Adenoviral-mediated transfer of Escherichia coli uracil phosphoribosyltransferase (UPRT) gene to modulate the sensitivity of the human colon cancer cells to 5-fluorouracil.
5-Fluorouracil (5-FU) has been used as a chemotherapeutic drug for colorectal cancer. Escherichia coli uracil phosphoribosyltransferase (UPRT), a pyrimidine salvage enzyme, converts 5-FU into 5-fluorouridine monophosphate (5-FUMP) at the initial step of 5-FU activation. We investigated the effects of adenoviral-mediated transfer of the E. coli UPRT gene into human colon cancer cells on 5-FU metabolism and 5-FU chemosensitivity. Three cell lines were used (HT29, KM12 and SW1116). The intracellular levels of 5-fluorodeoxyuridine monophosphate (5-FdUMP) and 5-FU incorporated into RNA after 5-FU treatment in cells infected with adenovirus containing the UPRT gene (AdCA-UPRT) were significantly higher than those of non-infected cells. This was accompanied by marked inhibition of thymidylate synthase (TS) in all cell lines. Furthermore, HT29, KM12 and SW1116 infected with AdCA-UPRT were, respectively, 13.1-, 30.2- and 70.5-fold more sensitive to 5-FU than non-infected cells. Most importantly, treatment with AdCA-UPRT and 5-FU effectively inhibited the growth of HT29-xenografted subcutaneous tumours in nude mice. Therefore, AdCA-UPRT/5-FU treatment had the potential to enhance the actions of 5-FU at both the DNA and RNA levels. Treatment augmented the sensitivity of human colon cancer cells to 5-FU both in vitro and in vivo. We conclude that adenoviral-mediated transfer of the E. coli UPRT gene into colon cancer cells can achieve biochemical modulation of 5-FU and this provides a new approach in the treatment of colorectal cancer.
Koyama
F
F
First Department of Surgery, Nara Medical University, Kashihara-city, Japan. fkoyama@nmu-gw.naramed-u.ac.jp
Sawada
H
H
Fuji
H
H
Hamada
H
H
Hirao
T
T
Ueno
M
M
Nakano
H
H
D000256:Adenoviridae; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D003110:Colonic Neoplasms / Q000628:therapy*; D004926:Escherichia coli / Q000235:genetics*; D005472:Fluorouracil / Q000627:therapeutic use*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D010430:Pentosyltransferases / Q000235:genetics*; D014407:Tumor Cells, Cultured
D000964:Antimetabolites, Antineoplastic; D010430:Pentosyltransferases; C023269:uracil phosphoribosyltransferase; D005472:Fluorouracil