Targeting TRPM2 Channels Impairs Radiation-Induced Cell Cycle Arrest and Fosters Cell Death of T Cell Leukemia Cells in a Bcl-2-Dependent Manner

Figure 5

IR induces Ca²⁺ signaling and a G₂/M cell cycle arrest in Jurkat cells. (a) Dot plot recorded by flow cytometry showing the Ca²⁺-specific fluo-3 fluorescence intensity in dependence on side scatter of Jurkat cells 24 h after IR with 0 Gy (grey) or 10 Gy (red). (b) Mean (± SE, ) percentage of control and irradiated Jurkat cells with high cytosolic free Ca²⁺ concentrations (determined by fluo-3 fluorescence in flow cytometry as described in (a), indicates , Welch-corrected -test). (c) Immunoblots from whole lysates of irradiated (0 or 5 Gy, 4 h after IR) Jurkat cells probed against phosphorylated and total Ca²⁺/CaM-dependent kinase II (CaMKII) isoforms, against the phosphorylated and total phosphatase cdc25b, the phosphorylated cell division cycle protein 2 (cdc2), and β-actin for loading control. (d) Flow cytometry histogram depicting the fluorescence intensity of the DNA-specific dye propidium iodide (PI) in Jurkat cells 24 h after IR with 0 (black) or 5 Gy (red).

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