Fig. 7.

Selective inhibition of KRAS(G12D)-driven tumorigenesis by monobody 12D4. (A and B) The effects of 12D4 expression on tumor growth in mouse xenograft models of Pa14C cells harboring KRAS(G12D) (A) and of PSN1 cells harboring KRAS(G12R) (B). The engineered PDAC cells were injected subcutaneously in the flanks of athymic nude mice. The mice were treated without (−) or with (+) DOX beginning on day 2 following injection, and tumor development was monitored. The mean tumor volumes are shown (n = 4 per condition). The error bars indicate SD. (C and D) Effect of DOX-induced CFP-12D4 expression on ERK–MAPK activation. Tumor lysates were probed for the indicated proteins by immunoblotting. Vinculin was used as a loading control. The graphs show the normalized pERK/ERK ratio for each set of tumor lysates. The P values were calculated using an unpaired Student’s t test. (E and F) Flow cytometric analysis for Ki-67 and cleaved caspase-3 for tumor cells from various cohorts. The gating strategy is shown in SI Appendix, Fig. S7 B–F. Cells from the dox-induced conditions had fewer cells in the analysis because they had low viability. The P values were calculated using an unpaired Student’s t test.