Thymidine phosphorylase and dihydropyrimidine dehydrogenase expression in hepatocellular carcinoma and metastatic liver cancer.
ABSTRACT Thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) are considered to be key enzymes affecting the prognosis for patients with various cancers. We tried to prove the correlation of TP and DPD expression in hepatocellular carcinoma (HCC) and liver metastasis. We quantified TP and DPD levels by an enzyme-linked immunosorbent assay (ELISA) in the tumor (T) and adjacent normal tissue (N) obtained from 8 HCC patients, and 11 liver metastasis patients together with 9 of their primary cancers. TP levels were higher in the primary cancer, liver metastasis, and HCC compared with each adjacent tissue. TP levels were higher in HCC than in liver metastasis, and TP levels in the adjacent tissues of HCC were also higher than those in adjacent tissues of liver metastasis. TP levels were higher in liver metastasis than in primary cancer, and TP levels in adjacent tissues of liver metastasis were also higher than those in adjacent tissues of primary cancer. However, there were no differences in TP T/N ratio between HCC and liver metastasis, and between primary cancer and liver metastasis. DPD levels were lower in the liver metastasis compared with the adjacent liver tissues, and DPD levels in liver metastasis or its adjacent liver tissues were higher than those in primary cancer or its adjacent tissues. There were no differences in DPD T/N ratio between HCC and liver metastasis, and between primary cancer and liver metastasis. Thus, we demonstrated that TP was highly expressed in liver malignancy. We may be able to increase the success of anticancer chemotherapy for liver malignancy while decreasing the side effects by analysis of T/N ratios in TP, DPD, and TP/DPD in addition to TP expression.
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ABSTRACT: Thymidine phosphorylase (TP) is a key enzyme involved in pyrimidine nucleoside metabolism. Dihydropyrimidine dehydrogenase (DPD) is the major catabolic enzyme of 5-fluorouracil (5-FU). These are important enzymes in the pyrimidine salvage pathway and are considered to be key enzymes for determining the prognosis of patients with gastrointestinal cancer. In the present study, TP and DPD were quantified and evaluated in gastric and colorectal cancer. In 111 cases of malignancy, including 30 gastric cancers and 81 colorectal cancers, the expression levels of both TP and DPD in fresh-frozen samples from either tumor or adjacent normal tissue were quantified using enzyme-linked immunosorbent assay (ELISA). The relationships between TP or DPD expression levels in tumor tissues or adjacent normal tissues and clinicopathological factors were evaluated. The TP expression levels in gastric or colorectal tumor tissues were found to be significantly higher than those in the adjacent normal tissue. Although the DPD expression levels in gastric tumor tissue were significantly higher than those in adjacent normal tissue, the DPD expression levels in colorectal tumor tissue were nearly identical to those in the adjacent normal tissue. The DPD expression levels in gastric tumor tissues were significantly higher than those in colorectal tumor tissues. The TP expression levels correlated significantly with the DPD expression levels in tumor or adjacent normal tissues. The DPD expression levels in tumor tissues significantly correlated with those in adjacent normal tissue. The difference in DPD expressions between gastric and colorectal cancer tissues may reflect the organ specificity of the carcinomas and a difference in chemotherapeutic sensitivity to 5-FU or its analogs. The correlation between TP and DPD expression levels suggests the existence of a common regulatory pathway.Anticancer research 11/2005; 25(6A):3755-61. · 1.83 Impact Factor
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ABSTRACT: Aim: The significance of dihydropyrimidine dehydrogenase (DPD) and thymidylate synthase (TS) gene expressions for the post-surgical prognosis of hepatocellular carcinoma (HCC) has not yet been determined. In the present study, we clarified the significance of DPD and TS gene expressions for the prognosis of HCC. Methods: Seventy-four patients, who underwent curative hepatic resection for primary HCC, were evaluated. The DPD and TS mRNA levels of the resected HCC specimens were evaluated using a microdissection technique and quantative real-time RT-PCR. The patients were categorized into high and low groups for each mRNA based on the median value. Various clinicopathological factors, including prognosis, and proliferation index using Ki-67 staining were evaluated in association with the DPD and TS mRNA expression levels. Results: The low DPD mRNA expression was related to younger age, advanced clinical stage, undifferentiated histology, and microscopic intrahepatic metastasis. The overall and recurrence-free survival were significantly lower in the low DPD group than in the high DPD group (P < 0.05). Furthermore, the proliferation index in the low DPD group was significantly higher than that in the high DPD group (P < 0.01). On the other hand, the high TS group showed a tendency of better prognosis than the low TS group, although it was not statistically significant. Conclusions: The low DPD mRNA expression is a significant poor prognostic factor. after curative resection of HCC.Hepatology Research 11/2008; 39(3):274 - 281. DOI:10.1111/j.1872-034X.2008.00457.x · 2.74 Impact Factor