To overcome this problem, we present here a new strategy for cancer therapy. In recent years, glycerol has been reported to act as a chemical chap erone to correct the conformation of proteins, which cause human diseases. Consistent with this, we have reported that glycerol full report acts as a chemical chaperone to restore the expression of WAF1 in some human cancer cell lines bearing mp53 and to restore apoptosis in p53 knockout mouse fibroblast cells transfected with mp53. Since the expression of WAF1 is up regulated by activated wtp53, glycerol appears to restore wtp53 function. In the present study, we further examined the ef fect of glycerol on p53 dependent apoptosis induction through bax expression and whether the heat sensitivity of cells bearing mp53 is enhanced by glycerol.

To enable a discussion of the results on the basis of p53 status only, we transfected A 172 cells with the mp53 gene, which had identical genetic backgrounds except for p53 status, and demonstrated so called dominant negative effect of mp53 protein. Recently, it was reported that the PI3 K family such as ATM, ATR and DNA PK contributes to the activation of p53 through the phosphorylation of serine 15 of p53. In the present study, to gain further insight into the mechanism of restoring mp53 to wtp53, we examined mediation of the phosphorylation of p53 by the PI3 K family to conformational change of mp53. Results and Discussion To elucidate the effect of glycerol on the heat sensitivity of transformed A 172 cells, the clonogenic surviving frac tions by heat after pre treatment with or without glycerol were measured.

As shown in Fig. 1a, A 172 cells tranfected with mp53 were more resistant to heat than the A 172/neo cells. By glycerol treatment, A 172/mp53/143 cells became about 1. 5 times more heat sensitive at D10 dose, whereas A 172/neo cells showed no enhanced heat sensitivity. In addition, A 172/mp53/143 and A 172/neo cells treated with glycerol alone showed about 80% survival fractions, and thus the concentration of glyc erol appeared to cause no serious cell damage regardless of p53 status. These results suggest that glycerol affects the heat sensitivity of those cells in a way that it enhances heat sensitivity in mp53 cells. The change of cellular contents of Bax after heating was analyzed in A 172/mp53/143 cells with Western blot. As shown in Fig.

1b, Bax was accumulated after heating in the presence of glycerol at 0. 6 M, although Bax accumulation was not induced after heating alone or treatment with 0. 6 M glycerol alone in the cells. It is possible that mp53 might function as a transcriptional factor in heat induced Bax accumulation under the presence of glycerol. In addi tion, Carfilzomib A 172/mp53/143 cells only heated accumulated large amounts of p53 but no significant Bax, suggesting that heat treatment induces accumulation of mp53 as is the case in human glioblastoma A 7 cells.