BACKGROUND: Blockade of androgen activity is a major effective therapy for advanced prostate cancer. Estrogen analogs have been used for prostate cancer therapy for years presumably by inhibiting testosterone biosyntheses, but with considerable adverse events due to their classic estrogenic activity. With the discovery of the estrogen receptor (ER) beta and its presence in prostate tumor cells, evaluation of estrogen analogs with less classic estrogenic activity in prostate cancer therapy is emerging. METHODS: The effects of 17alpha-estradiol (alphaE2), a stereo-isomer of 17beta-estradiol (betaE2), on dihydrotestosterone (DHT)-induced cell growth and gene expressions were examined in androgen-dependent LAPC-4 prostatic tumor cells and in LAPC-4 xenograft animals, and compared to those of betaE2. RESULTS: Both alphaE2 and betaE2 attenuated DHT induction of PSA gene expression, cell proliferation, and cell growth in cultured LAPC-4 cells. The inhibition of cell proliferation was associated with a blockade of DHT-induced cyclin A and cyclin D1 expression by alphaE2 and betaE2. In LAPC-4 xenograft mice, alphaE2 significantly inhibited tumor growth without altering the plasma testosterone level, while betaE2 failed to inhibit tumor growth even though it significantly inhibited PSA gene expression. CONCLUSION: alphaE2 is an effective agent for inhibition of DHT-induced PSA, cyclin A, cyclin D1 gene expression, and cell proliferation in LAPC-4 cells, and tumor growth in LAPC-4 xenograft mice.
BACKGROUND: Blockade of androgen activity is a major effective therapy for advanced prostate cancer. Estrogen analogs have been used for prostate cancer therapy for years presumably by inhibiting testosterone biosyntheses, but with considerable adverse events due to their classic estrogenic activity. With the discovery of the estrogen receptor (ER) beta and its presence in prostate tumor cells, evaluation of estrogen analogs with less classic estrogenic activity in prostate cancer therapy is emerging. METHODS: The effects of 17alpha-estradiol (alphaE2), a stereo-isomer of 17beta-estradiol (betaE2), on dihydrotestosterone (DHT)-induced cell growth and gene expressions were examined in androgen-dependent LAPC-4 prostatic tumor cells and in LAPC-4 xenograft animals, and compared to those of betaE2. RESULTS: Both alphaE2 and betaE2 attenuated DHT induction of PSA gene expression, cell proliferation, and cell growth in cultured LAPC-4 cells. The inhibition of cell proliferation was associated with a blockade of DHT-induced cyclin A and cyclin D1 expression by alphaE2 and betaE2. In LAPC-4 xenograft mice, alphaE2 significantly inhibited tumor growth without altering the plasma testosterone level, while betaE2 failed to inhibit tumor growth even though it significantly inhibited PSA gene expression. CONCLUSION: alphaE2 is an effective agent for inhibition of DHT-induced PSA, cyclin A, cyclin D1 gene expression, and cell proliferation in LAPC-4 cells, and tumor growth in LAPC-4 xenograft mice.
Authors: Nam Deuk Kim; Rajendra Mehta; Weiping Yu; Ishak Neeman; Talia Livney; Akiva Amichay; Donald Poirier; Paul Nicholls; Andrew Kirby; Wenguo Jiang; Robert Mansel; Cheppail Ramachandran; Thangaiyan Rabi; Boris Kaplan; Ephraim Lansky Journal: Breast Cancer Res Treat Date: 2002-02 Impact factor: 4.872
Authors: Z Weihua; S Makela; L C Andersson; S Salmi; S Saji; J I Webster; E V Jensen; S Nilsson; M Warner; J A Gustafsson Journal: Proc Natl Acad Sci U S A Date: 2001-05-22 Impact factor: 11.205
Authors: Ahmedin Jemal; Rebecca Siegel; Elizabeth Ward; Taylor Murray; Jiaquan Xu; Michael J Thun Journal: CA Cancer J Clin Date: 2007 Jan-Feb Impact factor: 508.702
Authors: Dimitry A Chistiakov; Veronika A Myasoedova; Alexandra A Melnichenko; Andrey V Grechko; Alexander N Orekhov Journal: Vasc Health Risk Manag Date: 2018-10-15