title: [Effect of 2-methoxyestradiol combined with quercetin on prostate cancer in vitro].
abstract: OBJECTIVE
  To detect the effects of quercetin (Que) combined with 2-methoxyestradiol (2-ME) on the proliferation of androgen-dependent LNCaP human prostate cancer cells line and androgen-independent PC-3 human prostate cancer cells line, and to evaluate the antitumor effects of different combos of the two drugs.
  
  
  METHODS
  After LNCaP and PC-3 cells were treated with different concentration of quercetin (0, 3.125, 6.25, 12.5, 25, 50, 100, 200 μmol/L) or 2-ME (0, 0.312 5, 0.625, 1.25, 2.5, 5, 10 μmol/L) for 48 h, the inhibitory rates of cell growth were tested using trypan blue staining method respectively. Then the concentration-effect curves were drawn and IC(50) values were calculated. According to the fitted dose-effect curves and IC(50) values, appropriate concentrations of quercetin and 2-ME were selected to compose 16 different combos. Then cells were treated with different combos of Que and 2-ME for 48 h, and then the growth inhibitory rates of cell growth were detected. According to the equation and median-effect principle, the CI values of 16 different combos of Que and 2-ME were calculated to evaluate their antitumor effects.
  
  
  RESULTS
  The inhibition rate of LNCaP or PC-3 cell growth treated with varying doses of quercetin or 2-ME alone showed a dose-dependent increase respectively. The IC(50) values of quercetin and 2-ME were 23.29 μmol/L and 1.89 μmol/L for LNCaP cells; and 22.12 μmol/L and 1.74 μmol/L for PC-3 cells respectively. After treated with 16 combos of Que (5, 10, 20, 40 μmol/L) and 2-ME (0.5, 1, 3, 5 μmol/L) for 48 h, for LNCaP cells, lower dose of Que (5 and 10 μmol/L) with higher dose of 2-ME (3 and 5 μmol/L) showed synergistic activity, whereas for PC-3 cells, besides the above combination of Que 10 μmol/L and 2-ME 3 μmol/L, higher dose of quercetin (20 and 40 μmol/L) with higher dose of 2-ME (3 and 5 μmol/L) also showed synergistic activity.
  
  
  CONCLUSIONS
  Both quercetin and 2-methoxyestradiol could inhibit the growth of LNCaP and PC-3 human prostate cancer cells in a dose dependent manner. We confirmed that combinations of quercetin and 2-ME at appropriate concentrations have the potential for synergetic antiproliferative activity in vitro.
authors.affiliation: Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
authors.forename: L M
authors.initials: LM
authors.lastname: Song
authors.forename: G D
authors.initials: GD
authors.lastname: Wang
authors.forename: H P
authors.initials: HP
authors.lastname: Wang
authors.forename: N Z
authors.initials: NZ
authors.lastname: Xing
mesh_terms: D000077584:2-Methoxyestradiol; D000728:Androgens; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004958:Estradiol / Q000031:analogs & derivatives; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms; D011794:Quercetin
chemical_list: D000728:Androgens; D004958:Estradiol; D000077584:2-Methoxyestradiol; D011794:Quercetin