Petterino C, Rossetti E, Bertoncello D, Martini M, Zappulli V, Bargelloni L, Castagnaro M
Department of Public Health, Comparative Pathology, and Veterinary Hygiene, Faculty of Veterinary Medicine, University of Padua, Via dell'Università 16, Agripolis, 35020, Legnaro (PD), Italy.
J Vet Med A Physiol Pathol Clin Med. 2006 May;53(4):174-8. doi: 10.1111/j.1439-0442.2006.00810.x.
Elevated levels of P-glycoprotein have been reported in multidrug-resistant tumours in both humans and dogs. In the present study, we investigated the expression of P-glycoprotein in 57 canine mammary gland tumours, 10 mammary gland hyperplasia and seven normal mammary glands by immunohistochemistry. Tissue sections were incubated with an anti-Pgp monoclonal antibody and visualized with En Vision-DAB polymer. Normal and hyperplastic mammary tissues were negative or showed slight cytoplasmic immunoreactivity. Neoplastic cells in benign mammary tumours showed diffuse cytoplasmic staining, in contrast to malignant tumours that showed mainly a membranous staining pattern for Pgp (C494). We observed statistically significant differences among all the different groups of tissues analysed except for benign tumours versus hyperplasia (P = 0.221). Receiver-operating characteristic analysis showed that the best cut-off point to differentiate the threshold to differentiate negative from positive tissue samples was 18.40% of immunostained cells. These results provide a first indication that routine evaluation of Pgp expression in canine mammary gland tumours, taking into consideration a cut-off point for positivity, may be useful for selecting cases for chemotherapy.
据报道，在人类和犬类的多药耐药肿瘤中，P-糖蛋白水平升高。在本研究中，我们通过免疫组织化学研究了57例犬乳腺肿瘤、10例乳腺增生和7个正常乳腺中P-糖蛋白的表达。组织切片用抗Pgp单克隆抗体孵育，并用En Vision-DAB聚合物显色。正常和增生性乳腺组织为阴性或显示轻微的细胞质免疫反应性。良性乳腺肿瘤中的肿瘤细胞显示弥漫性细胞质染色，而恶性肿瘤主要显示Pgp（C494）的膜性染色模式。除良性肿瘤与增生（P = 0.221）外，我们在所有分析的不同组织组之间观察到统计学上的显著差异。受试者工作特征分析表明，区分阴性和阳性组织样本的最佳临界点是免疫染色细胞的18.40%。这些结果首次表明，考虑到阳性的临界点，对犬乳腺肿瘤中Pgp表达进行常规评估可能有助于选择化疗病例。
