Effect of XRCC3 suppression on radiosensitization with dFdCyd in AA8 cells. AA8 cells were transduced with lentivirus-delivered shRNA for XRCC3, followed by selection of transduced cells with puromycin. Panel A: Extent of XRCC3 suppression by Western blot analysis. Panel B: AA8 cells transduced with XRCC3 shRNA were treated with radiation alone or after a 4 h incubation with 5 μM dFdCyd as described in Materials and Methods. Survival was measured by a colony formation assay. XRCC3 suppressed AA8 cells were treated with radiation alone (■), IR + NS shRNA (▲), XRCC3 shRNA followed by irradiation (●), dFdCyd followed by irradiation (□), NS shRNA followed by dFdCyd followed by irradiation (△), or XRCC3 shRNA followed by dFdCyd followed by irradiation (○). Shown is a representative graph of XRCC3 suppression on radiosensitization with dFdCyd; the experiment was performed three times.