Maekawa M, Sugano K, Sano H, Miyazaki S, Ushiama M, Fujita S, Gotoda T, Yokota T, Ohkura H, Kakizoe T, Sekiya T
Division of Clinical Laboratory, National Cancer Center Research Institute, Tokyo, Japan.
Jpn J Clin Oncol. 1998 Jul;28(7):421-6. doi: 10.1093/jjco/28.7.421.
Non-steroidal anti-inflammatory drugs can reduce the risk of colorectal cancer. Reportedly, mRNA expression of cyclooxygenase-2 (COX-2) is elevated in human colorectal cancers compared with accompanying normal mucosa. The present study was undertaken to establish a simple analytical procedure to quantify COX-2 expression levels and to characterize COX-2 expression levels in human colorectal cancers, adenomas and hyperplastic polyps.
The combination of PCR using common primers designed in the highly conserved regions and fluorescence-based single-strand conformation polymorphism (F-SSCP) analysis of the products is used for quantitative determination of the proportions of COX-2 mRNA in human colorectal cancers, adenomas, hyperplastic polyps and accompanying normal mucosa.
The present F-SSCP analysis was a simple and powerful method for quantitative determination of the proportions of COX-2 mRNA. The proportion of COX-2 mRNA was higher in cancer tissues than in accompanying normal mucosa in 46 of the 50 cancers. There was no significant correlation between the increase of the COX-2 proportion and tumor location or stages. The enhanced COX-2 expression was also observed in colorectal adenomas. On the other hand, the proportion of COX-2 mRNA in hyperplastic polyps was not significantly different from that in normal mucosa.
The proportion of COX-2 to COX-1 expression was elevated in most human colorectal cancers and adenomas, but not in hyperplastic polyps. Therefore, the increased proportion of COX-2 expression might be an early event in the carcinogenesis of colorectal cancer.
非甾体抗炎药可降低结直肠癌风险。据报道，与相应正常黏膜相比，环氧化酶-2（COX-2）的mRNA表达在人类结直肠癌中升高。本研究旨在建立一种简单的分析方法来定量COX-2表达水平，并对人类结直肠癌、腺瘤和增生性息肉中的COX-2表达水平进行特征描述。
使用在高度保守区域设计的通用引物进行PCR，并对产物进行基于荧光的单链构象多态性（F-SSCP）分析，用于定量测定人类结直肠癌、腺瘤、增生性息肉及相应正常黏膜中COX-2 mRNA的比例。
目前的F-SSCP分析是一种简单且有效的定量测定COX-2 mRNA比例的方法。在50例癌症中，有46例癌组织中COX-2 mRNA的比例高于相应正常黏膜。COX-2比例的增加与肿瘤位置或分期之间无显著相关性。在结直肠腺瘤中也观察到COX-2表达增强。另一方面，增生性息肉中COX-2 mRNA的比例与正常黏膜中的比例无显著差异。
在大多数人类结直肠癌和腺瘤中，COX-2与COX-1表达的比例升高，但在增生性息肉中并非如此。因此，COX-2表达比例的增加可能是结直肠癌发生过程中的早期事件。
