Figure 4.

Expression of WT but not Y318A MSLN enhances tumor cell growth. A, Schema of the engineered constructs. B, Growth rate of KLM1 cell lines (Mock, KO#2, and the transduced cell lines KO#2+WT or KO#2+Y318A) in culture was measured by counting triplicate wells on the indicated days. There was no statistically significant difference in cell count at 96 hours as determined by ANOVA (N.S.). C, Nude mice were inoculated into the abdominal cavity with 3 × 10⁶ cells of the indicated cell types. Mice were euthanized after approximately 6 weeks. All visible tumor in the abdominal cavity was harvested and weighed. Figure shows average for 10 mice per group; **, P < 0.01; ***, P < 0.001, N.S. not significant (Mann–Whitney nonparametric test). D, Growth rate of parent MIA PaCa-2 cells and those transduced with WT or Y318A mutant MSLN was measured by counting triplicate wells on the indicated days. A statistically significant increase in growth was found in +WT cells compared with parent and +Y318A (*, P < 0.05 on post hoc comparison). E, Intraperitoneal growth of MIA PaCa-2–derived cells was assessed as in C. Figure shows average for 9–10 mice per group; *, P < 0.05 and **, P < 0.01, N.S. = not significant (Mann–Whitney nonparametric test).