The roles of PD‐1/PD‐L1 and its signalling pathway in gastrointestinal tract cancers

Cancer immunotherapy has been increasingly applied in the treatment of advanced malignancies. Consequently, immune checkpoints have become a major concern. As PD‐1 is an important immunomodulatory protein, the blockade of PD‐1 and its ligand PD‐L1 is a promising tumour immunotherapy for human carcinoma. In this review, we first discuss the role of the PD‐1/PD‐L1 interaction in gastrointestinal tract cancers. Targeting PD‐1 and PD‐L1 in immune cells and tumour cells may show remarkable efficiency in gastrointestinal tract cancers. Second, the PD‐1/PD‐L1‐associated signalling pathway involved in cancer immunotherapy in gastrointestinal tract cancers is discussed. Most importantly, this review summarizes the PD‐1/PD‐L1‐targeted immunotherapy combinations with relevant signalling pathways, which may result in a breakthrough for the treatment of gastrointestinal tract cancers, such as gastric cancer, colorectal cancer and liver cancer. Meanwhile, the review provides a deeper insight into the mechanism of checkpoint blockade immunotherapies.     

Analyzing the percentage of different PD‐1+ T cell subsets in peripheral blood and bronchoalveolar lavage fluid of small cell lung cancer patients: A prospective study

The present study was designed to evaluate the percentage of different programmed cell death‐1 (PD‐1)⁺ T cell subsets in peripheral blood and bronchoalveolar lavage fluid (BALF) of small cell lung cancer (SCLC) patients. The percentages of PD‐1⁺ T cell subsets in peripheral blood and BALF samples obtained from 52 lung cancer and 20 pneumonia patients, and 20 healthy controls were examined by flow cytometry. In addition, clinical parameters, such as erythrocyte sedimentation rate (ESR) and C‐reactive protein (CRP) levels, were also determined using Spearman's correlation test to assess their association with PD‐1⁺ T cell subsets. These present results revealed that the percentage of circulating PD‐1⁺ Tfh and peripheral helper T cells (Tph) cells significantly increased in peripheral blood of SCLC patients, when compared to non‐small cell lung cancer (NSCLC) pneumonia patients and healthy controls. In addition, PD‐1⁺ Tfh cells were also significantly enhanced in patients in the extensive‐stage group. In contrast, the BALF samples of SCLC patients exhibited a significant decrease in percentage of Tph cells. An overall imbalance was observed between PD‐1⁺Tfh and Tph cells in both compartments. Furthermore, SCLC patients exhibited a significant decrease in the percentage of circulating PD‐1⁺ Tfh and Tph cells following chemotherapy, and the in vitro analysis revealed that the concentration of IL‐2 and IFN‐γ derived from PD‐1 + Tfh cells in SCLC were significantly lower than that from NSCLC. However, this had no significant correlation with disease severity. The present study indicated that elevated circulating PD‐1⁺ T cells can primarily be used as a biomarker for disease diagnosis and a potential therapeutic target.     

Synthesis and characterization of tritium labeled N‐((R)‐1‐((S)‐4‐(4‐chlorophenyl)‐4‐hydroxy‐3,3‐dimethylpiperidin‐1‐yl)‐3‐methyl‐1‐oxobutan‐2‐yl)‐3‐sulfamoylbenzamide

N‐((R)‐1‐((S)‐4‐(4‐chlorophenyl)‐4‐hydroxy‐3,3‐dimethylpiperidin‐1‐yl)‐3‐methyl‐1‐oxobutan‐2‐yl)‐3‐sulfamoylbenzamide is a potent C‐C chemokine receptor 1 (CCR1) antagonist. The compound, possessing benzamide functionality, successfully underwent tritium/hydrogen (T/H) exchange with an organoiridium catalyst (Crabtree's catalyst). The labeling pattern in the product was studied with liquid chromatography–mass spectrometry, time‐of‐flight mass spectrometry, and ³H‐NMR. Overall, multiple labeled species were identified. In addition to the anticipated incorporation of tritium in the benzamide moiety, tritium labeling was observed in the valine portion of the molecule including substitution at its chiral carbon. Using authentic standards, liquid chromatography analysis of the labeled compound showed complete retention of stereochemical configuration.     

