Objective: Cytidine deaminase (CDD) is involved in the metabolism of new pyrimidine analogues, capecitabine (N4-pentyloxycarbonyl-5′-deoxy-5-fluorocytidine) and gemcitabine (2′,2′-difluorodeoxycytidine). The purpose of the present study was to directly examine the role of CDD in tumor cells themselves in mediating the sensitivity to capecitabine compared with gemcitabine. Methods: The human bladder cancer cell line T24 was transfected with human CDD2 cDNA by the lipofectin method. Results: Transfection of CDD2 cDNA did not change the levels of thymidine phosphorylase, dihydropyrimidine dehydrogenase and thymidylate synthase (TS) but increased the CDD activity significantly (p < 0.01). Forced expression of CDD made T24 sensitive to 5′-deoxy-5-fluorocytidine (5′DFCR) in vitro and capecitabine in vivo, but resistant to gemcitabine both in vitro and in vivo. Tetrahydrouridine, a specific CDD inhibitor, abrogated the changes in the in vitro sensitivity to 5′DFCR and gemcitabine by transfection of CDD2 cDNA. Transfection of CDD2 cDNA resulted in a significant increase in cellular 5-fluorouracil level (p < 0.01) and inhibition of TS activity (p < 0.01) after treatment with 5′DFCR in vitro. Conclusions: The present study clearly showed direct evidence for the contribution of CDD in tumor cells themselves to the sensitivities to capecitabine and gemcitabine.

Keywords:
Capecitabine, Cytidine deaminase, Gemcitabine, Sensitivity, Transfection
1.
Miwa M, Ura M, Nishida M, Sawada N, Ishikawa T, Mori K, Shimma N, Umeda I, Ishitsuka H: Design of a novel oral fluoropyrimidine carbamate, capecitabine, which generates 5-fluorouracil selectively in tumours by enzymes concentrated in human liver and cancer tissue. Eur J Cancer 1998;34:1274–1281.
2.
Hertel LW, Boder GB Jr, Kroin JS, Rinzel SM, Poore GA, Todd GC, Grindey GB: Evaluation of the antitumor activity of gemcitabine (2′,2′-difluoro-2′-deoxycytidine). Cancer Res 1990;50:4417–4422.
3.
Blum JL, Jones SE, Buzdar AU, LoRusso M, Kuter I, Vogel C, Osterwalder B, Burger H-U, Brown CS, Griffin T: Multicenter phase II study of capecitabine in paclitaxel-refractory metastatic breast cancer. J Clin Oncol 1999;17:485–493.
4.
Hoff PM, Ansari R, Batist G, Cox J, Kocha W, Kuperminc M, Maroun J, Walde D, Weaver C, Harrison E, Burger HU, Osterwalder B, Wong AO, Wong R: Comparison of oral capecitabine versus intravenous fluorouracil plus leucovorin as first-line treatment in 605 patients with metastatic colorectal cancer: Results of a randomized phase III study. J Clin Oncol 2001;19:2282–2292.
5.
Furukawa T, Yoshimura A, Sumizawa T, Haraguchi M, Akiyama S, Fukui K, Ishizawa M, Yamada Y: Angiogenic factor. Nature 1992;356:668.
6.
Ishikawa F, Miyazono K, Hellman U, Drexler H, Wernstedt C, Hagiwara K, Usuki K, Takai F, Risau WW, Heldin C-H: Identification of angiogenic activity and the cloning and the expression of platelet-derived endothelial cell growth factor. Nature 1989;338:557–562.
7.
Kaye SB: Gemcitabine: Current status of phase I and II trials. J Clin Oncol 1994;12:1527–1531.
8.
Burris HA, Moore MJ, Andersen J, Green MR, Rothenberg ML, Modiano MR, Cripps MC, Portenoy RK, Storniolo AM, Tarassoff P, Nelson R, Dorr FA: Improvements in survival and clinical benefit with gemcitabine as first-line therapy for patients with advanced pancreas cancer: A randomized trial. J Clin Oncol 1997;15:2403–2413.
9.
Carmichael J: The role of gemcitabine in the treatment of other tumours. Br J Cancer 1998;78:21–25.
10.
Plunkett W, Huang P, Xu YZ, Heinemann V, Grunewald R, Gandhi V: Gemcitabine: Metabolism, mechanisms of action, and self-potentiation. Semin Oncol 1995;22:3–10.
11.
