PREVALENCE OF DELETIONS OF YY1-BINDING SITES IN EPISOMAL HPV-16 DNA FROM CERVICAL CANCERS
PREVALENCE OF DELETIONS OF YY1-BINDING SITES IN EPISOMAL HPV-16 DNA FROM CERVICAL CANCERS
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DOI：
10.1002/ijc.2910580609
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发表时间：
1994-09-15
影响因子：
6.4
通讯作者：
PFISTER, H
中科院分区：
文献类型：
--
作者：
DONG, XP;STUBENRAUCH, F;PFISTER, H
人乳头瘤病毒16型（HPV 16）的癌基因E6和E7的表达在癌前病变和恶性生殖器肿瘤中似乎增强。我们最近发现了一个转录沉默子上游的癌基因启动子P97，包括4个结合位点的细胞YYI蛋白。对6例宫颈癌原发灶和淋巴结转移灶的HPV 16游离型DNA进行长转录控制区（LCR）分析，发现其中4例存在YYI结合位点的缺失和点突变。为了测试P97启动子的活性，将突变的LCR克隆到荧光素酶报告基因载体中。YYI识别位点4的点突变，阻止DNA-蛋白质相互作用，并不影响启动子活性，可能是由于补偿重叠的YYI结合位点3。然而，5.5- 6.5倍增加的荧光素酶表达的控制下获得的3个缩短的LCR缺乏2至4个YYI结合位点。YYI识别位点2至4个YYI结合位点的点突变。在原发性肿瘤和转移瘤的HPV 16 LCR中可以检测到YYI识别位点2的点突变，该点突变先前显示刺激P97 3.5倍，表明该突变是与个体癌症相关的HPV 16 DNA的稳定特征。这些发现表明，YYI结合位点的缺失或突变在病毒癌基因的过度表达和肿瘤进展中起重要作用。(C)1994 Wiley-Liss，Inc.
Expression of the oncogenes E6 and E7 of human papillomavirus 16 (HPV 16) appears enhanced in pre-malignant and malignant genital tumors. We recently identified a transcriptional silencer upstream of the oncogene promoter P97, comprising 4 binding sites for the cellular YYI protein. The analysis of the long transcriptional control regions (LCR) of episomal HPV 16 DNAs from primary tumors and lymph-node metastases of 6 patients with cervical cancer revealed deletions and point mutations of YYI binding sites in 4 cases. To test for the activity of the P97 promoter, the mutated LCRs were cloned in a luciferase reporter gene vector. A point mutation in YYI-recognition site 4, which prevents DNA-protein interaction, did not affect promoter activity, probably due to compensation by the overlapping YYI-binding site 3. However, 5.5- to 6.5-fold increased luciferase expression was obtained under the control of 3 shortened LCRs lacking 2 to 4 YYI-binding sites. A point mutation in YYI-recognition site 2 to 4 YYI-binding sites. A point mutation in YYI-recognition site 2, which was previously shown to stimulate P97 3.5-fold, could be detected in the HPV 16 LCRs from both primary tumor and metastasis, indicating that the mutation is a stable characteristic of HPV 16 DNA associated with the individual cancer. These findings suggest that deletions or mutations of YYI-binding sites play a significant role in over-expression of viral oncogenes and tumor progression. (C) 1994 Wiley-Liss, Inc.