![]() |
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CELLULAR AND MOLECULAR
Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
Received July 28, 2006; accepted November 28, 2006.
| Abstract |
|---|
|
|
|---|
|
signaling pathways, and up-regulation of proapoptotic BCL-2-related proteins (Stayrook et al., 1997
Regulation of the mammalian cell cycle involves coordination of DNA replication with the physical act of mitosis. Essential cell cycle regulatory events involve a family of serine/threonine kinases, the cyclin-dependent kinases (Cdks), in association with their regulatory subunits (cyclins) and other activating and/or inhibiting cofactors (Meyerson et al., 1992
). Mitogenic stimulation of a cell induces it to progress through the G1 phase through the kinase activities of Cdk4 and/or Cdk6 in association with the D-type cyclins (Sherr, 1994
). The transition from G1 to S phase is mediated in part by the up-regulation and activation of Cdk2 initially associated with cyclin E and, later, the A-type cyclins. One well characterized target of cyclin E-Cdk2 kinase activity is the phosphorylation of histone H1 proteins (Arion et al., 1988
), resulting in relaxation of the chromosome protein scaffolding structure and facilitating access to DNA for replication purposes. However, this process may be interrupted in apparent stoichiometric fashion by an increased level of cyclin kinase inhibitor (CKI) proteins. Cells with elevated CKI expression typically arrest in G1 phase and/or undergo apoptosis. The two canonical CKI protein families include the INK4 and the Cip/Kip families of proteins (Sherr and Roberts, 1999
). Both families are classified as tumor suppressor families because inactivation of the corresponding genes is associated with increased risk of many forms of cancer and diminished prognosis during treatment (Bahuau et al., 1998
; Arcellana-Panlilio et al., 2002
). Unlike the Cip/Kip family, however, members of the INK4 family, and especially that of p16INK4a, are typically not functional in pancreatic adenocarcinomas due to either inactivating mutation or deletion (Ghiorzo et al., 2004
).
In this study, we demonstrate that perillyl alcohol, farnesol, and geraniol share a similar mechanism of action in human pancreatic adenocarcinoma cells. In keeping with their known cancer chemopreventive and chemotherapeutic activities, these isoprenoids cause arrest in G0/G1 phase of the cell cycle through induction of cyclin kinase inhibitors p21Cip1 and p27Kip1, resulting in a reduction in Cdk2 activity and decreased expression of downstream cell cycle-related proteins.
| Materials and Methods |
|---|
|
|
|---|
Cell Culture and Proliferation Assay. The human pancreatic ductal adenocarcinoma cell lines MIA PaCa-2 (CRL-1420) and BxPC-3 (CRL-1687) were purchased from the American Type Culture Collection (Manassas, VA). Cells were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum, 100 U/ml penicillin, 100 µg/ml streptomycin, and 2 mM L-glutamine (Invitrogen, Carlsbad, CA) at 37°C in 95% humidified air and 5% CO2. Cells used in experimentation were between passages 5 (post-American Type Culture Collection) and 20. One day before analysis of cell proliferation, MIA PaCa-2 and BxPC-3 cells were plated into six-well (10 cm2) culture plates in triplicate at a density of 5 x 105 cells/well. Cells were either untreated or treated with various concentrations of perillyl alcohol, farnesol, or geraniol. At the start of treatment (0 h) and at 24 h, the cells were trypsinized, sedimented by centrifugation, resuspended in phosphate-buffered saline (PBS, pH 7.4), diluted 1:200 (v/v) in Isoton II (Beckman Coulter, Miami, FL), and counted with a Coulter Z1 optical cell counter.
Cell Cycle Analysis. Cells were trypsinized, washed with ice-cold PBS, and resuspended in 2 ml of Vindelov's propidium iodide (0.01 M Tris, pH 8.0, 10 mM NaCl, 700 U of RNase, 75 µM propidium iodide, 0.1% NP-40). Cells were incubated at room temperature for 15 min. DNA content was determined using a Coulter Epics Elite cell flow cytometer. Cell cycle distribution was analyzed using ModFit LT 1.0 (Verity Software House, Topsham, ME). Flow cytometric analysis used 20,000 events/sample, and gating was used to exclude cell aggregates.
