This Article Abstract Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Padayatty, S. J. Articles by Cunningham, G. R. Search for Related Content PubMed PubMed Citation Articles by Padayatty, S. J. Articles by Cunningham, G. R.

Lovastatin-Induced Apoptosis in Prostate Stromal Cells

Departments of Medicine (S.J.P., M.M., T.C.S., G.R.C.) and Cell Biology (M.M., G.R.C.), VA Medical Center, and Baylor College of Medicine, Houston, Texas 77030

Address all correspondence and requests for reprints to: S. J. Padayatty, M.D., Research Service 151, VA Medical Center, 2002 Holcombe Blvd., Houston, Texas 77030.

	Abstract

Top Abstract Introduction Materials and Methods Results Discussion References

 
Benign prostatic hyperplasia (BPH) is a common disease of aging men. Current medical treatment for this condition is only partially effective, therefore many patients must undergo surgery for symptomatic relief. BPH is caused by an increase in prostate epithelial and stromal cells, especially the latter. Since BPH stromal cells have a long life span and are not very responsive to androgen withdrawal, cultured BPH stromal cells were used to explore the feasibility of pharmacologically inducing apoptosis in these cells.

We obtained BPH tissue during surgery, and stromal cells were isolated and maintained in culture. After cells achieved confluence, we induced apoptosis with the HMGCoA reductase inhibitor, lovastatin (30 µmol/L). The effects of testosterone (100 µmol/L), dihydrotestosterone (DHT; 100 µmol/L) and finasteride (100 µmol/L) on lovastatin-induced apoptosis were studied on cells grown in media containing charcoal stripped serum. Similarly, we examined the effect of the cholesterol pathway metabolites, mevalonic acid (30 µmol/L), geranyl geraniol (30 µmol/L), farnesol (10 µmol/L), squalene (30 µmol/L) and 7-ketocholesterol (3 µmol/L) on lovastatin-induced apoptosis. We demonstrated apoptosis by DNA laddering in agarose gels, by fluorescence microscopy following acridine orange staining, and by flow cytometry after end-labeling of DNA strand breaks with biotin-16-dUTP using deoxynucleotidyl exotransferase (TdT).

Lovastatin at 30 µmol/L, but not at lower concentrations, induced apoptosis in BPH prostate stromal cells. This was seen (by flow cytometry) in 16.6 ± 7.3% (mean ± SD) of BPH cells treated with lovastatin at 72 h vs. 2.5 ± 1.2% of cells treated with ethanol. Lovastatin-induced apoptosis was not increased in stripped serum or by the addition finasteride, and was not inhibited by testosterone or DHT. Only mevalonate and geranyl geraniol, prevented lovastatin-induced apoptosis whereas farnesol, squalene, or 7-ketocholesterol did not.

We conclude that lovastatin can induce apoptosis in BPH stromal cells in vitro, and this is not affected by androgen withdrawal or stimulation. It is unlikely that lovastatin, per se, will be an effective treatment for BPH in vivo, but it does provide a means for inducing apoptosis in vitro. Understanding the apoptotic process in BPH stromal cells ultimately may lead to new therapeutic strategies for BPH.

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion References

 
BENIGN PROSTATIC hyperplasia (BPH) is a disease of aging. In men 61–70 yr old, 69% have symptoms attributable to BPH (1); by the age of 80, 25–30% of men have required surgical treatment (2). BPH develops only in the presence of androgens. Once established, agents that reduce dihydrotestosterone (DHT) levels (3), testosterone and DHT levels (4), or androgen effects (5) produce only a modest reduction in BPH volume. However, of the two medical treatments currently used to produce symptomatic relief in BPH, -adrenergic blockade and 5 -reductase inhibition, only the latter reduces prostrate volume. For example, finasteride (6), a type II 5 -reductase inhibitor, reduces prostatic DHT by 85%, but reduces prostate volume by only 20% (5). While the remaining DHT or the increased testosterone could be sufficient to maintain BPH, reduction of both DHT and testosterone with a GnRH agonist causes similar changes in prostate volume and urine flow rates. Thus, although prostatic tissue is androgen-dependent, androgen ablation is only partly effective in reducing BPH volume and relieving symptoms after BPH has developed. Furthermore, complete androgen ablation produces unacceptable side effects.

