Table 1.

The effects of LeTx upon cell proliferation

Cell type	Relative proliferation
	Untreated	PA + LF(E687C)	Low LeTx	High LeTx	25 μM PD98059	50 μM PD98059
NIH 3T3	1	1.00  ± 0.04	0.81  ± 0.08	0.63  ± 0.07	0.70  ± 0.09	0.47  ± 0.03
V12 H-ras	1	0.94  ± 0.02	1.05  ± 0.02	0.87  ± 0.11	0.79  ± 0.07	0.77  ± 0.03

Cell proliferation was assayed in nontransformed (pDCR) or V12 H-ras-transformed NIH 3T3 cells treated with either medium alone, 100 ng/ml PA plus inactive 10 ng/ml LF(E687C), PA plus LF [100 ng/ml PA plus 10 or 1 ng/ml LF (high and low, respectively)], or PD98059 (25 μM or 50 μM from a 50 mM stock in DMSO) as described in Methods. Data are presented relative to proliferation of control samples incubated in the presence of culture medium alone and as an average of at least three measurements (±SD).