DPD Expression Research Articles

Abstract 2525: A novel splicing factor, SPF45/RBM17, might influence 5-FU resistance of gastric carcinoma

Abstract Background: SPF45/RBM17 was identified as a factor required for splicing of short introns in mRNA precursors transcribed from DNA. SPF45 is also thought to be related to anti-cancer drug resistance, suggesting that the SPF45 molecule has a different resistance mechanism from the conventional mechanism of anticancer drug resistance. In this study, we investigated the relationship between SPF45 expression and anticancer drug sensitivity in gastric cancer. Materials and Methods: A total of 654 gastric cancer cases were used in this study. SPF45 expression was examined using immunohistochemistry. The correlation between SPF45 expression and clinicopathological factors was evaluated. Results: Of the 654 gastric cancer cases, 240 were positive for SPF45 expression and 414 were negative for expression. There was no significant difference in age and gender between the two groups, but SPF45-positive cases were significantly more frequent in patients with undifferentiation (p = 0.004), lymphatic invasion (p = 0.013) and venous invasion (p < 0.001). As for anticancer drug therapy, 215 of the 654 patients with gastric cancer who underwent radical surgery were treated with adjuvant chemotherapy and 94 patients with advanced recurrent gastric cancer were treated with chemotherapy. 75 SPF45-positive-patients who received 5FU-based adjuvant chemotherapy (S-1, UFT, 5-DFUR) after surgery had significantly worse recurrence-free survival (RFS) than 140 SPF45-negative-patients (p=0.027). 102 SPF45-positive-patients who didn’t receive adjuvant chemotherapy was no significantly different in RFS from 203 SPF45-negative-patients. In the 215 patients who received adjuvant chemotherapy, 81 DPD-positive patients had significantly worse RFS than DPD-negative patients (p=0.043). In the 305 patients who didn’t receive adjuvant chemotherapy, there was no significant difference in RFS between DPD-positive patients and DPD-negative patients (p=0.880). SPF45-positive cases were significantly more frequent in patients with DPD expression (p < 0.001).In 94 patients with advanced recurrent gastric cancer treated with chemotherapy, there were 42 recurrent patients and 52 stage IV patients. 50 of SPF45-positive patients had significantly worse progression-free survival than 44 of SPF45-negative patients (p < 0.001). Regarding overall response, SPF45-positive-patients had worse response rate than SPF45-negative-patients (p=0.016). In SPF45 positive group, 20.0% responded (CR in 0% and PR in 20%) and 80.0% did not respond (SD in 52% and PD in 28%). In SPF45 negative group, 42.6% responded (CR in 0% and PR in 42.6%) and 57.4% did not respond (SD in 46.8% and PD in 10.6%) Conclusion: Our results suggest that the splicing factor SPF45 influences anticancer drugs such as 5-FU resistance in gastric cancer. Acknowledgments: We thank Kazuhiro Fukumura and Akila Mayeda, Fujita Health University. Citation Format: Koji Maruo, Masakazu Yashiro, Takashi Sakuma, Gen Tsujio, Yasuhiro Fukui, Hiroaki Kasashima, Kiyoshi Maeda. A novel splicing factor, SPF45/RBM17, might influence 5-FU resistance of gastric carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2525.

“My mind goes dead … I cannot speak”: an expression of DPD

ABSTRACT Introduction Here we present a case of Depersonalisation–Derealisation Disorder which involves an unusual environmental trigger and profile of symptoms in a patient with an underlying left frontal encephalomalacia. Methods The clinical information has been collected from multiple neurological, psychiatric, neuropsychological examinations and from the patient’s medical records. Results The neuropsychiatric assessment showed depersonalisation, derealisation, de-somatisation and de-affectualisation, along with a good response to SSRI + Lamotrigine; all typical features of DPD. The neuropsychological assessment showed language problems, and other mild cognitive difficulties that may provide a neuropsychological foundation contributing to the DPD episodes. Discussion and conclusion Given Mr R’s underlying neuropsychological deficit, hearing voices without speech-associated gestures might place excessive demands on his ability to process the information, exacerbating his feelings of threat. This sets up the pattern of suppressed insula activation, and possibly the suppression of the auditory cortex leading to the presented unusual DPD symptoms.