The modest reduction in prostate size is probably because BPH is primarily a disease of the stroma, and androgen ablation mainly affects epithelial cells. Finasteride reduces the number of secretory cells more than the number of stromal cells (7). Since stromal cells may have a life span of more than 30 yr (8), effective medical treatment of BPH may require local prostatic androgen deprivation to reduce the number of androgen-dependent cells, and some form of treatment that will cause apoptosis of stromal cells. We have, therefore, investigated the possibility of selectively inducing apoptosis in the prostate stromal cells with other pharmacologic agents.

Recently, HMG-CoA reductase inhibitors, which block the synthesis of cholesterol, have been reported to induce apoptosis in prostate cancer cells (9). The mechanisms of lovastatin-induced apoptosis are unclear, but they may be caused by the deficiency of certain cholesterol pathway metabolites such as geranyl and farnesyl pyrophosphate (10) (Fig. 1), which are required for the isoprenylation of many membrane-bound proteins. Therefore, we studied the effect of lovastatin on BPH stromal cells in culture and the effect of cholesterol pathway metabolites and androgen on lovastatin-induced apoptosis.

View larger version (19K): [in this window] [in a new window]   Figure 1. Intermediary metabolites in the synthesis of cholesterol from acetyl-CoA and site of lovastatin’s action on the pathway.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion References

Human BPH stromal cells, derived from the prostatic tissue of patients undergoing surgery for BPH, were cultured (11). Briefly, we obtained BPH chips from transurethral surgery of the prostate under a protocol approved by the Baylor Affiliated Hospitals Institutional Review Board. Viable tissue was washed three times in medium A [ a mixture of Ham’s F-12 and Waymouth MD 705/1 (1:1 v/v) supplemented with penicillin (200 U/mL) and streptomycin (200 µg/mL)]. We minced the tissue, digested it with collagenase (5 mg/mL) in medium A enriched with 2% fetal calf serum (FCS), and rotated it in a tube at room temperature for 4 h. Tissue was passed through a no. 18 needle 6–7 times and centrifuged at 1200 rpm for 10 min. We washed the pellets once with medium A, and the cells were resuspended in the culture medium, 10% FCS plus medium A (but the concentration of penicillin and streptomycin was reduced to 100 U/mL and 100 µg/mL respectively). The cells were frozen after the 6–7th passage. The resulting cells were vimentin-positive and cytokeratin-negative. Cells from passages 7–15 were used in these studies. These cells are known to have androgen receptors based on binding studies and immunocytochemistry, but cell proliferation (as measured by cell number and incorporation of (3)H-Thymidine) is not influenced by androgen at these passages. Similarly, we also cultured prostate stromal cells from normal human prostate (cadaveric organ donor).

We grew BPH stromal cells to confluence in Ham’s F-12 media with 10% FCS, penicillin (50 U/mL) and streptomycin (50 µg/mL). The cells were grown on sterile glass slides for microscopy, and in 12 well plates for flow cytometry. Following replacement with fresh media, cells were treated with lovastatin or vehicle alone (100% ethanol) and harvested at various intervals.

DNA extraction

The floating and adherent cells were collected separately for DNA extraction. We aspirated the media and pelleted the floating cells. Adherent cells were trypsinized and pelleted by centrifugation. Each experiment was done three times. We extracted the DNA using the Easy-DNA Kit, treated it with DNAse-free RNAse,and stored it at 4 C. DNA was quantified by spectrophotometry (at 260 nm).

Detection of apoptosis

DNA laddering.. We ran 5–20 µg DNA on 1.5% agarose gel stained with ethidium bromide and photographed it under ultraviolet light. Five µg of 123 DNA ladder was used as marker. The presence of a DNA ladder along with the reduction or absence of high molecular weight DNA indicates the occurrence of apoptosis (12).

Microscopy.. Following treatment, we immersed glass slides in 100% alcohol (>1 h), in 70% (5 min) and 50% (5 min) alcohol, washed with phosphate bufered saline (PBS), stained with acridine orange (5 mg/ml) for 20 min, washed twice with PBS, covered the cells with a coverslip and sealed them while they were still wet. Slides were stored in the dark at 4 C and were examined under a fluorescent microscope (at 520 nm). Apoptotic cells were identified by the characteristically bright, condensed, and fragmented nuclei with intact cell membranes (13). We counted normal and apoptotic cells (>500/slide) in four experiments.