Heinemann V, Xu YZ, Chubb S, Sen A, Hertel LW, Grindey GB, Plunkett W: Inhibition of ribonucleotide reduction in CCRF-CEM cells by 2′,2′-difluorodeoxycytidine. Mol Pharmacol 1990;38:567–572.
12.
Huang P, Chubb S, Hertel LW, Grindey GB, Plunkett W: Action of 2′,2′-difluorodeoxycytidine on DNA synthesis. Cancer Res 1991;51:6110–6117.
13.
Heinemann V, Xu YZ, Chubb S, Sen A, Hertel LW, Grindey GB, Plunkett W: Cellular elimination of 2’,2’-difluorodeoxycytidine 5’-triphosphate: A mechanism of self-potentiation. Cancer Res 1992;52:533–539.
14.
Bouffard DY, Laliberte J, Momparler RL: Kinetic studies on 2′,2′-difluorodeoxycytidine (gemcitabine) with purified human deoxycytidine kinase and cytidine deaminase. Biochem Pharmacol 1993;45:1857–1861.
15.
Neff T, Blau CA: Forced expression of cytidine deaminase confers resistance to cytosine arabinoside and gemcitabine. Exp Hematol 1996;24:1340–1346.
16.
Eda H, Ura M, F-Ouchi K, Tanaka Y, Miwa M, Ishitsuka H: The antiproliferative activity of DMDC is modulated by inhibition of cytidine deaminase. Cancer Res 1998;8:1165–1169.
17.
Miwa M, Eda H, Ura M, Ouchi KF, Keith DD, Foley LH, Ishitsuka H: High susceptibility of human cancer xenografts with higher levels of cytidine deaminase to a 2’-deoxycytidine antimetabolite, 2′-deoxy-2′-methylidenecytidine. Clin Cancer Res 1998;4:493–497.
18.
Ishikawa T, Sekiguchi F, Fukase Y, Sawada N, Ishitsuka H: Positive correlation between the efficacy of capecitabine and doxifluridine and the ratio of thymidine phosphorylase to dihydropyrimidine dehydrogenase activities in tumors in human cancer xenografts. Cancer Res 1998;58:685–690.
19.
Kirch HC, Schröder J, Hoppe H, Esche H, Seeber S, Schutte J: Recombinant gene products of two natural variants of the human cytidine deaminase gene confer different deamination rates of cytarabine in vitro. Exp Hematol 1998;26:421–425.
20.
Lowry OH, Rosenbrough NJ, Farr AL, Randall RJ: Protein measurement with the Folin phenol reagent. J Biol Chem 1951;193:265–275.
21.
Schröder JK, Kirch C, Seeber S, Schutte J: Structural and functional analysis of the cytidine deaminase gene in patients with acute myeloid leukaemia. Br J Haematol 1998;103:1096–1103.
22.
Schröder JK, Kirch C, Flasshove M, Kalweit H, Seidelmann M, Hilger R, Seeber S, Schutte J: Constitutive overexpression of the cytidine deaminase gene confers resistance to cytosine arabinoside in vitro. Leukemia 1996;10:1919–1924.
23.
Lau KM, LaSpina M, Long J, Ho SM: Expression of estrogen receptor (ER)-alpha and ER-beta in normal and malignant prostatic epithelial cells: Regulation by methylation and involvement in growth regulation. Cancer Res 2000;60:3175–3182.
24.
Nishida M, Hino A, Mori K, Matsumoto T, Yoshikubo T, Ishitsuka H: Preparation of anti-human thymidine phosphorylase monoclonal antibodies useful for detecting the enzyme levels in tumor tissues. Biol Pharm Bull 1996;19:1407–1411.
25.
Mori K, Hasegawa M, Nishida M, Toma H, Fukuda M, Kubota T, Nagasue N, Yamana H, Hirakawa YS, Chung K, Ikeda T, Takasaki K: Expression levels of thymidine phosphorylase and dihydropyrimidine dehydrogenase in various human tumor tissues. Int J Oncol 2000;17:33–38.
26.
Spears CP, Shahinian AH, Moran RG, Heidelberger C, Corbett TH: In vivo kinetics of thymidylate synthetase inhibition of 5-fluorouracil-sensitive and -resistant murine colon adenocarcinomas. Cancer Res 1982;42:450–456.
27.
