Figure 6.

Neither PER1 overexpression nor downregulation sensitizes human lung cancer cells to apoptosis or affects Chk2 phosphorylation following ionizing radiation (IR). (A) Overexpression of PER1. Protein levels were analyzed by immunoblotting 48 h after irradiation with IR with the indicated antibodies from NCI-H460 cells following transfection with either empty vector (pcDNA3) or a mPer1-overexpressing vector for 72 h. T-PARP and C-PARP stand for total PARP and cleaved PARP, respectively. (B) Downregulation of PER1. Protein levels from NCI-H460 cells transfected with either negative control (nontarget, NT) or Per1 siRNAs were analyzed by immunoblotting 48 h after irradiation with 0, 10, or 30 Gy of IR with the indicated antibodies.⁵⁹