S1PR2 inhibitors potently reverse 5-FU resistance by downregulating DPD expression in colorectal cancer

In this study, S1PR2 was reckoned as a brand-new GPCR target for designing inhibitors to reverse 5-FU resistance. Herein a series of pyrrolidine pyrazoles as the S1PR2 inhibitors were designed, synthesized and evaluated for their activities of anti-FU-resistance. Among them, the most promising compound JTE-013, exhibited excellent inhibition on DPD expression and potent anti-FU-resistance activity in various human cancer cell lines, along with the in vivo HCT116DPD cells xenograft model, in which the inhibition rate of 5-FU was greatly increased from 13.01%–75.87%. The underlying mechanism was uncovered that JTE-013 demonstrated an anti-FU-resistance activity by blocking S1PR2 internalization to the endoplasmic reticulum (ER), which inhibited the degradation of 5-FU into α-fluoro-β-alanine (FBAL) by downregulating tumoral DPD expression. Overall, JTE-013 could serve as the lead compound for the discovery of new anti-FU-resistance drugs. SignificanceThis study provides novel insights that S1PR2 inhibitors could sensitize 5-FU therapy in colorectal cancer.

Abstract 911: Targeting the mutant KRAS/BRAF-induced enhancer as an approach to overcome resistance to 5-fluorouracil-based chemotherapy in colorectal cancer

Abstract Colorectal cancer (CRC) is the third most common cancer and is expected to cause approximately 50,000 deaths in the US in 2017. The antimetabolite 5-fluorouracil (5-FU) is the cornerstone of first-line adjuvant chemotherapy regimens for CRC. Resistance to 5-FU-based chemotherapies develops over time and is the greatest obstacle to effective management in this disease. However, the resistance mechanisms of 5-FU are largely unknown. Approximately 50% of the CRC cases have activating mutations in KRAS or BRAF. Based on recent clinical data, it is now appreciated that KRAS/BRAF mutations are associated with worse survival in 5-FU-based chemotherapies for CRC. Therefore, there is an urgent unmet need for improved therapeutic options to treat mutant KRAS/BRAF tumors. We analyzed the differential activation status of enhancers in KRAS/BRAF mutant and wildtype CRC cell lines. Enhancers that associated with genes regulating pyrimidine metabolism were significantly enriched in KRAS/BRAF mutant CRC cells. Among them, the differential activation of an enhancer located ~400kb upstream of the DPYD promoter was most significant. By using CRISPR-dCas9 system, specifically targeting of p300 to the enhancer significantly increased DPYD expression, and Ezh2 significantly decreased expression. Knockout (KO) of this enhancer resulted in reductions in DPD expression and increased resistance to 5-FU. In mouse xenograft studies, enhancer-KO cells responded to doses of 5-FU that were otherwise ineffective against control cells. Treating KRAS mutant CRC cells with CBP30, H3K27 acetyl-transferase inhibitor, significantly reduced DPYD expression. Synergistic interactions was identified between CBP30 and 5-FU. Finally, mouse xenograft studies strongly suggest that inhibition of H3K27ac may significantly improve 5-FU effectiveness against KRAS mutant tumors. In summary, the present studies advance our understanding of how mutant KRAS/BRAF epigenetically regulates DPYD expression and results in 5-FU resistance in CRC. We showed that clinical treatment of CRC might be significantly improved by the development of future pharmacologic approaches targeting enhancers that are activated by mutant KRAS/BRAF. Citation Format: Rentian Wu, Qian Nie, Phillip A. Kubica, Zhiquan Wang, Shikshya Shrestha, Colbren S. Trogstad-Isaacson, Calvin R. Jerde, Erin E. Tapper, Kelly J. Bouchonville, Steven M. Offer, Robert B. Diasio. Targeting the mutant KRAS/BRAF-induced enhancer as an approach to overcome resistance to 5-fluorouracil-based chemotherapy in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 911.

Functional Characterization of 21 Allelic Variants of Dihydropyrimidine Dehydrogenase Identified in 1070 Japanese Individuals.

