Choice of Capecitabine or S1 in Combination with Oxaliplatin based on Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase Expression Status in Patients with Advanced Gastric Cancer

PURPOSE: To study the efficacy of capecitabine or S-1 plus oxaliplatin (CAPOX or SOX) for treating thymidine phosphorylase (TP)- or dihydropyrimidine dehydrogenase (DPD)-positive advanced gastric cancer.MATERIALS AND METHODS: Eighty-six patients with stage IIIC to IV gastric cancer were assessed for TP and DPD expression by immunohistochemistry. The association between CAPOX or SOX efficacy and TP/DPD expression was retrospectively analyzed.RESULTS: There were no significant differences in the objective remission rate (ORR, 52.27% vs. 47.62%; P>0.05), disease control rate (72.73% vs. 73.81%, P>0.05), progression-free survival (hazard ratio [HR], 1.119; 95% confidence interval [CI], 0.739–1.741; P=0.586), and overall survival (OS; HR, 0.855; 95% CI, 0.481–1.511; P=0.588) between CAPOX and SOX. A higher number of stage IV patients showed TP positivity, while DPD-positive patients predominantly showed intestinal type of gastric cancer. In TP-positive patients, the ORRs associated with CAPOX and SOX treatments were 57.14% and 38.10%, respectively; OS was better with CAPOX than with SOX (HR, 0.447; 95% CI, 0.179–0.978; P=0.046). Among DPD-positive patients, the SOX treatment-associated ORR (60.87%) was significantly higher than the CAPOX treatment-associated ORR (43.48%). Furthermore, SOX treatment resulted in better OS than did CAPOX treatment (HR, 2.020; 95% CI, 1.019–4.837; P=0.049).CONCLUSIONS: No significant difference in clinical efficacy was found between CAPOX and SOX. TP-positive patients might respond better to CAPOX while DPD-positive patients may respond better to SOX. Our findings might serve as a guide for personalized chemotherapy for gastric cancer.

Dihydropyrimidine dehydrogenase deficiency as a cause of fatal 5-Fluorouracil toxicity

5-Fluorouracil (5-FU), in combination with other cytotoxic drugs, is commonly used to treat a variety of cancers. Dihydropyrimidine dehydrogenase (DPD) catalyzes the first catabolic step of the 5-FU degradation pathway, converting 80% of 5-FU to its inactive metabolite. Approximately 0.3% of the population demonstrate complete DPD deficiency, translating to extreme toxicity of 5-FU. Here we present a case of a patient who had a fatal outcome after treatment with 5-FU who was found to have an unknown DPD deficiency discovered at autopsy.

Role of farnesoid X receptor in establishment of ontogeny of phase-I drug metabolizing enzyme genes in mouse liver

The expression of phase-I drug metabolizing enzymes in liver changes dramatically during postnatal liver maturation. Farnesoid X receptor (FXR) is critical for bile acid and lipid homeostasis in liver. However, the role of FXR in regulating ontogeny of phase-I drug metabolizing genes is not clear. Hence, we applied RNA-sequencing to quantify the developmental expression of phase-I genes in both-null and control (C57BL/6) mouse livers during development. Liver samples of male C57BL/6 and-null mice at 6 different ages from prenatal to adult were used. The-null showed an overall effect to diminish the "day-1 surge" of phase-I gene expression, including cytochrome P450s at neonatal ages. Among the 185 phase-I genes from 12 different families, 136 were expressed, and differential expression during development occurred in genes from all 12 phase-I families, including hydrolysis: carboxylesterase (), paraoxonase (), and epoxide hydrolase (); reduction: aldoketo reductase (), quinone oxidoreductase (), and dihydropyrimidine dehydrogenase (); and oxidation: alcohol dehydrogenase (), aldehyde dehydrogenase (), flavin monooxygenases (), molybdenum hydroxylase (and), cytochrome P450 (P450), and cytochrome P450 oxidoreductase (). The data also suggested new phase-I genes potentially targeted by FXR. These results revealed an important role of FXR in regulation of ontogeny of phase-I genes.

