Kato M, Maeta H, Kato S, Shinozawa T, Terada T
Second Department of Pathology, Faculty of Medicine, Tottori University, Yonago, Japan.
Mod Pathol. 2000 Oct;13(10):1060-5. doi: 10.1038/modpathol.3880195.
Midkine (MK) is a novel heparin-binding growth factor whose gene has been identified in embryonal carcinoma cells in early stages of retinoic acid-induced differentiation. We immunohistochemically examined 90 thyroid papillary carcinomas (85 invasive type and five encapsulated type), using a rat IgG2a monoclonal antibody against the carboxyl terminal region of human MK in archival paraffin sections. The thyroid tumors exhibited an intense reaction in the cytoplasm. Most of the papillary carcinomas (77/90), had tumor cells that expressed MK. These were classified into the following two types: invasive type (76/85) and encapsulated type (1/5). Notably, the intensity of MK was stronger at the invading border area of the tumors than in the center. In tissues adjacent to the cancer tissues, normal follicular epithelial cells expressed MK very faintly or not at all. The in situ hybridization analysis revealed that the signals of MK transcripts were found in the cytoplasm of the cancer cells. In the noncancerous follicular epithelial cells adjacent to neoplasm the signals of MK transcripts were detected very weakly or not at all. The distribution and localization of the MK-transcript signals determined by in situ hybridization analysis were similar to those obtained by immunohistochemical analysis. We conclude that thyroid papillary carcinoma strongly expresses MK protein and messenger RNA, and that this overexpression may relate to the development and invasion of these carcinomas.
中期因子（MK）是一种新型的肝素结合生长因子，其基因已在维甲酸诱导分化早期的胚胎癌细胞中被鉴定出来。我们使用针对人MK羧基末端区域的大鼠IgG2a单克隆抗体，对90例甲状腺乳头状癌（85例浸润型和5例包膜型）存档石蜡切片进行了免疫组织化学检查。甲状腺肿瘤在细胞质中呈现强烈反应。大多数乳头状癌（77/90）的肿瘤细胞表达MK。这些被分为以下两种类型：浸润型（76/85）和包膜型（1/5）。值得注意的是，肿瘤侵袭边缘区域的MK强度比中心更强。在癌组织相邻的组织中，正常滤泡上皮细胞非常微弱地表达MK或根本不表达。原位杂交分析显示，MK转录本信号存在于癌细胞的细胞质中。在肿瘤相邻的非癌性滤泡上皮细胞中，MK转录本信号检测非常微弱或根本未检测到。原位杂交分析确定的MK转录本信号的分布和定位与免疫组织化学分析获得的结果相似。我们得出结论，甲状腺乳头状癌强烈表达MK蛋白和信使RNA，这种过表达可能与这些癌症的发生和侵袭有关。
