Dietary n-3 polyunsaturated fatty acids enhance hormone ablation therapy in androgen-dependent prostate cancer.
Hormone ablation therapy typically causes regression of prostate cancer and represents an important means of treating this disease, particularly after metastasis. However, hormone therapy inevitably loses its effectiveness as tumors become androgen-independent, and this conversion often leads to death because of subsequent poor responses to other forms of treatment. Because environmental factors, such as diet, have been strongly linked to prostate cancer, we examined the affects of dietary polyunsaturated fatty acids (PUFAs; at 1.5 wt%) on growth of androgen-dependent (CWR22) and androgen-independent (CWR22R) human prostatic cancer xenografts, the acute response of CWR22 tumors to ablation therapy, and their progression to androgen independence. Significant diet-induced changes in tumor n-3 or n-6 PUFA content had no affect on CWR22 or CWR22R tumors growing with or without androgen support, respectively. However, dietary changes that increased tumor eicosapentaenoic acid and linoleic acid content enhanced responses to ablation therapy, measured by cancer cell apoptosis and mitosis. In addition, relapse to androgen-independent growth (measured by renewed increases in tumor volume and serum prostate-specific antigen after ablation) positively correlated with tumor arachidonic acid content. There was no correlation between expression of 15-lipoxygenase isozymes or their products and tumor growth or responses to ablation. In conclusion, dietary n-3 PUFA may enhance the response of prostate cancer to ablation therapy and retard progression to androgen-independent growth by altering tumor PUFA content.
Department of Pathobiology, University of Tennessee, 2407 River Dr., Rm A201, Knoxville, TN 37996-4542, USA. mmcentee@utk.edu
Michael F
MF
McEntee
Carol
C
Ziegler
Danielle
D
Reel
Kenneth
K
Tomer
Ahmed
A
Shoieb
Mark
M
Ray
Xiaoou
X
Li
Nancy
N
Neilsen
Fred B
FB
Lih
Dorcas
D
O'Rourke
Jay
J
Whelan
D000726:Androgen Antagonists / Q000627:therapeutic use; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D016718:Arachidonic Acid / Q000627:therapeutic use; D015153:Blotting, Western; D004042:Dietary Fats, Unsaturated / Q000627:therapeutic use*; D019008:Drug Resistance, Neoplasm / Q000502:physiology; D015777:Eicosanoids / Q000096:biosynthesis; D015118:Eicosapentaenoic Acid / Q000627:therapeutic use; D005231:Fatty Acids, Unsaturated / Q000627:therapeutic use*; D006801:Humans; D019787:Linoleic Acid / Q000627:therapeutic use; D008297:Male; D051379:Mice; D009376:Neoplasms, Hormone-Dependent / Q000178:diet therapy*; D019301:Oleic Acid / Q000627:therapeutic use; D011471:Prostatic Neoplasms / Q000178:diet therapy*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021241:Spectrometry, Mass, Electrospray Ionization; D023041:Xenograft Model Antitumor Assays
D000726:Androgen Antagonists; D004042:Dietary Fats, Unsaturated; D015777:Eicosanoids; D005231:Fatty Acids, Unsaturated; D016718:Arachidonic Acid; D019301:Oleic Acid; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid