A series of novel 2-pyridinyl-3-(4-methylsulfonyl)phenylpyridines has been synthesized and evaluated with respect to their ability to inhibit the isozymes of cyclooxygenase, COX-1, and COX-2. Optimum ...COX-2 activity is observed by introduction of a substituent at C5 of the central pyridine. 5-Chloro-3-(4-methylsulfonyl)phenyl-2-(2-methyl-5-pyridinyl)pyridine
33 was identified as the optimum compound in this series.
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Several inflammatory diseases, including asthma, arthritis and psoriasis are associated with the production of leukotrienes by neutrophils, mast cells and macrophages. The initial enzymatic step in ...the formation of leukotrienes is the oxidation of arachidonic acid by 5-lipoxygenase (5-LO) to leukotriene A4. Osteosarcoma cells transfected with 5-LO express active enzyme in broken cell preparations, but no leukotriene metabolites are produced by these cells when stimulated with the calcium ionophore A23187, indicating that an additional component is necessary for cellular 5-LO activity. A new class of indole leukotriene inhibitor has been described that inhibits the formation of cellular leukotrienes but has no direct inhibitory effect on soluble 5-LO activity. We have now used these potent agents to identify and isolate a novel membrane protein of relative molecular mass 18,000 which is necessary for cellular leukotriene synthesis.
A series of 2,3-diarylthiophene compounds was prepared and their biological activities were evaluated against human Cox-1 and Cox-2 enzymes. It appears that the methylsulfone group is essential for ...both the activity and selectivity for the Cox-2 enzyme. Removal of the methylsulfone group gave relatively selective Cox-1 inhibitors.
Several 2,3-diarythiophene compounds were prepared and their activities against both cyclooxygenase isoforms were evaluated.
Metabolites of the COX-2 inhibitor rofecoxib (MK-0966, Vioxx™) were prepared by synthetic or biosynthetic methods. Metabolites include products of oxidation, glucuronidation, reduction and hydrolytic ...ring opening. Based on an in vitro whole blood assay, none of the known human metabolites of rofecoxib inhibits COX-1 nor contributes significantly to the inhibition of COX-2.
The thiophene ring of DuP 697 was replaced by a variety of heterocycles and the products were tested for their ability to inhibit human Cox-2 and Cox-1, the isozymes of cyclooxygenase.
The thiophene ...ring of DuP 697 was replaced by a variety of heterocycles and the products were tested for their ability to inhibit Cox-2 and Cox-1, the isozymes of cyclooxygenase.
A series of 5,6-diarylimidazo2.1-bthiazole compounds were prepared and their inhibitory potencies against COX-2 and Cox-1 enzymes were measured. This led to the identification of L-766,112 as a ...potent, orally active and selective inhibitor of the COX-2 enzyme.
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An indole class of leukotriene synthesis inhibitors, exemplified by MK-886, which does not directly inhibit 5-lipoxygenase, has been shown to bind to an 18-kDa leukocyte membrane protein and to ...inhibit 5-lipoxygenase membrane translocation. It was demonstrated that the 18-kDa protein is necessary for the cellular activation of leukotriene synthesis and was named 5-lipoxygenase-activating protein (FLAP). We describe here a class of leukotriene synthesis inhibitors based on a quinoline structure, which is structurally distinct from MK-886. However, similar to MK-886, several quinolines are potent inhibitors of cellular leukotriene synthesis but are poor inhibitors of soluble 5-lipoxygenase. To determine whether FLAP is the protein target of leukotriene synthesis inhibitors of the quinoline class, we investigated the ability of these compounds to inhibit photoaffinity labeling of FLAP and to elute FLAP from indole affinity gels. The abilities of the quinoline inhibitors to interact with FLAP correlated well with their abilities to inhibit leukotriene synthesis in human polymorphonuclear leukocytes. L-674,573, a potent quinoline leukotriene synthesis inhibitor, inhibited indole photoaffinity labeling of FLAP in a concentration-dependent manner. In addition, L-674,573 selectively eluted FLAP from indole affinity gels, in contrast to L-671,480, a quinoline that was inactive as an inhibitor of leukotriene synthesis. When human leukocyte membranes were labeled with the indole photoaffinity probe 125IL-669,083 and immunoprecipitated with a FLAP antibody, the labeling of FLAP was inhibited by L-674,573 but not by L-671,480. These results suggest a direct binding site for the quinoline leukotriene synthesis inhibitors on FLAP and provide further evidence for the essential role of FLAP in cellular leukotriene synthesis.
Background.
