Aloe-emodin induces apoptosis in T24 human bladder cancer cells through the p53 dependent apoptotic pathway

Purpose: We investigated the anticancer effect of AE(1,8-dihydroy-3-[hydroxymethyl]-anthraquione) in the T24 human bladder cancer cell line (Food Industry Research and Development Institute, Hsinchu, Taiwan) by studying apoptosis regulation. Materials and Methods: AE, which is purified from aloe vera leaves, has been reported to have antitumor activity. Cell viability, cell cycle and apoptosis were determined by flow cytometric methods. Levels of cyclins, cyclin-dependent kinase 1 and other enzyme were examined by Western blotting methods. Results: AE inhibited cell viability, and induced G2/M arrest and apoptosis in T24 cells. AE increased the levels of Wee1 and cdc25c, and may have led to inhibition of the levels of cyclin-dependent kinase 1 and cyclin 131, which cause G2/M arrest. AE induced p53 expression and was accompanied by the induction of p21 and caspase-3 activation, which was associated with apoptosis. In addition, AE was associated with a marked increase in Fas/APO1 receptor and Bax expression but it inhibited 136-2 expression. Conclusions: AE induced apoptosis in T24 cells is mediated through the activation of p53, p2l, Fas/APO-1, Bax and caspase-3.