Key mechanisms underlying netrin‐1 prevention of impaired spatial and object memory in Aβ1‐42 CA1‐injected rats

Alzheimer's disease (AD) is a neurodegenerative disorder with an incompletely defined aetiology that is associated with memory and cognitive impairment. Currently available therapeutics only provide temporary assistance with symptoms. In spite of plentiful research in the field and the generation of thousands of studies, much is still to be clarified on precise mechanisms of pathobiology, prevention modalities, disease course and cure. Netrin‐1, a laminin family protein, is said to have anti‐inflammatory and anti‐apoptotic effects and has a key role in neurogenesis and morphogenesis of neural structures. Accordingly, this study was designed to investigate protective effects of bilateral intrahippocampal fissure microinjections of netrin‐1 on memory impairment in rat model of AD. Concomitant administration of netrin‐1 with amyloid beta 1‐42 (Aβ_1‐42) improved cognitive dysfunction in novel object recognition task (NOR), ameliorated impaired spatial memory in Morris water maze (MWM) setting, increased neuronal density and reduced amyloid aggregation in rat AD model. Netrin‐1 was also seen to prevent Aβ_1‐42‐induced caspase‐3, caspase‐7 and NF‐κB (nuclear factor kappa‐light‐chain‐enhancer of activated B cells) activation. Therefore, based on the data reported here, netrin‐1 may be a promising biologic therapeutic that addresses the memory and neuronal loss associated with AD.     

克罗恩病患者疾病活动指数应对方式与抑郁的相关性研究

目的 调查分析克罗恩病患者的疾病活动指数、应对方式与抑郁的相关性,为制订针对性的干预措施提供依据。 方法 以Harvey简化CDAI计算法、抑郁自评量表(SDS) 、应对方式量表(MCMQ)对100例克罗恩病患者进行调查。 结果 62%的克罗恩病患者存在抑郁;克罗恩病患者疾病活动指数与抑郁呈正相关(r=0.556,P< 0.01);面对与抑郁呈负相关(r=-0.578,P< 0.01);回避与抑郁呈正相关(r=0.165,P< 0.05);屈服与抑郁呈正相关(r=0.215,P< 0.01)。 结论 克罗恩病患者多存在抑郁,与疾病程度和应对方式有一定相关性,护理人员应根据患者特点进行心理护理,减少患者抑郁。     

18F‐labelling of a potent nonpeptide CCR1 antagonist: synthesis of 1‐(5‐chloro‐2‐{2‐[(2R)‐4‐(4‐[18F]fluorobenzyl)‐2‐methylpiperazin‐1‐yl]‐2‐oxoethoxy}phenyl)urea in an automated module

The synthesis of 1‐(5‐chloro‐2‐{2‐[(2R)‐4‐(4‐[¹⁸F]fluorobenzyl)‐2‐methylpiperazin‐1‐yl]‐2‐oxoethoxy}phenyl)urea ( [¹⁸F]4 ), a potent nonpeptide CCR1 antagonist, is described as a module‐assisted two‐step one‐pot procedure. The final product was obtained utilizing the reductive amination of the formed 4‐[¹⁸F]fluorobenzaldehyde ( 2 ) with a piperazine derivative 3 and sodium cyanoborohydride. After HPLC purification of the final product [¹⁸F]4 , its solid phase extraction, formulation and sterile filtration, the isolated (not decay‐corrected) radiochemical yields of [¹⁸F]4 were between 7 and 13% (n=28). The time of the entire manufacturing process did not exceed 95 min. The radiochemical purity of [¹⁸F]4 was higher than 95%, the chemical purity ?60% and the enantiomeric purity >99.5%. The specific radioactivity was in the range of 59–226 GBq/µmol at starting radioactivities of 23.6–65.0 GBq [¹⁸F]fluoride. Copyright © 2006 John Wiley & Sons, Ltd.     

Design,synthesis, and biological evaluation of 4‐aminopyrimidine or 4,6‐diaminopyrimidine derivatives as beta amyloid cleaving enzyme‐1 inhibitors

A series of novel aminopyrimidine and diaminopyrimidine derivatives were designed and optimized to improve their potency and permeability relative to lead compound 1 (IC₅₀ = 37.4 μM), which was discovered in a previous virtual screening. The potency of the optimized compound, 13g (IC₅₀ = 1.4 μM), was 26‐fold greater than that of 1 based on a fluorescence resonance energy transfer assay, and a parallel artificial membrane permeability assay suggested that it could pass through the blood‐brain barrier. Additionally, several compounds containing selenium showed good potencies and deserve further investigation as anti‐Alzheimer's agents.     

