Table 1. Specific CDase and UPRTase activities in LoVo cell line.

Vector	CDase 5-FC → 5-FU	UPRTase 5-FU → 5-FUMP
Mock	ND	ND
RCNVwt	ND	ND
RCNtk-/gfp::fcu1	17 ± 1.2	0.71 ± 0.2

CDase and UPRTase activities are expressed as the number of nanomoles of 5-FC deaminated per min per mg of protein and the number of nanomoles of 5-FU phosphorylated per min per mg of protein, respectively. The indicated enzymatic activities were measured as described in Materials and Methods. Each value represents the average of three independent experiments ± SD.

Abbreviations: CDase, cytosine deaminase; 5-FC, 5-fluorocytosine; 5-FU; 5-fluorouracil; 5-FUMP, 5-fluorouridine-5’-monophosphate; ND, not detectable; UPRTase, uracil phosphoribosyltransferase