Noriaki Sawada

Bio: Noriaki Sawada is an academic researcher from Hoffmann-La Roche. The author has contributed to research in topics: Thymidine phosphorylase & Capecitabine. The author has an hindex of 6, co-authored 6 publications receiving 2529 citations.

Induction of thymidine phosphorylase activity and enhancement of capecitabine efficacy by taxol/taxotere in human cancer xenografts.

Abstract: Thymidine phosphorylase (dThdPase) is an essential enzyme for the activation of the cytostatics capecitabine (N(4)-pentyloxycarbonyl-5'-deoxy-5-fluorocytidine) and its intermediate metabolite [5'-deoxy-5-fluorouridine (5'-dFUrd)] to 5-fluorouracil in tumors. We have tried to identify the best partners of capecitabine in combination therapy, such as dThdPase up-regulators, which may enhance the efficacy of this compound. Among various cytostatics studied with the WiDr human colon cancer xenograft model, Taxol, Taxotere, and mitomycin C greatly increased levels of human dThdPase in tumors, and cyclophosphamide slightly increased the enzyme level. These cytostatics simultaneously increased the levels of human tumor necrosis factor alpha (TNFalpha), which is an up-regulator of dThdPase. In cultures of the WiDr cells, however, Taxol did not up-regulate TNFalpha to a detectable level and only slightly enhanced levels of dThdPase. These results suggest that Taxol might indirectly elevate TNFalpha in tumor cells, which in turn up-regulated dThdPase in the tumor cells in the WiDr cancer xenograft. In the combination therapy, the efficacy of Taxol and Taxotere with either capecitabine or 5'-dFUrd was more than just additive. In contrast, Taxol and either 5-fluorouracil or UFT (a mixture of tegafur and uracil) in combination showed only additive activity. Taxol and Taxotere might enhance the efficacy of capecitabine and 5'-dFUrd, probably by modulating dThdPase activity in tumor tissues.

X-Ray Irradiation Induces Thymidine Phosphorylase and Enhances the Efficacy of Capecitabine (Xeloda) in Human Cancer Xenografts

Abstract: Thymidine phosphorylase (dThdPase) is an essential enzyme for the activation of the cytostatics capecitabine (N4-pentyloxycarbonyl-5'-deoxy-5-fluorocytidine) and its intermediate metabolite 5'-deoxy-5-fluorouridine (5'-dFUrd) to 5-fluorouracil (5-FUra) in tumors. We observed previously that several cytokines and cytostatics up-regulated dThdPase expression and consequently enhanced the efficacy of capecitabine and 5'-dFUrd. In the present study, we found that X-ray irradiation also up-regulated dThdPase expression in several human cancer xenografts. A single-dose local irradiation at 5 Gy increased dThdPase levels by up to 13-fold at 9 days after the irradiation. Whole-body irradiation also up-regulated dThdPase in a tumor, but it did not increase the enzyme level in the liver. We also observed that the irradiation increased the levels of human tumor necrosis factor alpha (TNF-alpha), which is an up-regulator of dThdPase, prior to the dThdPase up-regulation. These results indicate that X-ray irradiation might increase dThdPase levels indirectly through the human TNF-alpha in the tumor tissue. In the WiDr colon and MX-1 mammary human cancer xenograft models, the combination of a single local X-ray irradiation with either capecitabine or 5'-dFUrd was much more effective than either radiation or chemotherapy alone. In contrast, treatment with X-ray irradiation and 5-FUra in combination showed no clear additive effects. Combined modality treatment of cancer patients with cape-citabine and X-ray irradiation would have greater potential usefulness than conventional radiochemotherapy with 5-FUra.

5-Fluorouracil: mechanisms of action and clinical strategies

Abstract: 5-fluorouracil (5-FU) is widely used in the treatment of cancer. Over the past 20 years, increased understanding of the mechanism of action of 5-FU has led to the development of strategies that increase its anticancer activity. Despite these advances, drug resistance remains a significant limitation to the clinical use of 5-FU. Emerging technologies, such as DNA microarray profiling, have the potential to identify novel genes that are involved in mediating resistance to 5-FU. Such target genes might prove to be therapeutically valuable as new targets for chemotherapy, or as predictive biomarkers of response to 5-FU-based chemotherapy.

Fluorine in pharmaceutical industry: fluorine-containing drugs introduced to the market in the last decade (2001-2011).