Western Blot Analysis. Cells were trypsinized, pelleted, and washed twice in ice-cold PBS. Protein concentration was determined using the Bio-Rad Protein Assay (Bio-Rad, Hercules, CA), and samples were boiled for 5 min in sample buffer (62 mM Tris, pH 6.8, 2% SDS, 10% glycerol, and 5%
-mercaptoethanol) at a protein concentration of 2 µg/µl. Proteins were resolved on 12% SDS-polyacrylamide gel electrophoresis gels (Bio-Rad) at 30 µg/sample lane and transferred to a 0.45-mm polyvinylidene difluoride membrane (Bio-Rad). The membranes were blocked overnight in Tris-buffered saline with Tween 20 with 5% nonfat dry milk (NFDM) at 4°C with agitation and then allowed to equilibrate for 1 h at room temperature. The membranes were incubated for 2 h in primary antibody diluted 1:500 (1:1000 for
-actin) in 5% NFDM. This was followed by incubation with a secondary antibody (anti-mouse IgG, anti-rabbit IgG, or anti-goat IgG) conjugated with horseradish peroxidase (Calbiochem, La Jolla, CA) diluted 1:1000 in 5% NFDM. Proteins were visualized using Western Lightning chemiluminescent reagent (PerkinElmer Life and Analytical Sciences, Boston, MA) and X-OMAT AR Scientific Imaging Film (Eastman Kodak Co., Rochester, NY). Images were quantified using scanning densitometry (Bio-Rad).
Cdk2 Kinase Activity and Immunoprecipitation. Cell monolayers were washed twice with ice-cold PBS, and cells were scraped into ice-cold lysis buffer (PBS, pH 7.4, 1% NP-40; Calbiochem) containing Complete Mini protease inhibitors (Roche Diagnostics, Mannheim, Germany). Lysates were clarified by centrifugation at 13,000g for 15 min at 4°C. Cdk2 protein complexes were immunoprecipitated with 10 µl/ml extract of goat monoclonal anti-Cdk2 antibody (sc-163g; Santa Cruz Biotechnology) for 15 min with continuous agitation at 4°C, followed by incubation for 90 min with 15 µl of protein A/G-agarose (Oncogene Research Products, La Jolla, CA). Immunoprecipitates were recovered by centrifugation and washed twice with PBS + protease inhibitors and twice with kinase buffer (50 mM HEPES, pH 7.5, 10 mM MgCl2, 1 mM dithiothreitol, and Complete Mini protease inhibitors). After the final wash, pellets were resuspended in kinase buffer to a final volume of 30 µl. To this suspension, 5 µCi of [
-32P]ATP (GE Healthcare, Little Chalfont, Buckinghamshire, UK), 20 mM (final concentration) ice-cold ATP (Roche), and 2 µg of histone H1 protein (Roche Diagnostics) were added, and suspensions were incubated at 30°C for 30 min with agitation every 10 min. The kinase reaction was terminated by adding 5x sample buffer. Samples were then boiled for 5 min and resolved on a 12% SDS-polyacrylamide gel electrophoresis gel (Bio-Rad). Incorporation of 32P onto histone H1 was quantified using a PhosphorImager with ImageQuant software (GE Healthcare). The data displayed are indicative of four independent experiments.
|
RNA Interference of p21Cip1 and p27Kip1. MIA PaCa-2 cells were plated in 24-well plates at a density of 1 x 105 cells/ml and incubated for 24 h in 0.5 ml of antibiotic-free DMEM. Media were then removed and exchanged for 100 µl of serum-free, antibiotic-free DMEM with either Lipofectamine 2000 (LF2000) alone or LF2000 in combination with 5 nM RNAi SmartPool (Dharmacon, Lafayette, CO) against p21Cip1, p27Kip1, a combination (5 nM total) of p21Cip1 and p27Kip1, or a mixture (5 nM total) of scrambled RNAi sequences matched for nucleotide content to the proprietary sequences of each SmartPool. After overnight incubation, LF2000 media were exchanged for antibiotic-free DMEM, and cells were allowed to incubate for an additional 24 h. At this time, three random samples of each 24-well plate were trypsinized and counted to determine cell population at beginning of therapy time course (time = 0 h). Remaining wells were randomly assigned to either control (normal DMEM) or isoprenoid (300 and 600 µM POH, 200 and 400 µM GOH, and 60 and 90 µM FOH) groups (n = 3). After 24 h of incubation, all samples were trypsinized, washed in PBS, counted, and analyzed by Western analysis for expression of p21Cip1 p27Kip1, and cyclin A as described previously.