A novel method for the synthesis of carbon‐14‐labeled N‐[3‐(1‐methyl‐4‐piperidinyl)‐1H‐pyrrolo[3,2‐b]pyridin‐5‐yl]propanamide and its use in quantitative whole‐body autoradiography studies

Sumitriptan ( 1 ), a non‐selective 5‐HT_1B/1D agonist is an effective therapeutic agent for the acute treatment of migraine, but it is contraindicated for use in patients with known heart disease. The first Selective Serotonin One F Receptor Agonist (SSOFRA), 5‐(4′‐fluorobenz‐amido)‐3‐(N‐methyl‐piperidin‐4‐yl)‐1H‐indole ( 2 ) was demonstrated to be clinically useful in the treatment of migraine. Although 2 exhibited high affinity for the 5‐HT_1F receptor as well as high selectivity for the 5‐HT_1F receptor relative to 5‐HT_1B and 5‐HT_1D receptors, it demonstrated appreciable affinity for the 5‐HT_1A receptor. Subsequently, a program was launched to discover SSOFRA's with improved selectivity over other 5‐HT₁ receptor subtypes. As a result of these efforts, N‐[3‐(1‐methyl‐4‐piperidinyl)‐1H‐pyrrolo[3,2‐b]pyridin‐5‐yl]propanamide ( 3 ) was found to possess greater than 100‐fold selectivity over 5‐HT_1A, 5‐HT_1B and 5‐HT_1D receptors. Pursuant to a potential clinical investigation of 3 , its carbon‐14‐labeled isotopomer has been prepared by a circuitous route from unlabeled 3 and used in quantitative whole‐body autoradiography studies in rats. The results of these efforts are reported herein. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis and 11C‐labelling of (E,E)‐1‐(3′,4′‐dihydroxystyryl)‐4‐(3′‐methoxy‐4′‐hydroxystyryl) benzene for PET imaging of amyloid deposits†

Carboxylic acid derivatives of the amyloid‐binding dye Congo red do not enter the brain well and are thus unable to serve as in vivo amyloid‐imaging agents. A neutral amyloid probe, (E,E)‐1‐(3′,4′‐dihydroxystyryl)‐4‐(3′‐methoxy‐4′‐hydroxystyryl)benzene ( 3 ), devoid of any carboxylate groups has been designed and synthesized via a 12‐step reaction sequence with a total yield of 30%. The unsymmetric compound 3 has also been labelled with C‐11 via [¹¹C]methyl iodide ([¹¹C]CH₃I) methylation of a symmetric 4,4′‐dimesyl protected precursor followed by deprotection. Preliminary evaluation indicated that compound 3 selectively stained plaques and neurofibrillary tangles in post‐mortem AD brain, and exhibited good binding affinity (K_i=38±8 nM) for Aβ(1–40) fibrils in vitro. In vivo pharmacokinetic studies indicated that [¹¹C] 3 exhibited higher brain uptake than its carboxylic acid analogs and good clearance from normal control mouse brain. [¹¹C] 3 also exhibited specific in vivo binding to pancreatic amyloid deposits in the NOR‐beta transgenic mouse model. These results justify further investigation of 3 and similar derivatives as surrogate markers for in vivo quantitation of amyloid deposits. Copyright © 2002 John Wiley & Sons, Ltd.     

Interaction of metronidazole with phenobarbital, cimetidine, prednisone, and sulfasalazine in Crohn's disease

