After the publication of the article, the authors noted that in Fig. 5c, the image of β-actin is incorrect. The corrected version of Fig. 5c is shown below. In Fig. 6a, the histogarms are incorrect, and the corrected Fig. 6a is shown below. In Fig. 7, the figure of PrEC is incorrect, and the corrected Fig. 7 (PrEC) is shown below. The corrected figures demonstrate the same findings as the original figures. These corrections do not alter the interpretation of the results and conclusions. [the original article was published in the International Journal of Oncology 40: 1483-1491, 2012; DOI: 10.3892/ijo.2012.1353].