| Results |
|---|
|
|
|---|
0.05) inhibition was achieved at all concentrations higher than 300 µM perillyl alcohol, 20 µM farnesol, and 200 µM geraniol, respectively, in MIA PaCa-2 cells (Fig. 2A), and 500 µM perillyl alcohol, 60 µM farnesol, and 400 µM geraniol, respectively, in BxPC-3 cells (Fig. 2B). Simultaneous Combination of Isoprenoids Results in an Additive Antiproliferative Effect. To begin to test whether the isoprenoids had similar or different mechanisms of action, we performed cell proliferation assays with isoprenoid drug combinations, assuming that combinations of compounds with similar mechanisms would be additive in nature. With all isoprenoid combinations, exposure to two drugs at low concentration resulted in an antiproliferative effect equal to that of the single-agent in higher concentration (Fig. 2C), suggesting that the isoprenoid combinatorial effects were additive in nature.
Perillyl Alcohol, Farnesol, and Geraniol Arrest Pancreatic Cancer Cells in G1 Phase of the Cell Cycle. Based on our prior observation that perillyl alcohol and farnesol decrease DNA replication in pancreatic epithelial cells (Burke et al., 2002
), we tested the hypotheses that isoprenoid-induced inhibition of pancreatic cancer proliferation would inhibit G1 to S phase progression through the cell cycle. Therefore, we analyzed MIA PaCa-2 cell-cycle phase distribution using propidium iodide staining and flow-cytometric analysis after a 24-h exposure to varying doses of each isoprenoid. Isoprenoid-treated pancreatic cancer cells exhibited dose-dependent increases in the percentage of cells in the G0/G1 phase of the cell cycle and decreases in the percentage of cells present in either S or G2/M phases (Figs. 3, A and B).
|
-actin protein level by Western blot analysis. Treatment of human pancreatic adenocarcinoma cells with perillyl alcohol, farnesol, or geraniol resulted in significant increases in the expression of the cyclin-dependent kinase inhibitor proteins p21Cip1 and p27Kip1 as well as reductions in the levels of cyclin A, cyclin B1, and cdk2 (Fig. 4). In addition, farnesol and geraniol reduced cyclin D1 protein levels in MIA PaCa-2 cells but not in BxPC-3 cells, and POH exposure resulted in increased cyclin D1 expression in both cell lines. There were no significant observed effects of the isoprenoids on cyclin E and p57Kip2 protein expression.
|
Increased Association of Cyclin-Dependent Kinase Inhibitor Proteins p21Cip1 and p27Kip1 with Cdk2 following Isoprenoid Treatment. Because isoprenoids increased the expression of p21Cip1 and p27Kip1 CKI proteins, we hypothesized that the increases in CKI protein concentration would result in greater CKI association with cell cycle-promoting kinases such as Cdk2. Indeed, we found that, in the presence of perillyl alcohol, farnesol, or geraniol, significantly greater amounts of p21Cip1 and p27Kip1 coimmunoprecipitated with Cdk2 protein in situ (Fig. 5).
|
|
RNA Interference of p21Cip1 and p27Kip1 Causes Conditional Resistance to Isoprenoids in MIA PaCa-2 Cells. Given the previous data, we hypothesized that human pancreatic cancer cells could be rescued from the antiproliferative effects of perillyl alcohol, farnesol, and geraniol through reduction of intracellular protein concentrations of p21Cip1 and p27Kip1. Using commercially available small interfering RNA "pools," significant reductions in both proteins were achieved. However, it was important during this study not to completely eliminate the expression of either protein from the cells because it has been shown that basal levels of p21Cip1 and p27Kip1 are required for proper assembly of promitogenic cyclin-cdk complexes (Cheng et al., 1999
; Sherr and Roberts, 1999
). Therefore, we used RNAi concentrations that significantly reduced but did not entirely eliminate p21Cip1 and p27Kip1 protein expression (Fig. 7). In the presence of perillyl alcohol, farnesol, or geraniol, simultaneous RNA interference of p21Cip1 and p27Kip1 CKI proteins resulted in significant protection from the isoprenoid antiproliferative effect (Fig. 7), whereas no such protection occurred in untransfected, single-gene, or scrambled RNAi-treated cells. Thus, p21Cip1 and p27Kip1 serve complimentary roles as inhibitors of cell-cycle progression in pancreatic cancer cells treated with the isoprenoids perillyl alcohol, farnesol, or geraniol.
