High Dihydropyrimidine Dehydrogenase Expression Research Articles

Dihydropyrimidine Dehydrogenase (DPD) as a Bridge between the Immune Microenvironment of Colon Cancers and 5-FU Resistance.

The purpose of the present study was to investigate the role of the 5-Fluorouracil (5-FU) resistance-related factor dihydropyrimidine dehydrogenase (DPD) in tumor immunity and prognosis and to study the relationship between drug resistance and the immune microenvironment of colon cancer. Bioinformatics methods were used to analyze the expression of DPD associated with prognosis, immunity, microsatellite instability, and tumor mutational burden in colon cancer. Immunohistochemistry (IHC) was used to detect DPD, MLH1, MSH2, MSH6, and PMS2 in 219 colon cancer tissue samples. Additional IHC analyses were conducted to detect CD4, CD8, CD20, and CD163 in 30 colon cancer tissue samples with the most extensive immune infiltration. The significance of the correlations and clinical significance of DPD with immune infiltration, immune-related markers, microsatellite instability-related indicators, and prognosis were evaluated. The major findings of the present study are as follows: (1) DPD was expressed in tumor and immune cells and associated with certain immune cell-related markers, particularly M2 macrophages that expressed CD163. (2) DPD expression significantly and positively correlated with immune cell markers and immune checkpoints PD-1 and PD-L1. High expression of DPD in immune cells, but not tumor cells, led to increased immune infiltration. (3) High expression of DPD in immune and tumor cells induced 5-FU resistance and was associated with unfavorable prognosis. (4) DPD expression closely correlated with microsatellite instability and tumor mutational burden and led to resistance to 5-FU in patients with microsatellite instability. (5) Bioinformatics analyses revealed that DPD was enriched in immune-related functions and pathways such as activation of T cells and macrophages. DPD plays an important role in the immune microenvironment and drug resistance of colon cancers and their functional association.

Human equilibrative nucleoside transporter-1 expression is a predictor in patients with resected pancreatic cancer treated with adjuvant S-1 chemotherapy.

The high expression of human equilibrative nucleoside transporter‐1 (hENT1) and the low expression of dihydropyrimidine dehydrogenase (DPD) are reported to predict a favorable prognosis in patients treated with gemcitabine (GEM) and 5‐fluorouracil (5FU) as the adjuvant setting, respectively. The expression of hENT1 and DPD were analyzed in patients registered in the JASPAC 01 trial, which showed a better survival of S‐1 over GEM as adjuvant chemotherapy after resection for pancreatic cancer, and their possible roles for predicting treatment outcomes and selecting a chemotherapeutic agent were investigated. Intensity of hENT1 and DPD expression was categorized into no, weak, moderate or strong by immunohistochemistry staining, and the patients were classified into high (strong/moderate) and low (no/weak) groups. Specimens were available for 326 of 377 (86.5%) patients. High expression of hENT1 and DPD was detected in 100 (30.7%) and 63 (19.3%) of 326 patients, respectively. In the S‐1 arm, the median overall survival (OS) with low hENT1, 58.0 months, was significantly better than that with high hENT1, 30.9 months (hazard ratio 1.75, P = 0.007). In contrast, there were no significant differences in OS between DPD low and high groups in the S‐1 arm and neither the expression levels of hENT1 nor DPD revealed a relationship with treatment outcomes in the GEM arm. The present study did not show that the DPD and hENT1 are useful biomarkers for choosing S‐1 or GEM as adjuvant chemotherapy. However, hENT1 expression is a significant prognostic factor for survival in the S‐1 arm.

The Prognostic and Predictive Value of Dihydropyrimidine Dehydrogenase-Related Indicators in Clinical Outcomes of Chemotherapy in Colorectal Cancer Patients: a Systematic Review and Meta-Analysis.

