1
|
Wu D, Casey PJ. GPCR-Gα13 Involvement in Mitochondrial Function, Oxidative Stress, and Prostate Cancer. Int J Mol Sci 2024; 25:7162. [PMID: 39000269 PMCID: PMC11241654 DOI: 10.3390/ijms25137162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/20/2024] [Accepted: 06/26/2024] [Indexed: 07/16/2024] Open
Abstract
Gα13 and Gα12, encoded by the GNA13 and GNA12 genes, respectively, are members of the G12 family of Gα proteins that, along with their associated Gβγ subunits, mediate signaling from specific G protein-coupled receptors (GPCRs). Advanced prostate cancers have increased expression of GPCRs such as CXC Motif Chemokine Receptor 4 (CXCR4), lysophosphatidic acid receptor (LPAR), and protease activated receptor 1 (PAR-1). These GPCRs signal through either the G12 family, or through Gα13 exclusively, often in addition to other G proteins. The effect of Gα13 can be distinct from that of Gα12, and the role of Gα13 in prostate cancer initiation and progression is largely unexplored. The oncogenic effect of Gα13 on cell migration and invasion in prostate cancer has been characterized, but little is known about other biological processes such as mitochondrial function and oxidative stress. Current knowledge on the link between Gα13 and oxidative stress is based on animal studies in which GPCR-Gα13 signaling decreased superoxide levels, and the overexpression of constitutively active Gα13 promoted antioxidant gene activation. In human samples, mitochondrial superoxide dismutase 2 (SOD2) correlates with prostate cancer risk and prognostic Gleason grade. However, overexpression of SOD2 in prostate cancer cells yielded conflicting results on cell growth and survival under basal versus oxidative stress conditions. Hence, it is necessary to explore the effect of Gα13 on prostate cancer tumorigenesis, as well as the effect of Gα13 on SOD2 in prostate cancer cell growth under oxidative stress conditions.
Collapse
Affiliation(s)
- Di Wu
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore;
| | - Patrick J. Casey
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore;
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, 308 Research Drive, Durham, NC 27710, USA
| |
Collapse
|
2
|
Thamilselvan V, Menon M, Stein GS, Valeriote F, Thamilselvan S. Combination of Carmustine and Selenite Inhibits EGFR Mediated Growth Signaling in Androgen-Independent Prostate Cancer Cells. J Cell Biochem 2017; 118:4331-4340. [PMID: 28430389 DOI: 10.1002/jcb.26086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 01/21/2023]
Abstract
Although aberrant androgen receptor (AR) signaling is a central mechanism for castration resistant prostate cancer (CRPC) progression, AR-independent growth signaling is also present in CRPC. The current therapeutic options for patients with CRPC are limited and new drugs are desperately needed to eliminate these crucial growth signaling pathways. We have previously shown that combination of carmustine and selenite effectively induces apoptosis and growth inhibition by targeting AR and AR-variants in CRPC cells. High levels of EGFR expression present in the CRPC cells mediates the cell proliferation via AR-independent growth signaling mechanisms. Therefore, in this study, we investigated whether the combination of carmustine and selenite could inhibit EGFR mediated growth signaling and induce apoptosis in androgen independent-AR negative prostate cancer cells. EGF exposure dose and time dependently increased phospho-EGFR (Tyr845, Tyr1068, and Tyr1045), pAkt (Ser473), and pERK1/2 (Thr204/Tyr202) protein expression levels in AIPC cells. Combination of carmustine and selenite treatment markedly suppressed EGF-stimulated proliferation and survival of AIPC cells and effectively induced apoptosis. The ROS generated by the combination of carmustine and selenite exhibited a strong inhibition on EGF stimulated EGFR and its downstream signaling molecules such as Akt, NF-kB, ERK1/2, and Cyclin D1. Individual agent treatment showed only partial effect. Overall, our findings demonstrated that the combination of carmustine and selenite treatment dramatically inhibits EGFR signaling, proliferation, and induces apoptosis in AIPC cells, suggesting a potential candidate for the treatment of CRPC. The results of the study further suggest that the combination of carmustine and selenite treatment can overcome EGFR mediated AR-independent growth response in CRPC during anti-androgen therapy. J. Cell. Biochem. 118: 4331-4340, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | - Mani Menon
