Sakurai Yoichi, Sakamoto Kazuki, Sugimoto Yoshikazu, Yoshida Ikuo, Masui Toshihiko, Tonomura Shuhei, Inaba Kazuki, Shoji Mitsutaka, Nakamura Yasuko, Uyama Ichiro, Komori Yoshiyuki, Ochiai Masahiro, Matsuura Shiro, Tanaka Hideyuki, Oka Toshinori, Fukushima Masakazu
Department of Surgery, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
Cancer Sci. 2006 Jun;97(6):492-8. doi: 10.1111/j.1349-7006.2006.00200.x.
A number of enzymes have been shown to be involved in the process of activation and/or degradation of 5-fluorouracil (5-FU), and are potential candidates for predicting chemosensitivity to 5-FU. Among these, orotate phosphoribosyltransferase (OPRT EC 2.4.2.10) is a key enzyme related to the first-step activation process of 5-FU and has been shown to be an important enzyme that helps to predict sensitivity to 5-FU and its related derivatives. We developed a new enzyme-linked immunosorbent assay (ELISA) to accurately assess intratumoral activity of OPRT. A new sandwich ELISA was established using anti-OPRT polyclonal antibodies obtained from the rabbit immunized with the recombinant human peptides of the OPRT molecule. OPRT levels were measured in eight human cancer xenografts and in 75 gastric cancer tissues using both a newly established ELISA and a conventional enzyme assay, using radiolabeled 5-FU as a substrate. There was a significant correlation between OPRT levels measured by this ELISA and OPRT enzyme activity the in eight human cancer xenografts (r2 = 0.782) and gastric carcinoma tissue (r2 = 0.617). The ELISA system for OPRT requires a minimal amount of carcinoma tissue, making it an easy-to-use assay system to predict sensitivity to 5-FU and its derivatives in gastric carcinoma. There was a significant correlation between tumor growth inhibition rates against the oral administration of oral-uracil/tegafur (UFT) and OPRT enzyme activity in the human cancer xenografts (r2 = 0.574). These results suggest that this newly developed sandwich ELISA system for the quantification of OPRT levels is technically simple, feasible and a useful tool to predict sensitivity to fluoropyrimidine-based anticancer chemotherapy in patients with gastric carcinoma and other cancers.
已有多种酶被证明参与5-氟尿嘧啶（5-FU）的激活和/或降解过程，并且是预测对5-FU化疗敏感性的潜在候选因素。其中，乳清酸磷酸核糖基转移酶（OPRT，EC 2.4.2.10）是与5-FU第一步激活过程相关的关键酶，已被证明是有助于预测对5-FU及其相关衍生物敏感性的重要酶。我们开发了一种新的酶联免疫吸附测定法（ELISA），以准确评估肿瘤内OPRT的活性。使用从用OPRT分子的重组人肽免疫的兔子获得的抗OPRT多克隆抗体建立了一种新的夹心ELISA。使用新建立的ELISA和传统酶测定法，以放射性标记的5-FU为底物，在8种人癌异种移植瘤和75例胃癌组织中测量OPRT水平。通过该ELISA测量的OPRT水平与8种人癌异种移植瘤（r2 = 0.782）和胃癌组织（r2 = 0.617）中的OPRT酶活性之间存在显著相关性。用于OPRT的ELISA系统所需的癌组织量极少，使其成为一种易于使用的测定系统，可用于预测胃癌中对5-FU及其衍生物的敏感性。在人癌异种移植瘤中，口服尿嘧啶/替加氟（UFT）的肿瘤生长抑制率与OPRT酶活性之间存在显著相关性（r2 = 0.574）。这些结果表明，这种新开发的用于定量OPRT水平的夹心ELISA系统技术简单、可行，是预测胃癌和其他癌症患者对基于氟嘧啶的抗癌化疗敏感性的有用工具。