Shirasaka T, Nakano K, Takechi T, Satake H, Uchida J, Fujioka A, Saito H, Okabe H, Oyama K, Takeda S, Unemi N, Fukushima M: Antitumor activity of 1 M tegafur-0.4 M 5-chloro-2,4-dihydroxypyridine-1 M potassium oxonate (S-1) against human colon carcinoma orthotopically implanted into nude rats. Cancer Res 1996;56:2602–2606.
28.
Marunaka T, Umeno Y, Yoshida K, Nagamachi M, Minami Y, Fujii S: High-pressure liquid chromatographic determination of ftorafur [1-(tetrahydro-2-furanyl)-5-fluorouracil] and GLC-mass spectrometric determination of 5-fluorouracil and uracil in biological materials after oral administration of uracil plus ftorafur. J Pharm Sci 1980;69:1296–1300.
29.
Ahmed SA, Gogal RM Jr, Walsh JE: A new rapid and simple non-radioactive assay to monitor and determine the proliferation of lymphocytes: An alternative to 3H-thymidine incorporation assay. J Immunol Methods 1994;170:211–224.
30.
Morita T, Tokue A: Biomodulation of 5-fluorouracil by interferon α in human renal carcinoma cells: Relation to the expression of thymidine phosphorylase. Cancer Chem Pharm 1999;44:91–96.
31.
Veerman G, Ruiz van Haperen VW, Vermorken JB, Noordhuis P, Braakhuis BJ, Pinedo HM, Peters GJ: Antitumor activity of prolonged as compared with bolus administration of 2′,2′-difluorodeoxycytidine in vivo against murine colon tumors. Cancer Chemother Pharmacol 1996;38:335–342.
32.
Ishikawa T, Sekiguchi F, Fukase Y, Sawada N, Ishitsuka H: Positive correlation between the efficacy of capecitabine and doxifluridine and the ratio of thymidine phosphorylase to dihydropyrimidine dehydrogenase activities in tumors in human cancer xenografts. Cancer Res 1998;58:685–690.
33.
Reigner B, Verweij J, Dirix L, Cassidy J, Twelves C, Allman D, Weidekamm E, Roos B, Banken L, Utoh M, Osterwalder B: Effect of food on the pharmacokinetics of capecitabine and its metabolites following oral administration in cancer patients. Clin Cancer Res 1998;4:941–948.
34.
Budman DR, Meropol NJ, Reigner B, Creaven PJ, Lichtman SM, Berghorn E, Behr J, Gordon RJ, Osterwalder B, Griffin T: Preliminary studies of a novel oral fluoropyrimidine carbamate: Capecitabine. J Clin Oncol 1998;16:1795–1802.
35.
Morita T, Matsuzaki A, Suzuki K, Tokue A: Role of thymidine phosphorylase in biomodulation of fluoropyrimidines. Curr Pharm Biotechnol 2001;2:257–267.
36.
Morita T, Matsuzaki A, Tokue A: Enhancement of sensitivity to capecitabine in human renal carcinoma cells transfected with thymidine phosphorylase cDNA. Int J Cancer 2001;92:451–456.
37.
Hidalgo M, Castellano D, Paz-Ares L, Gravalos C, Diaz-Puente M, Hitt R, Alonso S, Cortes-Funes H: Phase I–II study of gemcitabine and fluorouracil as a continuous infusion in patients with pancreatic cancer. J Clin Oncol 1999;17:585–592.
38.
Rini BI, Vogelzang NJ, Dumas MC, Wade JL 3rd, Taber DA, Stadler WM: Phase II trial of weekly intravenous gemcitabine with continuous infusion fluorouracil in patients with metastatic renal cell cancer. J Clin Oncol 2000;18:2419–2426.
39.
Mani S, Vogelzang NJ, Bertucci D, Stadler WM, Schilsky RL, Ratain MJ: Phase I study to evaluate multiple regimens of intravenous 5-fluorouracil administered in combination with weekly gemcitabine in patients with advanced solid tumors: A potential broadly active regimen for advanced solid tumor malignancies. Cancer 2001;92:1567–1576.
40.
Herrmann R, Borner M, Morant RAD, Roth AD, Ludwig C, Bedoucha V: Combining gemcitabine (GEM) and capecitabine (CAP) in advanced pancreatic cancer. Proc Am Soc Clin Oncol 2000;19:267a.
41.
Schilsky RL, Bertucci D, Vogelzang NJ, Kindler HL, Ratain MJ: Dose-escalating study of capecitabine plus gemcitabine combination therapy in patients with advanced cancer. J Clin Oncol 2002;20:582–587.
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2003
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