Gum mastic inhibits the expression and function of the androgen receptor in prostate cancer cells

Abstract

Accumulating evidence suggests that the androgen receptor (AR) may play an important role in the development and progression of prostate cancer. To find new, useful compounds that effectively may attenuate the function of AR in prostate cancer cells, the authors investigated the effect of gum mastic, a natural resin, on AR activity. An androgen-responsive prostate cancer cell line LNCaP was used as a model for this study. Gene transfer, reverse transcriptase-polymerase chain reaction analysis, electrophoretic mobility shift assay, and Western blot analysis were used to test the effect of gum mastic on the expression and function of the AR. To demonstrate the inhibitory effect of gum mastic on the function of the AR, the expression of androgen-regulated genes, including prostate-specific antigen (PSA), human kallikrein 2 (hK2), and NKX3.1 were measured. In addition, transient transfection assays with the PSA promoter and the AR promoter also were used to test the effects of mastic. The results showed that gum mastic inhibited the expression of the AR at the transcriptional level, resulting in the down-regulation of both AR messenger RNA and protein levels. Therefore, the function of the AR was inhibited, as reflected by the reduced expression of NKX3.1 and PSA and by androgen-stimulated growth. Because gum mastic exhibited a strong in vitro potency to attenuate the expression and function of the AR, further investigation will be required to determine whether this naturally occurring substance has in vivo potency to inhibit prostate cancer development.

Chemopreventive Activity of Mediterranean Medicinal Plants

“…They concluded that the ethanol-terpene-rich extract was the most effective. A similar mechanism was observed in prostate cancer cells (He et al, 2006;He et al 2007aHe et al , 2007b.…”

“…5 g/day/person (Triantafyllou et al, 2007), 4 g/day/person (Bebb et al,2003), 2.2 g/day/parson (Kaliora et al, 2007a(Kaliora et al, , 2007b, or 1 g/day/person (Al-Habbal et al, 1984). Favorable effects of mastic such as anticarcinogenic potential could be achieved at relatively low doses without any toxicity (He et al, 2006). Further studies must elucidate the mechanisms underlying and determine safety levels in humans.…”

Gemcitabine combined with gum mastic causes potent growth inhibition and apoptosis of pancreatic cancer cells

“…The antitumor activity of a drug is associated with inhibition of tumor cell proliferation, promotion of cellular differentiation, and induction of apoptosis. Gum mastic is a natural extract of Pistacia lentiscus trees, and its anticancer properties are newly identified [16][17][18]22] . In vitro, gum mastic has been proven to inhibit growth of prostate cancer cells and induce apoptosis of colon cancer cells.…”

Dihydrotestosterone alters urocortin levels in human umbilical vein endothelial cells

“…For semiquantitative RT-PCR, Tag DNA polymerase was used in the reaction system. Primer sequences for AR (He et al 2006) and GAPDH were synthesized from published sequences as shown in Table 2.…”