To determine whether 5-fluorouracil (5-FU) sensitivity is associated with the mRNA expressions of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and thymidine phosphorylase (TP) in patients with hepatocellular carcinoma (HCC) treated with 5-FU-based transarterial chemoembolization (TACE).
Formalin-fixed, paraffin-embedded tumor specimens from 40 patients treated with 5-FU-based TACE were selected for the examination of TS, DPD, and TP expression level by a quantitative real-time reverse transcription- polymerase chain reaction (PCR) technique. Patients were categorized into high and low expression groups according to the median expression level of each enzyme. Associations between the mRNA expression levels of TS, DPD, and TP and clinical parameters including treatment efficacies, clinicopathological factors, and prognosis were assessed.
High DPD expression was associated with worse treatment outcome, including intrahepatic disease progression rate (hazard ratio [HR] for high DPD versus low DPD, 2.212; 95% confidence interval [CI], 1.030–4.753; P = 0.042), extrahepatic disease progression rate (HR for high versus low DPD, 3.171; 95% CI, 1.003–10.023; P = 0.049), and progression-free survival (HR for high versus low DPD, 2.308; 95% CI, 1.102–4.836; P = 0.027). No correlation was found between the mRNA expression of TS/TP and treatment outcome.
DPD mRNA expression level was negatively correlated with the clinical outcomes of HCC patients treated with 5-FU-based TACE. These results provide indirect evidence that high DPD mRNA expression is a predictive marker of treatment resistance for 5-FU.
dihydropyrimidine dehydrogenase; 5-fluorouracil; hepatocellular carcinoma; thymidylate synthase; thymidine phosphorylase; transarterial chemoembolization
The efficacy of 5-fluorouracil (5-FU)-based chemotherapy for colorectal cancer (CRC) widely varies among patients; therefore, it is difficult to accurately predict chemotherapeutic responses. Some recent studies have found that key enzymes in the various metabolic pathways activated by 5-FU present potential predictors of treatment outcome. Of these enzymes, thymidylate synthase (TS), thymidine phosphorylase (TP), and dihydropyrimidine dehydrogenase (DPD) are known to play important roles in the efficacy of therapeutic agents. Here, we measured expression levels of TS, TP, and DPD in formalin-fixed, paraffin-embedded, CRC specimens and paracancerous tissue with normal mucosa by immunohistochemical and fluorescence real-time quantitative polymerase chain reaction techniques. We found no significant differences in TS, TP, and DPD expression levels between CRC specimens and paracancerous tissues (P > 0.05), although overall survival and the chemotherapeutic effect were relatively poor in CRC patients with relatively high expression levels of TS, TP, and DPD, as compared to those with comparatively low expression levels (P < 0.05). Therefore, TS, TP, and DPD mRNA levels appear to be suitable indicators of the efficacy of 5-FU-based chemotherapy and prognosis of CRC.
Colorectal cancer; 5-fluorouracil; metabolic enzymes; immunohistochemistry; qRT-PCR; chemotherapy efficacy
Recently, S-1, a novel 5-fluorouracil (5-FU)-based agent containing the strong dihydropyrimidine dehydrogenase (DPD) inhibitor, 5-chloro-2,4-dihydropyrimidine (CDHP) has been clinically used to treat various non-urothelial carcinomas (UC). High levels of thymidylate synthase (TS), the target enzyme of 5-FU and DPD which degrades the majority of 5-FU, are associated with poor prognosis in some cancers. However, only a few reports have dealt with this in UC. The aim of this study was to investigate the clinical significance of TS and DPD in upper tract urothelial carcinoma (UTUC) and evaluate the role of TS and DPD on the sensitivity of 5-FU in UC cell lines and the anti-tumor effect of S-1 in UC xenograft model.
Firstly, we evaluated the immunohistochemical expression of TS and DPD in 176 patients with UTUC to determine their prognostic significance. Secondly, the levels of TS and DPD in UC cell lines were measured by ELISA and real-time PCR. Furthermore, the association between their levels and the sensitivity to 5-FU was examined using the small interfering RNA (siRNA) specific for TS and DPD. Thirdly, the anti-tumor effect of S-1 was evaluated in UC xenograft model.
Immunohistochemical evaluation of TS and DPD in UTUC human samples revealed that TS expression was significantly associated with stage, grade, and lymphovascular invasion and DPD expression was significantly associated with grade. Multivariate analysis revealed that high TS expression was an independent predictor of disease-specific survival in them. In in vitro study using UC cell lines, high levels of TS and DPD were associated with low response to 5-FU and these associations were confirmed with siRNA specific for TS and DPD. In in vivo study using UC xenograft model, S-1 treatment dramatically inhibited tumor growth compared to controls, tegafur, or UFT in UC tumor with a high level of DPD.
TS plays an important role in the prognosis of UTUC and S-1 may be a key agent for UC tumor, especially with a high level of DPD.