Flow cytometry.. We pooled floating and adherent cells after treatment with trypsin and labeled DNA strand breaks with biotin-16-dUTP using deoxynucleotidyl exotransferase (TdT) (14). Briefly, we fixed the cells in 1% paraformaldehyde in PBS on ice for 15 min, washed with PBS, and stored them in 70% alcohol at -20 C. The cells were pelleted, washed in PBS, and resuspended in 50 µL PBS. Fifty µL TdT reaction mixture (10 µL 5X reaction buffer, 5 µL CoCl₂, 1.5 µL TdT, 0.5 µL biotin-16-dUTP made up to 50 µL with distilled water) was added, and the cells were incubated for 1 h at 37 C. The cells were harvested after the addition of 1 mL PBS, resuspended in 50 µL of PBS, and incubated with 100 µL Avidin Fitc buffer (2.5 mg/mL Avidin DCS Fitc, 4X SSC, 0.1% triton X-100, 5% w/v nonfat dry milk) at room temperature in the dark for 30 min. Cells were harvested with PBS and 0.1% Triton X-100 and resuspended in one mL of propidium iodide (PI)/RNAse solution (PBS with 5 µg/mL of PI, 0.1% RNAse A). The percentages of apoptotic cells were determined by flow cytometry (Epics Profile Analyzer, Coulter, Miami, FL), using untreated cells as negative controls. Each experiment used duplicates for each treatment, and the results represent the means of at least four experiments.

Materials

Lovastatin and finasteride were gifts from Merck and Co., West Point, PA. Testosterone and DHT were obtained from Steraloids, Wilton, NH. We purchased the cholesterol pathway metabolites mevalonic acid, geranyl geraniol, squalene, farnesol, and 7-ketocholesterol, as well as Acridine Orange, Propidium Iodine, and RNAse from Sigma Chemical Company, St. Louis, MO. We obtained culture media, antibiotics, and 123 DNA ladder from Gibco BRL, Life Technologies, Gaithersburg, MD; tissue culture plates from Corning Glass Ware, Corning, NY; Easy-DNA kits from Invitrogen Corporation, San Diego CA; TdT and buffers from Boehringer Mannheim Corporation, Indianapolis, IN; Avidin DCS Fitc from Vector Laboratories, Burlingame, CA; nonfat dry milk from Carnation Co., Los Angeles, CA; and Polaroid Black and White film 667, from Polaroid Corporation, Cambridge, MA.

Statistical analysis

The control and the experimental groups were compared using unpaired two-sided t test, assuming unequal variance (Welch t test).

	Results

Top Abstract Introduction Materials and Methods Results Discussion References

 
Dose response

Treatment with lovastatin at a final concentration of 30 µmol/L but not 0.1, 0.3, 3, or 10 µmol/L or with alcohol alone for 72 h induced apoptosis, as shown by DNA laddering (Fig. 2). Floating cells exhibited DNA laddering more than adherent cells. Acridine orange staining permitted identification of apoptotic cells (Fig. 3). After 72 h treatment, the percentages of apoptotic cells were 22.6 ± 10.5 (mean ± SD) and 3 ± 1% for 30 and 10 µmol/L lovastatin, and 0% for alcohol, 3, 1, and 0.3 µmol/L lovastatin.

View larger version (50K): [in this window] [in a new window]   Figure 2. The effect of lovastatin (30 µmol/L) treatment (72 h) on BPH stromal cells. DNA was extracted separately from cells in the supernatant (SUPN) and from adherent (ADH) cells, run on 1.5% agarose gels, and stained with ethidium bromide. Apoptosis is shown by DNA laddering and the absence or reduction in high molecular weight DNA.

View larger version (152K): [in this window] [in a new window]   Figure 3. Apoptosis in BPH stromal cells grown on glass slides, in media containing 30 µmol/L lovastatin (72 h). The cells were stained with acridine orange and were viewed under a florescence microscope (520 nm). Apoptotic cells have small, bright, condensed, and fragmented nuclei with intact cell membranes. Panels A and C: treated with vehicle alone. Panels B and D: treated with lovastatin.

Treatment with 30 µmol/L lovastatin induced apoptosis in floating and adherent cells at 48 h and 72 h, as illustrated by DNA laddering. Acridine orange staining exhibited 0% apoptosis at time 0 and 24 h, 2.1 ± 1.3% at 48 h, 19.4 ± 9.8% at 72 h, and 45 ± 21% on day 4 at 96 h. Control cells had 0% apoptosis at each time (Fig. 4). Estimation of apoptosis by flow cytometry showed 2.2 ± 0.58% apoptosis at 24 h (vs. control 1.33 ± 0.25%), 4.24 ± 2.17% at 48 h (vs. control 1.24 ± 0.11%) and 16.62 ± 7.3% at 72 h (vs. control 2.47 ± 0.1.2%) (Fig. 5).

