Simple combinations of 5-FU pathway genes predict the outcome of metastatic gastric cancer patients treated by S-1.

We evaluated the expression of 5-FU pathway genes in prechemotherapeutic fresh frozen samples obtained from primary tumors to predict response and survival of 59 metastatic gastric cancer patients treated with S-1 monotherapy as first line treatment. Five 5-FU pathway genes, including thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyltransferase (OPRT), thymidine phosphorylase (TP) and uridine phosphorylase (UP), were analyzed by the quantitative real-time reverse transcriptional PCR method. Median values of each gene were selected for cut-off values separating high and low gene expressions. In univariate analyses, low TS, high OPRT and low TP were significantly associated with a tumor shrinkage and a long survival, whereas DPD and UP gene expressions did not correlate with response and survival. Multivariate analyses revealed that independent variables were OPRT and TS for response and TS and TP for survival. When OPRT and TS were combined, a significantly increased accuracy rate of 91.5% was seen for response. Similarly, an increased hazard ratio of 10.29 was observed for survival in patients possessing low TS and low TP, compared with those with high TS or high TP. The simple combinations of 2 genes, OPRT and TS for response and TS and TP for survival, may allow identification of gastric cancer patients who will benefit from S-1 chemotherapy.

Thymidylate synthase and dihydropyrimidine dehydrogenase gene expression in breast cancer predicts 5-FU sensitivity by a histocultural drug sensitivity test.

Thymidylate synthase (TS), Dihydropyrimidine dehydrogenase (DPD) and Thymidine Phosphorylase (TP) gene expressions are reported to be predictive markers for 5-fluorouracil (5-FU) sensitivity in gastrointestinal cancer. However, in breast cancer, it is still controversial whether those molecular markers predict 5-FU sensitivity or not. One possible reason for the difficulty may be the histological heterogeneity in breast cancer specimens. In this study, TS, DPD and TP mRNA expression in 40 breast cancer tumors were semi-quantified separately in cancer cells (Ca), cancerous stroma (Str) and normal glands (Nor) using laser capture microdissection and real time RT-PCR (LCM+RT-PCR). The histoculture drug response assay (HDRA) for 5-FU sensitivity was performed for 22 tumors. TS and TP mRNA expressions were higher in Ca than Str, although DPD gene expression was lower in Ca than Str. The group of high TS and high DPD gene expression in Ca was resistant to 5-FU, and the group of low TS and low DPD gene expression in Ca was sensitive to 5-FU (P=0.048 chi-square test). TS and DPD mRNA expressions measured using LCM+RT-PCR might be useful predictive markers for 5-FU sensitivity in human breast cancer.

High gene expression of TS1, GSTP1, and ERCC1 are risk factors for survival in patients treated with trimodality therapy for esophageal cancer.

PURPOSE: To assess the relationship between molecular markers associated with chemotherapy resistance and survival in esophageal cancer patients treated with trimodality therapy. EXPERIMENTAL DESIGN: The original pretreatment formalin-fixed, paraffin-embedded endoscopic esophageal tumor biopsy material was obtained from 99 patients treated with concurrent cisplatin plus 5-fluorouracil plus 45 Gy radiation followed by resection at Duke University Medical Center (Durham, NC) from 1986 to 1997. cDNA was derived from the biopsy and analyzed to determine mRNA expression relative to an internal reference gene (beta-actin) using fluorescence-based, real-time reverse transcription-PCR. Possible markers of platinum chemotherapy association [glutathione S-transferase pi (GSTP1) and excision cross-complementing gene 1 (ERCC1)] and 5-fluorouracil association [thymidylate synthase 1 (TS1)] were measured. RESULTS: Cox proportional hazards model revealed a significant inverse, linear effect for TS1 with respect to survival (P = 0.007). An inverse relationship between TS1 expression and treatment response was also detected (P < or = 0.001). Univariate analysis identified an association with decreased survival for GSTP1 > or = 3.0 (P = 0.05). In multivariate analyses, TS1 >6.0, ERCC1 >3, and GSTP1 >3 were statistically significant predictors of decreased survival (P = 0.007). Additionally, the presence of ERCC1 >3.0 or TS1 >6.0 was associated with an approximately 2-fold increase in the risk of cancer recurrence (P = 0.086 and 0.003, respectively). CONCLUSION: The measurement of relative gene expression of molecular markers associated with chemoresistance in endoscopic esophageal tumor biopsies may be a useful tool in assessing outcome in patients with trimodality-treated esophageal cancer. These data should be validated further in larger prospective studies.

