Open AccessCircumvention of 5‐Fluorouracil Resistance in Human Stomach Cancer Cells by Uracil Phosphoribosyltransferase Gene Transduction
Author(s) -
Inaba Makoto,
Sawada Hiroko,
Sadata Akiko,
Hamada Hirofumi
Publication year - 1999
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1999.tb00754.x
Subject(s) - biology , transfection , cell culture , microbiology and biotechnology , cancer research , genetics
A human stomach cancer cell line with acquired resistance to 5‐fluorouracil (5‐FU), NUGC‐3/5FU/L, has been found to possess reduced ability to convert 5‐FU into active metabolites. We attempted in vitro gene therapy for this 5‐FU‐resistant cell line. NUGC‐3 and NUGC‐3/5FU/L cells were infected with recombinant adenovirus (Ad) containing Escherichia coli uracil phosphoribosyltransferase ( UPRT ) gene driven by CAG promoter (CA), AdCA‐UPRT, and changes in their 5‐FU metabolism and sensitivity were investigated. Activities of orotate phosphoribosyltransferase increased from 10.2 and 1.56 (nmol/mg protein/30 min) in the uninfected cells of NUGC‐3 and NUGC‐3/5FU/L to 216 and 237, respectively, after the transfection of UPRT gene. The 5‐FU nucleotide level in the acid‐insoluble fraction increased from 7.32 to 15.9 (pmol/mg protein) in NUGC‐3 cells on infection with AdCA‐UPRT, and in NUGC‐3/5FU/L cells it increased from 1.91 to 21.4. The 50% growth‐inhibition concentration (IC50) was 12.7 μmol/liter for NUGC‐3 and much higher than 100 μmol/liter for NUGC‐3/5FU/L, indicating over 8‐fold resistance. NUGC‐3/5FU/L transfected with the UPRT gene showed very high sensitivity to 5‐FU with an IC 50 of 3.2 μmol/liter. The high resistance in this metabolic activation‐deficient cell line was thus completely reversed by transduction of an exogenous gene coding for a 5‐FU‐anabolizing enzyme.