TABLE 2.

Tumorigenicity of Rat-1 cells transfected with the HCV-K core gene

Clone	No. of foci formeda	Colony formation in soft agar assay (%)b	Size of tumors on nude mice (mm)
pCI-neo	0	0.05 ± 0.03	NDc
pCI-neo-core K(H)d	124 ± 6	13.19 ± 0.57	6.5 ± 0.5
pCI-neo-core K(L)d	3 ± 1	3.20 ± 0.08	4.5 ± 0.5
H-ras	231 ± 7	22.96 ± 0.78	NTe

^aA total of 5 × 10⁴ cells of each clone were mixed with Rat-1 control cells at a ratio of 1:10 and incubated for 6 days. 

^bThe data is expressed as the percentage of colonies containing more than 200 cells 2 weeks after plating. Colony numbers are means of three independent experiments. 

^cND, not detected. 

^dpCI-neo-core K(H) clones express the HCV-K core protein at higher level than pCI-neo-core K(L) clones. The data is represented as the mean of the results for three independent clones. 

^eNT, not tested.