Figure 1.

Host strain determines tumor onset but does not alter tumor growth kinetics. (A) Kaplan–Meyer curve of tumor-free survival. Formation of Nf1/p53-deleted malignant peripheral nerve sheath tumors (MPNSTs) is accelerated in BALB/c mice. Tumor initiation occurs within a similar timeframe in mice from 129/SvJae, C57BL/6, and 129X1 backgrounds. (B) Growth kinetics are similar across all background strains for genetically-identical MPNSTs (n= 6–8 tumors per strain). Growth rates are calculated as the number of days required for tumors to double from an initial volume of 150 mm³. 129X1 (red circles), C57BL/6 (black triangles), BABL/c (white squares), and 129/SvJae (blue triangles). (C) Representative images of MPNSTs from different host strains stained for H&E (20×), S100 (20×), and Ki67 (20×). (D) Quantification of Ki67 confirms that background strain does not alter the rate of tumor proliferation (n= 5 tumors per strain). (B,D) analyzed by one-way ANOVA with Tukey’s multiple comparison test.