Prostate-specific natural health products (dietary supplements) radiosensitize normal prostate cells.
OBJECTIVE
Prostate-specific health products (dietary supplements) are taken by cancer patients to alleviate the symptoms linked with poor prostate health. However, the effect of these agents on evidence-based radiotherapy practice is poorly understood. The present study aimed to determine whether dietary supplements radiosensitized normal prostate or prostate cancer cell lines.


METHODS
Three well-known prostate-specific dietary supplements were purchased from commercial sources available to patients (Trinovin, Provelex, and Prostate Rx). The cells used in the study included normal prostate lines (RWPE-1 and PWR-1E), prostate tumor lines (PC3, DU145, and LNCaP), and a normal nonprostate line (HaCaT). Supplement toxicity was assessed using cell proliferation assays [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and cellular radiosensitivity using conventional clonogenic assays (0.5-4Gy). Cell cycle kinetics were assessed using the bromodeoxyuridine/propidium iodide pulse-labeling technique, apoptosis by scoring caspase-3 activation, and DNA repair by assessing gammaH2AX.


RESULTS
The cell growth and radiosensitivity of the malignant PC3, DU145, and LNcaP cells were not affected by any of the dietary prostate supplements (Provelex [2 microg/mL], Trinovin [10 microg/mL], and Prostate Rx [50 microg/mL]). However, both Trinovin (10 microg/mL) and Prostate Rx (6 microg/mL) inhibited the growth rate of the normal prostate cell lines. Prostate Rx increased cellular radiosensitivity of RWPE-1 cells through the inhibition of DNA repair.


CONCLUSIONS
The use of prostate-specific dietary supplements should be discouraged during radiotherapy owing to the preferential radiosensitization of normal prostate cells.
Hasan
Yasmin
Y
William Beaumont Hospital, Royal Oak, MI 48073, USA.
Schoenherr
Diane
D
Martinez
Alvaro A
AA
Wilson
George D
GD
Marples
Brian
B
D001688:Biological Products / Q000494:pharmacology*; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D003114:Colony-Forming Units Assay / Q000379:methods; D019587:Dietary Supplements; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D008297:Male; D009928:Organ Specificity; D011467:Prostate / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects*; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011836:Radiation Tolerance / Q000187:drug effects*
D001688:Biological Products