|
| Discussion |
|---|
|
|
|---|
In this study, we observed that perillyl alcohol, farnesol, and geraniol caused dose-dependent decreases in cyclins A and B1, and Cdk2 protein levels in pancreatic adenocarcinoma cells, consistent with their ability to arrest the cell cycle in the G1 phase. After mitogenic induction, cells arise from a quiescent G0 phase, entering G1 phase typically with an increase in protein levels of the D-type cyclins, Cdk4 and Cdk6. It is believed that the resulting Cdk4-cyclin D and Cdk6-cyclin D holoenzyme complexes assemble and function to promote cell-cycle progression. These complexes translocate to the nucleus, are phosphorylated by a CDK-activating kinase, and become catalytically active, phosphorylating serine and threonine residues on target proteins, including the transcriptional repressor and tumor suppressor protein Rb (Chen et al., 1989
). Once phosphorylated, Rb disassociates from its binding partners, including the E2F transcription factor, which is now free to activate transcription of genes necessary for DNA synthesis. The genes for cyclins E and A are both believed to be regulated by E2F (Nevins et al., 1991
). A second proposed function of the cyclin D-Cdk4/6 complexes is the sequestration of CKIs, including gp21Cip1 and p27Kip1, from binding to and inhibiting cyclin E-Cdk2 and cyclin A-Cdk4 complexes (Sherr and Roberts, 1999
). Furthermore, it is proposed that these CKIs act as a "biological rheostat" in that any signal that causes a net protein concentration increase of p21Cip1 and p27Kip1 allows them to overwhelm the sequestration function of cyclin D-Cdk4/6; thus, unsequestered p21Cip1 and p27Kip1 are free to inhibit the Cdk2 complexes, ultimately halting the progression of the cell cycle. Significant effects on the protein level, CKI association, and kinase activity of Cdk2 were observed after isoprenoid treatment, whereas preliminary experiments indicated that the isoprenoids did not affect Cdk4 and Cdk6. The isoprenoid-induced increases in p21Cip1 and p27Kip1 proteins associating with Cdk2, the decreased kinase activity of Cdk2, and the attenuation of the isoprenoid antiproliferative effects in the presence of p21Cip1 and p27Kip1 siRNAs argue for a p21Cip1- and p27Kip1-dependent isoprenoid mechanism in pancreatic adenocarcinoma cells. In addition to the data presented here, similar G1 arrest has been noted in colorectal and mammary carcinoma cell lines treated with perillyl alcohol (Karlson et al., 1996
; Reddy et al., 1997
; Bardon et al., 1998
; Ariazi et al., 1999
; Shi and Gould, 2002
). As such, it is increasingly clear that one of the primary in vitro mechanisms of action of perillyl alcohol, farnesol, and geraniol is inducing cell-cycle arrest in the G0/G1 phase.
The mechanisms by which perillyl alcohol, farnesol, and geraniol induce p21Cip1 and p27Kip1 protein expression in pancreatic cancer cells is not currently known and will be the subject of future investigation. Also not known are the reasons behind the differences in potency of these three compounds. As such, several possibilities exist, including differences in binding efficiency to an as-of-yet unidentified isoprenoid receptor or that perhaps farnesol can interact with a greater number of receptors than do geraniol or perillyl alcohol. Farnesoid receptors, of which farnesol is one identified ligand, have been identified and characterized (Kozak et al., 1996), but it is not known whether geraniol and/or perillyl alcohol are ligands for this receptor. Our finding that perillyl alcohol was the only isoprenoid of the three we studied that did not down-regulate cyclin D1 expression in MIA PaCa-2 cells argues for the possibility that differing abilities to modulate cell cycle-associated proteins as an explanation. However, in BxPC-3 cells, both perillyl alcohol and geraniol exposure caused increased cyclin D1 protein expression, with no apparent difference in antiproliferative potency relative to MIA PaCa-2 cells.