Expression of 5-Fluorouracil metabolic enZyme in colorectal cancer and its clinical signifi-cance / 临床与实验病理学杂志

Purpose To ana1yze the expression features of 5-F1uorouraci1(5-FU)metabo1ic enzyme thymidy1ate synthetase(TS),thy-midine phosphory1ase( TP),dihydropyrimidine dehydrogenase( DPD)and its re1ationship with c1inicopatho1ogica1 factors and progno-sis in co1orecta1 cancer,in order to further exp1ore its potentia1 significance in guiding co1orecta1 cancer chemotherapy. Methods Es-tab1ishment of a tissue microarray containing 72 patients with co1orecta1 cancer,and 56 norma1 tissue( dista1 cut edge tissue near carci-noma)was used to detect TS,TP,and DPD by immunohistochemistry,and to ana1yze its re1ationship with c1inicopatho1ogica1 factors and prognosis of co1orecta1 cancer through statistica1 method. Results The expression of TS in co1orecta1 cancer was 1ower than that in norma1 tissue(P=0. 876),which was associated with TNM(P=0. 043)and positive1y corre1ated with patients’overa11 surviva1(P=0. 027),the expression of TP in co1orecta1 cancer was higher than that in norma1 tissue(P=0. 315)that was associated with 1ymph node metastasis(P=0. 009)and negative1y corre1ated with the prognosis of patients(P=0. 040),DPD expression in co1orecta1 canc-er was higher than that in norma1 tissue(P=0. 071),which was re1ated to the histo1ogic type(P=0. 029). Overa11 surviva1 was sig-nificant1y shortened in co1orecta1 cancer with DPD high expression( P=0. 011). Conclusions TS,TP and DPD might be app1ied as important index of prognosis in co1orecta1 cancer patients using 5-FU adjuvant chemotherapy. The expression of TS re1ated c1ose1y with the c1inica1 stage is a bio1ogica1 marker of tumor progression. TP expression is c1ose1y re1ated to 1ymph nodes metastasis and recur-rence,which is an important factor of postoperative recurrence and metastasis.

An incidental case of dihydropyrimidine dehydrogenase deficiency: One case, multiple challenges.

Dihydropyrimidine dehydrogenase (DPD) deficiency is an autosomal recessive disorder that shows large phenotypical variability, ranging from no symptoms to intellectual disability, motor retardation, and convulsions. In addition, homozygous and heterozygous mutation carriers can develop severe 5‑fluorouracil (5‑FU) toxicity. The lack of genotype‑phenotype correlation and the possibility of other factors playing a role in the manifestation of the neurological abnormalities, make the management and education of asymptomatic DPD individuals more challenging. We describe a 3‑month‑old baby who was incidentally found by urine organic acid testing (done as part of positive newborn screen) to have very high level of thymine and uracil, consistent with DPD deficiency. Since the prevalence of asymptomatic DPD deficiency in the general population is fairly significant (1 in 10,000), we emphasize in this case study the importance of developing a guideline in genetic counseling and patient education for this condition as well as other incidental laboratory findings.

Screening of Dihydropyrimidine Dehydrogenase Genetic Variants by Direct Sequencing in Different Ethnic Groups

Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.

Screening of Dihydropyrimidine Dehydrogenase Genetic Variants by Direct Sequencing in Different Ethnic Groups

Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.

Expressions and significance of orotate phosphoribosyl transferase and dihydropyrimidine dehydrogenase mRNA in gastric cancer tissues / 中华消化外科杂志

ObjectiveTo detect the expressions of orotate phosphoribosyl transferase (OPRT) and dihydropyrimidine dchydrogenase (DPD) mRNA in gastric cancer tissues,and investigate their relationship with the clinicopathological factors.MethodsThe gastric cancer tissues and adjacent normal tissues were collected from 53 patients with gastric cancer at the Affiliated Hospital of Inner Mongolia Medical College from June 2007 to November 2008.The mRNA expressions of OPRT and DPD were detected by reverse transcriptional-polymerase chain reaction,and the correlation between the mRNA expressions of OPRT and DPD and the clinicopathological factors was analyzed.All data were analyzed by using the t test and the one-way analysis of variance.Results The mRNA expression of OPRT in the gastric cancer tissue was 1.15 ± 0.56,which was significantly higher than 0.88 ± 0.31 in the adjacent normal tissues ( t =3.66,P ＜ 0.05 ).The mRNA expressions of DPD in gastric cancer tissues and the adjacent normal tissues were 0.95 ± 0.50 and 0.90 ± 0.41,respectively,with no significant difference between the 2 groups (t =0.68,P ＞ 0.05 ).The mRNA cxprcssions of OPRT in the gastric cancer tissues with no lymph node metastasis was 1.42 ± 0.54,which was significantly higher than 1.00 ± 0.52 in the gastric cancer tissues with lymph node metastasis (t =7.94,P ＜ 0.05 ).Poorly differentiated adenocarcinoma (0.93 ± 0.24) and mucinous adenocarcinoma (1.58 ± 0.38) showed a significantly higher DPD mRNA expression than moderately differentiated or well differentiated adenocarcinoma ( 0.67 ± 0.36 ) ( F =27.71,P ＜ 0.05 ).Conclusions The mRNA expre ssion of OPRT in gastric cancer tissue is higher than that in the adjacent normal tissues,and its expression in patients with lvmph node metastasis is lower than that in patients without lymph node metastasis.Poorly differentiated adenocarcinoma showed higher DPD mRNA expression than moderately or well differentiated adenocarcinoma,and its expression is highest in mucinous adenocarcinoma.

