Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3584 CM, Utrecht, The Netherlands.
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3584 CM, Utrecht, The Netherlands.
Domest Anim Endocrinol. 2014 Apr;47:73-82. doi: 10.1016/j.domaniend.2013.11.004. Epub 2013 Nov 16.
The aim of this study was to evaluate the expression of angiogenesis-related genes in canine cortisol-secreting adrenocortical tumors (ATs). Quantitative RT-PCR analysis revealed mRNA encoding for vascular endothelial growth factor, vascular endothelial growth factor receptors 1 and 2, angiopoietin 1 and 2 (ANGPT1 and ANGPT2), the splice variant ANGPT2443, the ANGPT-receptor Tie2, and basic fibroblast growth factor in 38 canine cortisol-secreting ATs (26 carcinomas and 12 adenomas) and 15 normal adrenals. The relative expression of both ANGPT2 and ANGPT2443 was higher in adenomas (P = 0.020 for ANGPT2 and P = 0.002 for ANGPT2443) and carcinomas (P = 0.003 for ANGPT2 and P < 0.001 for ANGPT2443) compared with normal adrenals, and this enhanced expression was also detected with Western blot analysis. Immunohistochemistry indicated expression of ANGPT2 protein in AT cells and in vascular endothelial cells of carcinomas, whereas Tie2 was mainly present in the tumor vascular endothelial cells. The ANGPT2-to-ANGTPT1 ratio, a marker for a proangiogenic state, was higher in both adenomas (P = 0.020) and carcinomas (P = 0.043). With the use of the human H295R cortisol-producing adrenocortical carcinoma cell line, we were able to demonstrate that the ANGPT2 expression was stimulated by cyclic adenosine monophosphate and progesterone but not by cortisol. In conclusion, canine cortisol-secreting ATs have enhanced ANGPT2 expression with a concomitant shift toward a proangiogenic state. On the basis of this information, treatment modalities may be developed that interfere with ANGPT2 expression, including inhibition of the cyclic adenosine monophosphate/protein kinase A pathway, or of the effect of ANGPT2, by using specific ANGPT2 inhibitors.
本研究旨在评估血管生成相关基因在犬皮质醇分泌性肾上腺皮质肿瘤（AT）中的表达。定量 RT-PCR 分析显示，血管内皮生长因子、血管内皮生长因子受体 1 和 2、血管生成素 1 和 2（ANGPT1 和 ANGPT2）、剪接变体 ANGPT2443、ANGPT 受体 Tie2 和碱性成纤维细胞生长因子的 mRNA 在 38 例犬皮质醇分泌性 AT（26 例癌和 12 例腺瘤）和 15 例正常肾上腺中表达。腺瘤（ANGPT2：P = 0.020；ANGPT2443：P = 0.002）和癌（ANGPT2：P = 0.003；ANGPT2443：P < 0.001）中 ANGPT2 和 ANGPT2443 的相对表达均高于正常肾上腺，Western blot 分析也检测到这种增强的表达。免疫组织化学显示 ANGPT2 蛋白在 AT 细胞和癌的血管内皮细胞中表达，而 Tie2 主要存在于肿瘤血管内皮细胞中。ANGPT2/ANGPT1 比值是促血管生成状态的标志物，在腺瘤（P = 0.020）和癌（P = 0.043）中均较高。使用人 H295R 皮质醇产生肾上腺皮质癌细胞系，我们能够证明 ANGPT2 表达受环磷酸腺苷和孕酮刺激，但不受皮质醇刺激。总之，犬皮质醇分泌性 AT 中 ANGPT2 表达增强，伴有向促血管生成状态的转变。基于这些信息，可能会开发出干扰 ANGPT2 表达的治疗方法，包括抑制环磷酸腺苷/蛋白激酶 A 途径，或通过使用特异性 ANGPT2 抑制剂来抑制 ANGPT2 的作用。
