Table 1.

Effect of FdUrd on the sensitivity of HCT 116 0–1, HCT116 1–2 and SW620 cells to ionizing radiation.

MLH1 expression	Cell line	[FdUrd]	Radiation Enhancement Ratio	D-bar (no drug)
Inactivated	HCT116 0–1	0.25µM (IC10)	1.8 ± 0.33†
		3.5 µM (IC50)	1.8 ± 0.28†	3.1 ± 0.19
Wildtype	HCT116 1–2	0.125 µM (IC10)	1.2 ± 0.03
		0.75 µM (IC50)	1.1 ± 0.10	2.9 ± 0.14
		3.5 µM (IC90)	1.4 ± 0.10*†
Suppressed	HCT116 1–2 +	0.75 µM	1.5 ± 0.06*†	2.8 ± 0.21*
	shRNA-MLH1	3.5 µM	1.7 ± 0.13*†
				2.8 ± 0.13*
Wildtype	HCT116 1–2 + shRNA-non- specific	0.75 µM	1.1 ± 0.10*
wild-type	SW620	0.35 µM (IC50)	1.2 ± 0.12
		3.5 µM (IC90)	1.4 ± 0.04†	2.2 ± 0.14
Suppressed	SW620 + shRNA-MLH1	0.35 µM	1.6 ± 0.10†	2.3 ± 0.24
		3.5 µM	1.8 ± 0.03*†
Wildtype	SW620 + shRNA-non-specific	0.35 µM	1.2 ± 0.08	2.3 ± 0.17

Radiation enhancement ratios (mean ± SE) are shown for all cell lines after a 24 hr drug incubation followed by irradiation. Sensitivity to radiation in control cells (no drug) is shown as the D-bar.

Each value is an average of at least three separate (mean ± SE), or two separate (mean ± SD*) experiments.

^†significantly >1 (p < 0.05)