Cané Stefania, Bignotti Eliana, Bellone Stefania, Palmieri Michela, De las Casas Luis, Roman Juan J, Pecorelli Sergio, Cannon Martin J, O'brien Timothy, Santin Alessandro D
Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR 72205,USA.
Am J Obstet Gynecol. 2004 Jan;190(1):60-6. doi: 10.1016/j.ajog.2003.07.020.
Serine proteases are redundant enzymes implicated in the extracellular modulation required for tumor growth and invasion. Tumor-associated differentially expressed gene-14 (TADG-14) is a novel transmembrane serine protease recently reported by our group to be highly overexpressed in ovarian carcinomas. The goal of this study was to investigate the frequency of expression of the TADG-14 gene in human cervical tumors.
TADG-14 expression was evaluated in 19 cervical cancer cell lines (11 primary and 8 established cell lines) as well as in 8 normal cervical keratinocyte cultures by reverse transcriptase polymerase chain reaction. In addition, to validate gene expression data at the protein level, TADG-14 expression was evaluated by immunohistochemistry on paraffin-embedded tissue from which all 11 primary tumor cell lines were established.
TADG-14 was found to be highly expressed in 82% (9/11) primary cervical cancer cell lines and in 87% (7/8) established cervical cancer cell lines by reverse transcriptase-polymerase chain reaction. Expression of TADG-14 by primary squamous cervical tumors was 100% (6/6), whereas 60% (3/5) of primary adenocarcinomas expressed TADG-14. In contrast, none of the normal cervical keratinocyte control cultures (n=4) or flash frozen normal cervical biopsy specimens (n=4) expressed TADG-14. Immunohistochemistry staining of paraffin-embedded cervical cancer specimens confirmed TADG-14 expression in tumor cells and its absence on normal cervical epithelial cells.
Cervical cancer expressed a high level of TADG-14, suggesting that this protease may play an important role in invasion and metastasis. Because TADG-14 appears only in abundance in tumor tissue and contains a secretion signal sequence, suggesting that TADG-14 is secreted, it may prove to be a useful diagnostic tool for the early detection of recurrent/persistent cervical cancer after standard treatment or as a novel molecular target for cervical cancer therapy.
丝氨酸蛋白酶是一类功能冗余的酶，参与肿瘤生长和侵袭所需的细胞外调节过程。肿瘤相关差异表达基因14（TADG - 14）是一种新型跨膜丝氨酸蛋白酶，最近我们小组报道其在卵巢癌中高度过表达。本研究的目的是调查TADG - 14基因在人宫颈肿瘤中的表达频率。
通过逆转录聚合酶链反应评估19种宫颈癌细胞系（11种原代细胞系和8种已建立的细胞系）以及8种正常宫颈角质形成细胞培养物中TADG - 14的表达。此外，为了在蛋白质水平验证基因表达数据，通过免疫组织化学对来自所有11种原代肿瘤细胞系所建立的石蜡包埋组织进行TADG - 14表达评估。
通过逆转录 - 聚合酶链反应发现，TADG - 14在82%（9/11）的原代宫颈癌细胞系和87%（7/8）的已建立宫颈癌细胞系中高度表达。原发性宫颈鳞状肿瘤中TADG - 14的表达率为100%（6/6），而原发性腺癌中有60%（3/5）表达TADG - 14。相比之下，正常宫颈角质形成细胞对照培养物（n = 4）或快速冷冻的正常宫颈活检标本（n = 4）均未表达TADG - 14。石蜡包埋的宫颈癌标本免疫组织化学染色证实肿瘤细胞中存在TADG - 14表达，而正常宫颈上皮细胞中不存在。
宫颈癌中TADG - 14表达水平较高，提示该蛋白酶可能在侵袭和转移中起重要作用。由于TADG - 14仅在肿瘤组织中大量出现且含有分泌信号序列，表明TADG - 14是分泌型的，它可能被证明是标准治疗后早期检测复发性/持续性宫颈癌的有用诊断工具，或作为宫颈癌治疗的新型分子靶点。
