Sulforaphane Inhibits Histone Deacetylase Activity in BPH

Sulforaphane inhibits histone deacetylase activity in BPH-1, LnCaP, and PC-3 prostate epithelial cells.
Carcinogenesis. 2005 Nov 9
Myzak MC, Hardin K, Wang R, Dashwood RH, Ho E.
Linus Pauling Institute, Oregon State University, Corvallis, OR 97331; Molecular and Cellular Biology Program, Oregon State University, Corvallis, OR 97331.

Sulforaphane (SFN), an isothiocyanate first isolated from broccoli, exhibits chemopreventive properties in prostate cancer cells through mechanisms that are poorly understood. We recently reported on a novel mechanism of chemoprotection by SFN in human colon cancer cells, namely the inhibition of histone deacetylase (HDAC). Here, we show that addition of 15 microM SFN also inhibited HDAC activity by 40%, 30% and 40% in BPH-1, LnCaP, and PC-3 prostate epithelial cells, respectively. The inhibition of HDAC was accompanied by a 50-100% increase in acetylated histones in all three prostate cell lines, and in BPH-1 cells treated with SFN there was enhanced interaction of acetylated histone H4 with the promoter region of the P21 gene and the bax gene. A corresponding 1.5 to 2-fold increase was seen for p21(Cip1/Waf1) and Bax protein expression, consistent with previous studies using HDAC inhibitors such as trichostatin A. The downstream events included cell cycle arrest and activation of apoptosis, as evidenced by changes in cell cycle kinetics and induction of multi-caspase activity. These findings provide new insight into the mechanisms of SFN action in benign prostate hyperplasia, androgen-dependent prostate cancer, and androgen-independent prostate cancer cells, and they suggest a novel approach to chemoprotection and chemotherapy of prostate cancer through the inhibition of HDAC.

Note from ISS:  Several crucifer sprouts including broccoli sprouts are currently the most potent natural source of sulforaphane known.  They often produce 10 to 100 times the amount of sulforaphane as their corresponding mature vegetables.