Colorectal cancer (CRC) is the third most common cancer worldwide. Predictive biomarkers are needed to predict patients' outcomes and to select a chemotherapy regimen. We assessed whether dihydropyrimidine dehydrogenase (DPD)-related indicators can predict CRC patients' outcomes. We searched the studies in PubMed, EmBase, and the Cochrane Library up to March 4, 2018. We mainly analyzed different CRC patients' outcomes according to specific DPD-related indicators. Twenty-five articles were included in the meta-analysis. The results showed that for disease-free survival (DFS), low DPD expression was significantly superior to high expression (I2= 72%; HR: 1.59; 95%CI: 1.21-2.09; p= 0.001). However, this result had a potential publication bias (Begg's test: p= 0.007; Egger's test: p= 0.004). Among patients treated with chemotherapy, a high thymidylate phosphorylase (TP)/DPD ratio was advantageous for DFS (I2= 63.7%; HR: 0.65; 95%CI: 0.46-0.92; p= 0.015), and this result did not have a publication bias. For overall survival (OS), low DPD expression was superior to high expression (I2= 74.4%; HR: 2.11; 95%CI: 1.48-3.00; p< 0.001), although this result had a publication bias (Egger's test: p= 0.003; Begg's test: p= 0.010). There was no difference in OS according to the TP/DPD ratio (I2= 0%; HR: 0.92; 95%CI: 0.75-1.13; p= 0.420). DFS and OS were better in CRC patients with low DPD expression than in those with high DPD expression. However, because of publication bias, more DPD indicator-related studies, especially with negative results, are still needed. Patients with a high TP/DPD ratio have better DFS but not OS.

Dihydropyrimidine dehydrogenase predicts survival and response to interferon-\u03b1 in hepatocellular carcinoma

Metastasis and recurrence contribute to poor prognosis of hepatocellular carcinoma (HCC). Recently, we reported that interferon-α (IFN-α) can suppress metastasis of HCC; however, the underlying mechanism has not been fully described. In this study, we demonstrated that expression of dihydropyrimidine dehydrogenase (DPYD), a pyrimidine catabolic enzyme, was dose-dependently downregulated by IFN-α in HCC tissues from nude mice. Notably, DPYD expression was found to be significantly increased in HCC cell lines with higher metastatic potentials compared with their controls. Moreover, upregulation of DPYD in HCC cells could promote in vitro migration, invasion, and in vivo lung metastasis, and inducing changes characteristic of epithelial-mesenchymal transition (EMT). In contrast, knockdown of DPYD inhibited these processes. Mechanistically, DPYD functioned as a positive regulator of EMT in HCC by targeting the p38/NF-κB/Snail1 pathway. Clinically, tissue microarray analysis showed that high DPYD expression was positively associated with aggressive tumor characteristics, including larger tumor size, tumor recurrence, and advanced tumor node metastasis (TNM) stage, and independently correlated with poorer overall survival times after curative resection. HCC patients with low DPYD expression have better response to IFN-α therapy. Taken together, our findings elucidate that IFN-α could downregulate DPYD expression to inhibit EMT and HCC metastasis, and suggest that DPYD might be a potential prognostic biomarker and a therapeutic target for HCC.

One hundred and fifty total laparoscopic pancreatoduodenectomy for patients with tumors of the head of the pancreas and the periampullare area

Chemotherapy with 5-FU and Streptozotocin (STZ) is recommended as first-line treatment in patients with metastatic pancreatic neuroendocrine neoplasms (PNEN). However, data about biomarkers involved in the 5-FU metabolism to predict response are still limited.Evaluation of clinicopathological features and potential predictive and prognostic markers of patients with PNEN treated with 5-FU based regimens.We retrospectively analyzed 41 patients with PNEN who were treated at the University Hospital Marburg between 2000 and 2013. Dihydropyrimidine-Dehydrogenase (DPD) and Thymidylate-Synthase (TS) expression was correlated with treatment response in 19 patients who had available tumour tissue and response data. The median overall survival (OS) and progression free survival (PFS) were calculated using Kaplan-Meier and Cox regression methods, respectively.The median PFS in patients receiving 5-FU/STZ was 17 months with a median OS of 50 months. Objective response rate (ORR) and disease control rate (DCR) were 32% and 73%, respectively. Biochemical response (p = 0.005) and high DPD expression (p = 0.018) were predictive markers of response to 5-FU-based chemotherapy. Univariate analysis identified Ki-67 > 10%, no biochemical response, positive 5-HIAA levels and TS deficiency as independent risk factors for shorter PFS. Moreover, performance status (PS) ≥1 was an independent risk factors for impaired OS.DPD expression and biochemical response represent promising predictive biomarkers for response to 5-FU based chemotherapy. Moreover, Ki-67, PS and TS are independent prognostic markers of OS and PFS in patients with PNEN.

