pathways to perform their biological functions in response to environmental stimuli. Identification of the exact cleavage sites provides necessary information for the study of their biological functions. Although proteomic approaches for profiling of protein N-termini have been developed extensively in the past few years, the N-terminal profiling strategy has its inherent disadvantages. Therefore, C-terminal profiling approaches might be a complementary approach for the identification of protein cleavages although it has similar shortcomings as N-terminal profiling methods. In this protocol, we describe an approach, termed ProC-TEL: Profiling of Protein C-Termini by Enzymatic Labeling, for affinity labeling of protein C-termini for a protein or proteome. This method uses the transpeptidase activity of carboxypeptidase Y to label protein C-termini with an affinity biotin tag for subsequent isolation with avidin beads and identification by mass spectrometer. It is complementary to the N-terminal profiling approaches and can be used to identify proteolytic cleavages for a specific protease or in cell signaling events, such as apoptosis.

Nitric oxide donor hybrid compounds as promising anticancer agents.

Nitric oxide (NO) plays important roles in cardiovascular regulation, nerve transmission delivery and immune responses. In the last semicenturry, it has been proved that though low concentration of NO is tumor-promoting, high concentration of NO could exhibit multiple antitumor effects, which led to the research and development of kinds of NO donors and NO donor hybrid compounds as antitumor agents. Herein, the recent development of NO donor hybrid compounds is briefly reviewed.