Urothelial carcinoma; S-1; 5-fluorouracil; Thymidylate synthase; Dihydropyrimidine dehydrogenase
We analyzed the expression levels of fluoropyrimidine-metabolizing enzymes (thymidylate synthase [TS], dihydropyrimidine dehydrogenase [DPD], thymidine phosphorylase [TP] and orotate phosphoribosyltransferase [OPRT]) to identify potential biomarkers related to treatment outcomes in gastric cancer (GC) patients receiving adjuvant S-1 chemotherapy. In this study, 184 patients who received curative gastrectomy (D2 lymph node dissection) and adjuvant S-1 were included. Immunohistochemistry and quantitative reverse transcription polymerase chain reaction were performed to measure the protein and mRNA levels of TS, DPD, TP, and OPRT in tumor tissue. In univariate analysis, low intratumoral DPD protein expression was related to poorer 5-year disease-free survival (DFS; 78% vs. 88%; P = 0.068). Low intratumoral DPD mRNA expression (1st [lowest] quartile) was also related to poorer DFS (69% vs. 90%; P < 0.001) compared to high intratumoral DPD expression (2nd to 4th quartiles). In multivariate analyses, low intratumoral DPD protein or mRNA expression was related to worse DFS (P < 0.05), irrespective of other clinical variables. TS, TP, and OPRT expression levels were not related to treatment outcomes. Severe non-hematologic toxicities (grade ≥ 3) had a trend towards more frequent development in patients with low intratumoral DPD mRNA expression (29% vs. 16%; P = 0.068). In conclusion, GC patients with high intratumoral DPD expression did not have inferior outcome following adjuvant S-1 therapy compared with those with low DPD expression. Instead, low intratumoral DPD expression was related to poor DFS.
Recently, it has been shown that 5-fluorouracil (5-FU) with a strong dihydropyrimidine dehydrogenase (DPD) inhibitor elicits a significant response in bladder cancer with a high level of DPD. However, only a few studies investigated the association between the level of the enzyme that regulates the metabolism of 5-FU and prognosis in bladder cancer. Furthermore, to our knowledge, there has also been no such report in T1G3 bladder tumors treated with BCG. Therefore, we evaluated enzymes that regulate the metabolism of 5-FU in T1G3 tumors treated with BCG immunotherapy using the Danenberg tumor profile (DTP) method, a highly accurate measurement of RNA from paraffin-embedded specimens.
This study included 28 patients with T1G3 bladder cancer, each of whom underwent complete transurethral tumor resection and BCG intravesical instillation at our institution. The median follow-up period was 39 months (range, 3 to 159 months). The DTP method was used to analyze the mRNA expression of 3 enzymes related to 5-FU: DPD, orotate phosphoribosyltransferase (OPRT), and thymidylate synthase (TS).
Among the 28 patients, 13 developed recurrences (46.4%) and 5 experienced disease progression (17.9%). An elevated DPD mRNA level was significantly associated with recurrence (p = 0.048) and progression (p = 0.045). However, TS and OPRT mRNA levels were not significantly associated with any other clinical features or outcomes. Furthermore, the high DPD group had a significantly lower recurrence-free survival rate than the low DPD group (p = 0.047). Among patients with low DPD, the 2- and 5-year recurrence-free survival rates were 88.9% and 74.1%, respectively; while among patients with high DPD, the corresponding rates were 61.3% and 36.8%, respectively. TS and OPRT were not significantly associated with recurrence-free survival rates.
DPD is significantly associated with recurrence and progression among T1G3 bladder cancer patients treated with BCG.
Urothelial carcinoma; S-1; 5-fluorouracil; Dihydropyrimidine dehydrogenase; Thymidylate synthase
The sensitivity to 5-fluorouracil (5-FU) has been reported to be associated with target molecule thymidylate synthase (TS), fluoropyrimidine-metabolising enzymes such as orotate phosphoribosyltransferase (OPRT), and dihydropyrimidine dehydrogenase (DPD). We performed an immunohistochemical study on the clinical significance of TS, OPRT, and DPD expression using 151 resected non-small-cell lung cancer (NSCLC) patients postoperatively treated with a combination of tegafur and uracil (UFT). Eighty-two carcinomas were TS-positive, 105 carcinomas were OPRT-positive, 68 carcinomas were DPD-positive. No correlation was observed in the HSCORE between the TS and OPRT expression (r=0.203), between the TS and DPD expression (r=0.098), or between the OPRT and DPD expression (r=0.074). Regarding the survival of NSCLC patients treated with UFT, the 5-year survival rate of patients with TS-negative tumours was significantly higher than that with TS-positive tumours (P=0.0133). The 5-year survival rate of patients with OPRT-positive stage II to III tumours was significantly higher than that with OPRT-negative stage II to III tumours (P=0.0145). In addition, the 5-year survival rate of patients with DPD-negative tumours was also significantly higher than that with DPD-positive tumours (P=0.0004). A Cox multivariate regression analysis revealed the TS status (hazard ratio 2.663; P=0.0003), OPRT status (hazard ratio 2.543; P=0.0005), and DPD status (hazard ratio 2.840; P<0.0001) to all be significant prognostic factors for the survival of resected NSCLC patients postoperatively treated with UFT.
lung cancer; 5-FU; thymidylate synthase; orotate phosphoribosyltransferase; dihydropyrimidine dehydrogenase
To test the prognostic value of tumour protein and genetic markers in colorectal cancer (CRC) and examine whether deficient mismatch repair (dMMR) tumours had a distinct profile relative to proficient mismatch repair (pMMR) tumours.
