Distribution of cathepsin D granules in normal and pathologic conditions in human prostate

Abstract

免疫組織化学的に蛋白分解酵素であるカテプシンDの分布を正常前立腺及びホルモン療法後の前立腺全摘後の標本で癌組織のない部分でその相違を検討し, 更に肥大症組織及びホルモン療法後の癌組織部でもその発現を検討した.カテプシンD顆粒は細かい顆粒といわゆるアポトーシス体とよばれる大きな顆粒の2種類に分類でき, 前者は前立腺上皮に不均一であるが普遍的に認められた.後者のアポトーシス体は成人前立腺では尿道近位側の主導管部, 男性子宮及び精阜上皮に比較的多く認めるが, 末梢腺房上皮では認めなかった.ホルモン療法後の非癌組織ではこの傾向は逆転し, 末梢腺房部で多く認め, 主導管や男性子宮での発現は減少していた.アポトーシス体は思春期前の前立腺や前立腺肥大症組織では認めなかった.ホルモン療法後の癌組織ではかなりのアポトーシス体をその腺腔内や間質に認めた

Although cathepsin D has been implicated in prostate cancer invasion and metastasis, the distribution of this enzyme in normal human prostate is unknown. We investigated immunohistochemically the distribution of cathepsin D granules in normal prostatic tissues with or without androgen ablation. We also examined the cancer tissues after androgen ablation and the hyperplastic tissues. Changes in the distribution pattern of the larger cathepsin D-positive granules (apoptotic bodies) were observed in the normal prostate as well as in the normal tissue of the anti-androgen-treated cancer specimens. While the apoptotic bodies were denser in the proximal duct of the normal adult prostate, they were more abundant in the normal peripheral acini of the anti-androgen-treated cases. There were few apoptotic bodies in the adenoma tissues, but many in the hormonally treated cancer tissues. These results showed that the distribution pattern and density of cathepsin D granules well reflected the status of the human prostatic cells in relation to age, hormonal environment and hyperplastic or neoplastic change.