ONCOLOGY LETTERS 15: 3167-3172, 2018 Simvastatin in combination with meclofenamic acid inhibits the proliferation and migration of human prostate cancer PC‑3 cells via an AKR1C3 mechanism YOSHITAKA SEKINE, HIROSHI NAKAYAMA, YOSHIYUKI MIYAZAWA, HARUO KATO, YOSUKE FURUYA, SEIJI ARAI, HIDEKAZU KOIKE, HIROSHI MATSUI, YASUHIRO SHIBATA, KAZUTO ITO and KAZUHIRO SUZUKI Department of Urology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan Received July 25, 2017; Accepted December 11, 2017 DOI: 10.3892/ol.2017.7721 Abstract. Statins have become of interest in research due in PC-3 cells following siRNA transfection was not associ- to their anticancer effects. However, the exact mechanism ated with basal cell proliferation and migration; however, of their anticancer properties remains unclear. The authors treatment with simvastatin decreased cell proliferation and previously reported that statins decrease intracellular migration. The combination of simvastatin and meclofenamic cholesterol levels in androgen-independent prostate cancer acid, an AKR1C3 inhibitor, further enhanced the inhibition cells. In de novo androgen synthesis, cholesterol is the of cell proliferation and migration compared with treat- primary material and certain enzymes have important roles. ment with either drug alone. Furthermore, treatment with The present study aimed to determine whether simvastatin simvastatin attenuated insulin-like growth factor 1-induced alters the expression of androgen synthesis-associated Akt activation; however, the combination of simvastatin and enzymes in androgen-independent prostate cancer cells. A meclofenamic acid further inhibited Akt activation. These novel combination therapy of statins and other drugs that results suggest that the combination of simvastatin and inhibit the overexpression of enzymes involved in androgen meclofenamic acid may be an effective strategy for the treat- synthesis was explored. The cytotoxicity of simvastatin ment of castration-resistant prostate cancer. and meclofenamic acid was assessed in prostate cancer cells using MTS and migration assays. Testosterone and Introduction dihydrotestosterone concentrations in the culture medium were measured using liquid chromatography-tandem mass A statin is a drug used to treat hyperlipidemia and functions spectrometry. RAC-α-serine/threonine-protein kinase (Akt) by inhibiting 3-hydroxy-3-metylglutaryl coenzyme A reduc- phosphorylation was detected by western blot analysis. tase. Statins have gained much recent attention due to their Following treatment with simvastatin, aldo-keto reductase anticancer effects. Previous studies have shown that statins family 1 member C3 (AKR1C3) expression increased in PC-3 can prolong survival, while others have reported no benefits in (>60-fold) and LNCaP-LA cells, however not in 22Rv1 cells. cancer patients (1). Concerning prostate cancer, the anticancer Small interfering (si)RNA was used to clarify the effects of effect of statins is controversial (2,3). We previously reported AKR1C3 expression. The reduction in AKR1C3 expression that statins inhibit prostate cancer progression via suppressing the expression of insulin-like growth factor 1 receptor (IGF1R) and increasing ANXA10 (4,5). However, the exact mechanism of their anticancer properties remains unclear. Correspondence to: Dr Yoshitaka Sekine, Department of There has been recent interest and concerns regarding Urology, Gunma University Graduate School of Medicine, intratumoral de novo androgen synthesis in castration-resis- 3-9-22 Showa-machi, Maebashi, Gunma 371-8511, Japan tant prostate cancer (CRPC). Now we are treating CRPC E-mail: [email protected] patients with enzalutamide and abiraterone, which attenuate the effects of intratumoral de novo androgens. In de novo Abbreviations: AKR1C3, aldo-keto reductase family 1 androgen synthesis, cholesterol is the primary material, member C3; IGF1R, insulin-like growth factor 1 receptor; CRPC, castration-resistant prostate cancer, DHT, dihydrotestosterone; and various enzymes play important roles. We previously LC-MS/MS, liquid chromatography coupled with tandem mass reported that intracellular cholesterol levels are decreased spectrometry; FBS, fetal bovine serum; IGF, insulin-like growth in androgen-independent prostate cancer cells after treat- factor; NSAIDs, non-steroidal anti-inflammatory drugs ment with simvastatin (6); however, alterations in androgen synthesis-related enzymes are not clear. Key words: prostate cancer, statins, meclofenamic acid, AKR1C3 In this study, we determined whether simvastatin alters the expression of enzymes involved in androgen synthesis in CRPC cells. We also explored a new combination therapy 3168 SEKINE et al: STATINS PLUS NSAIDS INHIBIT PROSTATE CANCER of statins and other drugs that inhibit the overexpression of medium to inhibit cell proliferation. Photographs were taken at androgen synthesis-related enzymes. 