TY - JOUR
T1 - 1,4-Phenylenebis(methylene)selenocyanate, but not selenomethionine, inhibits androgen receptor and Akt signaling in human prostate cancer cells
AU - Facompre, Nicole D.
AU - El-Bayoumy, Karam
AU - Sun, Yuan Wan
AU - Pinto, John T.
AU - Sinha, Raghu
PY - 2010/8
Y1 - 2010/8
N2 - The lack of treatment for worried-well patients with high-grade prostatic intraepithelial neoplasia combined with issues of recurrence and hormone resistance in prostate cancer survivors remains a major public health obstacle. The long latency of prostate cancer development provides an opportunity to intervene with agents of known mechanisms at various stages of disease progression. A number of signaling cascades have been shown to play important roles in prostate cancer development and progression, including the androgen receptor (AR) and phosphatidylinositol 3-kinase/Akt signaling pathways. Crosstalk between these two pathways is also thought to contribute to progression and hormonerefractory prostate disease. Our initial investigations show that the naturally occurring organoselenium compound selenomethionine (SM) and the synthetic 1,4-phenylenebis(methylene)selenocyanate (p-XSC) can inhibit human prostate cancer cell viability; however, in contrast to SM, p-XSC is active at physiologically relevant doses. In the current investigation, we show that p-XSC, but not an equivalent dose of SM, alters molecular targets and induces apoptosis in androgen-responsive LNCaP and androgen-independent LNCaP C4-2 human prostate cancer cells. p-XSC effectively inhibits AR expression and transcriptional activity in both cell lines. p-XSC also decreases Akt phosphorylation as well as Akt-specific phosphorylation of the AR. Inhibition of Akt, however, does not fully attenuate p-XSC-mediated downregulation of AR activity, suggesting that inhibition of AR signaling by p-XSC does not occur solely through alterations in the phosphatidylinositol 3-kinase/Akt survival pathway. Our data suggest that p-XSC inhibits multiple signaling pathways in prostate cancer, likely accounting for the downstream effects on proliferation and apoptosis.
AB - The lack of treatment for worried-well patients with high-grade prostatic intraepithelial neoplasia combined with issues of recurrence and hormone resistance in prostate cancer survivors remains a major public health obstacle. The long latency of prostate cancer development provides an opportunity to intervene with agents of known mechanisms at various stages of disease progression. A number of signaling cascades have been shown to play important roles in prostate cancer development and progression, including the androgen receptor (AR) and phosphatidylinositol 3-kinase/Akt signaling pathways. Crosstalk between these two pathways is also thought to contribute to progression and hormonerefractory prostate disease. Our initial investigations show that the naturally occurring organoselenium compound selenomethionine (SM) and the synthetic 1,4-phenylenebis(methylene)selenocyanate (p-XSC) can inhibit human prostate cancer cell viability; however, in contrast to SM, p-XSC is active at physiologically relevant doses. In the current investigation, we show that p-XSC, but not an equivalent dose of SM, alters molecular targets and induces apoptosis in androgen-responsive LNCaP and androgen-independent LNCaP C4-2 human prostate cancer cells. p-XSC effectively inhibits AR expression and transcriptional activity in both cell lines. p-XSC also decreases Akt phosphorylation as well as Akt-specific phosphorylation of the AR. Inhibition of Akt, however, does not fully attenuate p-XSC-mediated downregulation of AR activity, suggesting that inhibition of AR signaling by p-XSC does not occur solely through alterations in the phosphatidylinositol 3-kinase/Akt survival pathway. Our data suggest that p-XSC inhibits multiple signaling pathways in prostate cancer, likely accounting for the downstream effects on proliferation and apoptosis.
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U2 - 10.1158/1940-6207.CAPR-10-0054
DO - 10.1158/1940-6207.CAPR-10-0054
M3 - Article
C2 - 20606040
AN - SCOPUS:77955438911
SN - 1940-6207
VL - 3
SP - 975
EP - 984
JO - Cancer Prevention Research
JF - Cancer Prevention Research
IS - 8
ER -