South Carolina Center for Biotechnology, Claflin University, 400 Magniolia Street, Orangeburg, SC 29115, USA.
Methods. 2010 Dec;52(4):316-21. doi: 10.1016/j.ymeth.2010.08.004. Epub 2010 Aug 10.
Zinc (Zn) is essential for a very large number and variety of cellular functions but is also potentially toxic. Zn homeostasis is therefore dynamically maintained by a variety of transporters and other proteins distributed in distinct cellular and subcellular compartments. Zn transport is mediated by two major protein families: the Zip family, which mediates Zn influx, and the ZnTs which are primarily linked to Zn sequestration into intracellular compartments and are, thereby, involved in lowering cytoplasmic Zn free ion concentrations. In the prostate epithelial cell, the accumulation of high cellular zinc is a specialized function that is necessary for these cells to carry out the major physiological functions of production and secretion of prostatic fluids. The loss of Zn accumulation is the most consistent and persistent characteristic of prostate malignancy. Currently, there are no direct methods to determine the relative Zn levels in various cell types of prostate gland (i.e. stroma, glandular epithelia, acini, and muscular) and no reliable ways to compare the Zn in normal versus malignant areas of the gland. Here we report a new method to show a differential Zn staining method that correlates with various stages of prostate cancer development in situ and expression of a human Zn transporter1-hZIP1 -in situ by in situ reverse transcriptase-polymerase chain reaction hybridization (ISRTPCR) that correlate with the relative Zn levels determined by the differential Zn staining method. By utilizing these methods, we show for the first time that: (1) the relative Zn levels are very low to absent in the malignant glands, (2) normal glands show high Zn levels in both glandular epithelia as well as in stromal tissues, (3) the Zn levels begin to decrease in pre-malignant glands and precedes the development of malignancy, and (4) the expression of human Zn transporter1 (hZIP1) appears to correlate with the Zn levels in the prostate glands and may be the major Zn regulator in this organ.
锌（Zn）对于许多细胞功能都是必需的，但也具有潜在毒性。因此，Zn 稳态通过分布在不同细胞和亚细胞隔室中的各种转运蛋白和其他蛋白动态维持。Zn 转运由两个主要的蛋白家族介导：Zip 家族，介导 Zn 内流，以及 ZnTs，它们主要与 Zn 隔离到细胞内隔室有关，从而参与降低细胞质 Zn 自由离子浓度。在前列腺上皮细胞中，高细胞内锌的积累是一种特殊功能，这对于这些细胞执行产生和分泌前列腺液的主要生理功能是必要的。Zn 积累的丧失是前列腺恶性肿瘤最一致和持久的特征。目前，没有直接的方法来确定前列腺腺体内各种细胞类型（即基质、腺上皮、腺泡和肌肉）的相对 Zn 水平，也没有可靠的方法来比较正常与腺体恶性区域的 Zn。在这里，我们报告了一种新的方法，可以显示与原位前列腺癌发展的各个阶段相关的差异 Zn 染色方法，以及通过原位逆转录聚合酶链反应杂交（ISRTPCR）原位表达人类 Zn 转运蛋白 1-hZIP1 -与通过差异 Zn 染色方法确定的相对 Zn 水平相关。利用这些方法，我们首次表明：（1）恶性腺体中的相对 Zn 水平非常低或不存在，（2）正常腺体在腺上皮和基质组织中均显示出高 Zn 水平，（3）Zn 水平在癌前腺体中开始降低，并先于恶性肿瘤的发展，（4）人 Zn 转运蛋白 1（hZIP1）的表达似乎与前列腺中的 Zn 水平相关，并且可能是该器官中的主要 Zn 调节剂。