The Impact of the Expression Level of Intratumoral Dihydropyrimidine Dehydrogenase on Chemotherapy Sensitivity and Survival of Patients in Gastric Cancer: A Meta-Analysis.

The potential impact that the intratumoral expression level of dihydropyrimidine dehydrogenase (DPD) has on chemotherapy sensitivity and long-term survival for gastric cancer (GC) patients remains controversial; therefore, this study seeks to clarify this issue. Our meta-analysis was performed using Review Manager (RevMan) 5.3 software. In vitro drug sensitivity tests, correlation coefficients between sensitivity to 5-fluorouracil (5-FU), and expression levels of intratumoral DPD were used as effective indexes to analyse. Overall survival (OS) and progression-free survival (PFS) were used as endpoints for patient outcome, and hazard ratios (HRs) and 95% confidence intervals (CIs) were noted as measures of effect. There were 15 eligible studies including 1805 patients for the final analysis. The analysis revealed a statistically significant difference between the expression level of intratumoral DPD activity, DPD mRNA levels, and sensitivity to 5-FU in GC patients, with high expression levels of intratumoral DPD resulting in low sensitivity to 5-FU. However, no matter what therapeutic regimens were used, there was no significant difference for patient outcomes between high and low DPD expression groups, either in OS or in PFS. In conclusion, high levels of intratumoral DPD expression have a negative impact on sensitivity to 5-FU in GC patients, but no prognostic value for long-term survival was uncovered.

Relevance of dihydropyrimidine-dehydrogenase and thymidylate-synthase in patients with pancreatic neuroendocrine neoplasms treated with 5-FU-based chemotherapy

BackgroundChemotherapy with 5-FU and Streptozotocin (STZ) is recommended as first-line treatment in patients with metastatic pancreatic neuroendocrine neoplasms (PNEN). However, data about biomarkers involved in the 5-FU metabolism to predict response are still limited. ObjectivesEvaluation of clinicopathological features and potential predictive and prognostic markers of patients with PNEN treated with 5-FU based regimens. Patients and methodsWe retrospectively analyzed 41 patients with PNEN who were treated at the University Hospital Marburg between 2000 and 2013. Dihydropyrimidine-Dehydrogenase (DPD) and Thymidylate-Synthase (TS) expression was correlated with treatment response in 19 patients who had available tumour tissue and response data. The median overall survival (OS) and progression free survival (PFS) were calculated using Kaplan-Meier and Cox regression methods, respectively. ResultsThe median PFS in patients receiving 5-FU/STZ was 17 months with a median OS of 50 months. Objective response rate (ORR) and disease control rate (DCR) were 32% and 73%, respectively. Biochemical response (p = 0.005) and high DPD expression (p = 0.018) were predictive markers of response to 5-FU-based chemotherapy. Univariate analysis identified Ki-67 > 10%, no biochemical response, positive 5-HIAA levels and TS deficiency as independent risk factors for shorter PFS. Moreover, performance status (PS) ≥1 was an independent risk factors for impaired OS. ConclusionsDPD expression and biochemical response represent promising predictive biomarkers for response to 5-FU based chemotherapy. Moreover, Ki-67, PS and TS are independent prognostic markers of OS and PFS in patients with PNEN.

