Radiation of MiaPaCa2 cells impairs migration and PNI predominantly through compromised cellular viability.

<p>A. Colony-forming assays of MiaPaCa2 cells show susceptibility to single-fraction radiation doses, with logarithmically diminishing surviving fractions up through 8 Gy. B. MiaPaCa2 cells were radiated at varying single fraction doses, 24 hours later serum starved overnight, and then added (2×10⁵) to the upper chamber of migration assays. The lower chamber contained control media, DRG, or GDNF (100 ng/mL). Radiation reduced the number of migrating cells towards DRG or GDNF in a dose-dependent fashion. MiaPaCa2 were radiated and simultaneously plated with migration assays, under identical conditions, and counted after 24 hours. Dose-dependent decreases in cancer cell number, attributable to radiation induced cell death, correlated with results from migration assay. C. Single fraction doses of radiation (2–8 Gy) were applied to MiaPaCa2 cells prior to their addition to the DRG co-culture model of PNI. Radiation doses as low as 2 Gy significantly decreased the area of invasion († p<0.05, t-test). MiaPaCa2 were radiated and simultaneously plated with DRG co-culture assays, under identical conditions, and counted after 8 days. Dose-dependent decreases in cancer cell number, attributable to radiation induced compromised cell viability, correlated with decreases in area of invasion. D. MiaPaCa2 colonies adjacent to the DRG (*) at day 8 show diminished viability with increasing radiation dose, consistent with cell numbers quantified in Fig. 3C. White bar, 1000 µm, black bar, 250 µm.