Enhancement of drug sensitivity and a bystander effect in PC-9 cells transfected with a platelet-derived endothelial cell growth factor thymidine phosphorylase cDNA

• Published in: British journal of cancer Vol. 75; no. 4; pp. 506 - 511
• Main Authors: KATO, Y, MATSUKAWA, S, MURAOKA, R, TANIGAWA, N
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.01.1997; Nature Publishing Group|1
• Subjects: Antineoplastic agents; Antineoplastic Agents - pharmacology; Biological and medical sciences; Cell Communication; DNA, Complementary - genetics; Drug Screening Assays, Antitumor; Floxuridine - pharmacology; General aspects; Humans; Medical sciences; Pharmacology. Drug treatments; Platelet-Derived Growth Factor - genetics; Thymidine Phosphorylase - genetics; Transfection; Tumor Cells, Cultured - drug effects; Tumor Cells, Cultured - enzymology; Tumor Cells, Cultured - pathology; Adenocarcinoma; Antineoplastic agent; Tegafur; Glycosyltransferases; Cytotoxicity; Bronchopulmonary; Transfection; Established cell line; Bronchus disease; Platelet derived growth factor; Thymidine phosphorylase; Fluorouracil; Human; Lung disease; Respiratory disease; Enzyme; Doxifluridine; Fluoropyrimidine derivatives; Transferases; Cytokine; Malignant tumor; In vitro; Antimetabolic; Complementary DNA; Polypeptide; Fluorine Organic compounds; Pentosyltransferases; Growth factor
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.1997.88

5'-Deoxy-5-fluorouridine (5'-DFUR) and 1-(tetrahydro-2-furyl)-5-fluorouracil (tegafur), prodrugs of 5-fluorouracil (5-FU), are anticancer agents activated by thymidine phosphorylase (dThdPase). As it is well known that the levels of dThdPase are higher in tumours than in normal tissue, it should be advantageous to use such pyrimidine antimetabolites for the selective inhibition of tumour growth. However, tumours are not necessarily sensitive to 5'-DFUR and tegafur because their levels of dThdPase vary. In this study, we examined whether transfection of tumour cells with a human platelet-derived endothelial cell growth factor (PD-ECGF) complementary DNA (cDNA) expressing dThdPase would sensitize the cells to the cytotoxic effects of pyrimidine antimetabolites in vitro. A cDNA encoding PD-ECGF was transfected into PC-9 cells (human lung adenocarcinoma). The transfected cells, PC9-DPE2, had a more than 50 times higher activity of dThdPase than the parental PC-9 cells or control PC-9 cells transfected with the pcDNA3 vector alone (PC9-D1). They were more sensitive than parental PC-9 or PC9-D1 cells not only to 5'-DFUR and tegafur but also to 5-FU. In addition, we demonstrated that PC9-DPE2 cells are able to potentiate the cytotoxic effects of 5'-DFUR towards co-cultured parental PC-9 cells. This "bystander effect' did not require cell-cell contact. These results suggest that transfection of PD-ECGF (dThdPase) genes may be useful as a gene therapy strategy for cancer treatment.