Construction of possible integrated predictive index based on EGFR and ANXA3 polymorphisms for chemotherapy response in fluoropyrimidine-treated Japanese gastric cancer patients using a bioinformatic method.

BackgroundVariability in drug response between individual patients is a serious concern in medicine. To identify single-nucleotide polymorphisms (SNPs) related to drug response variability, many genome-wide association studies have been conducted.MethodsWe previously applied a knowledge-based bioinformatic approach to a pharmacogenomics study in which 119 fluoropyrimidine-treated gastric cancer patients were genotyped at 109,365 SNPs using the Illumina Human-1 BeadChip. We identified the SNP rs2293347 in the human epidermal growth factor receptor (EGFR) gene as a novel genetic factor related to chemotherapeutic response. In the present study, we reanalyzed these hypothesis-free genomic data using extended knowledge.ResultsWe identified rs2867461 in annexin A3 (ANXA3) gene as another candidate. Using logistic regression, we confirmed that the performance of the rs2867461 + rs2293347 model was superior to those of the single factor models. Furthermore, we propose a novel integrated predictive index (iEA) based on these two polymorphisms in EGFR and ANXA3. The p value for iEA was 1.47 × 10−8 by Fisher’s exact test. Recent studies showed that the mutations in EGFR is associated with high expression of dihydropyrimidine dehydrogenase, which is an inactivating and rate-limiting enzyme for fluoropyrimidine, and suggested that the combination of chemotherapy with fluoropyrimidine and EGFR-targeting agents is effective against EGFR-overexpressing gastric tumors, while ANXA3 overexpression confers resistance to tyrosine kinase inhibitors targeting the EGFR pathway.ConclusionsThese results suggest that the iEA index or a combination of polymorphisms in EGFR and ANXA3 may serve as predictive factors of drug response, and therefore could be useful for optimal selection of chemotherapy regimens.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1721-z) contains supplementary material, which is available to authorized users.

Abstract 1406: High expression of DPD and ALDH1 are associated with poor prognosis in pancreatic cancer

Abstract Background: Pancreatic cancer is a highly aggressive disease and currently the fourth leading cause for cancer related mortality. The annual incidence of it has been shown to be approximately equal to the annual death rate caused by it because of the propensity for early metastatic spread and because the disease is highly resistant to radiation and chemotherapy. Recently, cancer stem cells may play a crucial role in the development and progression of tumor. According to recent studies, cancer stem cell population in human pancreatic cancers are expressing the cell surface markers CD44+, c-Met, and ALDH1. 5-Fluorouracil (5-FU) is one of the key drugs and widely used in the treatment of pancreatic cancer. Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme for 5-FU catabolism in liver, and it was reported that high DPD expression in cancer tissue was associated with 5-FU resistance and poor prognosis. The aim of this study is to examine if the pancreatic cancer stem cells express high DPD as a result acquiring chemoresistance to 5-FU. Methods: A total of 121 patients who underwent curative pancreatectomy for pancreatic cancer from April 2002 to December 2013 were analyzed. Immunohistochemical staining of DPD, ALDH1 and c-Met was performed using paraffin-embedded section of tissues. Expression of them were analyzed in interrelationship each other. Clinical relevance of those markers was confirmed with clinicopathological characteristics that were prospectively collected in our database. Results: Immunohistochemical analysis on clinical sample revealed that DPD expression was high in 55 (45.5%) patients, and high c-Met and ALDH1 expression were seen in 58 (47.9%) and 58 (47.9%) patients retrospectively. ALDH1 activity, DPD expression and sensitivity to 5-FU were examined using pancreatic cancer cell lines in vitro. High DPD expression was significantly associated with high ALDH1 expression not but c-Met, and associated with elderly patients (P = 0.0294) and overall survival (P = 0.0274). Pancreatic cell line with high DPD expression was more resistant to 5-FU than cells with low DPD expression in vitro. Low c-Met expression was significantly associated with high local infiltration (P = 0.0102). ALDH1 expression was significantly associated with relapse free survival (P = 0.0392) and overall survival (P = 0.0358). Conclusion: Our study demonstrated that high DPD expression was significantly associated with specific pancreatic cancer stem cell marker expression, may be involved in resistance to 5-FU treatment in pancreatic cancer. Citation Format: Kota Arima, Hirohisa Okabe, Daisuke Hashimoto, Takayoshi Kaida, Takaaki Higashi, Katsunobu Taki, Hideaki Takeyama, Hidetoshi Nitta, Hiromitsu Hayashi, Akira Chikamoto, Toru Beppu, Hideo Baba. High expression of DPD and ALDH1 are associated with poor prognosis in pancreatic cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1406. doi:10.1158/1538-7445.AM2015-1406

