目的:纤维组织的特征是色氨酸2,3双加氧酶(TDO2)的明显过表达。这项研究的目的是确定体内施用TDO2(680C91)抑制剂对纤维瘤大小和基因表达的有效性。
方法:动物和离体人研究。
方法:学术研究机构。
方法:用载体和TDO2抑制剂治疗的携带人纤维瘤异种移植物的重度联合免疫缺陷小鼠。
方法:每天腹膜内施用680C91或载体,持续2个月,并且用纤维瘤外植体进行体外研究。
方法:异种移植物的肿瘤重量和基因表达谱以及使用纤维瘤外植体的体外机制实验。
结果:化合物680C91耐受良好,对血液化学和体重没有影响。用680C91治疗的小鼠在治疗2个月后导致纤维瘤异种移植物的重量减少了30%,并且如预期的那样,犬尿氨酸水平较低,在异种移植物中色氨酸降解的副产物和芳香烃受体(AhR)的内源性配体。细胞色素P450家族1亚家族B成员1(CYP1B1)的表达,转化生长因子β3(TGF-β3),纤连蛋白(FN1),细胞周期蛋白依赖性激酶2(CDK2),E2F转录因子1(E2F1),与载体对照相比,在用680C91处理的小鼠的异种移植物中,白细胞介素8(IL-8)和分泌的酸性蛋白和富含半胱氨酸(SPARC)mRNA较低。同样,胶原蛋白的蛋白质丰富,与载体对照相比,在680C9处理的小鼠的异种移植物中FN1、CYP1B1和SPARC较低。异种移植物的免疫组织化学分析显示胶原表达降低,Ki67和E2F1,但用680C91处理的小鼠中裂解的caspase3表达没有显着变化。异种移植物中犬尿氨酸的水平与肿瘤重量和FN1水平直接相关。用纤维瘤外植体进行的体外研究显示色氨酸对CYP1B1,TGF-β3,FN1,CDK2,E2F1,IL8和SPARCmRNA的显着诱导,可以通过与680C91和AhR拮抗剂CH-223191共同处理来阻断。
结论:结果表明,通过减少细胞增殖和细胞外基质积累,纠正肌瘤中异常色氨酸分解代谢可能是一种有效的治疗方法。
OBJECTIVE: Fibroids are characterized by marked overexpression of tryptophan 2,3 dioxygenase (
TDO2). The objective of this study was to determine the effectiveness of in vivo administration of an inhibitor of
TDO2 (680C91) on fibroid size and gene expression.
METHODS: Animal and ex vivo human study.
METHODS: Academic Research Institution.
METHODS: Severe combined immunodeficiency mice bearing human fibroid xenografts treated with vehicle and
TDO2 inhibitor.
METHODS: Daily intraperitoneal administration of 680C91 or vehicle for 2 months and in vitro studies with fibroid explants.
METHODS: Tumor weight and gene expression profile of xenografts and in vitro mechanistic experiments using fibroid explants.
RESULTS: Compound 680C91 was well-tolerated with no effects on blood chemistry and body weight. Treatment of mice with 680C91 resulted in 30% reduction in the weight of fibroid xenografts after 2 months of treatment and as expected lower levels of kynurenine, the byproduct of tryptophan degradation and an endogenous ligand of aryl hydrocarbon receptor (AhR) in the xenografts. The expression of cytochrome P450 family 1 subfamily B member 1 (CYP1B1), transforming growth factor β3 (TGF-β3), fibronectin (FN1), cyclin-dependent kinase 2 (CDK2), E2F transcription factor 1 (E2F1), interleukin 8 (IL-8) and secreted protein acidic and cysteine rich (SPARC) mRNA were lower in the xenografts of mice treated with 680C91 compared with vehicle controls. Similarly, the protein abundance of collagen, FN1, CYP1B1, and SPARC were lower in the xenografts of 680C9- treated mice compared with vehicle controls. Immunohistochemical analysis of xenografts indicated decreased expression of collagen, Ki67 and E2F1 but no significant changes in cleaved caspase 3 expression in mice treated with 680C91. The levels of kynurenine in the xenografts showed a direct correlation with the tumor weight and FN1 levels. In vitro studies with fibroid explants showed a significant induction of CYP1B1, TGF-β3, FN1, CDK2, E2F1, IL8, and SPARC mRNA by tryptophan, which could be blocked by cotreatment with 680C91 and the AhR antagonist CH-223191.
CONCLUSIONS: The results indicate that correction of aberrant tryptophan catabolism in fibroids could be an effective treatment through its effect to reduce cell proliferation and extracellular matrix accumulation.