View larger version (14K): [in this window] [in a new window]   Figure 4. Time course for lovastatin-induced (30 µmol/L) apoptosis in BPH stromal cells. The cells were grown on glass slides, stained with acridine orange, and examined under a fluorescence microscope. At least 500 cells were counted per slide. N 4 at each time point. On day 5, the lovastatin-treated group showed 99% apoptosis, but there were very few cells to count. This part of the graph is therefore shown as a stippled line.

View larger version (21K): [in this window] [in a new window]   Figure 5. Lovastatin-induced (30 µmol/L, 72 h) apoptosis in BPH stromal cells determined by flow cytometry following biotin-16-dUTP labeling of DNA strand breaks using TdT. All experiments were done in duplicate. Each point represents the mean ± SD of 4 or more experiments.

Cells grown in charcoal-stripped serum did not exhibit any more apoptosis than those in normal media. Lovastatin induced apoptosis equally when media contained normal serum or charcoal-stripped serum (Fig. 6). Treatment with testosterone, DHT, finasteride, or testosterone plus finasteride had no effect on lovastatin-induced apoptosis, as shown by the inability of any of these substances to prevent DNA laddering. Flow cytometry confirmed that DHT did not inhibit lovastatin-induced apoptosis (Fig. 6).

View larger version (25K): [in this window] [in a new window]   Figure 6. The effect of androgens on lovastatin-induced (30 µmol/L) apoptosis in BPH stromal cells, measured by flow cytometry. The cells were grown in charcoal stripped serum and treated with DHT (100 µmol/L) for 72 h. Each experiment used duplicates for each treatment. Each point represents the mean ± SD of 4 or more experiments.

Concurrent treatment with mevalonate (30 µmol/L) or geranyl geraniol (30 µmol/L), but not farnesol (3 µmol/L), squalene (30 µmol/L), or 7-ketocholesterol (3 µmol/L) prevented lovastatin-induced apoptosis, as shown by the absence of a DNA ladder. This was confirmed by flow cytometry (Fig. 7). Lower concentrations of geranyl geraniol (3 µmol/L) reduced but did not abolish apoptosis. Higher concentrations of farnesol (10 and 30 µmol/L), squalene (100 µmol/L), and 7-ketocholesterol (30 µmol/L) proved toxic to the cells.

View larger version (19K): [in this window] [in a new window]   Figure 7. The effect of cholesterol pathway intermediary metabolites on lovastatin-induced (30 µmol/L) apoptosis, measured by flow cytometry. The cells were treated with the metabolite shown for 72 h. All experiments were done in duplicate. Each point represents the mean ± SD of 4 or more experiments.

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion References

Lovastatin can reduce cell number by inducing apoptosis and/or by arresting cells in the G1 phase of the cell cycle, but the effects we observed are primarily on apoptosis. Confluent cells stop dividing because of contact inhibition and, untreated, show minimal evidence of proliferation or cell death. Using confluent cells simulates the situation in the human prostate, where stromal cells divide infrequently and have long life spans. Lovastatin has been shown to arrest cells in the GI phase of the cell cycle, thereby inhibiting cell proliferation. Lovastatin inhibits metastasis of mouse melanoma cells (15) and growth of pancreatic adenocarcinoma (16). Simvastatin, when combined with carmustine, shows a dose-related retardation of tumor growth in rats inoculated with G6 astrocytoma cell line (17). Mevalonate is essential for post-translational modification of p21-ras and for overcoming lovastatin-induced cell cycle synchronization in G1 phase (18, 19). Mevalonate and farnesol, but not cholesterol, reverse lovastatin-induced inhibition of human vascular smooth muscle cell proliferation (20). Similarly, simvastatin or fluvastatin inhibits the proliferation of cultured rat vascular smooth muscle cells; this effect was completely abolished by mevalonate, but only partially reduced by geranyl geraniol and farnesol and not affected by squalene (21). These studies indicate that lovastatin may inhibit cell division by the depletion of isoprene intermediary substances.