Elevation in 5-FU-induced apoptosis in head and neck cancer stem cells by a combination of CDHP and GSK3β inhibitors.

Cancer stem cells (CSCs) are involved in both tumourigenesis and in tumour recurrence after therapy. In head and neck squamous cell carcinoma (HNSCC), there are two biologically different CSC phenotypes both of which express high levels of CD44 but differ in their expression levels of epithelial-specific antigen (ESA). One phenotype is CD44(high)/ESA(high) and has epithelial features (Epi-CSCs), while the other is CD44(high) /ESA(low), has undergone epithelial to mesenchymal transition (EMT-CSCs), has mesenchymal features and is migratory (Biddle et al., 2011). CSCs are resistant to therapeutically induced apoptosis but the molecular mechanisms by which they develop apoptotic resistance remains unclear. However, glycogen synthase kinase 3β (GSK3β) contributes to regulation of both the self-renewal and switching of these two CSC phenotypes (Shigeishi et al., 2013). CD44(high) /ESA(low), CD44(high) /ESA(high) and CD44(low) cells were FACS sorted from the HNSCC cell line LUC4, and 5-FU-induced apoptosis was analysed by Annexin V staining followed by flow cytometry analysis. CD44(high) /ESA(low) cells exhibited marked resistance to 5-FU-induced apoptosis and had high expression of dihydropyrimidine dehydrogenase (DPD). The DPD inhibitor, 5-chloro-2, 4-dihydroxypyridine (CDHP) significantly enhanced 5-FU-induced apoptosis of CD44(high)/ESA(low) cells. Inhibition of GSK3β induced CD44(high) /ESA(low) cells to undergo mesenchymal-to-epithelial transition (MET) to CD44(high)/ESA(high) cells and pre-existing CD44(high) /ESA(high) cells to differentiate. Apoptosis induced by 5-FU was thus facilitated. Combination of both CDHP and GSK3β inhibitors markedly enhanced 5-FU-induced apoptosis of CD44(high) /ESA(low) cells. Our results suggest potentially new approaches for the elimination of the therapy resistant HNSCC CSC population.

High Expression of Dihydropyrimidine Dehydrogenase in Lung Adenocarcinoma is Associated With Mutations in Epidermal Growth Factor Receptor: Implications for the Treatment of Non–Small-Cell Lung Cancer Using 5-Fluorouracil