This prospective multicentric study involved 251 stage I–III CRC patients. Analysed biomarkers were EGFR (binding assay), VEGFA, thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) expressions, MMR status, mutations of KRAS (codons 12–13), BRAF (V600E), PIK3CA (exons 9 and 20), APC (exon 15) and P53 (exons 4–9), CpG island methylation phenotype status, ploidy, S-phase, LOH.
The only significant predictor of relapse-free survival (RFS) was tumour staging. Analyses restricted to stage III showed a trend towards a shorter RFS in KRAS-mutated (P=0.005), BRAF wt (P=0.009) and pMMR tumours (P=0.036). Deficient mismatch repair tumours significantly demonstrated higher TS (median 3.1 vs 1.4) and TP (median 5.8 vs 3.5) expression relative to pMMR (P<0.001) and show higher DPD expression (median 14.9 vs 7.9, P=0.027) and EGFR content (median 69 vs 38, P=0.037) relative to pMMR.
Present data suggesting that both TS and DPD are overexpressed in dMMR tumours as compared with pMMR tumours provide a strong rationale that may explain the resistance of dMMR tumours to 5FU-based therapy.
colorectal cancer; mismatch repair; fluoropyrimidine; thymidylate synthase; dihydropyrimidine dehydrogenase; gene expression
The aim of this study was to analyse the impact of epidermal growth factor receptor (EGFR), thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), aurora kinase (ARK) A/B, and excision repair cross-complementing gene 1 (ERCC1) on the efficacy of adjuvant chemotherapy with 5-fluorouracil and cisplatin (FP) after curative gastric resection. Normal and cancer tissue were separately obtained from gastrectomy samples of 153 patients with AJCC stage III–IV (M0) who subsequently treated with adjuvant FP chemotherapy. TS, DPD, TP, ERCC1, and ARK proteins were measured by immunohistochemistry (IHC). EGFR expression was investigated using a standardized IHC with the EGFR PharmDx assay. Amplification of EGFR gene was analysed using fluorescent in situ hybridisation (FISH). In multivariate analysis, stage, ratio of positive to removed lymph nodes, and EGFR expression were significant prognostic factors for overall survival. Patients with higher EGFR expression had better overall survival than those with lower expression (relative risk: 0.475 (95% confidence interval, 0.282–0.791, P=0.005). Low EGFR expression might be a predictive marker for relapse in curative resected stage III–IV (M0) gastric cancer patients who received adjuvant FP chemotherapy.
gastric cancer; adjuvant chemotherapy; pharmacogenetics; epidermal growth factor receptor; thymidine phosphorylase; excision repair cross-complementing gene 1
Although 5-fluorouracil (5-FU) is an important drug for colorectal cancer (CRC) treatment, no useful biomarker is currently available to predict treatment response. Since 5-FU is converted into active or inactive forms by orotate phosphoribosyltransferase (OPRT) or dihydropyrimidine dehydrogenase (DPD), a correlation between these enzymes and response to 5-FU has been suggested. However, such a correlation has not been investigated prospectively. Therefore, in the present study, we aimed to prospectively evaluate whether OPRT and DPD were predictive factors of the response to 5-FU treatment in patients with resectable CRC. The present investigation was designed as a multicenter prospective cohort study. OPRT and DPD activities were assessed in biopsy samples, obtained surgically from patients with resectable CRC. The OPRT/DPD ratio was calculated and the cut-off values for this ratio were determined for 5-year disease-free survival (DFS) and overall survival (OS). Patients were treated with 5-FU/leucovorin (LV) regimens and oral 5-FU. The endpoint of this study was the correlation between the OPRT/DPD ratio and 5-year DFS and OS. The cut-off value for the OPRT/DPD ratio was determined by using the maximum χ2 statistic method against 5-year DFS and OS. Sixty-eight patients were enrolled from July 2003 to May 2005. The median follow-up period was 1925 days. The OPRT/DPD ratio cut-off values for 5-year DFS and OS were 0.015 and 0.013, respectively. During the 5-year DFS and OS periods, patients with higher cut-off values had a better prognosis than those with lower ratios (P=0.03 and 0.02, respectively). In conclusion, our results suggest that the OPRT/DPD ratio could be a predictive factor for response to 5-FU/LV adjuvant chemotherapy.
5-fluorouracil; orotate phosphoribosyltransferase; dihydropyrimidine dehydrogenase; adjuvant chemotherapy; colorectal cancer
The efficacy of 5-fluorouracil (5FU)-based therapy, which remains the cornerstone of gastrointestinal cancer treatment, depends upon the expression of enzymes involved in pyrimidine metabolism, including thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), and orotate phosphoribosyltransferase (OPRT). We analyzed the expression of these genes in patients enrolled in the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) and their possible roles as biomarkers for treatment outcomes.
Formalin-fixed, paraffin-embedded specimens were available for 829 of a total of 1,059 (78.3 %) patients. TS, DPD, TP, and OPRT expression was measured by RT-PCR in manually microdissected tumor specimens and normalized to the reference gene, β-actin. The expression level of each gene was categorized as low or high using cutoffs at the 33.3rd, 50th, or 66.7th percentiles.
