Kwong J, Chan F L, Jiang S, Guo Y, Imasato Y, Sakai H, Koropatnick J, Chin J L, Xuan J W
Department of Anatomy, Chinese University of Hong Kong, Shatin, Hong Kong.
J Cell Biochem. 1999 Sep 1;74(3):406-17.
Prostate secretory protein (PSP94, 94 amino acids) is one of the most abundant proteins secreted from the prostate. Its biological role is unknown and still controversial, although it is assumed to have the potential to be a biomarker and a suppressor of prostate cancer. In order to establish an animal model to further elucidate its biological role, we expressed the mature form of rat PSP94 in Escherichia coli, using a glutathione S-transferase (GST) fusion expression vector; we generated a polyclonal rabbit antibody against the recombinant protein. The antibody specifically recognized recombinant rat PSP94 and cross-reacted only very weakly with its human homologue. Using the characterized anti-rat PSP94 antibody, we found that PSP94 was located primarily in rat prostate. Furthermore, PSP94 is present at different levels in different lobes of rat prostate, with significant levels detectable only in the lateral lobe (LP). In addition, the most abundant PSP94 expression was found in the prostate lobe secretions, and PSP94 levels in LP secretions were at least seven times higher than in secretions from the dorsal prostate (DP). The rat ventral prostate (VP) and other regions of the male accessory glands were found to be almost completely devoid of PSP94. Since most rat prostate dysplasia induced by steroid hormone treatment occurs only in dorsolateral prostate, prostate tissue-specific expression and the expression of PSP94 in dorsolateral, but not other, lobes of the prostate suggest a potential role in prostate targeting and prostate cancer development.
前列腺分泌蛋白（PSP94，94个氨基酸）是前列腺分泌的最丰富的蛋白质之一。尽管它被认为有潜力成为前列腺癌的生物标志物和抑制剂，但其生物学作用仍不明确且存在争议。为了建立一个动物模型以进一步阐明其生物学作用，我们使用谷胱甘肽S-转移酶（GST）融合表达载体在大肠杆菌中表达了大鼠PSP94的成熟形式；我们制备了针对该重组蛋白的兔多克隆抗体。该抗体能特异性识别重组大鼠PSP94，且与其人类同源物仅有非常微弱的交叉反应。利用已鉴定的抗大鼠PSP94抗体，我们发现PSP94主要位于大鼠前列腺中。此外，PSP94在大鼠前列腺的不同叶中含量不同，仅在外侧叶（LP）可检测到显著水平。此外，在前列腺叶分泌物中发现PSP94表达最为丰富，LP分泌物中的PSP94水平至少比背侧前列腺（DP）分泌物中的高7倍。发现大鼠腹侧前列腺（VP）和雄性附属腺的其他区域几乎完全没有PSP94。由于大多数由类固醇激素治疗诱导的大鼠前列腺发育异常仅发生在背外侧前列腺，前列腺组织特异性表达以及PSP94在前列腺背外侧叶而非其他叶中的表达表明其在前列腺靶向和前列腺癌发展中可能发挥作用。