In summary, the data presented here strongly suggest that isoprenoids, as well as other pharmacological agents that induce p21Cip1 and p27Kip1 expression, may have chemother-apeutic activity toward pancreatic cancer. This CKI induction could be used in the screening and development of more potent isoprenoid or other compounds for the chemotherapy of pancreatic cancer, which remains recalcitrant to available systemic therapies.
| Footnotes |
|---|
Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
ABBREVIATIONS: POH, perillyl alcohol; GOH, geraniol; FOH, farnesol; Cdk, cyclin-dependent kinase; CKI, cyclin kinase inhibitor; DMEM, Dulbecco's modified Eagle's medium; PBS, phosphate-buffered saline; NFDM, nonfat dry milk.
Address correspondence to: Dr. Pamela L. Crowell, Department of Biology, Indiana University-Purdue University Indianapolis, 723 West Michigan Street, SL306, Indianapolis, IN 46202-5132. E-mail: pcrowel{at}iupui.edu
| References |
|---|
|
|
|---|
Arcellana-Panlilio MY, Egeler RM, Ujack E, Magliocco A, Stuart GC, Robbins SM, and Coppes MJ (2002) Evidence of a role for the INK4 family of cyclin-dependent kinase inhibitors in ovarian granulosa cell tumors. Genes Chromosomes Cancer 35: 176-181.[CrossRef][Medline]
Ariazi EA, Satomi Y, Ellis MJ, Haag JD, Shi W, Sattler CA, and Gould MN (1999) Activation of the transforming growth factor beta signaling pathway and induction of cytostasis and apoptosis in mammary carcinomas treated with the anticancer agent perillyl alcohol. Cancer Res 59: 1917-1928.
Arion D, Meijer L, Brizuela L, and Beach D (1988) cdc2 is a component of the M phase-specific histone H1 kinase: evidence for identity with MPF. Cell 55: 371-378.[CrossRef][Medline]
Azzoli CG, Miller VA, Ng KK, Krug LM, Spriggs DR, Tong WP, Riedel ER, and Kris MG (2003) A phase I trial of perillyl alcohol in patients with advanced solid tumors. Cancer Chemother Pharmacol 51: 493-498.[Medline]
Bahuau M, Vidaud D, Jenkins RB, Bieche I, Kimmel DW, Assouline B, Smith JS, Alderete B, Cayuela JM, Harpey JP, et al. (1998) Germ-line deletion involving the INK4 locus in familial proneness to melanoma and nervous system tumors. Cancer Res 58: 2298-2303.
Bailey HH, Levy D, Harris LS, Schink JC, Foss F, Beatty P, and Wadler S (2002) A phase II trial of daily perillyl alcohol in patients with advanced ovarian cancer: Eastern Cooperative Oncology Group Study E2E96. Gynecol Oncol 85: 464-468.[CrossRef][Medline]
Bardon S, Picard K, and Martel P (1998) Monoterpenes inhibit cell growth, cell cycle progression, and cyclin D1 gene expression in human breast cancer cell lines. Nutr Cancer 32: 1-7.[Medline]
Burke YD, Ayoubi AS, Werner SR, McFarland BC, Heilman DK, Ruggeri BA, and Crowell PL (2002) Effects of the isoprenoids perillyl alcohol and farnesol on apoptosis biomarkers in pancreatic cancer chemoprevention. Anticancer Res 22: 3127-3134.[Medline]
Carnesecchi S, Bradaia A, Fischer B, Coelho D, Scholler-Guinard M, Gosse F, and Raul F (2002) Perturbation by geraniol of cell membrane permeability and signal transduction pathways in human colon cancer cells. J Pharmacol Exp Ther 303: 711-715.
Carnesecchi S, Schneider Y, Ceraline J, Duranton B, Gosse F, Seiler N, and Raul F (2001) Geraniol, a component of plant essential oils, inhibits growth and polyamine biosynthesis in human colon cancer cells. J Pharmacol Exp Ther 298: 197-200.
