Figure 3. Effects of overexpression of SLURP-1 and -2 on the tumorigenic activity of NNK in Het-1A cells.
Intact Het-1A cells or the cells transfected with either control or SLURP-1 or -2 vectors were preincubated for 24 h with 1 μM of NNK, after which their tumorigenic activities were measured in vitro and in vivo as detailed in Methods. Asterisks indicate significant (p<0.05) differences compared to results obtained using intact Het-1A cells exposed to NNK. Pound sign indicates p=0.05.
A, Overexpression of SLURP-1 or -2 in each case reduces numbers of colonies in soft agar produced by nitrosamine-treated Het-1A cells.
B, Overexpression of SLURP-1 or -2 in each case reduces number of tumor nodules