Korean J Urol.  2009 Jan;50(1):72-80. 10.4111/kju.2009.50.1.72.

Effects of alpha-Lipoic Acid on the Antioxidant System in Prostate Cancer Cells

• Choi S
• Min K
• Choi I
• Kang D

• KMID: 2140118
• DOI: http://doi.org/10.4111/kju.2009.50.1.72

Abstract

PURPOSE: Overproduction of lipid peroxidation byproducts and disturbances in the antioxidant defense system have been implicated in the pathogenesis of several diseases, including prostate cancer. Although several studies have investigated the level of lipid peroxidation and antioxidants in prostate cancer, there are no reports on alpha-lipoic acid (ALA) in prostate cancer. Here we assessed the effects of ALA on the antioxidant system in prostate cancer cells.
MATERIALS AND METHODS
PC-3, LNCaP, and RWPE-2 cell lines were used in this study. Redox factor (Ref)-1 protein was measured by Western blot analysis after treatment with ALA. Real-time polymerase chain reaction (RT-PCR) was performed to detect superoxide dismutase (SOD)-1 and -2, catalase, and glutathione peroxidase (GSH-Px) mRNA expression.
RESULTS
Ref-1 was expressed in the PC-3, LNCaP, and RWPE-2 cell lines. The expression of Ref-1 protein was increased after treatment with 125, 250, and 500 microM ALA in the PC-3 (p<0.05) and LNCaP (p>0.05) cells compared with the RWPE-2 cells at 48 hours. In PC-3 cells, the mRNA expression of SOD-1, SOD-2, catalase, and GSH-Px decreased at 24 and 48 hours dose-dependently compared with that in RWPE-2 cells (p<0.05). The mRNA expression of SOD-2, catalase, and GSH-Px in LNCaP cell decreased at 48 hours dose-dependently (p<0.05).
CONCLUSIONS
The expression of Ref-1 protein and antioxidant enzymes changed after ALA exposure in prostate cancer cells. Our findings suggest that ALA affects the antioxidant system in prostate cancer cells and may be related to compensatory changes in the antioxidant defense system of the cells.

Keyword

Prostatic neoplasms; Thioctic acid; Antioxidants

MeSH Terms

Antioxidants
Blotting, Western
Catalase
Cell Line
Glutathione Peroxidase
Lipid Peroxidation
Oxidation-Reduction
Prostate
Prostatic Neoplasms
Real-Time Polymerase Chain Reaction
RNA, Messenger
Superoxide Dismutase
Thioctic Acid
Antioxidants
Catalase
Glutathione Peroxidase
RNA, Messenger
Superoxide Dismutase
Thioctic Acid

Figure

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  Fig. 1. The growth rate of the LNCaP cell line. *: inhibitory concentration (IC)50.

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  Fig. 2. Effects of α-lipoic acid on the expression of redox factor (Ref)-1 protein in PC-3 and LNCaP prostatic cancer cells and RWPE-2 cells. (A) Ref-1 protein was isolated and Western blot analysis was performed. The bar diagrams (B) show means±SE of Ref-1 expression. *p＜0.05, versus untreated control as analyzed by one-way ANOVA and Turkey’s multiple-comparison tests.

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  Fig. 3. Effects of α-lipoic acid on the expression of superoxide dismutase (SOD)-1 mRNA in PC-3 (A) and LNCaP (B) prostatic cancer cells and RWPE-2 cells (C). The bar diagrams show means±SE of mRNA expression. *p＜0.05, versus untreated control as analyzed by one-way ANOVA and Turkey’s multiple-comparison tests.

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  Fig. 4. Effects of α-lipoic acid on the expression of superoxide dismutase(SOD)-2 mRNA in PC-3(A) and LNCaP(B) prostatic cancer cells and RWPE-2 cells (C). The bar diagrams show means±SE of mRNA expression. *p＜0.05, versus untreated control as analyzed by one-way ANOVA and Turkey’s multiple-comparison tests.

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  Fig. 5. Effects of α-lipoic acid on the expression of catalase mRNA in PC-3 (A) and LNCaP (B) prostatic cancer cells and RWPE-2 cells (C). The bar diagrams show means±SE of mRNA expression. *p＜0.05, versus untreated control as analyzed by one-way ANOVA and Turkey’s multiple-comparison tests.

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  Fig. 6. Effects of α-lipoic acid on the expression of glutathione peroxidase mRNA in PC-3 (A) and LNCaP (B) prostatic cancer cells and RWPE-2 cells (C). The bar diagrams show means±SE of mRNA expression. *p＜0.05, versus untreated control as analyzed by one-way ANOVA and Turkey’s multiple-comparison tests.

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