Dihydropyrimidine dehydrogenase (DPD, EC 1.3.1.2), encoded by the DPYD gene, is the rate-limiting enzyme in the degradation pathway of endogenous pyrimidine and fluoropyrimidine drugs such as 5-fluorouracil (5-FU). DPD catalyzes the reduction of uracil, thymine, and 5-FU. In Caucasians, DPYD mutations, including DPYD*2A, DPYD*13, c.2846A>T, and c.1129-5923C>G/hapB3, are known to contribute to interindividual variations in the toxicity of 5-FU; however, none of these DPYD polymorphisms has been identified in the Asian population. Recently, 21 DPYD allelic variants, including some novel single-nucleotide variants (SNVs), were identified in 1070 healthy Japanese individuals by analyzing their whole-genome sequences (WGSs), but the functional alterations caused by these variants remain unknown. In this study, in vitro analysis was performed on 22 DPD allelic variants by transiently expressing wild-type DPD and 21 DPD variants in 293FT cells and characterizing their enzymatic activities using 5-FU as a substrate. DPD expression levels and dimeric forms were determined using immunoblotting and blue-native PAGE, respectively. Additionally, the values of three kinetic parameters-the Michaelis constant (Km ), maximum velocity (Vmax ), and intrinsic clearance (CLint = Vmax/Km )-were determined for the reduction of 5-FU. Eleven variants exhibited significantly decreased intrinsic clearance compared with wild-type DPD. Moreover, the band patterns observed in the immunoblots of blue-native gels indicated that DPD dimerization is required for enzymatic activity in DPD. Thus, the detection of rare DPYD variants might facilitate severe adverse effect prediction of 5-FU-based chemotherapy in the Japanese population.

Immunohistochemical expression of hENT1 and DPD in EUS-FNAB samples before gemcitabine+S1-based chemoradiotherapy for pancreatic ductal adenocarcinoma: Technical feasibility and prognostic significance

Immunohistochemical expression of hENT1 and DPD in EUS-FNAB samples before gemcitabine+S1-based chemoradiotherapy for pancreatic ductal adenocarcinoma: Technical feasibility and prognostic significance

A72: Particular qualities of the expression of markers of sensitivity to cytostatics at patients various solid tumours

Background To evaluate the expression of markers of sensitivity to chemotherapy in patients various solid tumors. Materials and methods The work includes paraffin blocks NSCLC patients (n = 486); CRC (n = 262); Breast cancer (n = 55); cervical cancer (n = 19); kidney (n = 35); squamous head and neck cancer (n = 15); stomach (n = 51); ovarian (n = 25); melanoma (n = 58); soft tissue sarcomas (n = 52). On our panel discussed the spectrum of expression of enzymes DPD, TP, TS, ERCC1, β-tubulin. Measurement of the expression of these genes produced by polymerase chain reaction in real time according to the method developed at the Institute of Oncology. NN Petrova. Results The combination of markers of sensitivity to fluoropyrimidine (low levels of DPD, TS, and low/high TP) was observed in patients with NSCLC in 30.9%, 41.9% in colorectal cancer, breast cancer in 31.1%, renal cell carcinona 41.1%, head and neck carcinoma in 14.3%, of gastric cancer in 42.5% melanoma in 39.5% of cases. Marker sensitivity to platinum drugs (low ERCC1) occurs in patients with NSCLC in 68.8%, 57.1% in colorectal cancer, breast cancer in 55.0%, renal cancer in 70.8% of squamous cell carcinoma of the head and neck 50, 0% of gastric cancer in 87.9% in melanoma 63.6% of cases. Marker, is an indirect measure of sensitivity to taxane drugs (low β-tubulin) in patients with NSCLC diagnosed in 72.7% of cases, in 75% of colorectal cancer, breast cancer in 66.7%, renal cancer in 92.3% of gastric cancer to 86.6%, melanoma in 73.5%. Conclusion The expression of markers in tumor tissue is heterogeneous. Significant heterogeneity of expression of predictive marker indicates on one hand the futility of the empirical approach to the choice of therapy, and on the other the need for their determination in all patients. Information about the molecular and genetic features of the tumor can afford to individualize the choice of drug. Objective data about the informativeness of molecular genetic markers can be obtained on the basis of randomized clinical trials.

