Suppression of FOXM1 by RNAi sensitizes human cancer cells to irradiation.

<p>(<b>A</b>) MIA PaCa-2 control and FOXM1 knockdown pancreatic cancer cells were γ-irradiated with 8 and 10 Gy. Seventy-two hours after irradiation cells were harvested and immunoblotting was carried out with antibodies for FOXM1 and cleaved caspase-3. β-actin was used as the loading control. (<b>B</b>) MDA-MB-231 control and FOXM1 knockdown breast cancer cells were subjected to γ-irradiation with the indicated doses. Forty-eight hours following irradiation cells were harvested and immunoblotting was performed for FOXM1, cleaved caspase-3 and β-actin as the loading control. (<b>C–D</b>) Degree of cell death was assessed by flow cytometry following propidium iodide staining in MIA PaCa-2 pancreatic and MDA-MB-231 breast control and FOXM1 knockdown cancer cells, respectively, 48 hours after γ-irradiation. Graph shows quantification as a percentage of apoptotic cells compared to the vector control nontreated cells, ±SD of a representative triplicate (<b>C</b>) or duplicate (<b>D</b>) experiment.