Ko Jesang, Ryu Ki Sung, Lee Young Han, Na Doe Sun, Kim Yoon Suk, Oh Young Mi, Kim In Sik, Kim Jin Woo
Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, 138-736, Korea.
Exp Cell Res. 2002 Nov 1;280(2):280-7. doi: 10.1006/excr.2002.5649.
To identify genes involved in cervical carcinogenesis, the mRNA differential display method was used. A 220-bp cDNA fragment called CA11 was present in normal cervical tissue but not in primary cervical cancer tissue or cervical cancer cell lines. CA11 exhibited 98% homology with the recorded human secreted frizzled-related protein (hsFRP) sequence. A dominant hsFRP mRNA transcript of approximately 4.6 kb was present in three normal cervical tissues examined. Expression of the transcript was nearly absent from three cervical cancer tissues and from five human cervical cancer-derived cell lines. Results from in situ hybridization showed that the hsFRP transcript was confined to the normal cervical epithelial layer. When hsFRP-transfected HeLa and CUMC-6 cervical cancer cells were cultured in serum-free medium, most of the cells died within 8 days. This effect is associated with the apoptotic process. The caspase-3 inhibitor 1, Ac-DEVD-CHO, blocked hsFRP-induced apoptotic cell death. Additionally, cleavage of poly (ADP-ribose) polymerase in hsFRP-transfected cells was confirmed by colorimetric assay. These results indicate that the hsFRP gene probably functions as a tumor suppressor in normal cervical epithelium and down-regulation of hsFRP contributes to development of cervical cancer.
为了鉴定参与宫颈癌发生的基因，采用了mRNA差异显示法。一个名为CA11的220 bp cDNA片段存在于正常宫颈组织中，但在原发性宫颈癌组织或宫颈癌细胞系中不存在。CA11与已记录的人分泌型卷曲相关蛋白（hsFRP）序列具有98%的同源性。在所检测的三个正常宫颈组织中存在一种约4.6 kb的主要hsFRP mRNA转录本。在三个宫颈癌组织和五个人源宫颈癌细胞系中几乎不存在该转录本的表达。原位杂交结果显示，hsFRP转录本局限于正常宫颈上皮层。当用hsFRP转染的HeLa和CUMC-6宫颈癌细胞在无血清培养基中培养时，大多数细胞在8天内死亡。这种效应与凋亡过程相关。半胱天冬酶-3抑制剂1，Ac-DEVD-CHO，可阻断hsFRP诱导的凋亡细胞死亡。此外，通过比色法证实了hsFRP转染细胞中聚（ADP-核糖）聚合酶的裂解。这些结果表明，hsFRP基因可能在正常宫颈上皮中起肿瘤抑制作用，hsFRP的下调有助于宫颈癌的发展。