Relationship between the Expression of Thymidylate Synthase,Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase and Survival in Epithelial Ovarian Cancer / 华中科技大学学报（医学）（英德文版）

The mRNA and protein expression of thymidylate synthase(TS),thymidine phosphorylase(TP)and dihydropyrimidine dehydrogenase(DPD)and their relationship with prognosis were investigated.Real-time quantitative RT-PCR(Taqman)was used to detect the mRNA expression of TS,TP and DPD in formalin-fixed and paraffin-embedded 106 samples of epithelial ovarian cancer and 29 normal ovaries.A TATA box-binding protein(TBP)was used as an endogenous reference gene.A relationship between TS,TE DPD expression and clinicopathologic features was investigated.The protein location and expression of TS,TP and DPD was examined in the same patients by an avidin-biotin-peroxidase immunohistochemistry.TS and TP mRNA expression levels were significantly higher in tumor group than in normal controls,with the average value of TS and TP mRNA being 6.14±0.62 and 0.59±0.06 in tumor tissue,and 0.71±0.14 and 0.16±0.04 in normal tissue,respectively.DPD mRNA expression levels were significantly lower in tumor group(0.11±0.02)than in normal controls(0.38±0.05).There was statistically significant difference in TS and TP mRNA expression levels among different pathological grades and clinical stages(P<0.05),but histological subtype was not significantly associated with TS and TP mRNA expression.DPD gene expression was not significantly associated with any clinicopathological parameters.Immunohistochemistry revealed that TP protein was mainly distributed in nucleus,and TS and DPD mainly in cytoplasm.The protein expression intensity of TS,TP and DPD was coincided with the mRNA expression levels.It was concluded that TS,TP mRNA and protein expression levels were significantly higher in epithelial ovarian cancer,and DPD mRNA and protein expression levels were significantly lower.The expression levels of TS and DPD were related to the patients' prognosis and survival.Combined gene expression levels of TS,TP and DPD represent a new variable to predict the clinical outcome in ovarian cancer.The association of TS,TP and DPD expression levels with survival suggests an importance of these genes for tumor occurrence and progression.

The role of serum dihydropyrimidine dehydrogenase activity in patients with gastric cancer resistance to fluorouracil: a prospective study / 中国医师进修杂志

Objective To investigate the mechanism of the fluorouracil(FU)drug resistance and to prove deeply the role of serum dihydropyrimidine dehydrogenase(DPD)activity in patients with gastric cancer resistance to FU with the level of cell culture. Methods The peripheral blood was collected from 45 patients with advanced gastric cancer before chemotherapy to detect the activity of DPD by high performance liquid chromatography(HPLC).The patients were divided into two groups(high activity group and low activity group)according to the results. The FU drug inhibitory rate of gastric cancer cell cultured in vitro were tested with MTT to compare the effects of the two groups. Result The FU drug inhibitory rate of gastric cancer cell cultured in vitro was obviously lower in high activity group than that in low activity group,(47.6±±4.0)%,(53.7±8.0)%respectively. Conclusion The activity of serum DPD may be simple and convenient indicators in predicting the resistance to FU.