The hazard ratio (HR) for overall survival (OS) after S-1 treatment versus surgery alone was significantly lower in high (>66.7th percentile; HR = 0.370; 95 % CI 0.221–0.619) compared to low (<66.7th percentile; HR = 0.757; 95 % CI 0.563–1.018) TS expression groups (P = 0.015). Similarly, the HR for OS after S-1 therapy versus surgery alone was significantly lower in high (>33.3rd percentile; HR = 0.520, 95 % CI 0.376–0.720) compared to low (<33.3rd percentile; HR = 0.848, 95 % CI 0.563–1.276) DPD expression groups (P = 0.065). There was no interaction between TP or OPRT expression and OS.
This large biomarker study showed that high TS and DPD gene expression in tumors was associated with enhanced benefit from postoperative adjuvant S-1 treatment in gastric cancer. There was no interaction between TP and OPRT expression and S-1 treatment.
Electronic supplementary material
The online version of this article (doi:10.1007/s10120-014-0413-8) contains supplementary material, which is available to authorized users.
Stomach neoplasms; Thymidylate synthase; Dihydrouracil dehydrogenase; Chemotherapy, adjuvant; Biological markers
Nucleic acid-metabolizing enzymes, such as thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP) and orotate phosphoribosyl transferase (OPRT), have attracted attention as candidates for response determinants of 5-fluorouracil (5-FU). Whether the expression levels of these enzymes can be adopted as valuable parameters for 5-FU sensitivity in breast cancer has yet to be elucidated. In the present study, intratumoral mRNA expression of TS, DPD, TP and OPRT were determined in formalin-fixed paraffin-embedded surgical specimens collected from 217 breast cancer patients, using the Danenberg Tumor Profile method, which combines microdissection and real-time-polymerase chain reaction. The significance of these enzymes as prognostic and 5-FU efficacy-predicting factors was evaluated. Our data showed that a low DPD expression is related to a high nuclear grade and other factors including hormone receptor-negativity. Low expression levels of TP were found in hormone receptor-negative tumors. TS and OPRT expression were not related to various clinicopathological factors, but patients with a high TS mRNA expression showed a significantly poorer prognosis in cases where 5-FU was not administered. The efficacy of 5-FU was more significant when administered for more than 6 months in the group with a high TS mRNA expression. These data suggest that TS mRNA expression in breast cancer tissue is an ideal predictor of outcomes for patients with no administration of 5-FU, and of the efficacy of 5-FU.
thymidylate synthase; breast cancer; 5-fluorouracil; real-time polymerase chain reaction
Pretreatment knowledge of chemosensitivity and side-effects of chemotherapy for colorectal cancer (CRC) patients are likely to ensure the best chemotherapeutic outcome. The aim of this study was to identify additional predictive factors of chemosensitivity to the key CRC treatment drug 5-fluorouracil (5-FU). Surgically obtained specimens from 106 patients treated for CRC were immunohistochemically assessed to investigate the correlation between the protein expression of the 5-FU metabolic enzymes orotate phosphoribosyltransferase (OPRT), thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD), and clinicopathological characteristics as well as the correlation between the protein expression and outcomes of 5-FU-based chemotherapy. A correlation was detected between the high expression of the 5-FU metabolic enzyme OPRT and negative lymph node metastasis (P=0.0496), as well as between DPD and advanced Tumor-Node-Metastasis (TNM) grade cases (IIIA–IVB) and positive lymph node metastases (P=0.0414, respectively). In all 106 patients and in 79 patients undergoing 5-FU-based chemotherapy, survival was improved in those patients with a positive OPRT expression (P=0.0144 and 0.0167, respectively). OPRT expression was higher in the 79 patients with no recurrence (P=0.0179) as well as in patients treated with R0 surgery and 5-FU-based chemotherapy without side-effects (P=0.0126). Disease-free survival (DFS) rate was higher in patients without side-effects, and in patients with a positive OPRT expression without side-effects (P=0.0021 and 0.0031, respectively). Findings of this study demonstrated that OPRT expression positively correlated with fewer side-effects of 5-FU-based chemotherapy and longer patient survival.
orotate phosphoribosyltransferase; 5-fluorouracil-based chemotherapy; prognosis; side-effect
Microsatellite instability (MSI) refers to mutations in short motifs of tandemly repeated nucleotides resulting from replication errors and deficient mismatch repair (MMR). Colorectal cancer with MSI has characteristic biology and chemosensitivity, however the molecular basis remains unclarified. The association of MSI and MMR status with outcome and with thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) expression in colorectal cancer were evaluated.
MSI in five reference loci, MMR enzymes (hMSH2, hMSH6, hMLH1 and hPMS2), thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) expression were assessed in paraffin embedded tumor specimens, and associated with outcome in 340 consecutive patients completely resected for colorectal cancer stages II-IV and subsequently receiving adjuvant 5-fluorouracil therapy.