Impact of intratumoral expression levels of fluoropyrimidine-metabolizing enzymes on treatment outcomes of adjuvant S-1 therapy in gastric cancer.

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.

568P - Tumor Location and Histological Type Related to Intratumoral Expression of 5-Fu Metabolizing Enzymes in Stage III Colon Cancer: a Multicenter, Prospective Cohort Study [B-Cast Study

ABSTRACT Aim: Several oral 5-FU derivatives with different properties are used in adjuvant therapy for colon cancer in Japan. The B-CAST study is a prospective cohort study aimed efficacy prediction of 5-FU derivatives, through evaluating the intratumoral biomarker expressions and treatment outcome. We evaluated relationships between the relevant biomarker expressions and patient characteristics, as baseline analysis of the study. Methods: The frozen specimens of patients with stage III colon cancer who received postoperative adjuvant chemotherapy were examined. The expressions of TP, DPD, EGFR, and VEGF protein and TP, DPD, TS and OPRT mRNA were evaluated by using ELISA and qRT-PCR, respectively. Patients were divided into subgroups according to the biomarker expression levels by using a tree-based regression model with baseline patient characteristics as explanatory factors. Results: Among 2128 patients from the 217 institutions enrolled between Apr. 2009 and Mar. 2012, 2018 were used for analysis. The protein and mRNA expressions were successfully estimated in 100% and 89% of the examined samples, respectively. The logarithmic values of expressions of all examined biomarkers followed normal distributions. In the tree-based model, tumor was the most relevant variable to explain the expression of TP protein and OPRT mRNA (p Conclusions: This large cohort study revealed considerable degrees of correlations between location as well as histological type and the intratumoral expression of TP, DPD, TS, OPRT, and VEGF. The results would provide useful information for future studies in personalization of chemotherapy using 5-FU derivatives. Disclosure: M. Ishiguro: B-CAST study is conducted as a part of joint research of Tokyo Medical and Dental University and the Foundation for Biomedical Research and Innovation (FBRI), with funding from FBRI. All authors declare no relevant competing interest.All other authors have declared no conflicts of interest.

MicroRNAs miR-27a and miR-27b Directly Regulate Liver Dihydropyrimidine Dehydrogenase Expression through Two Conserved Binding Sites

Dihydropyrimidine dehydrogenase (DPD, encoded by DPYD) is the rate-limiting enzyme in the uracil catabolic pathway and has a pivotal role in the pharmacokinetics of the commonly prescribed anticancer drug 5-fluorouracil (5-FU). Deficiency of DPD, whether due to inadequate expression or deleterious variants in DPYD, has been linked to severe toxic responses to 5-FU. Little is known about the mechanisms governing DPD expression in the liver. In this report, we show increased accumulation of RNA-induced silencing complex (RISC) proteins on DPYD mRNA in cells overexpressing the highly homologous microRNAs (miRNA) miR-27a and miR-27b. These miRNAs were shown to repress DPD expression through two conserved recognition sites in DPYD. The IC50 of 5-FU for HCT116 cells overexpressing miR-27a or miR-27b was 4.4 μmol/L (both), significantly lower than that for cells expressing a nontargeting (scramble) control miRNA (14.3 μmol/L; P = 3.3 × 10(-5) and P = 1.5 × 10(-7), respectively). Mouse liver DPD enzyme activity was inversely correlated with expression levels of miR-27a (R(2) = 0.49; P = 0.0012) and miR-27b (R(2) = 0.29; P = 0.022). A common variant in the hairpin loop region of hsa-mir-27a (rs895819) was also shown to be associated with elevated expression of the miR-27a in a panel of cell lines (P = 0.029) and in a transgenic overexpression model (P = 0.0011). Furthermore, rs895819 was associated with reduced DPD enzyme activity (P = 0.028) in a cohort of 40 healthy volunteers. Taken together, these results suggest that miR-27a and miR-27b expression may be pharmacologically relevant modulators of DPD enzyme function in the liver. Furthermore, our data suggest that rs895819 may be a potential risk allele for 5-FU sensitivity.

