Bonkhoff H
Institute of Pathology, University of the Saarland, Homburg/Saar, Germany.
Eur Urol. 1996;30(2):201-5. doi: 10.1159/000474170.
Prostatic intraepithelial neoplasias (PIN) result from abnormal differentiation and proliferation processes within the prostatic epithelial cell system. Recent data indicate that basal cells are essentially involved in normal and abnormal growth patterns of the human prostate.
The basal cell layer represents the proliferative compartment and most probably houses the prostatic stem cell population. Basal cells are targets of several regulatory factors including estrogens, androgens, epidermal growth factor and other nonsteroidal growth factors. During the malignant transformation of the prostatic epithelium (PIN), the basal cell layer loses its proliferative function which is transferred to secretory luminal cell types. These proliferative abnormalities are attended by severe regulatory disorders of the programmed cell death within the prostatic epithelial cell system. The Bcl-2 oncoprotein which blocks the programmed cell death in the proliferative compartment (basal cell layer) in normal conditions, extends to the secretory luminal cell types in high-grade PIN lesions. This, in turn, may increase the genetic instability of the dysplastic epithelium. During the process of tumor invasion, the transformed cells lose their basal cell-specific phenotype and acquire features of exocrine cell types which represent the major phenotype in common prostate cancer. At the point of stromal invasion, the transformed cells produce neoplastic basement membrane material which allows them to penetrate the extracellular matrix.
These data provide theoretical bases for a stem cell concept in the development of prostate cancer and highlights the importance of basal cells in this multifactorial process.
前列腺上皮内瘤变（PIN）源于前列腺上皮细胞系统内异常的分化和增殖过程。近期数据表明，基底细胞本质上参与了人类前列腺的正常和异常生长模式。
基底细胞层代表增殖区室，很可能容纳前列腺干细胞群体。基底细胞是多种调节因子的作用靶点，包括雌激素、雄激素、表皮生长因子和其他非甾体类生长因子。在前列腺上皮的恶性转化（PIN）过程中，基底细胞层失去其增殖功能，该功能转移至分泌性腔面细胞类型。这些增殖异常伴随着前列腺上皮细胞系统内程序性细胞死亡的严重调节紊乱。在正常情况下，Bcl-2癌蛋白可阻断增殖区室（基底细胞层）中的程序性细胞死亡，而在高级别PIN病变中，它会扩展至分泌性腔面细胞类型。这反过来可能会增加发育异常上皮的遗传不稳定性。在肿瘤侵袭过程中，转化细胞失去其基底细胞特异性表型，并获得外分泌细胞类型的特征，而外分泌细胞类型是常见前列腺癌的主要表型。在基质侵袭点，转化细胞产生肿瘤性基底膜物质，使其能够穿透细胞外基质。
这些数据为前列腺癌发生发展中的干细胞概念提供了理论依据，并突出了基底细胞在这一多因素过程中的重要性。
