Ochiai T, Sugitani M, Nishimura K, Noguchi H, Watanabe T, Sengoku H, Kihara A, Okano M
Dept. of Surgery, Toubu Chiiki Hospital, Tokyo Metropolitan, Health and Medical Treatment Corporation.
Gan To Kagaku Ryoho. 2001 Mar;28(3):345-50.
Orotate phosphoribosyl transferase (OPRT) is an enzyme that converts the pyrimidine fluoride-class anticancer drug 5-fluorouracil (5-FU) into the active nucleotide form. As such, it can be considered a primary enzyme in the first stage inhibiting DNA and RNA expression. The present study measured OPRT activity both in gastric carcinoma tissue and in surrounding normal tissue, and investigated the correlation between these findings and clinicopathologic characteristics in the patients. The study subjects were 20 patients with gastric carcinoma who were treated by surgical resection in our department. The relationship between OPRT activity in gastric carcinoma and surrounding normal tissue and patient age, sex, tissue type, extent of tumor invasion, extent of metastasis to the lymph nodes, lymphatic invasion and the existence of venous invasion of the gastric wall were investigated. The mean OPRT activity for all patients was 0.039 +/- 0.042 nmol/min/mg-prot in normal tissue and 0.120 +/- 0.099 nmol/min/mg-prot in tumor tissue, and the mean ORPT activity was significantly higher in tumor tissue than in surrounding normal tissue (p < 0.01). The OPRT ratio for tumor tissue/normal tissue (T/N) was significantly decreased as the invasiveness of the tumor increased, and was also significantly lower in patients with lymph node metastasis (p < 0.05) than in patients without lymph node metastasis. A decrease of OPRT activity in tumor tissue is a possible reason for the equivocal results of 5-FU-based chemotherapy in advanced gastric carcinoma.
乳清酸磷酸核糖基转移酶（OPRT）是一种将嘧啶氟类抗癌药物5-氟尿嘧啶（5-FU）转化为活性核苷酸形式的酶。因此，它可被视为抑制DNA和RNA表达第一阶段的主要酶。本研究测定了胃癌组织及周围正常组织中的OPRT活性，并研究了这些结果与患者临床病理特征之间的相关性。研究对象为20例在我科接受手术切除治疗的胃癌患者。研究了胃癌组织和周围正常组织中OPRT活性与患者年龄、性别、组织类型、肿瘤浸润范围、淋巴结转移范围、淋巴管浸润以及胃壁静脉浸润情况之间的关系。所有患者正常组织中的平均OPRT活性为0.039±0.042 nmol/min/mg蛋白，肿瘤组织中的平均OPRT活性为0.120±0.099 nmol/min/mg蛋白，肿瘤组织中的平均ORPT活性显著高于周围正常组织（p<0.01）。肿瘤组织/正常组织（T/N）的OPRT比值随着肿瘤侵袭性的增加而显著降低，且有淋巴结转移患者的该比值也显著低于无淋巴结转移患者（p<0.05）。肿瘤组织中OPRT活性降低可能是晚期胃癌基于5-FU化疗结果不明确的一个原因。
