This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Giovannetti, E. Articles by Del Tacca, M. Search for Related Content PubMed PubMed Citation Articles by Giovannetti, E. Articles by Del Tacca, M.

Synergistic Cytotoxicity and Pharmacogenetics of Gemcitabine and Pemetrexed Combination in Pancreatic Cancer Cell Lines

Division of Pharmacology and Chemotherapy, Department of Oncology, Transplants and Advanced Technologies in Medicine, Pisa, Italy

ABSTRACT

Purpose: Gemcitabine is an inhibitor of ribonucleotide reductase (RR) and DNA synthesis and is an effective agent in the treatment of pancreas cancer. The present study investigates whether the multitargeted antifolate pemetrexed would be synergistic with gemcitabine against MIA PaCa-2, PANC-1, and Capan-1 pancreatic cancer cell lines.

Experimental Design: Cells were treated with gemcitabine and pemetrexed, and the type of drug interaction was assessed using the combination index. Cytotoxicity of gemcitabine was examined with inhibitors of (a) deoxycytidine kinase (dCK), which activates gemcitabine by phosphorylation, and (b) 5'-nucleotidase (drug dephosphorylation) and cytidine deaminase (drug deamination), the main inactivating enzymes. The effects of gemcitabine and pemetrexed on cell cycle were analyzed by flow cytometry, and apoptosis was examined by fluorescence microscopy. Finally, quantitative, real-time PCR was used to study the pharmacogenetics of the drug combination.

Results: Synergistic cytotoxicity and enhancement of apoptosis was demonstrated, mostly with the sequence pemetrexedgemcitabine. Pemetrexed increased cells in S phase, the most sensitive to gemcitabine, and a positive correlation was found between the expression ratio of dCK:RR and gemcitabine sensitivity. Indeed, pemetrexed significantly enhanced dCK gene expression (+227.9, +86.0, and +135.5% in MIA PaCa-2, PANC-1, and Capan-1 cells, respectively), and the crucial role of this enzyme was confirmed by impairment of gemcitabine cytotoxicity after dCK saturation with 2'-deoxycytidine.

Conclusions: These data demonstrate that the gemcitabine and pemetrexed combination displays schedule-dependent synergistic cytotoxic activity, favorably modulates cell cycle, induces apoptosis, and enhances dCK expression in pancreatic cancer cells.

This article has been cited by other articles:

				S. Michienzi, B. Bucci, C. Verga Falzacappa, V. Patriarca, A. Stigliano, L. Panacchia, E. Brunetti, V. Toscano, and S. Misiti 3,3',5-Triiodo-L-thyronine inhibits ductal pancreatic adenocarcinoma proliferation improving the cytotoxic effect of chemotherapy J. Endocrinol., May 1, 2007; 193(2): 209 - 223. [Abstract] [Full Text] [PDF]

				S. Malempati, H. S. Nicholson, J. M. Reid, S. M. Blaney, A. M. Ingle, M. Krailo, L. C. Stork, A. S. Melemed, R. McGovern, S. Safgren, et al. Phase I Trial and Pharmacokinetic Study of Pemetrexed in Children With Refractory Solid Tumors: The Children's Oncology Group J. Clin. Oncol., April 20, 2007; 25(12): 1505 - 1511. [Abstract] [Full Text] [PDF]

				S. Chattopadhyay, R. G. Moran, and I. D. Goldman Pemetrexed: biochemical and cellular pharmacology, mechanisms, and clinical applications Mol. Cancer Ther., February 1, 2007; 6(2): 404 - 417. [Abstract] [Full Text] [PDF]

				E. K. Rowinsky, M. Beeram, L. A. Hammond, G. Schwartz, J. De Bono, B. Forouzesh, Q. Chu, J. E. Latz, S. Hong, W. John, et al. A Phase I and Pharmacokinetic Study of Pemetrexed Plus Irinotecan in Patients with Advanced Solid Malignancies Clin. Cancer Res., January 15, 2007; 13(2): 532 - 539. [Abstract] [Full Text] [PDF]

				C. Bianco, E. Giovannetti, F. Ciardiello, V. Mey, S. Nannizzi, G. Tortora, T. Troiani, F. Pasqualetti, G. Eckhardt, M. de Liguoro, et al. Synergistic Antitumor Activity of ZD6474, An Inhibitor of Vascular Endothelial Growth Factor Receptor and Epidermal Growth Factor Receptor Signaling, with Gemcitabine and Ionizing Radiation against Pancreatic Cancer Clin. Cancer Res., December 1, 2006; 12(23): 7099 - 7107. [Abstract] [Full Text] [PDF]

				T. Oguri, H. Achiwa, S. Sato, Y. Bessho, Y. Takano, M. Miyazaki, H. Muramatsu, H. Maeda, T. Niimi, and R. Ueda The determinants of sensitivity and acquired resistance to gemcitabine differ in non-small cell lung cancer: a role of ABCC5 in gemcitabine sensitivity. Mol. Cancer Ther., July 1, 2006; 5(7): 1800 - 1806. [Abstract] [Full Text] [PDF]

				E. Giovannetti, V. Mey, S. Nannizzi, G. Pasqualetti, M. Del Tacca, and R. Danesi Pharmacogenetics of anticancer drug sensitivity in pancreatic cancer. Mol. Cancer Ther., June 1, 2006; 5(6): 1387 - 1395. [Abstract] [Full Text] [PDF]

				E. Giovannetti, M. Del Tacca, V. Mey, N. Funel, S. Nannizzi, S. Ricci, C. Orlandini, U. Boggi, D. Campani, M. Del Chiaro, et al. Transcription analysis of human equilibrative nucleoside transporter-1 predicts survival in pancreas cancer patients treated with gemcitabine. Cancer Res., April 1, 2006; 66(7): 3928 - 3935. [Abstract] [Full Text] [PDF]

				L. E. Toner, R. Vrhovac, E. A. Smith, J. Gardner, M. Heaney, M. Gonen, J. Teruya-Feldstein, F. Sirotnak, and O. A. O'Connor The Schedule-Dependent Effects of the Novel Antifolate Pralatrexate and Gemcitabine Are Superior to Methotrexate and Cytarabine in Models of Human Non-Hodgkin's Lymphoma Clin. Cancer Res., February 1, 2006; 12(3): 924 - 932. [Abstract] [Full Text] [PDF]

				E. Giovannetti, V. Mey, S. Nannizzi, G. Pasqualetti, L. Marini, M. Del Tacca, and R. Danesi Cellular and Pharmacogenetics Foundation of Synergistic Interaction of Pemetrexed and Gemcitabine in Human Non-Small-Cell Lung Cancer Cells Mol. Pharmacol., July 1, 2005; 68(1): 110 - 118. [Abstract] [Full Text] [PDF]