The influence of prednisone(PR), sulfasalazine(SZ), cimetidine(CM), and phenobarbital(PB) on the pharmacokinetics of metronidazole was investigated in six Crohn's patients. Metronidazole was first administered alone (250 mg bid, po) and then with prednisone (10 mg bid, po), sulfasalazine (1 g bid, po), cimetidine (600 mg bid) or phenobarbital (60 mg bid, po). Each regimen was followed for 6 days and sampling of blood and urine was carried out on the 7th day after the first dose of each regimen. Plasma and urine samples were analysed for the drug and its two principal metabolites, hydroxymetronidazole and metronidazole-1-acetic acid, by HPLC. When given alone, metronidazole had a mean volume of distribution of 0.667 +/- 0.15 lkg-1, a half-life of 9.7 +/- 3.1 h and an oral clearance of 0.852 +/- 0.23 (ml-1 min) kg-1. The disposition kinetics of metronidazole and its metabolites was not altered by CM and SZ. Induction of metabolism of metronidazole by PR was made manifest in significant increases in oral clearance of the former and urinary excretion of the hydroxy metabolite, and significant decrease in AUC of the parent compound. PB also induced the metabolism of metronidazole. This induction was reflected in significant increases in the oral clearance of metronidazole and AUC of the hydroxy metabolite as well as significant decreases in AUC, half-life, and urinary excretion of the parent drug.     

In silico screening and surface plasma resonance‐based verification of programmed death 1‐targeted peptides

Programmed death 1 (PD‐1) is a key immune checkpoint molecule. When it binds to programmed death‐ligand 1 (PD‐L1), it can negatively regulate the immune response. Therefore, blockade of the PD‐1/PD‐L1 interaction could unleash the power of immune system. Though successes achieved by anti‐PD‐1/PD‐L1 antibody drugs in clinical for various cancers, many intrinsic limitations of the high molecular weight drugs require alternatives such as peptide drugs and chemical compounds. In this study, we described a novel in silico approach which was used to screen peptides from PDB database and aimed to identify peptides that have potential to bind the PD‐L1 binding area of PD‐1 molecule. Based on the docking poses, eight peptides were synthesized and measured for their binding abilities by surface plasma resonance technique. The K_D values of the synthesized peptides ranged from 10.0 to 133.0 μM. Furthermore, the binding mechanism between PD‐1 and the peptides was studied. In conclusion, we established a fast and reliable screening method for peptide discovery, which could be applied for identifying peptide inhibitors of various targets. The synthesized peptides could be served as starting points for designing PD‐1 drug for cancer immunotherapy.     

Endoscopic and histologic evidence of persistent mucosal healing and correlation with clinical improvement following sustained infliximab treatment for Crohn's disease

ABSTRACT

Objectives: The long-term effect of infliximab on endoscopic and histologic disease activity and expression of inflammatory markers was assessed in Crohn's disease patients who received infliximab as episodic or scheduled maintenance therapy over 54 weeks (ACCENT I).

Methods: All patients received infliximab 5?mg/kg at week 0 and at week 2 were then randomized as responders or nonresponders to placebo or infliximab (5 or 10?mg/kg). Patients received placebo or infliximab 5?mg/kg at weeks 2 and 6 followed by placebo or infliximab (5 or 10?mg/kg) every 8 weeks or episodically on loss of response. Crohn's Disease Activity Index (CDAI), Crohn's Disease Endoscopic Index of Severity (CDEIS), Inflammatory Bowel Disease Questionnaire (IBDQ), and colonic and ileal Global Histologic Disease Activity (CGHAS and IGHAS) scores were determined at weeks 0, 10, and 54. Tumor necrosis factor-alpha (TNF‐α), gelatinase B, infliximab, tenascin, clusters of differentiation marker 68 (CD68), and intercellular adhesion molecule‐1 (ICAM‐1) were detected in mucosal biopsies by immunohistochemistry.

Results: At baseline, CDEIS significantly correlated with CGHAS only. Further at baseline, both CDEIS and the worst CGHAS or IGHAS, were significantly correlated with CD68, ICAM‐1, and gelatinase B expression. At week 10, improvement in CGHAS only, correlated significantly with better CDAI, CDEIS, and IBDQ scores. Improvements in CDEIS and GHAS at week 10 correlated with reductions in gelatinase B and CD68, whereas only GHAS improvement correlated with decreased TNF‐α expression. At week 54, decreased gelatinase B expression continued to correlate with improved CDEIS and GHAS while decreased CD68 and TNF-α expression correlated with GHAS and CDEIS improvement, respectively.

Conclusions: Endoscopic and histologic evidence of mucosal healing was associated with a sustained reduction in the expression of inflammatory markers. Infliximab-induced improvement in the clinical signs and symptoms of Crohn's disease was associated with endoscopic and histologic evidence of sustained mucosal healing.     