BackgroundIt has been shown that 5-fluorouracil (5-FU) sensitivity in patients with non–small-cell lung cancer (NSCLC) is associated with epidermal growth factor receptor (EGFR) mutation status. However, the relationship between dihydropyrimidine dehydrogenase (DPD), a 5-FU degrading enzyme, and EGFR mutation status is unknown. Here, we focus on clinicopathologic factors and in vitro correlations between DPD expression and EGFR mutation status. Patients and MethodsEGFR mutations and messenger RNA (mRNA) levels of DPD and thymidylate synthase (TS) were analyzed in 47 resected NSCLC tumors by laser-capture microdissection. In addition, relationships between EGFR mutation status and the immunohistochemical expression of DPD and TS in 49 patients with primary NSCLC who were treated with a 5-FU derivative of S-1 postoperatively were examined. Correlations among clinicopathologic factors were evaluated. The effect of epidermal growth factor on DPD expression was also investigated in vitro in various cell lines. ResultsAdenocarcinoma in situ showed significantly higher DPD mRNA levels and more EGFR mutation frequency than other histological types (P < .05). DPD immunopositive cases were more frequently observed in adenocarcinoma, in females, and in nonsmokers. DPD immunopositive cases were correlated with EGFR mutation status (P < .003). The prognoses of wild-type EGFR and mutated EGFR populations were similarly favorable with postoperative S-1 treatment, which overcomes the problem of 5-FU degradation in mutated EGFR. In vitro, EGFR-mutated cell lines showed high DPD mRNA and protein expression. ConclusionHigh DPD expression was shown to be correlated with EGFR mutation in adenocarcinoma cells and tissues. Clinicians should take this finding into consideration when using 5-FU to treat patients with NSCLC.

Somatic copy number changes in DPYD are associated with lower risk of recurrence in triple-negative breast cancers

Background: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.Methods: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.Results: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).Conclusion: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.

Clinical significance of the thymidylate synthase, dihydropyrimidine dehydrogenase, and thymidine phosphorylase mRNA expressions in hepatocellular carcinoma patients receiving 5-fluorouracil-based transarterial chemoembolization treatment

PurposeTo 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).MethodsFormalin-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.ResultsHigh 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.ConclusionDPD 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.

Role of thymidylate synthase and dihydropyrimidine dehydrogenase mRNA in intrahepatic cholangiocarcinoma

Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are important enzymes in the metabolism of 5-fluorouracil and possible predictive markers. We conducted this study to clarify if TS and DPD gene expressions are a prognostic indicator for intrahepatic cholangiocarcinoma (IHCC). The subjects of this study were 21 patients with IHCC who had undergone surgical resection. Intratumoral TS and DPD mRNA expressions were examined using the Danenberg tumor profile method and classified into two groups according to the median value of each. We then compared the clinicopathological variables, including prognosis, between the high and low expression groups. Low DPD expression was correlated with macroscopic type, namely, mass-forming + infiltrative (P = 0.08). Postoperative survival rates in the low DPD expression group were significantly lower than those in the high DPD expression group. Multivariate analysis revealed macroscopic type to be an independent prognostic factor, whereas TS mRNA expression did not correlate with any clinicopathological variables, including prognosis. Low DPD mRNA expression was related to macroscopic type and associated with poor prognosis. DPD mRNA expression in tumor cells is suggested to be an important regulator of malignant behavior in IHCC.

Prognostic impact of dihydropyrimidine dehydrogenase expression on pancreatic adenocarcinoma patients treated with S‐1‐based adjuvant chemotherapy after surgical resection

The aim of this study is to investigate the prognostic value of intratumoral expression of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and orotate phosphoribosyltransferase (OPRT) in patients treated with S-1-based chemotherapy after surgical resection for pancreatic adenocarcinoma. Intratumoral TS, DPD, and OPRT expression was investigated in 106 patients with resected pancreatic adenocarcinoma by immunohistochemistry. Associations between clinicopathological factors, including intratumoral TS, DPD, and OPRT expression, and survival were evaluated by univariate and multivariate analyses. Of 106 patients, 72 had received S-1-based adjuvant chemotherapy (S-1(+) group), and 34 had not (S-1(-) group). High TS, DPD, and OPRT expression was observed in 64%, 37%, and 66% of patients, respectively. Among S-1(+) group patients, survival was significantly better for patients with low DPD expression than for patients with high DPD expression (P = 0.022). Intratumoral DPD expression was the only independent prognostic factor for patients treated with S-1-based adjuvant chemotherapy by multivariate analysis (P = 0.037). Intratumoral TS and OPRT expression did not appear to influence survival. Intratumoral DPD expression may be a relevant predictive marker of survival benefit associated with S-1-based adjuvant chemotherapy for pancreatic adenocarcinoma.

