Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 268, Zurich, Switzerland.
Vet Pathol. 2013 Sep;50(5):789-96. doi: 10.1177/0300985813478212. Epub 2013 Feb 15.
The BH3-only protein Bad is a proapoptotic Bcl-2 family member that acts as a sensitizer in intrinsic apoptosis by inactivating antiapoptotic members through heterodimer formation. Bad has been shown to contribute to tumorigenesis, including lymphoma formation in humans and mice, through alteration in expression or functional status. Here, its immunohistochemical expression was analyzed in canine nonneoplastic and lymphoma tissues using tissue microarrays. Bad was expressed in the cytoplasm of a wide range of nonneoplastic tissues, especially epithelial cells. Nonneoplastic lymph nodes displayed weak immunostaining in the follicular germinal centers only. Immunoblotting supported these observations but also revealed presence of nonspecific labeling in some organs. Of 81 lymphomas, 29 (35.8%) displayed moderate to strong immunohistochemical Bad labeling, and a significant expression increase was found in lymphomas (especially B cell and double negative) compared to nonneoplastic lymph nodes. These findings warrant further investigations of the functional status, the involvement of partner proteins, and a possible impact of Bad on prognosis in canine lymphoma.
BH3 仅蛋白 Bad 是一种促凋亡的 Bcl-2 家族成员，通过形成异二聚体使抗凋亡成员失活，从而作为内在凋亡的敏化剂发挥作用。Bad 的表达或功能状态的改变已被证明与肿瘤发生有关，包括人类和小鼠的淋巴瘤形成。在这里，使用组织微阵列分析了犬非肿瘤和淋巴瘤组织中 Bad 的免疫组织化学表达。Bad 在广泛的非肿瘤组织中表达于细胞质中，特别是上皮细胞。非肿瘤性淋巴结仅在滤泡生发中心显示弱阳性免疫染色。免疫印迹支持了这些观察结果，但也显示在一些器官中存在非特异性标记。在 81 个淋巴瘤中，有 29 个（35.8%）显示中等至强的免疫组织化学 Bad 标记，与非肿瘤性淋巴结相比，淋巴瘤（尤其是 B 细胞和双阴性）中 Bad 的表达显著增加。这些发现表明需要进一步研究 Bad 的功能状态、伙伴蛋白的参与以及 Bad 对犬淋巴瘤预后的可能影响。