Angiosarcomas account for <2% of all soft tissue sarcomas. This subtype is one of the most aggressive forms of soft tissue sarcoma. The prognosis for angiosarcoma patients in the advanced ...phase remains poor with current cytotoxic agents (progression‐free survival PFS time of ∼4 months and overall survival OS time of ∼8 months). We investigated the antitumor activity of sorafenib in patients with metastatic or advanced angiosarcomas in a phase II trial.
Methods.
We conducted a stratified phase II trial. The primary endpoint was the progression‐free rate (PFR) at 9 months according to the Response Evaluation Criteria in Solid Tumors. A two‐stage design (optimal Simon design) was used. Patients received sorafenib (400 mg twice daily) for 9 months until unacceptable toxicity or tumor progression. Central pathological and radiological reviews were performed. Data on stratum A (superficial angiosarcoma) and stratum B (visceral angiosarcoma) are currently available. This trial is registered with ClinicalTrials.gov (identifier, NCT00874874).
Findings.
Strata A and B recruited 26 and 15 patients, respectively. The median age was 63 years (range, 31–82 years), with 17 male and 24 female patients. Fourteen cases arose in irradiated fields. Thirty patients (73.0%) had been pretreated with conventional chemotherapy. No unexpected toxicity occurred. The PFR at 9 months was 3.8% in stratum A and 0.0% in stratum B. The median PFS times were 1.8 months and 3.8 months, respectively, whereas the median OS times were 12.0 months and 9.0 months, respectively. No responses were observed in chemotherapy‐naïve patients, whereas a 40% tumor control rate and 23% response rate were observed in the pretreated population. In this cohort, no activating mutation of the KDR gene (exons 15, 16, 24) was detected.
Interpretation.
Sorafenib showed limited antitumor activity in pretreated patients only, for both visceral and superficial angiosarcoma, but tumor control was of short duration.
摘要
研究背景. 血管肉瘤在所有软组织肉瘤中所占比例不足2％。这种亚型是恶性程度最高的软组织肉瘤之一。接受目前的细胞毒性药物治疗的晚期血管肉瘤患者预后仍然较差无进展生存期(PFS)大约为4个月，总生存期(OS)大约为8个月。我们在II期临床试验中研究了索拉非尼治疗转移性或晚期肉瘤的抗肿瘤活性。
方法. 我们进行了分层II期临床试验。根据实体瘤疗效评价标准，主要终点为9个月时的无进展率（PFR）。采用两阶段设计（Simon最佳设计）。患者接受9个月的索拉非尼（400 mg，每天两次），直至出现不可接受的毒性或肿瘤进展。进行中心病理和影像学评价。目前得到了A层（浅表性血管肉瘤）和B层（内脏血管肉瘤）的数据。这项试验在ClinicalTrials.gov进行了注册（标识号，NCT00874874）。
结果. A层和B层分别纳入26和15例患者。年龄中位数为63岁（范围31‐82岁），男性患者17例，女性患者24例。共14例病灶出现在照射野。30例患者（73.0％）既往接受过常规化疗。未发生意外的毒性反应。9个月的A层和B层的PFR分别为3.8％和0.0％，中位PFS分别为1.8个月和3.8个月，而中位OS分别为12.0个月和9.0个月。既往无化疗史的患者表现为无缓解，而接受过化疗的患者，表现出40％的肿瘤控制率和23％的缓解率。在受试患者中，未检测到KDR基因（外显子15，16，24）的激活突变。
结论. 索拉非尼仅对既往接受过化疗的内脏和浅表性血管肉瘤患者表现出有限的抗肿瘤活性，但肿瘤控制作用的持续时间短暂。
The antitumor activity of sorafenib in patients with metastatic or advanced angiosarcomas was investigated in a phase II trial. Sorafenib showed limited antitumor activity in pretreated patients only, but tumor control was of short duration.
Pioneer transcription factors are characterized by having the unique property of enabling the opening of closed chromatin sites, for implementation of cell fates. We previously found that the pioneer ...Pax7 specifies melanotrope cells through deployment of an enhancer repertoire, which allows binding of Tpit, a nonpioneer factor that determines the related lineages of melanotropes and corticotropes. Here, we investigate the relation between these two factors in the pioneer mechanism. Cell-specific gene expression and chromatin landscapes are defined by scRNAseq and chromatin accessibility profiling. We find that in vivo deployment of the melanotrope enhancer repertoire and chromatin opening requires both Pax7 and Tpit. In cells, binding of heterochromatin targets by Pax7 is independent of Tpit but Pax7-dependent chromatin opening requires Tpit. The present work shows that pioneer core properties are limited to the ability to recognize heterochromatin targets and facilitate nonpioneer binding. Chromatin opening per se may be provided through cooperation with nonpioneer factors.
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