Abstract 2198: Possible circadian modulation of dihydropyrimidine dehydrogenase by mir-27a and mir-27b.

Abstract 5-fluorouracil (5-FU) is a commonly administered chemotherapy drug used for the treatment of various aggressive cancers. Dihydropyrimidine dehydrogenase (DPD, encoded by the DPYD gene) is the rate limiting enzyme of the 5-flourouracil (5-FU) catabolic pathway, and as such limits the amount of drug available for conversion into active metabolites. Reduced expression of DPD has been linked to severe adverse toxicity to 5-FU, including mucositis, diarrhea, hematological toxicities, and, in extreme cases, death. DPD has been previously shown to follow circadian patterns of expression in rodent models and in humans. Many microRNAs also exhibit circadian variations in expression and have been suggested to control oscillations in target protein expression. Using in silico prediction, we identified two putative binding domains for the microRNAs mir-27a and mir-27b within the DPYD gene. One of these sites is located in the 3’ untranslated region (UTR) and the other is located within the coding region just upstream from the stop codon. Using a reporter system, we show that mir-27a and mir-27b are able to bind to both predicted binding sites. Furthermore, over-expression of either microRNA reduced endogenous DPD protein levels in the HT-29 colon cancer cell line. To investigate mir-27a/b as a potential circadian regulator of DPD expression, expression was measured in livers collected at 4-hour intervals from chrono-synchronized mice. As expected, the circadian pattern of DPD enzyme activity closely matched that of DPD expression. The expression patterns for mir-27a and mir-27b were inverse of those for DPD expression and activity. These data suggest that mir-27a and mir-27b may direct circadian variations in DPD enzyme activity. Citation Format: Gabriel L. Butterfield, Steven M. Offer, Robert B. Diasio. Possible circadian modulation of dihydropyrimidine dehydrogenase by mir-27a and mir-27b. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2198. doi:10.1158/1538-7445.AM2013-2198

Evidence for predictive role of BRCA1 and bTUBIII in gastric cancer

Sensitivity of gastric cancer (GC) to conventional cytotoxic therapy may be at least in part attributed to molecular features of the tumor cells. We analyzed all patients with metastatic GC treated in the N.N. Petrov Institute of Oncology (St. Petersburg) within years 1999-2010 and identified 65 cases with evaluable treatment response and available biological material. Two of 65 patients (3 %) carried germ-line BRCA1 5382insC mutation and demonstrated particularly pronounced response to the treatment; both of their tumors showed loss of the remaining BRCA1 allele, thus confirming the causative role of BRCA1 heterozygosity in GC predisposition. RNA expression of TS, DPD, BRCA1, ERCC, TOP2A and bTUBIII was analyzed in the remaining 63 tumors. Low BRCA1 expression was associated with increased response rate [6/9 (67 %) vs. 17/54 (32 %), p = 0.04]. Low bTUBIII level correlated with the improved probability of tumor response [21/49 (43 %) vs. 1/13 (8 %), p = 0.02] and prolonged overall survival (10.5 vs. 7.1 months, p = 0.02); this trend was maintained both for taxane-containing and for taxane-free drug combinations. We conclude that GC should be considered as a part of BRCA1-related hereditary cancer syndrome. Tumors with BRCA1 inactivation and low bTUBIII expression demonstrate improved response to cytotoxic therapy.

Role of Conventional Chemosensitivity Test and Tissue Biomarker Expression in Predicting Response to Treatment of Peritoneal Carcinomatosis From Colon Cancer