Chen PL, Scully P, Shew JY, Wang JY, and Lee WH (1989) Phosphorylation of the retinoblastoma gene product is modulated during the cell cycle and cellular differentiation. Cell 58: 1193-1198.[CrossRef][Medline]
Cheng M, Olivier P, Diehl JA, Fero M, Roussel MF, Roberts JM, and Sherr CJ (1999) The p21(Cip1) and p27(Kip1) CDK "inhibitors" are essential activators of cyclin D-dependent kinases in murine fibroblasts. EMBO (Eur Mol Biol Organ) J 18: 1571-1583.[CrossRef][Medline]
Clark SS, Perman SM, Sahin MB, Jenkins GJ, and Elegbede JA (2002) Antileukemia activity of perillyl alcohol (POH): uncoupling apoptosis from G0/G1 arrest suggests that the primary effect of POH on Bcr/Abl-transformed cells is to induce growth arrest. Leukemia 16: 213-222.[CrossRef][Medline]
Craig W (1999) Health promoting properties of common herbs. Am J Clin Nutr 70: 491S-499S.
Crowell PL (1999) Prevention and therapy of cancer by dietary monoterpenes. J Nutr 129: 775S-778S.
Crowell PL, Chang RR, Ren ZB, Elson CE, and Gould MN (1991) Selective inhibition of isoprenylation of 2126-kDa proteins by the anticarcinogen D-limonene and its metabolites. J Biol Chem 266: 17679-17685.
Elegbede JA, Flores R, and Wang RC (2003) Perillyl alcohol and perillaldehyde induced cell cycle arrest and cell death in BroTo and A549 cells cultured in vitro. Life Sci 73: 2831-2840.[CrossRef][Medline]
Elson CE and Yu SG (1994) The chemoprevention of cancer by mevalonate-derived constituents of fruits and vegetables. J Nutr 124: 607-614.
Ghiorzo P, Pastorino L, Bonelli L, Cusano R, Nicora A, Zupo S, Queirolo P, Sertoli M, Pugliese V, and Bianchi-Scarra G (2004) INK4/ARF germline alterations in pancreatic cancer patients. Ann Oncol 15: 70-78.
Haug JS, Goldner CM, Yazlovitskaya EM, Voziyan PA, and Melnykovych G (1994) Directed cell killing (apoptosis) in human lymphoblastoid cells incubated in the presence of farnesol: effect of phosphatidylcholine. Biochim Biophys Acta 1223: 133-140.[Medline]
Hudes GR, Szarka CE, Adams A, Ranganathan S, McCauley RA, Weiner LM, Langer CJ, Litwin S, Yeslow G, Halberr T, et al. (2000) Phase I pharmacokinetic trial of perillyl alcohol (NSC 641066) in patients with refractory solid malignancies. Clin Cancer Res 6: 3071-3080.
Karlson J, Borg-Karlson AK, Unelius R, Shoshan MC, Wilking N, Ringborg U, and Linder S (1996) Inhibition of tumor cell growth by monoterpenes in vitro: evidence of a Ras-independent mechanism of action. Anticancer Drugs 7: 422-429.[CrossRef][Medline]
Kozak CA, Adamson MC, and Weinberger C (2006) Genetic mapping of gene encoding the farnesoid receptor, Fxr, to mouse chromosome 10. Mamm Genome 7: 165-165.
Loutrari H, Hatziapostolou M, Skouridou V, Papadimitriou E, Roussos C, Kolisis FN, and Papapetropoulos A (2004) Perillyl alcohol is an angiogenesis inhibitor. J Pharmacol Exp Ther 311: 568-575.
Meyerson M, Enders GH, Wu CL, Su LK, Gorka C, Nelson C, Harlow E, and Tsai LH (1992) A family of human cdc2-related protein kinases. EMBO (Eur Mol Biol Organ) J 11: 2909-2917.[Medline]
Mills JJ, Chari RS, Boyer IJ, Gould MN, and Jirtle RL (1995) Induction of apoptosis in liver tumors by the monoterpene perillyl alcohol. Cancer Res 55: 979-983.