Thymidylate synthase and dihydropyrimidine dehydrogenase gene expression in relation to differentiation of gastric cancer.

Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are important enzymes of DNA de novo synthesis and the salvage pathway in cancer cells, respectively. Intratumoral TS and DPD gene expressions were evaluated to determine the correlation between the expression of the 2 genes in both normal stromal tissues and tissues with different degrees of malignant differentiation in primary gastric cancer. The study population consisted of 78 consecutive patients with advanced gastric cancer who underwent surgical treatment. Laser-captured microdissection of malignant or normal stromal tissues was performed in formalin-fixed, paraffin-embedded specimens. After extraction of RNA, TS and DPD gene expressions were measured by the real-time reverse transcriptional PCR method. Apart from degree of differentiation, TS and DPD in malignant tissue showed no correlation with clinicopathologic factors. TS in malignant tissue was higher in differentiated type cases than undifferentiated type cases (p < 0.01). However, DPD in malignant tissue of undifferentiated type cases was statistically higher than that of differentiated type cases (p < 0.05). In normal stromal tissue, neither TS nor DPD had any correlation with clinicopathologic factors. TS in malignant tissue was statistically higher than in normal stromal tissue in both differentiated and undifferentiated types (p < 0.0001). DPD in differentiated type malignant tissue was statistically lower than in normal stromal tissue (p < 0.001), but no difference was seen in undifferentiated type cases. TS and DPD gene expressions in primary gastric cancer differ according to degree of differentiation and between malignant and normal stromal tissue.

[Thymidylate synthase and dihydropyrimidine dehydrogenase gene expressions in colorectal cancer using the Danenberg tumor profile method].

Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) have been identified as a predictor of response to 5-fluorouracil (5-FU). Danenberg et al. developed a technology to evaluate gene expressions in formalin-fixed paraffin-embedded (FFPE) specimens (DTP; Danenberg tumor profile). In this study, TS and DPD gene expressions were measured in 47 primary colorectal cancer tumors and 12 metastatic tumors using FFPE specimens. In primary tumors, expression of TS genes in cancerous tissues was statistically higher than in stromal tissues, while DPD gene expressions in stromal tissues were higher than those in cancerous tissues. The median TS mRNA level was 0.86 in hepatic metastasis and 1.95 in lymph node metastasis. The median DPD mRNA level was 0.86 in hepatic metastasis and 1.96 in lymph node metastasis. Both gene expressions differed among primary tumors and metastatic tumors, especially in metastatic sites. DTP might be useful to evaluate the 2 gene expressions in colorectal cancer. Further studies would be needed to clarify the mechanisms of difference of gene expressions in cancerous and stromal tissues, or in primary tumors and metastatic tumors.

Gene expression of 5-fluorouracil metabolic enzymes in primary colorectal cancer and corresponding liver metastasis.

