Epidemiological studies have demonstrated a protective association between dietary intake of cruciferous vegetables and the incidence of renal cell carcinoma. Isothiocyanates (ITCs) are a class of sulfur‐containing phytochemicals found uniquely and abundantly in cruciferous vegetables (broccoli, cauliflower, brussel sprouts, etc). We hypothesize that the inhibition of renal carcinoma cell growth and viability by ITCs underlies the protective effect of cruciferous vegetables on renal cell carcinoma. To test this hypothesis, we examined the effects of two ITCs: the naturally‐occurring phenethyl ITC (PEITC) and the synthetic 4‐phenylbutyl ITC (PBITC) on the Caki‐1 human renal carcinoma cell line. Both PEITC and PBITC inhibited the proliferation of Caki‐1 cells in a concentration‐dependent manner. Cell cycle analysis revealed that PEITC and PBITC caused an arrest in the G2/M phase. Additionally, higher concentrations of PEITC and PBITC were cytotoxic to Caki‐1 cells (IC50 of 7.0 and 4.8 µM, respectively). PEITC and PBITC induced caspase‐3/7 activity in a concentration‐ and time‐dependent manner, indicating that the ITCs induce apoptosis in the cells. These results indicate that PEITC and PBITC may be efficacious against renal cell carcinoma and suggest that the preventive effect of diets rich in cruciferous vegetables is due to their ITC content.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B74.

Copyright © January 7, 2010, American Association for Cancer Research
2010