Mol J A, van Garderen E, Selman P J, Wolfswinkel J, Rijinberk A, Rutteman G R
Department of Clinical Sciences of Companion Animals, Utrecht University, The Netherlands.
J Clin Invest. 1995 May;95(5):2028-34. doi: 10.1172/JCI117888.
We have shown recently that in the dog progestin administration results in mammary production of immunoreactive growth hormone (GH). At present we demonstrate the expression of the gene encoding GH in the mammary gland of dogs and cats using reverse-transcriptase PCR. GH mRNA was found in the great majority of normal mammary tissues as well as benign and malignant mammary tumors of the dog and was associated with the presence of immunoreactive GH in cryostat sections. The mammary PCR product proved to be identical to that of the pituitary. The highest expression levels were found after prolonged treatment with progestins. In carcinomas GH mRNA was also found in progesterone receptor-negative tissue samples, indicating that after malignant transformation GH gene expression may become progestin independent. GH mRNA was also present in mammary tissues of cats with progestin-induced fibroadenomatous changes. It is concluded that GH gene expression occurs in normal, hyperplastic, and neoplastic mammary tissue of the dog. The expression in normal tissue is stimulated by progestins and might mediate the progestin-stimulated development of canine mammary tumors. The demonstration of progestin-stimulated GH expression in mammary tissue of cats indicates that the phenomenon is more generalized among mammals.
我们最近发现，给犬使用孕激素会导致乳腺产生免疫反应性生长激素（GH）。目前，我们使用逆转录聚合酶链反应（RT-PCR）在犬和猫的乳腺中证实了编码GH的基因的表达。在绝大多数正常乳腺组织以及犬的良性和恶性乳腺肿瘤中都发现了GH mRNA，并且在冷冻切片中它与免疫反应性GH的存在相关。乳腺PCR产物被证明与垂体的产物相同。在用孕激素长期治疗后发现表达水平最高。在癌组织中，在孕激素受体阴性的组织样本中也发现了GH mRNA，这表明恶性转化后GH基因表达可能变得不依赖孕激素。在有孕激素诱导的纤维腺瘤样改变的猫的乳腺组织中也存在GH mRNA。结论是，GH基因表达发生在犬的正常、增生性和肿瘤性乳腺组织中。正常组织中的表达受孕激素刺激，可能介导孕激素刺激的犬乳腺肿瘤的发展。在猫的乳腺组织中证明孕激素刺激的GH表达表明这种现象在哺乳动物中更普遍。