PURPOSE: Expression of thymidylate synthase (TS) and the 5-fluorouracil (5-FU) metabolic enzymes, including dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), thymidine phosphorylase (TP), and uridine phosphorylase (UP), has been reported to be associated with the sensitivity to 5-FU-based chemotherapy in colorectal cancer. We evaluated the correlation of the expression of these genes between primary tumors and corresponding liver metastases. METHOD: The mRNA levels of TS, DPD, OPRT, TP, and UP were measured by real-time quantitative RT-PCR in samples from 23 consecutive patients with both primary colorectal adenocarcinoma and liver metastasis. RESULTS: The DPD, OPRT, TP, and UP mRNA levels were significantly higher in liver metastases than in primary tumor (expression in relation to that of beta-actin mRNA: 0.42 vs 0.16, P=0.00053; 1.4 vs 0.92, P=0.016; 23 vs 11, P=0.00014; 0.36 vs 0.25, P=0.0026; respectively). However, the TS mRNA level did not differ significantly between liver metastases than primary tumor (0.20 vs 0.16, P=0.28). No correlation was observed for any gene between primary tumor and liver metastases. In both primary tumor and liver metastasis, the TS mRNA levels correlated significantly with the OPRT mRNA level (primary rS=0.83, P=0.00000081; liver metastasis rS=0.49, P=0.017), while the DPD mRNA level correlated significantly with the TP mRNA level rS=0.81, P=0.0000024; rS=0.63, P=0.0014; respectively). CONCLUSIONS: The differential gene expression of 5-FU metabolic enzymes between primary colorectal cancer and corresponding liver metastases should be taken into consideration when estimating the sensitivity to 5-FU-based chemotherapy in colorectal cancer. The gene expression of TS and OPRT, which are involved in de novo pyrimidine synthesis, and that of DPD and TP, may be coregulated.

Combination of dihydropyrimidine dehydrogenase and thymidylate synthase gene expressions in primary tumors as predictive parameters for the efficacy of fluoropyrimidine-based chemotherapy for metastatic colorectal cancer.

Dihydropyrimidine dehydrogenase (DPD) and thymidylate synthase (TS) gene expressions in metastatic colorectal cancer have been reported to be predictive parameters for the efficacy of fluoropyrimidine-based chemotherapy. In this study, we investigated the association between both DPD and TS expressions in primary colorectal tumor and the antitumor effect in patients with metastatic colorectal cancer when treated with a fluoropyrimidine-based protocol. DPD and TS expressions were measured by reverse transcription-PCR in surgically resected materials of primary colorectal tumors from 37 patients who went on to receive oral treatment of uracil and tegafur and leucovorin for either synchronous or metachronous metastatic diseases. Relative mRNA amounts of DPD or TS were expressed as the ratios of targeted gene to glyceraldehyde-3-phosphate dehydrogenase reverse transcription-PCR products. Median values of DPD mRNA expressions were 0.30 and 0.65 for responding tumors and nonresponding ones, respectively, with a statistical significance (P < 0.0001). No responding tumor had a DPD mRNA expression >/= 0.5. A total of 19 tumors had low DPD mRNA expressions of <0.5, and 63% of them showed response. There was no responding tumor with both high DPD and high TS (TS mRNA expression >/= 1.0). However, the response rate was 75% in tumors with both low DPD and low TS. The median survival time was 16.3 months in patients with both low DPD and low TS versus 8.4 months in patients with high DPD or high TS mRNA expression. In conclusion, the combination of DPD and TS mRNA expressions in the primary tumor might be useful as predictive parameters for the efficacy of fluoropyrimidine-based chemotherapy for metastatic colorectal cancer.

Intratumoral dihydropyrimidine dehydrogenase messenger RNA level reflects tumor progression in human colorectal cancer.

BACKGROUND: Determination of intratumoral dihydropyrimidine dehydrogenase (DPD) is of clinical interest because increased DPD levels can influence the tumor response to 5-fluorouracil-based chemotherapy through increased inactivation of the agent in tumor cells. METHODS: DPD messenger RNA (mRNA) levels were evaluated in 80 consecutive patients undergoing surgery for primary colorectal cancer and 12 cases of liver metastasis. RESULTS: Higher DPD mRNA levels were associated with higher pathologic classification, corresponding to the T categories (r =.267; P =.003). The DPD mRNA level was statistically higher in tumors with microscopic lymph node metastasis than in those without (P =.002). Hence, the DPD mRNA level increased in accordance with Dukes' classification (r =.387; P =.0001). The DPD mRNA level of the liver metastasis from colorectal cancer was significantly higher than that of primary lesions (P =.002). In eight patients, the DPD mRNA level of the liver metastasis was significantly higher than that of the matched primary tumor (P =.017). CONCLUSIONS: Increases of the DPD mRNA level in cancerous tissue seem to reflect tumor progression. High DPD mRNA levels in liver metastasis and advanced colorectal cancer may have clinical importance for 5-fluorouracil-based chemosensitivity.