Nem-szteroid gyulladásgátlók alkalmazása az 5-fluorouracil hatékonyságának növelésére kísérletes rendszerekben

The elevated cyclooxygenase-2 (COX-2) expression has been shown to affect the carcinogenesis and tumor progression processes, including cell proliferation, motility and angiogenesis. COX-2 is overexpressed in approximately 80% of sporadic colorectal carcinomas and COX-2 enzyme is the best defined target of non-steroidal anti-inflammatory drugs (NSAIDs). In the chemotherapy of colorectal carcinomas 5-fluorouracil (5-FU) has been the most important of the basic drugs for more than 40 years. In order to improve the effectiveness of 5-FU therapy different biological modifiers i.e. inhibitors of its catabolism or activators of anabolism have been studied recently. The rate-limiting enzyme of 5-FU catabolism is dihydropyrimidine dehydrogenase (DPD) since more than 80% of the administered 5-FU is catabolized by DPD. Tumoral DPD has become of clinical interest because elevated intratumoral DPD can decrease the tumor response to 5-FU therapy. The main purpose of our experiments was to investigate the effect of COX inhibitors on the efficacy of 5-FU on high and low COX-2 expressing HCA-7 and HT-29 human colon adenocarcinoma cell lines, respectively, and also on xenografts derived from HT-29 cells. The cytotoxic and antitumor effects of 5-FU in the presence of low doses of indomethacin (non-selective COX-2 inhibitor) and that of NS-398 (highly selective COX-2 inhibitor) on HT-29 and HCA-7 cells and also on the HT-29 xenograft were investigated. In addition, our intention was to understand the mechanism(s) by which NSAIDs could enhance the cytotoxic effect of 5-FU. Our data indicated that the elevated COX-2 expression of HCA-7, the collagen-induced HT-29-C cells and of the HT-29 xenograft were associated with reduced 5-FU sensitivity. Based on the fact that at the same time DPD activity was also increased it might be conceivable that a possible explanation for the decrease of 5-FU sensitivity is the co-existence of high COX-2 and DPD activity. Indomethacin or NS-398 enhanced in a simultaneous and significant manner the sensitivity and cytotoxic effect of 5-FU on high COX-2 expressing cells and xenografts through the modulation of DPD - decrease of its mRNA expression and/or enzyme activity. Based on our results it could be presumable that 5-FU efficacy is limited by the COX-2 associated high DPD expression and activity in patients with colorectal cancer as well, therefore further clinical studies are warranted to decide if NSAIDs in the therapeutic protocol might improve the antitumor potency of 5-FU. Réti A. Application of non-steroidal anti-inflammatory drugs to enhance 5-fluorouracil efficacy in experimental systems.

Dihydropyrimidine dehydrogenase and orotate phosphoribosyltransferase in esophageal cancer patients: Correlation with clinicopathological factors and prognosis

Thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyltransferase (OPRT) are fluoropyrimidine metabolic enzymes which play important roles in the response of cancer patients to chemotherapy. In esophageal cancer, little is known about the relationship between the expression of these enzymes and corresponding clinicopathological features. In the present study, TS, DPD and OPRT expression levels were evaluated in 72 resected esophageal cancer specimens using immunohistochemistry. The relationship between enzyme expression and clinicopathological features was assessed using Fisher's exact test or the χ2 test (categorical variables), or the Mann-Whitney rank-sum test (continuous variables). Survival curves were calculated using the Kaplan-Meier method, and differences evaluated using the log-rank test. The Cox proportional hazards model was also used. High DPD expression was associated with depth of invasion, nodal status, tumor stage, lymphatic invasion and venous invasion (P<0.001, P=0.004, P<0.001, P=0.006, P=0.038, respectively), as well as with decreased patient survival (P=0.007). In patients receiving adjuvant chemotherapy, low DPD expression did not significantly improve recurrence-free survival. OPRT was particularly expressed in esophageal cancer cells as compared to normal squamous cells. High OPRT expression was associated with depth of invasion and venous invasion (P=0.006, P=0.003, respectively). To conclude, in esophageal cancer DPD expression was associated with tumor progression and prognosis, and OPRT expression was correlated with carcinogenesis and tumor progression.

