Bogenrieder T, Finstad C L, Freeman R H, Papandreou C N, Scher H I, Albino A P, Reuter V E, Nanus D M
Laboratory of Mammalian Cell Transformation, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Prostate. 1997 Dec 1;33(4):225-32. doi: 10.1002/(sici)1097-0045(19971201)33:4<225::aid-pros1>3.0.co;2-g.
Cell-surface peptidases are ectoenzymes which regulate the access of bioactive peptides to their receptors on cell membranes. Abnormalities in their expression and function result in altered peptide activity which contribute to neoplastic transformation and/or progression.
Expression of aminopeptidase A (APA), aminopeptidase N (APN, CD13), and dipeptidyl peptidase IV (DPP IV, CD26) was immunohistochemically examined in 20 benign and 33 malignant prostate tissues (19 primaries and 14 metastases).
Benign prostatic stroma exhibited no APA, APN, or DPP IV immunoreactivity. Stromal cells surrounding prostatic carcinoma cells demonstrated increased APA expression in 24/33 (73%) of tumors. Benign prostatic epithelial cells strongly expressed APN and DPP IV but not APA. In contrast, APN was expressed in > 80% of tumor cells in 5/33 (15%) of specimens, heterogeneously expressed (20-80% of cells positive) in 4/33 (12%) of specimens, and minimally expressed or absent in 24/33 (73%) of tumor specimens, with a similar pattern of expression in primary and metastatic tumors. DPP IV was expressed by > 80% of tumor cells in 18/19 (95%) of primary prostate cancer specimens, but in only 7/14 (50%) of metastases.
These data show that cell-surface peptidases are differentially expressed by normal prostatic stromal and epithelial cells, with increased expression of APA in the stroma surrounding prostate cancer cells, absent APN expression in most tumor cells, and a decreased frequency of DPP IV expression in metastatic tumors. Further studies will elucidate the biological effects of the presence or loss of cell-surface peptidases in the benign and malignant prostate.
细胞表面肽酶是一种外切酶，可调节生物活性肽与细胞膜上受体的结合。其表达和功能异常会导致肽活性改变，进而促进肿瘤转化和/或进展。
采用免疫组织化学方法检测20例良性前列腺组织和33例恶性前列腺组织（19例原发性肿瘤和14例转移瘤）中氨肽酶A（APA）、氨肽酶N（APN，CD13）和二肽基肽酶IV（DPP IV，CD26）的表达。
良性前列腺基质中未检测到APA、APN或DPP IV免疫反应性。前列腺癌细胞周围的基质细胞在24/33（73%）的肿瘤中表现出APA表达增加。良性前列腺上皮细胞强烈表达APN和DPP IV，但不表达APA。相比之下，5/33（15%）的标本中超过80%的肿瘤细胞表达APN，4/33（12%）的标本中APN呈异质性表达（20%-80%的细胞阳性），24/33（73%）的肿瘤标本中APN表达极少或缺失，原发性肿瘤和转移瘤中的表达模式相似。18/19（95%）的原发性前列腺癌标本中超过80%的肿瘤细胞表达DPP IV，但在转移瘤中仅7/14（50%）表达。
这些数据表明，正常前列腺基质和上皮细胞中细胞表面肽酶的表达存在差异，前列腺癌细胞周围基质中APA表达增加，大多数肿瘤细胞中APN表达缺失，转移瘤中DPP IV表达频率降低。进一步的研究将阐明细胞表面肽酶在良性和恶性前列腺组织中的存在或缺失所产生的生物学效应。