Miquel K, Pradines A, Terce F, Selmi S, and Favre G (1998) Competitive inhibition of choline phosphotransferase by geranylgeraniol and farnesol inhibits phosphatidylcholine synthesis and induces apoptosis in human lung adenocarcinoma A549 cells. J Biol Chem 273: 26179-26186.
Nevins JR, Chellappan SP, Mudryj M, Hiebert S, Devoto S, Horowitz J, Hunter T, and Pines J (1991) E2F transcription factor is a target for the RB protein and the cyclin A protein. Cold Spring Harb Symp Quant Biol 56: 157-162.[Medline]
Peffley DM and Gayen AK (2003) Plant-derived monoterpenes suppress hamster kidney cell 3-hydroxy-3-methylglutaryl coenzyme a reductase synthesis at the post-transcriptional level. J Nutr 133: 38-44.
Rajesh D and Howard SP (2003) Perillyl alcohol mediated radiosensitization via augmentation of the Fas pathway in prostate cancer cells. Prostate 57: 14-23.[CrossRef][Medline]
Reddy BS, Wang CX, Samaha H, Lubet R, Steele VE, Kelloff GJ, and Rao CV (1997) Chemoprevention of colon carcinogenesis by dietary perillyl alcohol. Cancer Res 57: 420-425.
Ren Z, Elson CE, and Gould MN (1997) Inhibition of type I and type II geranylgeranyl-protein transferases by the monoterpene perillyl alcohol in NIH3T3 cells. Biochem Pharmacol 54: 113-120.[CrossRef][Medline]
Ren Z and Gould MN (1994) Inhibition of ubiquinone and cholesterol synthesis by the monoterpene perillyl alcohol. Cancer Lett 76: 185-190.[CrossRef][Medline]
Rioja A, Pizzey AR, Marson CM, and Thomas NS (2000) Preferential induction of apoptosis of leukaemic cells by farnesol. FEBS Lett 467: 291-295.[CrossRef][Medline]
Samaila D, Toy BJ, Wang RC, and Elegbede JA (2004) Monoterpenes enhanced the sensitivity of head and neck cancer cells to radiation treatment in vitro. Anticancer Res 24: 3089-3095.[Medline]
Sherr CJ (1994) G1 phase progression: cycling on cue. Cell 79: 551-555.[CrossRef][Medline]
Sherr CJ and Roberts JM (1999) CDK inhibitors: positive and negative regulators of G1-phase progression. Genes Dev 13: 1501-1512.
Shi W and Gould MN (2002) Induction of cytostasis in mammary carcinoma cells treated with the anticancer agent perillyl alcohol. Carcinogenesis 23: 131-142.
Stayrook KR, McKinzie JH, Burke YD, Burke YA, and Crowell PL (1997) Induction of the apoptosis-promoting protein Bak by perillyl alcohol in pancreatic ductal adenocarcinoma relative to untransformed ductal epithelial cells. Carcinogenesis 18: 1655-1658.
Xu M, Floyd HS, Greth SM, Chang WC, Lohman K, Stoyanova R, Kucera GL, Kute TE, Willingham MC, and Miller MS (2004) Perillyl alcohol-mediated inhibition of lung cancer cell line proliferation: potential mechanisms for its chemotherapeutic effects. Toxicol Appl Pharmacol 195: 232-246.[CrossRef][Medline]
Yu SG, Hildebrandt LA, and Elson CE (1995) Geraniol, an inhibitor of mevalonate biosynthesis, suppresses the growth of hepatomas and melanomas transplanted to rats and mice. J Nutr 125: 2763-2767.
This article has been cited by other articles:
![]() |
J. H. Joo and A. M. Jetten NF-{kappa}B-dependent Transcriptional Activation in Lung Carcinoma Cells by Farnesol Involves p65/RelA(Ser276) Phosphorylation via the MEK-MSK1 Signaling Pathway J. Biol. Chem., June 13, 2008; 283(24): 16391 - 16399. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. H. Joo, G. Liao, J. B. Collins, S. F. Grissom, and A. M. Jetten Farnesol-Induced Apoptosis in Human Lung Carcinoma Cells Is Coupled to the Endoplasmic Reticulum Stress Response Cancer Res., August 15, 2007; 67(16): 7929 - 7936. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||