The delay in induction of apoptosis may be lovastatin’s needing to be converted to the active form, or to the time required to deplete preformed cholesterol pathway intermediary substances. Earlier detection of apoptosis may be limited by available techniques. Lovastatin induces apoptosis in a number of human cell lines, including prostate cancer cells (PC3-M-3) (9), malignant glioma cells (22), and promyelocytic HL-60 cells (23). In the latter, lovastatin-induced apoptosis is unaffected by cholesterol but can be prevented by mevalonate. The inhibition of apoptosis by mevalonate and geranyl geraniol but not by farnesol, squalene, or 7-keto cholesterol is in keeping with the observation that lovastatin-induced apoptosis is not due to a deficiency of cholesterol. The intermediary substances farnesyl and geranyl pyrophosphate are necessary for the isoprenyletion (by the enzymes geranyl and farnesyl-protein transferase) of a number of membrane-bound proteins, including cellular ras, nuclear lamins, and ras-related proteins (24). It is likely that the effects of lovastatin on cell cycle and apoptosis are mediated by the inability to isoprenalyte critical proteins required for cell cycle regulation and other vital functions such as the maintenance of membrane integrity.

Lovastatin-induced apoptosis was not enhanced by finasteride or by growing cells in charcoal-stripped serum. It appears that androgen withdrawal did not induce or sensitize the cells to the apoptotic effects of lovastatin, nor did the addition of saturating concentrations of DHT inhibit apoptosis. Fetal and adult prostate fibroblasts are known to have nuclear androgen receptors, and cell proliferation may be increased by androgen (25) during early passages. In man, finasteride treatment causes some apoptosis of the prostate epithelial but not the stromal cells (7).

In summary, lovastatin induces apoptosis in cultured prostate stromal cells from normal or BPH tissues. This most likely results from depletion of geranyl pyrophosphate and a deficiency of isoprenylated membrane proteins. Lovastatin-induced apoptosis of BPH stromal cells provides a good model for studying mechanisms of apoptosis in these cells. Selective intervention at some point in this cascade to promote apoptosis confined to the prostate may have therapeutic potential for the treatment of BPH.

Received November 5, 1996.

Accepted February 13, 1997.

	References

Top Abstract Introduction Materials and Methods Results Discussion References

 