Background5-Fluorouracil- or oxaliplatin-based regimens are the treatments of choice in patients with PC from colon cancer. There are currently no useful preclinical evaluations to guide the decision-making process for tailored therapy. The aim of the present study was to compare the advantages and limits of a conventional in vitro chemosensitivity test with those of a panel of biomolecular markers in predicting clinical response to different drugs used to treat colon cancer-derived PC. Patients and MethodsFresh surgical biopsy specimens were obtained from 28 patients with peritoneal carcinomatosis from colon cancer. TS, TP, DPD, MDR1, MRP-1, MGMT, BRCA1, ERCC1, GSTP1, and XPD gene expression levels were determined by real-time reverse transcription polymerase chain reaction. An in vitro chemosensitivity test was used to define a sensitivity or resistance profile to the drugs used to treat each patient. ResultsExpression levels of the genes analyzed were generally poorly related to each other. TS and ERCC1 expression was inversely related to response to 5-FU-and/or oxaliplatin-containing regimens. Significant predictivity in terms of sensitivity but poor predictivity of resistance (56.2%) (P = .037) were observed for ERCC1 expression (90%), and high predictivity of resistance (100%) but very low predictivity of sensitivity (40%) (P = .014) were registered for TS. The best overall and significant predictivity was observed for chemosensitivity test results (62.5% sensitivity and 89% resistance; P = .005). ConclusionsSensitivity and resistance to drugs used in vivo was better defined by the chemosensitivity test than by biomarker expression.

Analysis of the mRNA expression of chemotherapy-related genes in colorectal carcinoma using the danenberg tumor profile method.

The establishment of individualized chemotherapy for colorectal carcinoma based on the expression of genes involved in chemotherapeutic sensitivity or prognosis is necessary. To achieve this, the expression profiles of genes within tumors and their relationship to clinicopathological factors must be elucidated. Here, we selected 10 genes (TS, DPD, TP, FPGS, GGH, DHFR, ERCC1, TOPO-1, VEGF, and EGFR), examined differences in their mRNA expression between the upper and lower thirds of tumors by laser-captured microdissection and real-time RT-PCR (the Danenberg tumor profile), and analyzed the relationships between their expression profiles and clinicopathological factors. Interestingly, the mRNA expression of DPD, TP, and VEGF was significantly higher in the lower third than in the upper third of tumors (P = 0.044, 0.023, and 0.013, resp.). Furthermore, increased ERCC1 mRNA expression in the lower third of tumors correlated with recurrence (P = 0.049), and VEGF mRNA expression was significantly higher in cases with recurrence than in cases without recurrence, both in the upper and lower thirds of tumors (P = 0.018 and 0.036, resp.). These results implied that heterogeneity in DPD, TP, and VEGF expression may exist in colorectal carcinoma and that ERCC-1 and VEGF may be markers predicting recurrence after curative operation.

Combination of low-dose docetaxel and standard-dose S-1 for the treatment of advanced gastric cancer: efficacy, toxicity, and potential predictive factor

The aim of this study was to evaluate the efficacy and toxicity of low dose of docetaxel in combination with standard dose of S-1 for patients with advanced or recurrent gastric cancer and to investigate whether the protein expression level of dihydropyrimidine dehydrogenase is a predictive factor of toxicities or responses. Between March 2010 and December 2011, 61 patients from the Department of Medical Oncology of Shanghai Zhong Shan Hospital, Fudan University, were enrolled in the study. Patients with advanced or recurrent gastric adenocarcinoma were treated with docetaxel of 40 mg/m(2) intravenously on day 1 and S-1 of 80 mg/m(2) orally on days 1-14 every 3 weeks as first-line chemotherapy. The chemotherapeutic effects were evaluated following every 3 cycles of chemotherapy using the Response Evaluation Criteria In Solid Tumors (RECIST). The serum of peripheral blood was obtained at the start of the study and at each evaluation point to analyze the protein expression level of DPD, which was estimated using an enzyme-linked immunosorbent assay. All the patients were followed-up until the time of progression, death, or the censor time, to calculate progression-free survival and overall survival (OS) time. In total, 61 patients [median age 60 years (range 28-76 years)] received a total of 318 treatment cycles [median 5 (range 2-9)], and 94 cycles of single S-1 maintenance treatment. One complete response (CR) and 25 partial responses (PR) were observed, with an overall response rate of 42.6%. A total of 29 patients (47.5%) had stable disease (SD) and 6 patients (9.8%) had progressive disease (PD). The disease control rate (DCR, CR + PR + SD) was 90.2%. Median overall survival was 13.0 months [95% confidence interval (CI) 10.76-15.24 months], and median PFS was 6.0 months (95% CI 4.61-7.39 months). Progression-free survival was far longer in peritoneal metastatic patients than that in patients with other metastases (7.3 ± 2. 6 vs. 5.4 ± 2.8 months; P < 0.05); however, this was not the case for OS. Grade 3-4 neutropenia was well controlled and grade 4 non-hematologic toxicities did not occur. Baseline expression level of DPD was not associated with efficacy. Lower expression level of DPD was correlated with high grade of toxicities (P < 0.05). This combination of standard dose of S-1 and low dose of docetaxel is effective and well tolerated in patients with advanced or recurrent gastric cancer. Peritoneal metastasis is treated more effectively by this regimen than other forms of metastases. Baseline DPD expression level in the serum is associated with toxicity, but not tumor response.

