title: The expression profiles of orotate phosphoribosyltransferase and dihydropyrimidine dehydrogenase in gastric cancer and their clinical significance.
abstract: Orotate phosphoribosyltransferase (OPRT) is an enzyme that causes the activation of 5-fluorouracil (5-FU). Dihydropyrimidine dehydrogenase (DPD) is known to catabolize 5-FU, which is widely used in chemotherapeutic treatments for patients with a variety of malignant tumors including gastric and colorectal cancer. The expression and activities of these two enzymes therefore play important roles in the response of cancer patients to chemotherapy. However, little is known about the expression of these enzymes in gastric cancer. In the present study, we further elucidate the expression patterns of ORPT and DPD and their clinicopathological significance by immunohistochemical analysis in 221 and RT-PCR in 36 gastric cancer samples. The expression of OPRT by immunohistochemical analysis was detected in 117 (52.9%) cases, whereas DPD was detected in 66 (29.9%) cases. Moreover, the level of expression of OPRT was found to correlate with the depth of tumor invasion and a poorer prognosis. Although the mRNA and protein expression of OPRT and DPD levels did not correlate, an inverse correlation in the expression of OPRT and DPD was observed by RT-PCR. The survival benefit of post-operative adjuvant chemotherapy could not be confirmed in our present analysis. However, among the patients who had received such treatment with 5-FU or its derivatives, the prognosis in cases with low DPD levels was better than that in cases with high DPD expression by immunohistochemical analysis. These results indicate that the expression of OPRT and DPD are important predictors of both survival and the response to adjuvant chemotherapy in gastric cancer patients.
authors.affiliation: Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Oeda
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sanada
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Wada
authors.forename: Takahisa
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hirozumi
authors.initials: H
authors.lastname: Mizuiri
authors.forename: Kazuo
authors.initials: K
authors.lastname: Konishi
authors.forename: Hideo
authors.initials: H
authors.lastname: Shigematsu
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Tanabe
authors.forename: Masakazu
authors.initials: M
authors.lastname: Fukushima
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000201:enzymology* / Q000401:mortality; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000032:analysis*; D017024:Chemotherapy, Adjuvant; D042943:Dihydrouracil Dehydrogenase (NADP) / Q000096:biosynthesis*; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009097:Multienzyme Complexes / Q000096:biosynthesis*; D009962:Orotate Phosphoribosyltransferase / Q000096:biosynthesis*; D009964:Orotidine-5'-Phosphate Decarboxylase / Q000096:biosynthesis*; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000401:mortality; D016019:Survival Analysis; D015996:Survival Rate
chemical_list: D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D009097:Multienzyme Complexes; D012333:RNA, Messenger; C027157:uridine 5'-monophosphate synthase; D042943:Dihydrouracil Dehydrogenase (NADP); D009962:Orotate Phosphoribosyltransferase; D009964:Orotidine-5'-Phosphate Decarboxylase; D005472:Fluorouracil