Luteolin Overcomes Resistance to Benzyl Isothiocyanate-Induced Apoptosis in Human Colorectal Cancer HCT-116 Cells   全文下載

Luteolin Overcomes Resistance to Benzyl Isothiocyanate-Induced Apoptosis in Human Colorectal Cancer HCT-116 Cells

We have previously identified p53, a universal sensor of genotoxic stress, as a negative regulator of the apoptosis induction by benzyl isothiocyanate (BITC) in the normal colon fibroblastoid cells. In the present study, we further confirmed that BITC has a potential to induce cytotoxicity in the p53-mutated colon cancer HT-29 cells in preference to HCT-116 cells with wild-type p53. To obtain effective induction of BITC-stimulated apoptosis in p53-positive cells, we investigated the combination effect of BITC and food ingredient that may overcome resistance to BITC. Pretreatment with luteolin potentiated the cytotoxicity induction by BITC in HCT-116 cells but not in HT-29 cells. The biochemical events related to apoptosis such as DNA ladder formation and caspase-3 activation were also enhanced by luteolin. Luteolin attenuated the expression of p21waf1/cip1, a key downstream target of p53. These results suggest the role of p21waf1/cip1 pathway in the overcoming BITC resistance by luteolin.