Phase II study of pharmacogenetic-tailored therapy in elderly colorectal cancer patients

Background Retrospective analyses suggested that a pharmacogenetic approach may allow a tailored selection of chemotherapy for metastatic colorectal cancer. Aim We conducted a phase II study of pharmacogenetic-selected first-line chemotherapy in elderly patients with advanced colorectal cancer, with the aim to improve efficacy and to reduce toxicity in this group of patients. Methods 24 patients were enrolled in this study. Chemotherapy regimen was prospectively assigned based on TS, DPD, ERCC-1 and UGT1A1 genotyping results. Twelve patients (50%) were treated with modified FOLFIRI, 11 patients (46%) with modified FOLFOX6 and 1 (4%) with De Gramont regimen. Results A partial remission was obtained in 4 cases (17%), stable disease in 8 cases (33%) and progressive disease in 12 cases (50%). Grade 3–4 neutropenia was observed in 7 patients (29%) and diarrhoea in 3 cases (12%). The trial was then interrupted according to study design requiring 13 partial remissions out of the first 24 patients enrolled as the necessary response rate level in order to continue. Conclusion Prospective selection of chemotherapy based on TS, DPD, ERCC-1 and UGT1A1 expression in elderly advanced colorectal cancer patients failed to confirm previous results. A more accurate validation of retrospective findings is warranted before these molecular markers can be used for treatment selection in the clinical practice.

Abstract 2552: Synergistic antitumor effects of FGFR2 inhibitor with 5-fluorouracil on diffuse-type gastric carcinoma

Abstract Purpose: Diffuse-type gastric carcinoma carries the highest mortality because of a frequent metastasis to lymph node. S1, a 5-fluorouracil (5-FU) analog, is clinically available for gastric cancer at advanced stage. Fibroblast growth factor receptor 2 (FGFR2) is required for the proliferation of diffuse-type gastric carcinoma. The objective of this study is to clarify the benefit of a combination of S1 and kinase inhibitors including FGFR2 inhibitor Ki23057 in gastric cancer. Experimental Design: OCUM-2MLN and KATO-III were derived from diffuse-type gastric carcinoma. MKN-7 and MKN-74 were derived from intestinal-type gastric carcinoma. MTT assay was used to examine the growth-inhibitory activity of 5 small-synthetic molecules including Ki23057, Sunitinib, Glivec, Lapatinib, or SU11274, in cells cultured with 5-FU. Combination effects of 5-FU with Ki23057 on proliferation, apoptosis, and mRNA expression were examined. S1 and/or Ki23057 were administered to murine models of diffuse-type gastric carcinoma created by the orthotopic inoculation of OCUM-2MLN cells. Results: Ki23057 at 100 nM significantly (p&amp;lt;0.01) inhibited the proliferation, and decreased the phosphorylation of FGFR2 in diffuse-type gastric carcinoma cells, but not in intestinal-type gastric carcinoma. Ki23057 showed synergistic anti-tumor effects for diffuse-type gastric carcinoma cells in combination with 5-FU using CalcuSyn analysis, but Sunitinib, Glivec, Lapatinib, and SU11274 did not. The combination of Ki23057 and 5-FU decreased DPD expression, and increased apoptosis rates, and p21 expression level of diffuse-type gastric carcinoma cells. The combined administration of S1 and Ki23057 significantly (p&amp;lt;0.05) decreased orthotopic tumors as well as lymph node metastasis more effectively than S1 alone. Conclusion: The combined treatment with 5-FU and Ki23057 produced synergistic anti-tumor effects, and is a therapeutically promising for diffuse-type gastric carcinoma treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2552. doi:10.1158/1538-7445.AM2011-2552