Angiotensin‐(1‐7)‐mediated Mas1 receptor/NF‐κB‐p65 signaling is involved in a cigarette smoke‐induced chronic obstructive pulmonary disease mouse model

Angiotensin‐(1‐7) [Ang‐(1‐7)] has been shown to play a significant role in the pathogenesis of lung inflammation via Mas receptor; however, its effect in chronic obstructive pulmonary disease (COPD) remains unknown. To explore the effect of Ang‐(1‐7) on a cigarette smoke (CS) exposure‐induced COPD model, 40 C57BL/6J mice were divided into four groups (n = 10) and exposed to air or CS for 8 weeks. After that, they were treated with saline or Ang‐(1‐7) at 0.3 mg/kg for 2 weeks by subcutaneous infusion using osmotic pump. The day following drug/vehicle challenge, lung function was examined and bronchoalveolar lavage (BAL) was performed. Chemokine (C–X–C motif) ligand 1, interleukin‐6, and tumor necrosis factor‐α protein levels in BAL fluid were determined using ELISA; the corresponding mRNA levels in lung tissues were measured using RT‐PCR. Mas1 receptor, pIκBα, IκBα, nuclear NF‐κB‐p65 protein, pERK1/2, ERK2, pp38, and p38 proteins expression in lung tissues were examined by immunohistochemical staining and western blotting. Ang‐(1‐7) challenge had no effect on the decreased lung function and emphysema induced by CS exposure. However, Ang‐(1‐7) treatment blocked CS exposure‐induced lung inflammatory responses and lung fibrosis, as determined by Masson's Trichrome staining. Exposure to CS for 8 weeks caused irreversible loss of lung function and emphysema, which could not be reversed by Ang‐(1‐7) treatment. Thus, the beneficial effect of Ang‐(1‐7) may be confined to pulmonary inflammation and fibrosis.     

Interstitial Foxp3‐positive T cells may predict renal survival in patients with myeroperoxidase anti‐neutrophil cytoplasmic antibody‐associated glomerulonephritis

1. Regulatory T cells (T_reg) and cytotoxic T cells (CTL) are involved in various immune diseases. However, the prognostic impact of T_reg and CTL in patients with myeroperoxidase anti‐neutrophil cytoplasmic antibody‐associated glomerulonephritis (MPO‐ANCA‐GN) is not well known. Therefore, in the present study, we examined the relationship between expression of forkhead box P3 (Foxp3) and T cell intracytoplasmic antigen (TIA)‐1, T_reg and CTL markers and renal survival in patients with MPO‐ANCA‐GN. 2. Forty patients with MPO‐ANCA‐GN and 10 patients with minimal change nephrotic syndrome (MCNS) underwent physical examination, determination of blood chemistry and renal biopsy. Immunohistochemical staining for Foxp3 and TIA‐1 was performed on paraffin‐embedded renal sections. 3. Although almost all patients received standard immunosuppressive treatment for 6 months, seven MPO‐ANCA‐GN patients needed maintenance haemodialysis (HD), whereas 33 patients did not (non‐HD). Both Foxp3‐ and TIA‐1‐positive cells were detected in the interstitium and glomeruli of MPO‐ANCA‐GN patients, whereas they were rarely detected in patients with MCNS. The total crescent rate was significantly higher in the HD group than in the non‐HD group (35.9 ± 3.5 vs 65.8 ± 7.4, respectively). In the interstitium, the age‐adjusted Foxp3/TIA‐1 ratio was significantly higher in the non‐HD group than in the HD group (0.016 ± 0.016 vs 0.004 ± 0.008, respectively; P < 0.05). The Foxp3/TIA‐1 ratio, but not the Foxp3/CD3 ratio, remained significantly higher in the non‐HD group than in the HD group even after adjustment for crescent rate. Age‐ and total crescent rate‐adjusted renal survival rates were higher in patients with a Foxp3/TIA‐1 ratio ≥ 0.06 than in patients with a Foxp3/TIA‐1 ratio < 0.06 (P = 0.02). 4. The results of the present study suggest that T_reg could play a protective role against MPO‐ANCA‐GN and that a decreased Foxp3/TIA‐1 ratio in interstitial areas may predict future renal failure in patients with MPO‐ANCA‐GN.