MSI was found in 43 (13.8%) tumors. Absence of repair protein expression was assessed in 52 (17.0%) tumors, which had primarily lost hMLH1 in 39 (12.7%), hMSH2 in 5 (1.6%), and hMSH6 in 8 (2.6%) tumors. In multivariate analysis MSI (instable) compared to MSS (stable) tumors were significantly associated with lower risk of recurrence (hazard ratio (HR) = 0.3; 95% CI: 0.2–0.7; P = 0.0007) and death (HR = 0.4; 95% CI: 0.2–0.9; P = 0.02) independently of the TS and DPD expressions. A direct relationship between MSI and TS intensity (P = 0.001) was found, while there was no significant association with DPD intensity (P = 0.1).
The favourable outcome of MSI colorectal carcinomas is ascribed mainly to the tumor biology and to a lesser extent to antitumor response to 5-fluorouracil therapy. There is no evidence that differential TS or DPD expression may account for these outcome characteristics.
Adjuvant chemotherapy for stage III colon cancer is internationally accepted as standard treatment with established efficacy. Several oral fluorouracil (5-FU) derivatives with different properties are available in Japan, but which drug is the most appropriate for each patient has not been established. Although efficacy prediction of 5-FU derivatives using expression of 5-FU activation/metabolism enzymes in tumors has been studied, it has not been clinically applied.
The B-CAST study is a multicenter, prospective cohort study aimed to identify the patients who benefit from adjuvant chemotherapy with each 5-FU regimen, through evaluating the relationship between tumor biomarker expression and treatment outcome. The frozen tumor specimens of patients with stage III colon cancer who receives postoperative adjuvant chemotherapy are examined. Protein expression of thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), epidermal growth factor receptor (EGFR), and vascular endothelial growth factor (VEGF) are evaluated using enzyme-linked immunosorbent assay (ELISA). mRNA expression of TP, DPD, thymidylate synthase (TS) and orotate phosphoribosyl transferase (OPRT) are evaluated using reverse transcription polymerase chain reaction (RT-PCR). The patients’ clinical data reviewed are as follow: demographic and pathological characteristics, regimen, drug doses and treatment duration of adjuvant therapy, types and severity of adverse events, disease free survival, relapse free survival and overall survival. Then, relationships among the protein/mRNA expression, clinicopathological characteristics and the treatment outcomes are analyzed for each 5-FU derivative.
A total of 2,128 patients from the 217 institutions were enrolled between April 2009 and March 2012. The B-CAST study demonstrated that large-scale, multicenter translational research using frozen samples was feasible when the sample shipment and Web-based data collection were well organized. The results of the study will identify the predictors of benefit from each 5-FU derivative, and will contribute to establish the “personalized therapy” in adjuvant chemotherapy for colon cancer.
ClinicalTrials.gov: NCT00918827, UMIN Clinical Trials Registry (UMIN-CTR) UMIN000002013
Colon cancer; Adjuvant chemotherapy; 5-FU; Personalized therapy; Cohort study; Translational research; Thymidine phosphorylase (TP); Thymidylate synthase (TS); Dihydropyrimidine dehydrogenase (DPD); Orotate phosphoribosyl transferase (OPRT)
Thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP) and orotate phosphoribosyl transferase (OPRT) are enzymes involved in nucleic acid metabolism. It has been reported (based on observations of various tumor types) that the extent of the mRNA expression of these enzymes within tumor tissues may be used as a factor to define tumor prognosis. It has also been reported that the mRNA expression patterns differ in each type of tumor. However, few reports are available on the distribution of mRNA expression in prostate cancers. This study was conducted on tissue specimens obtained from 172 patients who were diagnosed with prostate cancer and had undergone total prostatectomies. The mRNA expression of TS, DPD, OPRT and TP was quantitatively analyzed using the Danenberg tumor profile (DTP) method. The results were used to examine the correlations between the distributions of the mRNAs and clinicopathological factors, as well as the significance of their expression as a prognostic factor. Patients with poorly differentiated cancers in their tissues showed a significant increase in the mRNA expression of TS and OPRT. The increases in the TP mRNA content were proportional to an increase in the Gleason scores. The prognosis was significantly poorer in those cases with a high expression of TS or OPRT mRNA and a low expression of DPD mRNA. In conclusion, the expression levels of mRNAs for TS, DPD and OPRT among the enzymes related to nucleic acid metabolism are useful as prognostic factors in patients with prostate cancers.
thymidylate synthase; dihydropyrimidine dehydrogenase; thymidine phosphorylase; orotate phosphoribosyl transferase; prostate cancer; prognostic factor
A number of studies have investigated whether the activity levels of enzymes involved in 5-fluorouracil (5-FU) metabolism are prognostic factors for survival in patients with colorectal carcinoma. Most reports have examined thymidylate synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) in unresectable or metastatic cases, therefore it is unclear whether the activity of these enzymes is of prognostic value in colorectal cancer patients treated with radical resection and adjuvant chemotherapy with 5-FU.
This study examined fresh frozen specimens of colorectal carcinoma from 40 patients who had undergone curative operation and were orally administered adjuvant tegafur/uracil (UFT) chemotherapy. TS, DPD and orotate phosphoribosyl transferase (OPRT) activities were assayed in cancer tissue and adjacent normal tissue and their association with clinicopathological variables was investigated. In addition, the relationships between TS, DPD and OPRT activities and patient survival were examined to determine whether any of these enzymes could be useful prognostic factors.