Relationship Between Gene Expression of 5-Fluorouracil Metabolic Enzymes and 5-Fluorouracil Sensitivity in Primary Cancer Cells Isolated from Malignant Ascites

This study was designed to investigate the predictive role of 5-FU metabolic enzymes in malignant ascites. Forty-three malignant ascites were collected and primary cancer cells were isolated. Gene expression was detected by quantitative RT-PCR. We found that DPD mRNA was higher in patients with pancreatic cancers than those with gastric cancers, colon cancers, and liver cancers. Significant correlations were found between expression of DPD and TP, and between TS and OPRT. mRNA levels of TS and OPRT correlated significantly with the chemosensitivity of 5-FU. Assessing gene expression would be useful in predicting 5-FU sensitivity for patients with malignant ascites.

A quantitative evaluation of the determinant proteins for S-1 responsiveness in a biopsy specimen assists in patient selection to neoadjuvant therapy in cases of advanced gastric cancer

Neoadjuvant chemotherapy (NAC) by 5-fluorouracil including S-1 is administered to advanced gastric cancer patients. However, the therapeutic benefit from this pre-operative treatment remains uncertain. The present study analyzed the expression of 5-fluorouracil related enzymes, TS, DPD and OPRT in 47 gastric cancer biopsy specimens using quantitative double-fluorescence immunohistochemistry (qDFIHC), which is a newly developed system to quantify protein expression. The study first determined whether the cancer heterogeneity within the sample influences evaluation by qDFIHC system. Thereafter, the expression values of the TS, DPD, OPRT and OPRT/TS, OPRT/DPD, OPRT/(TS+DPD) ratios were retrospectively correlated with the clinical or pathological response in the patients. The expression values of TS, DPD and OPRT at a single field were significantly correlated with mean of the values evaluated at three fields. Among the 6 candidate factors analyzed, OPRT, OPRT/TS, OPRT/DPD and OPRT/(TS+DPD) showed significant correlations with the clinical response in 47 patients. Cut-off values to differentiate the clinical response were determined in the four factors. OPRT/TS showed the strongest correlation with the clinical response. qDFIHC was able to quantify the TS, DPD and OPRT expressions in cancer biopsy specimens without being affected by the heterogeneity. Effective therapy using tailored S-1 NAC according to the OPRT/TS ratio is therefore expected in advanced gastric cancer patients.

Clinical significance of dihydropyrimidine dehydrogenase and thymidylate synthase expression in patients with pancreatic cancer

Little is known about the clinical significance of TS and DPD in pancreatic cancer. We aimed to evaluate TS and DPD expression levels in not only pancreatic cancer but also surrounding normal pancreatic tissues to assess the clinical implications of the expression of TS and DPD in this study. Pancreatic cancer and normal pancreatic tissues were obtained from 18 patients with pancreatic cancer who underwent pancreatic resection to measure TS and DPD activities. The TS and DPD activities were determined by enzyme-linked immunosorbent assay using non-fixed fresh-frozen specimens. Pancreatic cancer tissues had significantly higher DPD and TS enzyme activities than surrounding normal tissue. Anaplastic ductal carcinoma had higher DPD and TS activities than the other histological types. Patients with high DPD in this study demonstrated poorer prognosis than those with low DPD. On the other hand, there was no statistically significant difference in survival between the high and the low TS groups. The efficacy of 5-FU may be lower in pancreatic cancer tissue than in normal tissue because DPD activity is upregulated in pancreatic cancer tissue compared to normal pancreatic tissue. It is necessary to develop an effective 5-FU delivery system and/or 5-FU combined with an inhibitor for DPD that can be used when 5-FU must be administered to patients with pancreatic cancer. High DPD activity may be a prognostic factor in patients with pancreatic cancer.