Comparative inhibitory activities of sulforaphane and phenethyl isothiocyanate against leukemia resistant CEM/C2 cancer cells

The potentials of sulforaphane and phenethyl isothiocyanate as functional food ingredients against hematological malignancies were evaluated on the intracellular targets of these antiangiogenic compounds in CEM/C2 T leukemia cells. CEM/C2 cells were seeded and incubated with various concentrations of sulforaphane or phenethyl isothiocyanate for 24 or 48 h. Sulforaphane at 0–30 μmol/L dose-dependently suppressed CEM/C2 cell growth and proliferation and caused cell death by apoptosis with down-regulation of bcl-2 and increased release of cytochrome c within 48 h. Phenethyl isothiocyanate at 0–15 μmol/L dose-dependently inhibited CEM/C2 cell viability within 48 h and caused cell death by apoptosis with down-regulation of bcl-2 and increased expression of cytochrome c. CEM/C2 cell death was accompanied by inhibition of IκB phosphorylation and degradation and nuclear translocation of p65-nuclear factor kappaB (NF-κB) by sulforaphane as well as phenethyl isothiocyanate. CEM/C2 cell viability and proliferation can be inhibited by functional food ingredient inhibitors of the NF-κB pathway.