While there was no clear relationship between pathological findings and TS or DPD activity, OPRT activity was significantly lower in tumors with lymph node metastasis than in tumors lacking lymph node metastasis. Postoperative survival was significantly better in the groups with low TS activity and/or high OPRT activity.
TS and OPRT activity levels in tumor tissue may be important prognostic factors for survival in Dukes' B and C colorectal carcinoma with radical resection and adjuvant chemotherapy with UFT.
AIM: To determine the expression levels of three metabolic enzymes of fluoropyrimidines: thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) in seven human gastrointestinal cancer cell lines, and to compare the enzyme levels with the sensitivity to 5-fluorouracil (5-FU) and 5-fluoro-2’-deoxyuridine (FdUrd).
METHODS: TS, TP and DPD mRNA levels were assessed by semi-quantitative RT-PCR, TP and DPD protein contents were measured by ELISA. Fifty percent inhibitory concentrations of growth (IC50), representing the sensitivity to drugs, were determined by MTT assay.
RESULTS: IC50 values ranged from 1.28 to 12.26 uM for 5-FU, and from 5.02 to 24.21 uM for FdUrd, respectively. Cell lines with lower DPD mRNA and protein levels tended to be more sensitive to 5-FU (P < 0.05), but neither TS nor TP correlated with 5-FU IC50 (P > 0.05). Only TS mRNA level was sharply related with FdUrd sensitivity (P < 0.05), but TP and DPD were not (P > 0.05). A correlation was found between mRNA and protein levels of DPD (P < 0.05), but not TP (P < 0.05).
CONCLUSION: DPD and TS enzyme levels may be useful indicators in predicting the antitumor activity of 5-FU or FdUrd, respectively.
5-Fluorouracil (5-FU) is one of the most widely used anticancer drugs; however, the activity of 5-FU is determined by the presence of several enzymes that limit its activation or degradation, and these include dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), thymidylate synthase (TS), thymidine kinase (TK), thymidine phosphorylase (TP) and deoxyuridine triphosphatase (dUTPase). The aim of this study was to compare the expression levels of these enzymes between the primary colorectal cancer of patients with and without distant metastases. Furthermore, there was a comparison of these expression levels between the primary tumour and the corresponding metastasis.
Of 55 patients with colorectal cancer, 20 had no metastasis and the other 35 had distant metastasis. A strong expression was classified as positive, while weak to moderate or no expression was negative by immunohistochemistry.
Of the six 5-FU-related enzymes, the numbers of patients with expression of dUTPase (54% versus 15%; p = 0.005), TK (26% versus 0%; p = 0.019) and DPD (17% versus 45%; p = 0.033) were significantly different in those with primary tumours with metastasis compared with those with non-metastasis, respectively. The altered expression of OPRT (34.3%), TS (40.0%) and dUTPase (42.9%) was significantly greater from primary to metastasis among the 35 patients with metastasis. By contrast, the expression of OPRT, TS and dUTPase was decreased in 6, 5 and 7 patients, respectively, in metastatic sites.
From this comparative study of the six 5-FU-related enzymes in colorectal cancer, the expression of dUTPase was most significantly different between primary tumours and their corresponding metastatic tumour. It is suggested that dUTPase may be a predictive biomarker for the metastatic potential of colorectal cancer.
Over-expression of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) in tumor tissue is associated with insensitivity to 5-fluorouracil (5-FU). Over-expression of ERCC1 correlates with insensitivity to oxaliplatin (OX) therapy, while high thymidine phosphorylase (TP) levels predict for increased sensitivity to capecitabine (Xel).
Biopsies of metastatic tumor were taken before OX (130 mg/m2 day 1) given with Xel (1200–3000 mg/m2 in two divided doses days 1–5 and 8–12) every 3-weeks. Micro-dissected metastatic and primary tumors were analyzed for relative gene expression by real-time quantitative polymerase chain reaction. The clinical protocol prospectively identified the molecular targets of interest that would be tested. Endpoints for the molecular analyses were correlation of median, first and third quartiles for relative gene expression of each target with response, time to treatment failure (TTF), and survival.
Among 91 patients participating in this trial; 97% had colorectal cancer. The median number of prior chemotherapy regimens was 2, and most had prior 5-FU and irinotecan. In paired samples, median mRNA levels were significantly higher in metastatic versus primary tumor (-fold): TS (1.9), DPD (3.8), ERCC1 (2.1) and TP (1.6). A strong positive correlation was noted between DPD and TP mRNA levels in both primary (r = 0.693, p < 0.0005) and metastatic tissue (r = 0.697, p < 0.00001). There was an association between TS gene expression and responsive and stable disease: patients whose intratumoral TS mRNA levels were above the median value had significantly greater risk of early disease progression (43% vs 17%), but this did not translate into a significant difference in TTF. ERCC1 gene expression above the third quartile was associated with a shorter TTF (median 85 vs 162 days, p = 0.046). Patients whose TS mRNA levels in metastatic tumor tissue were below the median had a longer overall survival (median 417 vs 294 days, p = 0.042).
