Figure 6. Ewing sarcoma cells that survived co-culture with LAK cells express higher levels of APLP2 and have more resistance to irradiation-induced apoptosis. (A) Lysates of the TC71 cell line and LAK-escaping LCT1la, LCT2la, and LCT2t cell lines were immunoblotted for APLP2 or actin. The results shown are representative of the findings from two separate experiments. (B) All four LCT cell lines have reduced sensitivity to irradiation-mediated apoptosis, compared with TC71 cells. Log-phase cells were exposed to 25 Gy gamma radiation, then cultured for 24 h prior to propidium iodide staining and DNA content analysis. Error bars denote the standard error of the mean; n = 3. Statistical significance was determined for all LAK-escaping cell lines compared with the parental TC71 cell line using the Student t test. The data shown were acquired in 2 independent experiments.