- Vattikuti Urology Institute, Henry Ford Health System, Detroit, Michigan 48202
| | - Gary S Stein
- University of Vermont Cancer Center and Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405
| | - Fred Valeriote
- Division of Hematology and Oncology, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan 48202
| | | |
Collapse
|
3
|
Ruscica M, Magni P, Steffani L, Gatto F, Albertelli M, Rametta R, Valenti L, Ameri P, Magnaghi V, Culler MD, Minuto F, Ferone D, Arvigo M. Characterization and sub-cellular localization of SS1R, SS2R, and SS5R in human late-stage prostate cancer cells: effect of mono- and bi-specific somatostatin analogs on cell growth. Mol Cell Endocrinol 2014; 382:860-70. [PMID: 24211300 DOI: 10.1016/j.mce.2013.10.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 10/24/2013] [Accepted: 10/24/2013] [Indexed: 01/10/2023]
Abstract
Somatostatin (SST) and SST receptors (SS1R, SS2R, SS3R, SS4R and SS5R) appear to play a significant role in the progression of human prostate cancer (PCa), which is associated with heterogeneity of SSRs expression and specific cell localization as we already demonstrated in the LNCaP cell line, an in vitro model of human androgen-dependent PCa. In this study, PC-3 and DU-145 human castration-resistant PCa cells were found to express all SSRs, while LNCaP expressed all but SS4R. A 48-h treatment with BIM-23244 (SS2R/SS5R) or BIM-23926 (SS1R) SST analogs was more effective in inhibiting cell proliferation, compared to BIM-23120 (SS2R), BIM-23206 (SS5R) and BIM-23704 (SS1R/SS2R). BIM-23926 (SS1R) treatment increased the amount of p21 and decreased phosphorylated (p) ERK1/2. BIM-23244 (SS2R/SS5R) led to p21 increment only in PC-3 cells, and to pERK1/2 reduction in both cell lines. SS1R/SS2R and SS2R/SS5R receptor dimers were natively present on cell membrane and their amount was increased by BIM-23704 (SS1R/SS2R) or BIM-23244 (SS2R/SS5R) treatment, respectively. SS1R, SS2R and SS5R were differently distributed among nuclear, lysosomal and microsomal compartment, according to their different recycling dynamics. These results show that, in PC-3, DU-145 and LNCaP cells, activation of SS1R and SS2R/SS5R leads to relevant antiproliferative effects.
Collapse
Affiliation(s)
- M Ruscica
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - P Magni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - L Steffani
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - F Gatto
- Department of Internal Medicine and Medical Specialities & Center of Excellence for Biomedical Research, IRCCS AOU San Martino-IST, Università di Genova, Italy
| | - M Albertelli
- Department of Internal Medicine and Medical Specialities & Center of Excellence for Biomedical Research, IRCCS AOU San Martino-IST, Università di Genova, Italy
| | - R Rametta
- Pathophysiology and Transplantation, Università degli Studi di Milano, UO Medicina Interna 1B, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Italy
| | - L Valenti
- Pathophysiology and Transplantation, Università degli Studi di Milano, UO Medicina Interna 1B, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Italy
| | - P Ameri
- Department of Internal Medicine and Medical Specialities & Center of Excellence for Biomedical Research, IRCCS AOU San Martino-IST, Università di Genova, Italy
| | - V Magnaghi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - M D Culler
- Biomeasure Incorporated/IPSEN, Milford, MA, USA
| | - F Minuto
- Department of Internal Medicine and Medical Specialities & Center of Excellence for Biomedical Research, IRCCS AOU San Martino-IST, Università di Genova, Italy
| | - D Ferone
- Department of Internal Medicine and Medical Specialities & Center of Excellence for Biomedical Research, IRCCS AOU San Martino-IST, Università di Genova, Italy.
