关键词: 结肠癌细胞, ¹⁹F磁共振,  CD基因, 5-氟胞嘧啶, 基因治疗

Abstract:

To investigate the feasibility of using ¹⁹F-NMR spectroscopy to monitor cytosine deaminase (CD) transgene expression in human colon cancer cell line. The SW1116 cell line was transfected with a gene coding for CD from-E.coli- by the retroviral mediated method. The assessment of the expression of CD gene in the colon cancer cell line was carried out by RT-PCR, MTT assay of drug sensitivity to 5-FC and ¹⁹F-NMR spectroscopy. The results indicate that the transgenic SWCD₂ cell line was more sensitive to the prodrug 5-fluorcytosine (5-FC) (IC₅₀=66 μmol/L) as compared to the parent cancer cells SW1116 (IC₅₀=16 mmol/L). After incubation of the cultured CD⁺ cells in 774 μmol/L 5-FC for 24 h, ¹⁹F-NMR spectra of the intact cells showed two broad resonances corresponding to 5-FC (taken up into cell chemical shift relative to trifluoroacetate of δ-91.7) and 5-FC produced by the action of CD (chemical shif of δ-93.3), respectively. These results demonstrated the feasibility of using ¹⁹F-NMR spectroscopy to noninvasively monitor CD gene expression in human colon cancer cells. This capability provides a new approach for measuring gene expression that will be useful in clinical gene therapy trials.

Key words: NMR, colon cancer cells, cytosine deaminase gene, 5-fluroscytosine, gene therapy