Predictive Role of Thymidylate Synthase, Dihydropyrimidine Dehydrogenase and Thymidine Phosphorylase Expression in Colorectal Cancer Patients Receiving Adjuvant 5-Fluorouracil

Objective: The combined assessment of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and thymidine phosphorylase (TP) gene expressions in metastatic colorectal cancer has been reported to be able to predict the efficacy of fluoropyrimidine-based chemotherapy. In order to evaluate the prognostic role in the adjuvant setting, we investigated the TS, DPD and TP expression in primary tumors of colorectal cancer patients treated with 5-fluorouracil (5-FU). Methods: TS, DPD and TP expression levels were determined by immunohistochemistry in paraffin-embedded primary tumor tissues from 62 patients with Dukes’ stage B and C colorectal cancers who underwent surgery and received adjuvant systemic chemotherapy with 5-FU. The median follow-up was 90 months (range 17–127). Results: Dukes’ stage C cancer and high TS expression were independent markers of poor prognosis for disease-free survival (DFS; p = 0.0009 and p = 0.007, respectively) and overall survival (OS; p = 0.0005 and p = 0.011, respectively). By multivariate analysis, patients with high DPD expression had significantly shorter DFS (p = 0.007) and OS (p = 0.005) compared to patients with low DPD expression. In the combined analysis of 2 markers, patients with low TS and low DPD had the best outcome in terms of DFS (p = 0.007) and OS (p = 0.03). The analysis of all 3 proteins showed that the patients with low expression of all 3 markers had significantly longer DFS (p = 0.04) and OS (p = 0.01) than patients with a high value of any one of the protein expressions. However, the joint analysis of 3 markers (group with TS–/DPD–/TP–) could not identify a subgroup of patients with a better prognosis compared to the analysis of 2 markers (group with TS–/DPD–). The analysis of Dukes’ stage C cancer patients confirmed a significant benefit in terms of DFS and OS (p = 0.001 and p = 0.006, respectively) when all 3 markers had low expression. We also found a positive significant correlation between TS and TP protein expression (p = 0.033). Conclusions: This retrospective investigation suggests that the combined assessment of TS and DPD may be useful to evaluate the prognosis of patients with Dukes’ B and C colon carcinoma receiving 5-FU adjuvant chemotherapy. The role of TP as a predictor for 5-FU-based therapy needs further investigations.

The expression profiles of orotate phosphoribosyltransferase and dihydropyrimidine dehydrogenase in gastric cancer and their clinical significance

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.

Expression of thymidylate synthase and dihydropyrimidine dehydrogenase in adenoid cystic carcinoma of the head and neck: Correlation with clinical outcome

The purpose of this study was to estimate the possibility of using thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and p53 as predictive values of clinical outcome in adenoid cystic carcinoma (ACC). The expressions of TS, DPD, and p53 were examined with immunohistochemistry in 27 ACC patients, and the association with clinicopathological factors was determined. Cases with high DPD expression had significantly higher distant metastasis rates compared to those with low DPD expression (p=0.001), whereas neither TS nor p53 expression showed any significant correlation to clinicopathological factors. Interestingly, six of 14 early-stage patients had distant metastases and all of their tumors showed high DPD expression. Kaplan-Meier analysis revealed that a solid histological pattern and distant metastasis correlated with a poor prognosis. In early-stage patients, whose tumor was completely resected, those with high TS or DPD expression had a worse prognosis compared to those with low expression, but the difference did not reach statistical significance (TS, p=0.178; DPD, p=0.251). Our results suggest that assessment of DPD expression in ACC may be a useful tool in determining the mode of treatment as well as evaluating clinical outcome.