0 and 48 h, and the distance of cell migration was determined by subtracting the values obtained at 0 h from those obtained Materials and methods at 48 h. Migration distance is expressed as fold change over the control. Cells and chemicals. Human prostate cancer cell lines PC-3, LNCaP, and 22RV1 were purchased from DS Pharma siRNA transfection. Cells were transfected with Biomedical (Osaka, Japan) and cultured in RPMI 1640 ON-TARGETplus Non-targeting Pool (no. D-001810-10-05; (Sigma-Aldrich; Merck KGaA, Darmstadt, Germany) Dharmacon, Waltham, MA, USA) or ON-TARGETplus supplemented with 10% FBS (Moregate BioTech, Bulimba, AKR1C3 siRNA (No. L-008116-00-0005, Dharmacon) using Australia). PC-3 is an androgen receptor-negative human DharmaFect 2 (Dharmacon). Cells were incubated for 48 h prostate cancer cell line (7). LNCaP-LA cells, which were after transfection. generated from LNCaP cells, were cultured in medium containing 10% charcoal-stripped fetal bovine serum (FBS) Western blot analysis. Cell lysates were prepared in RIPA for more than 3 months. buffer containing 1 mM sodium orthovanadate (Sigma-Aldrich; Merck KGaA) and Halt Protease Inhibitor Cocktail (Pierce; Measurement of testosterone and dihydrotestosterone (DHT) Thermo Fisher Scientific, Inc.). Samples were boiled for 5 in culture medium. Cells were cultured on a 6-well plate and min; an equal amount of protein (30 µg/lane) was subjected incubated overnight in medium containing 10% FBS. Cells to 4-12% SDS-PAGE and transferred onto nitrocellulose were then incubated with or without simvastatin (5 µM). After membranes. Each membrane was incubated with the following 48 h, androstenedione (100 µM) was added to the medium. primary polyclonal antibodies: rabbit anti-Akt (1:1,000), After 24 h, culture medium was collected, and testosterone rabbit anti-phospho-Akt (Ser473) (1:1,000) (Cell Signaling and DHT concentrations were measured using liquid Technology, Inc., Beverly, MA, USA). Blots were developed chromatography-tandem mass spectrometry (LC-MS/MS) using a 1:2,000 dilution of the HRP-conjugated secondary (ASKA Pharmaceutical Medical Co., Ltd., Kawasaki, Japan). antibody (Cell Signaling Technology, Inc.). Proteins were RIPA buffer was added to wells and protein concentration was visualized using Immobilon (Merck Millipore, Darmstadt, measured by the DC Protein Assay (Bio-Rad Laboratories, Germany). Inc., Hercules, CA, USA). Testosterone and DHT levels were calculated by dividing the results of the protein assay by the Statistical analysis. Data are expressed as the mean ± stan- total protein concentration. dard deviation. Differences between values were evaluated by one-way ANOVA using Tukey's post hoc analysis and RT‑qPCR. Transcript levels were quantified using the Student's t-test. P<0.05 was considered to indicate a statisti- Applied Biosystems 7300 Real-Time PCR system (Applied cally significant difference. Biosystems; Thermo Fisher Scientific, Inc., Waltham, MA, USA) according to the manufacturer's protocol. Total RNA Results was extracted, cDNA was synthesized (8), and polymerase chain reaction (PCR) amplification was performed, using 2 µl Simvastatin altered the expression of genes encoding cDNA and the StAR, CYP11A1, CYP17A1, aldo-keto reduc- steroidogenic enzymes in androgen‑independent prostate tase family 1 member C3 (AKR1C3), HSD3B1, HSD3B2, cancer cells. We examined PC-3, LNCaP-LA and 22Rv1 cells SRD5A1, SRD5A2, and AKR1C2 primers (No. Hs00986559_ to determine whether simvastatin alters genes that encode g1, Hs00167984_m1, Hs01124136_m1, Hs00366267_m1, steroidogenic enzymes in androgen-independent prostate Hs00426435_m1, Hs00605123_m1, Hs00602694_mH, cancer cells. After treatment with simvastatin, the expression Hs00165843_m1, and Hs00912742_m1, respectively; Applied of AKR1C3 was increased in PC-3 and LNCaP-LA cells Biosystems). Next, PCR was performed for one cycle of 10 min (Figs. 1A and 2A) but not in 22Rv1 cells (data not shown). at 95˚C followed by 40 cycles of 15 sec at 95˚C and 60 sec at Moreover, the fold change was more than 60 times in PC-3 60˚C. b‑Actin (No. 4326315E, Applied Biosystems) transcript cells. Conversely, the expression of hydroxy-delta-5-steroid levels were used as the internal control. mRNA fold changes dehydrogenase, 3 beta- and steroid delta-isomerase 1 were quantified using ΔΔCq. (HSD3B1) was decreased in PC-3 and LNCaP-LA cells (Figs. 1A and 2A) but not in 22Rv1 cells (data not shown). MTS assay. Cells were plated onto a 96-well plate in 100 µl Moreover, simvastatin increased steroid 5 alpha-reductase 1 culture medium containing 10% FBS. After