1. Guess HA, Arrighi HM, Metter EJ, Fozard JL. 1990 Cumulative prevalence of prostatism matches the autopsy prevalence of benign prostatic hyperplasia. Prostate. 17:241–246.[Medline]
2. Carter HB, Coffey DS. 1990 The prostate: an increasing medical problem. Prostate. 16:39–48.[Medline]
3. Gormley GJ, Stoner E, Bruskewitz, et al. 1992 The effect of finasteride in men with benign prostatic hyperplasia. The Finasteride Study Group. N Engl J Med. 327:1185–1191.[Abstract]
4. Eri LM, Tveter KJ. 1993 A prospective, placebo-controlled study of the luteinizing hormone-releasing hormone agonist leuprolide as treatment for patients with benign prostatic hyperplasia. J Urol. 150:359–364.[Medline]
5. Stone NN, Clejan SJ. 1991 Response of prostate volume, prostate specific antigen, and testosterone to flutamide in men with benign prostatic hyperplasia. J Androl. 12:376–380.[Abstract/Free Full Text]
6. Geller L, Sionit L. 1992 Castration-like effects on the human prostate of a 5 -reductase inhibitor, finasteride. J Cell Biochem Suppl. 16H:109–112.
7. Rittmaster RS, Norman RW, Thomas LN, Rowden G. 1996 Evidence for atrophy and apoptosis in the prostates of men given finasteride. J Clin Endocrinol Metab. 81:814–819.[Abstract]
8. Tunn S, Nass R, Ekkernkamp A, Schulze H, Krieg M. 1989 Evaluation of average life span of epithelial and stromal cells of human prostate by superoxide dismutase activity. Prostate. 15:263–271.[Medline]
9. Borner MM, Myers CE, Sartor O, et al. 1995 Drug-induced apoptosis is not necessarily dependent on macromolecular synthesis or proliferation in the p53-negative human prostate cancer cell line PC-3. Cancer Res. 55:2122–2128.[Abstract/Free Full Text]
10. Mayes PA. 1988 Cholesterol synthesis, transport and excretion. In: Murray RK, Granner DK, Mayes PA, Rodwell VW, eds. Harpers biochemistry. 21st ed. East Norwalk, CT: Lange Medical Publications; 241–252.
11. Shao TC, Kong A, Cunningham GR. Effects of insulin and dihydrotestosterone on proliferation of BPH fibroblasts. Proceedings of the 76th Annual Meeting of The Endocrine Society, Annaheim, CA, 1994, p.557 (Abstract).
12. Wyllie AH. 1980 Glucocorticoid-induced thymocyte apoptosis is associated with endogenous endonuclease activation. Nature. 284:555–556.[CrossRef][Medline]
13. Abrams JM, White K, Fessler LI, Steller H. 1993 Programmed cell death during Drosophila embryogenesis. Development. 117:29–43.[Abstract/Free Full Text]
14. Gorczyca W, Gong J, Darzynkiewicz Z. 1993 Detection of DNA strand breaks in individual apoptotic cells by the in situ terminal deoxynucelotidyl transferase and nick translation assays. Cancer Res. 53:1945–1951.[Abstract/Free Full Text]
15. Jani JP, Specht S, Stemmler N, et al. 1993 Metastasis of B16F10 mouse melanoma inhibited by lovastatin, an inhibitor of cholesterol biosynthesis. Invasion Metastasis. 13:314–324.[Medline]
16. Sumi S, Beauchamp RD, Townsend Jr CM, et al. 1992 Inhibition of pancreatic adenocarcinoma cell growth by lovastatin. Gastroenterology. 103:982–989.[Medline]
17. Soma MR, Baetta R, De Renzis MR, et al. 1995 In vivo enhanced antitumor activity of carmustine [N, N'-Bis(2-chloroethyl)-N-nitrosourea] by simvastatin. Cancer Res. 33:597–602.
18. Keyomarsi K, Sandoval L, Band V, Pardee AB. 1991 Synchronization of tumor and normal cells from G1 to multiple cell cycles by lovastatin. Cancer Res. 51:3602–2609.[Abstract/Free Full Text]
19. Jakobisiak M, Bruno S, Skierski JS, Darzynkiewicz Z. 1991 Cell cycle-specific effects of lovastatin. Proc Natl Acad Sci USA. 88:3628–3632.[Abstract/Free Full Text]
20. Munro E, Patel M, Chan P, et al. 1994 Inhibition of human vascular smooth muscle cell proliferation by lovastatin: the role of isoprenoid intermediates of cholesterol synthesis. Eur J Clin Invest. 24:766–772 .[Medline]
21. Corsini A, Mazzotti M, Raiteri M, et al. 1993 Relationship between mevalonate pathway and arterial myocyte proliferation: in vitro studies with inhibitors of HMG-CoA reductase. Atherosclerosis. 101:117–125.[CrossRef][Medline]
22. Jones KD, Couldwell WT, Hinton DR, et al. 1994 Lovastatin induces growth inhibition and apoptosis in human malignant glioma cells. Biochem Biophys Res Commun. 205:1681–1687.[CrossRef][Medline]
23. P’erez-Sala D, Mollinedo F. 1994 Inhibition of isoprenoid biosynthesis induces apoptosis in human promyelocytic HL-60 cells. Biochem Biophys Res Commun. l99:l209–12l5.
24. Gibbs JB, Oliff A, Kohl NE. 1994 Farnesyltransferase inhibitors: Ras research yields a potential cancer therapeutic. Cell. 77:175–178.[CrossRef][Medline]
25. Levine AC, Ren M, Huber GK, Kirschenbaum A. 1992 The effect of androgen, estrogen, and growth factors on the proliferation of cultured fibroblasts derived from human fetal and adult prostates. Endocrinology. 130:2413–2419.[Abstract/Free Full Text]

This article has been cited by other articles:

				E. D. Flick, L. A. Habel, K. A. Chan, S. K. Van Den Eeden, V. P. Quinn, R. Haque, E. J. Orav, J. D. Seeger, M. C. Sadler, C. P. Quesenberry Jr., et al. Statin Use and Risk of Prostate Cancer in the California Men's Health Study Cohort Cancer Epidemiol. Biomarkers Prev., November 1, 2007; 16(11): 2218 - 2225. [Abstract] [Full Text] [PDF]

				M.-A. Shibata, Y. Ito, J. Morimoto, and Y. Otsuki Lovastatin inhibits tumor growth and lung metastasis in mouse mammary carcinoma model: a p53-independent mitochondrial-mediated apoptotic mechanism Carcinogenesis, October 1, 2004; 25(10): 1887 - 1898. [Abstract] [Full Text] [PDF]