Relationship between Microsatellite Instability and Dihydropyrimidine Dehydrogenase Expression as a Predictor of Response to 5-Fluorouracil Chemotherapy for Colorectal Cancer

PURPOSE: Dihydropyrimidine dehydrogenase (DPD) is a rate-limiting enzyme in 5-FU catabolism, so the enzymatic activity of DPD reflects the 5-FU response. Moreover, recent studies have revealed that microsatellite instability (MSI) status correlates well with the prognosis and the 5-FU chemosensitivity in colorectal cancer (CRC). This study aimed to determine whether DPD mRNA expression is related with the MSI status of primary CRC as a prognostic predictor. METHODS: Tumor samples and adjacent normal colonic mucosal tissues were collected from 59 patients. DPD mRNA expression was calculated by using the real-time RT-PCR method. The MSI status was examined by using multiplex fluorescent PCR with five reference markers. The results of DPD mRNA expression and MSI status were compared with the clinicopathologic variables and with each other. RESULTS: The mean age of the 59 patients was 59 (range: 36~81) years. In 55 patients (93.2%), the colorectal cancers were histologically well or moderately differentiated. Forty-nine of the tumors (49, 83.1%) were located distal to the splenic flexure, and 46 patients (78%) had TNM stage II (n=17) or stage III (n=29) cancer. The DPD mRNA expression level was informative in all 59 cases. The median expression level was 2.5 (range: 0~67.33). There was no correlation between the DPD mRNA expression level and age, gender, location, or TNM stage. MSI status was informative in 43 cases (72.9%). Thirty-six cases (36, 83.7%) were microsatellite-stable (MSS), 4 cases (9.3%) showed low-level microsatellite instability (MSI-L), and 3 cases (7.0%) showed high-level microsatellite instability (MSI-H). Proximal CRC showed a higher proportion of MSI-H than distal CRC (25% vs. 2.9%, P=0.03). We could not find any correlation between the DPD mRNA expression level and the MSI status in tumor tissues (r=0.29, P=0.09). CONCLUSIONS: The expression level of DPD mRNA raried among the tumors studied. The relatively low frequency of MSI in distal CRC prohibits the use of MSI status as a predictor of 5-FU chemosensitivity. We suggest that a well-designed large-scale study would be helpful to confirm the relation between DPD mRNA expression and MSI status as a predictor of 5-FU chemosensitivity in CRC patients.

Expression of metabolic enzymes of fluoropyrimidines in primary colorectal cancer and its clinical significance / 北京大学学报(医学版)

Objective:To investigate the expression of metabolic enzymes of fluoropyrimidines in primary colorectal cancer. Methods: Sixty-one cases of pathological confirmed primary colorectal cancer were collected in Beijing Cancer Hospital from August 2003 to February 2004. The expressions of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyl transferase (OPRT) were detected in paired tumor tissues and non-cancerous tissues by RT-PCR. Results: Expression of each enzyme in tumor tissues was positively correlated with that in paired non-cancerous tissues respectively. Compared with the expression of each enzyme in cancer with that in non-cancer, OPRT was higher in cancer while that of DPD and TS was comparable. The expression of OPRT was approximately 4.38-folds higher in colorectal cancer tissues than that in non-cancerous tissues (P0.000). The lowest expression of OPRT was found in mucinous carcinoma while the highest levels in poorly-differentiated adenocarcinoma. There were correlations between the ratio of tumor tissues / non-cancerous tissues OPRT expression (T/N) and metastasis to the lymph nodes (r0.36; P0.005), small vessel invasion (r0.26; P0.041) and differentiation (r-0.33; P0.009). Conclusion: The detection of three enzymes by means of RT-PCR is practical and can be used in clinical application. Our results also suggest that OPRT is a potential biomarker in predicating prognosis of colorectal cancer.

Clinicopathologic and prognostic significance of thymidine phosphorylase and dihydropyrimidine dehydrogenase activity in human colorectal carcinoma / 中国普通外科杂志

Objective This study was to investigate the relationship between the activities of thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) and clinicopathological parameters in human colorectal cancer,and the relationship between TP and/or DPD activity in tumor tissue and efficiency of chemotherapy. MethodsSixty-eight patients undergoing surgery for primary colorectal cancer were enrolled including 40 patients receiving postoperative adjuvant chemotherapy with 5-FU plus leucovorin(de Gramont regimen). The activities of TP and DPD both in tumor tissue and in normal tissue were determined by enzyme-linked immunosorbent assay(ELISA). Results The TP activity was significantly higher in tumor than in normal tissues(P