Target gene expression in primary tumor was significantly lower than that in paired metastatic tissue. High ERCC1 mRNA levels in metastatic tumor was associated with a shorter TTF. Lower expression of TS mRNA correlated with a lower chance of early PD with XelOX therapy and improved overall survival.
Objective: Malignant pleural mesothelioma (MPM) is a rare and aggressive, treatment-resistant cancer. Pemetrexed, an inhibitor of thymidylate synthase (TS), is used worldwide for MPM as a first-line chemotherapy regimen. However, there is little consensus for a second-line chemotherapy. S-1, a highly effective dihydropyrimidine dehydrogenase (DPD)-inhibitory fluoropyrimidine, mainly acts via a TS inhibitory mechanism similar to pemetrexed. Orotate phosphoribosyltransferase (OPRT) is a key enzyme related to the first step activation of 5-fluorouracil (5-FU) for inhibiting RNA synthesis. We investigated 5-FU related-metabolism proteins, especially focusing on OPRT expression, in MPM Methods and Patients: Fifteen MPM patients who were diagnosed between July 2004 and December 2013 were enrolled. We examined the protein levels of 5-FU metabolism-related enzymes (TS, DPD, OPRT, and thymidine phosphorylase [TP]) in 14 cases Results: High TS, DPD, OPRT, and TP expressions were seen in 28.6%, 71.4%, 85.7%, and 35.7% of patients, respectively. We found that OPRT expression was extremely high in MPM tissue. We experienced one remarkable case of highly effective S-1 combined therapy for pemetrexed refractory MPM. This case also showed high OPRT protein expression Conclusion: The present study suggests that OPRT expression is high in MPM tumors. Although pemetrexed is mainly used for MPM chemotherapy as a TS inhibitor, S-1 has potential as an anticancer drug not only as a TS inhibitor but also inhibiting RNA synthesis through the OPRT pathway. This is the first report investigating OPRT protein expressions in MPM.
dihydropyrimidine dehydrogenase (DPD); mesothelioma; orotate phosphoribosyltransferase (OPRT); S-1; thymidylate synthase (TS)
5-Fluorouracil (5-FU) is the backbone of the chemotherapy regimens approved for treatment of many malignancies, especially colorectal cancer (CRC). The incidence of cardiotoxicity associated with 5-FU ranges between 1.5% to 18% and is most commonly manifested as anginal symptoms. Cardiomyopathy is very rarely reported with 5-FU and capecitabine. A 35-year-old Caucasian male with T3, N1, M0 rectal cancer after the initial neoadjuvant chemoradiation with 5FU/LV followed by surgical abdominoperineal resection (APR), began mFOLFOX6 in the adjuvant setting. Following the first treatment, he developed severe cardiomyopathy, with a drop in ejection fraction (EF) to 19% from normal. The cardiac workup showed no ischemic or other etiologies to explain this cardiac event. He was a nonsmoker and only occasionally drank alcohol. He had no previous or family history of heart disease and had normal cholesterol level. He was treated for severe congestive heart failure (CHF). When the patient presented to us for second opinion, we decided to examine him for dihydropyrimidine dehydrogenase (DPD) deficiency and thymidylate synthase (TYMS) polymorphism. The patient was found to be heterozygous for the c.85T>C mutation, resulting in reduced DPYD enzymatic activity and homozygous for TYMS 5’TSER genotype 2R/2R *f. Our group first identified and reported P453L (1358C>T) type DPYD germline mutation in a patient who developed 5-FU induced cardiotoxicity. In this paper, we describe the first case of cardiomyopathy related to DPD deficiency and homozygous polymorphism of TYMS in a patient with colon cancer following 5-FU containing regimen. Fluorouracil-related cardiomyopathy has to be anticipated and treated to prevent the serious consequence of cardiac dysfunction. The prospective testing for DPD deficiency in patients might prevent DPD-deficient patients from severe toxicity or even death, and therefore the development of a unified screening method is warranted.
colon cancer; takotsubo cardiomyopathy; 5-fluorouracil; capecitabine; dihydropyrimidine dehydrogenase; thymidylate synthase
5-Fluorouracil (5-FU) is one of the most commonly used chemotherapeutic agents in solid tumors, including colon, gastric and breast cancers. The pharmacogenetic syndrome of dihydropyrimidine dehydrogenase (DPD) deficiency leading to severe toxicity after administration of 5-flourouracil (5-FU) and capecitabine has been well-recognized. However, the data about the association of the target enzyme, thymidylate synthase (TYMS) with the toxicity of these agents is limited. A 50-year-old Caucasian woman with T2N2M0 Stage IIIB squamous cell rectal cancer after local surgical excision initiated 5-FU therapy with mitomycin-C and radiation therapy in the adjuvant setting. Following the first treatment with 5-FU, she developed grade III mucositis and grade IV neutropenia which delayed her second dose of therapy. Following her second dose of 5-FU, she again developed grade III mucositis, grade II diarrhea, pancytopenia, fever, and rectal bleeding requiring hospitalization. She was treated with blood and platelet transfusion, pegfilgrastim, IV antibiotics, and supportive therapy. Due to her severe clinical toxicity following chemotherapy involving 5-FU, we tested her for both DPD deficiency andTYMS polymorphisms. The patient was found to be homozygous for the TYMS polymorphism 5’TSER genotype 2R/2R*f, which has been associated with increased 5-FU drug sensitivity and susceptibility to 5-FU toxicity. Our case report further underlines the fact that TYMS polymorphism not only predicts response to 5-FU by relating to intratumoral-TYMS mRNA expression but also the toxicity in these patients receiving fluoropyrimidines. In brief, TYMS genotype variations present a dilemma in 5-FU-driven cancer therapy- overexpression leads to decreased drug sensitivity and poor prognosis, while underexpression leads to the manifestation of toxic drug effects that may halt therapy altogether. Future prospective translational studies in a larger population are warranted to validate its role as a predictive and prognostic factor.
