Figure 5.

Restoration of ATF2 expression inhibited miR-144-5p-mediated radiosensitivity of lung cancer cells. A549 cells with or without ATF2 overexpression were transfected with agomir-144. (a) The levels of miR-144-5p in nontransfected A549 cells (control) and cells transfected with ATF2 lentiviral particles or mock particles (vector) were determined using western blot analysis. (b) After exposure to varying doses of radiation (0, 2, 4, 6, and 8 Gy), MTT assay was used to determine the cell viability. After 8 Gy radiation, cell apoptosis (c) and survival (d) were then determined using Annexin V/propidium iodide staining and the colony formation assay, respectively. (e) A total of 2 × 10⁶ A549 cells stably transfected with ATF2-overexpressing plasmid or vector were injected subcutaneously into mice (6 in each group) to establish a xenograft model. At 7 days after inoculation, agomir-144 was intratumorally injected into the implanted tumor every 3 days for seven times. At the same time, mice were irradiated with 4 Gy once per day for the following 5 days. Tumor volumes were measured every 3 days after injection. (f) Tumors were dissected, and the weights were measured on day 28 after inoculation. Data are representative images or expressed as the mean ± standard deviation of each group of cells from three separate experiments. ^∗P < 0.05 versus vector + miR-144. ^∗∗P < 0.01 versus vector + miR-144. & represents P < 0.01 versus vector.