				K. W. Siddals, E. Marshman, M. Westwood, and J. M. Gibson Abrogation of Insulin-like Growth Factor-I (IGF-I) and Insulin Action by Mevalonic Acid Depletion: SYNERGY BETWEEN PROTEIN PRENYLATION AND RECEPTOR GLYCOSYLATION PATHWAYS J. Biol. Chem., September 10, 2004; 279(37): 38353 - 38359. [Abstract] [Full Text] [PDF]

				M.-A. Shibata, C. Kavanaugh, E. Shibata, H. Abe, P. Nguyen, Y. Otsuki, J. B. Trepel, and J. E. Green Comparative effects of lovastatin on mammary and prostate oncogenesis in transgenic mouse models Carcinogenesis, March 1, 2003; 24(3): 453 - 459. [Abstract] [Full Text] [PDF]

				R. A. Zager, V. O. Shah, H. V. Shah, P. G. Zager, A. C. M. Johnson, and S. Hanson The Mevalonate Pathway during Acute Tubular Injury : Selected Determinants and Consequences Am. J. Pathol., August 1, 2002; 161(2): 681 - 692. [Abstract] [Full Text] [PDF]

				B. Agarwal, B. Halmos, A. S. Feoktistov, P. Protiva, W. G. Ramey, M. Chen, C. Pothoulakis, J.T. Lamont, and P. R. Holt Mechanism of lovastatin-induced apoptosis in intestinal epithelial cells Carcinogenesis, March 1, 2002; 23(3): 521 - 528. [Abstract] [Full Text] [PDF]

				W. W.-L. Wong, M. M. Tan, Z. Xia, J. Dimitroulakos, M. D. Minden, and L. Z. Penn Cerivastatin Triggers Tumor-specific Apoptosis with Higher Efficacy than Lovastatin Clin. Cancer Res., July 1, 2001; 7(7): 2067 - 2075. [Abstract] [Full Text] [PDF]

				T. Tanaka, I. Tatsuno, D. Uchida, I. Moroo, H. Morio, S. Nakamura, Y. Noguchi, T. Yasuda, M. Kitagawa, Y. Saito, et al. Geranylgeranyl-Pyrophosphate, an Isoprenoid of Mevalonate Cascade, Is a Critical Compound for Rat Primary Cultured Cortical Neurons to Protect the Cell Death Induced by 3-Hydroxy-3-Methylglutaryl-CoA Reductase Inhibition J. Neurosci., April 15, 2000; 20(8): 2852 - 2859. [Abstract] [Full Text] [PDF]

				B. Agarwal, S. Bhendwal, B. Halmos, S. F. Moss, W. G. Ramey, and P. R. Holt Lovastatin Augments Apoptosis Induced by Chemotherapeutic Agents in Colon Cancer Cells Clin. Cancer Res., August 1, 1999; 5(8): 2223 - 2229. [Abstract] [Full Text] [PDF]

				M. Vitale, T. Di Matola, G. Rossi, C. Laezza, G. Fenzi, and M. Bifulco Prenyltransferase Inhibitors Induce Apoptosis in Proliferating Thyroid Cells through a p53-Independent, CrmA-Sensitive, and Caspase-3-Like Protease- Dependent Mechanism Endocrinology, February 1, 1999; 140(2): 698 - 704. [Abstract] [Full Text]

				A. TAN, H. LEVREY, C. DAHM, V. A. POLUNOVSKY, J. RUBINS, and P. B. BITTERMAN Lovastatin Induces Fibroblast Apoptosis In Vitro and In Vivo . A Possible Therapy for Fibroproliferative Disorders Am. J. Respir. Crit. Care Med., January 1, 1999; 159(1): 220 - 227. [Abstract] [Full Text]

				F. P. Coxon, H. L. Benford, R. G. G. Russell, and M. J. Rogers Protein Synthesis Is Required for Caspase Activation and Induction of Apoptosis by Bisphosphonate Drugs Mol. Pharmacol., October 1, 1998; 54(4): 631 - 638. [Abstract] [Full Text]

This Article Abstract Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Padayatty, S. J. Articles by Cunningham, G. R. Search for Related Content PubMed PubMed Citation Articles by Padayatty, S. J. Articles by Cunningham, G. R.