Abstract: Introduced to the Market in the Last Decade (2001−2011) Jiang Wang,† María Sańchez-Rosello,́‡,§ Jose ́ Luis Aceña, Carlos del Pozo,‡ Alexander E. Sorochinsky, Santos Fustero,*,‡,§ Vadim A. Soloshonok,* and Hong Liu*,† †Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China ‡Department of Organic Chemistry, Faculty of Pharmacy, University of Valencia, Av. Vicente Andreś Estelleś, 46100 Burjassot, Valencia, Spain Laboratorio de Molećulas Orgańicas, Centro de Investigacioń Príncipe Felipe, C/ Eduardo Primo Yuf́era 3, 46012 Valencia, Spain Department of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel Lardizab́al 3, 20018 San Sebastian, Spain IKERBASQUE, Basque Foundation for Science, Alameda Urquijo, 36-5 Plaza Bizkaia, 48011 Bilbao, Spain Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Murmanska Street 1, 02660 Kyiv-94, Ukraine

Capecitabine and oxaliplatin for advanced esophagogastric cancer.

Abstract: For the capecitabine–fluorouracil comparison, the hazard ratio for death in the capecitabine group was 0.86 (95% confidence interval [CI], 0.80 to 0.99); for the oxaliplatin–cisplatin comparison, the hazard ratio for the oxaliplatin group was 0.92 (95% CI, 0.80 to 1.10). The upper limit of the confidence intervals for both hazard ratios excluded the predefined noninferiority margin of 1.23. Median survival times in the ECF, ECX, EOF, and EOX groups were 9.9 months, 9.9 months, 9.3 months, and 11.2 months, respectively; survival rates at 1 year were 37.7%, 40.8%, 40.4%, and 46.8%, respectively. In the secondary analysis, overall survival was longer with EOX than with ECF, with a hazard ratio for death of 0.80 in the EOX group (95% CI, 0.66 to 0.97; P = 0.02). Progression-free survival and response rates did not differ significantly among the regimens. Toxic effects of capecitabine and fluorouracil were similar. As compared with cisplatin, oxaliplatin was associated with lower incidences of grade 3 or 4 neutropenia, alopecia, renal toxicity, and thromboembolism but with slightly higher incidences of grade 3 or 4 diarrhea and neuropathy. Conclusions Capecitabine and oxaliplatin are as effective as fluorouracil and cisplatin, respectively, in patients with previously untreated esophagogastric cancer. (Current Controlled Trials number, ISRCTN51678883.)

Prodrugs: design and clinical applications

Abstract: Prodrugs are bioreversible derivatives of drug molecules that undergo an enzymatic and/or chemical transformation in vivo to release the active parent drug, which can then exert the desired pharmacological effect. In both drug discovery and development, prodrugs have become an established tool for improving physicochemical, biopharmaceutical or pharmacokinetic properties of pharmacologically active agents. About 5-7% of drugs approved worldwide can be classified as prodrugs, and the implementation of a prodrug approach in the early stages of drug discovery is a growing trend. To illustrate the applicability of the prodrug strategy, this article describes the most common functional groups that are amenable to prodrug design, and highlights examples of prodrugs that are either launched or are undergoing human trials.

Capecitabine as Adjuvant Treatment for Stage III Colon Cancer

Abstract: BACKGROUND Intravenous bolus fluorouracil plus leucovorin is the standard adjuvant treatment for colon cancer. The oral fluoropyrimidine capecitabine is an established alternative to bolus fluorouracil plus leucovorin as first-line treatment for metastatic colorectal cancer. We evaluated capecitabine in the adjuvant setting. METHODS We randomly assigned a total of 1987 patients with resected stage III colon cancer to receive either oral capecitabine (1004 patients) or bolus fluorouracil plus leucovorin (Mayo Clinic regimen; 983 patients) over a period of 24 weeks. The primary efficacy end point was at least equivalence in disease-free survival; the primary safety end point was the incidence of grade 3 or 4 toxic effects due to fluoropyrimidines. RESULTS Disease-free survival in the capecitabine group was at least equivalent to that in the fluorouracil-plus-leucovorin group (in the intention-to-treat analysis, P<0.001 for the comparison of the upper limit of the hazard ratio with the noninferiority margin of 1.20). Capecitabine improved relapse-free survival (hazard ratio, 0.86; 95 percent confidence interval, 0.74 to 0.99; P=0.04) and was associated with significantly fewer adverse events than fluorouracil plus leucovorin (P<0.001). CONCLUSIONS Oral capecitabine is an effective alternative to intravenous fluorouracil plus leucovorin in the adjuvant treatment of colon cancer.