5-fu; tyms; rectal cancer; toxicity; mucositis; neutropenia; thrombocytopenia
Biliary tract cancer (BTC) is a relatively uncommon type of cancer, accounting for ∼4% of the malignant neoplasms of the gastrointestinal tract. The aim of this study was to determine whether the expression of thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) predict clinical outcome in BTC patients treated with adjuvant 5-fluorouracil (5-FU)-based chemotherapy. TS and TP expression were found to be significantly correlated with cancer location (P=0.044 and 0.031, respectively). The multivariate analysis revealed that age [hazard ratio (HR)=2.157, P=0.008], stage (HR=2.234, P<0.001), resection margin status (HR=2.748, P=0.004) and TP expression (HR=2.014, P=0.039) were independently associated with overall survival (OS).
biliary tract cancer; 5-fluorouracil; thymidine phosphorylase
The updated randomised phase 2/3 FIRIS study demonstrated the noninferiority of IRIS (irinotecan and S-1) to FOLFIRI (irinotecan, folinic acid, and 5-FU) for metastatic colorectal cancer. Meanwhile, in the subset analysis including patients who previously have undergone oxaliplatin-containing chemotherapy, the IRIS group showed longer survival than the FOLFIRI group. However, the molecular mechanism underlying this result is still unknown.
The National Cancer Institute 60 (NCI60) cell line panel data were utilised to build the hypothesis. A total of 45 irinotecan-naive metastatic colorectal cancer patients who had undergone hepatic resection were included for the validation study. The mRNA expressions of excision repair cross-complementing group 1 (ERCC1), dihydropyrimidine dehydrogenase (DPD), and topoisomerase-1 (TOP1) were evaluated by quantitative RT–PCR. The expressions of ERCC1 and DPD were also evaluated by immunohistochemistry.
Sensitivity to oxaliplatin in 60 cell lines was significantly correlated with that of 5-FU. Resistant cells to oxaliplatin showed significantly higher ERCC1 and DPD expression than sensitive cells. In validation study, ERCC1 and DPD but not TOP1 expressions in cancer cells were significantly higher in FOLFOX (oxaliplatin, folinic acid, and 5-FU)-treated patients (N=24) than nontreated patients (N=21). The ERCC1 and DPD protein expressions were also significantly higher in FOLFOX-treated patients.
The ERCC1 and DPD expression levels at both mRNA and protein levels were significantly higher in patients with oxaliplatin as a first-line chemotherapy than those without oxaliplatin. The IRIS regimens with the DPD inhibitory fluoropyrimidine may show superior activity against DPD-high tumours (e.g., tumours treated with oxaliplatin) compared with FOLFIRI.
DPD; ERCC1; metastatic colorectal cancer; National Cancer Institute; oxaliplatin
Genomic rearrangements at the fragile site FRA1E may disrupt the dihydropyrimidine dehydrogenase gene (DPYD) which is involved in 5-fluorouracil (5-FU) catabolism. In triple-negative breast cancer (TNBC), a subtype of breast cancer frequently deficient in DNA repair, we have investigated the susceptibility to acquire copy number variations (CNVs) in DPYD and evaluated their impact on standard adjuvant treatment.
DPYD CNVs were analysed in 106 TNBC tumour specimens using multiplex ligation-dependent probe amplification (MLPA) analysis. Dihydropyrimidine dehydrogenase (DPD) expression was determined by immunohistochemistry in 146 tumour tissues.
In TNBC, we detected 43 (41%) tumour specimens with genomic deletions and/or duplications within DPYD which were associated with higher histological grade (P=0.006) and with rearrangements in the DNA repair gene BRCA1 (P=0.007). Immunohistochemical analysis revealed low, moderate and high DPD expression in 64%, 29% and 7% of all TNBCs, and in 40%, 53% and 7% of TNBCs with DPYD CNVs, respectively. Irrespective of DPD protein levels, the presence of CNVs was significantly related to longer time to progression in patients who had received 5-FU- and/or anthracycline-based polychemotherapy (hazard ratio=0.26 (95% CI: 0.07–0.91), log-rank P=0.023; adjusted for tumour stage: P=0.037).
Genomic rearrangements in DPYD, rather than aberrant DPD protein levels, reflect a distinct tumour profile associated with prolonged time to progression upon first-line chemotherapy in TNBC.
DPYD; BRCA1; copy number changes; fragile sites; triple-negative breast cancer