CispIatin inhibits survivaI of human esophageaI squamous carcinoma ceIIs via p53 activation / 中国药科大学学报

ABSTRACT

To study the mechanisms whereby cisplatin suppresses survival of human esophageal squamous cell carcinoma cells.The cytotoxicity of cisplatin in cisplatin-resistant cell line EC109 /CDDP and its parental cell line EC109 was measured by cell viability assay.Western blotting was used to investigate the protein expression of to-tal p53 and phosphorylated p53 at Ser15.Colony formation assay was employed to evaluate the ability of cells to recover from treatments and form colonies.The results indicated that EC109 /CDDP cells were more resistant to cisplatin-induced cytotoxicity than EC109 cells,with the IC50 values of (20.4 ±4.4)μmol /L and (5.7 ±0.1 )μmol /L,respectively.Although cisplatin did not alter the total protein level of p53,it obviously increased the phosphorylation of p53 at Ser15.Cisplatin inhibited survival of both EC109 /CDDP and EC109.Notably,inhibition of p53 by Pifithrin-αsignificantly promoted recovery of cisplatin-treated EC109 and EC109 /CDDP cells to differ-ent degrees.In this respect,p53 protein was found to be activated in response to cisplatin treatment in both EC109 /CDDP and EC109,which may contribute to the cytotoxic effect of cisplatin.