| | - M Arvigo
- Department of Internal Medicine and Medical Specialities & Center of Excellence for Biomedical Research, IRCCS AOU San Martino-IST, Università di Genova, Italy
| |
Collapse
|
4
|
Abstract
BACKGROUND GPRC6A is a nutrient sensing GPCR that is activated in vitro by a variety of ligands, including amino acids, calcium, zinc, osteocalcin (OC), and testosterone. The association between nutritional factors and risk of prostate cancer, the finding of increased expression of OC in prostate cancer cells, and the association between GPRC6A and risk of prostate cancer in Japanese men implicates a role of GPRC6A in prostate cancer. METHODS We examined if GPRC6A is expressed in human prostate cancer cell lines and used siRNA-mediated knockdown GPRC6A expression in prostate cancer cells to explore the function of GPRC6A in vitro. To assess the role of GPRC6A in prostate cancer progression in vivo, we intercrossed Gprc6a(-/-) mice onto the TRAMP mouse prostate cancer model. RESULTS GPRC6A transcripts were markedly increased in prostate cancer cell lines 22Rv1, PC-3, and LNCaP, compared to the normal prostate RWPE-1 cell line. In addition, a panel of GPRC6A ligands, including calcium, OC, and arginine, exhibited in prostate cancer cell lines a dose-dependent stimulation of ERK activity, cell proliferation, chemotaxis, and prostate specific antigen and Runx2 gene expression. These responses were inhibited by siRNA-mediated knockdown of GPRC6A. Finally, transfer of Gprc6a deficiency onto a TRAMP mouse model of prostate cancer significantly retarded prostate cancer progression and improved survival of compound Gprc6a(-/-) /TRAMP mice. CONCLUSIONS GPRC6A is a novel molecular target for regulating prostate growth and cancer progression. Increments in GPRC6A may augment the ability of prostate cancer cells to proliferate in response to dietary and bone derived ligands.
Collapse
Affiliation(s)
- Min Pi
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
| | | |
Collapse
|
5
|
Wijesinghe DS, Mayton EK, Mietla JA, Mukherjee A, Wu J, Fang X, Chalfant CE. Characterization of lysophosphatidic acid subspecies produced by autotaxin using a modified HPLC ESI-MS/MS method. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2011; 3:2822-2828. [PMID: 24648853 PMCID: PMC3956132 DOI: 10.1039/c1ay05459g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Lysophosphatidic acid (LPA) is a bioactive lipid with a plethora of biological functions including roles in cell survival, proliferation, and migration. Although high-performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC ESI-MS/MS) technology has been used to measure the levels of LPA in human blood, serum and plasma, current methods cannot readily detect the minute levels of LPA from cell culture. In this study, a modified HPLC ESI-MS/MS method with enhanced sensitivity was developed, which allows accurate measurements of LPA levels with a limit of quantitation at approximately 10 femtomoles. The method was validated by quantitation of LPA levels in the media of previously characterized cell lines ectopically expressing autotaxin. Specifically, autotaxin overexpression induced an increase in the 16:0, 18:2, 18:1, 18:0, and 20:4 subspecies of LPA, but not the 22:6 LPA subspecies. Lastly, this HPLC ESI-MS/MS method was cross-validated via biological assays previously utilized to assay LPA levels. Hence, this HPLC ESI-MS/MS method will allow researchers to measure in vitro LPA levels and also distinguish between specific LPA subspecies for the delineation of individual biological mechanisms.
Collapse
Affiliation(s)
- Dayanjan S. Wijesinghe
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980614, Richmond, Virginia, 23298-0614
- Research and Development, Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, Virginia, 23249
| | - Eric K. Mayton
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980614, Richmond, Virginia, 23298-0614
| | - Jennifer A. Mietla
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980614, Richmond, Virginia, 23298-0614
| | - Abir Mukherjee
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980614, Richmond, Virginia, 23298-0614
| | - Jinhua Wu
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980614, Richmond, Virginia, 23298-0614
| | - Xianjun Fang
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980614, Richmond, Virginia, 23298-0614
- The Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, 23298
| | - Charles E. Chalfant
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980614, Richmond, Virginia, 23298-0614
- Research and Development, Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, Virginia, 23249
- The Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, 23298
| |
Collapse
|
6
|
Monteagudo S, Pérez-Martínez FC, Pérez-Carrión MD, Guerra J, Merino S, Sánchez-Verdú MP, Ceña V. Inhibition of p42 MAPK using a nonviral vector-delivered siRNA potentiates the anti-tumor effect of metformin in prostate cancer cells. Nanomedicine (Lond) 2011; 7:493-506. [PMID: 21995500 DOI: 10.2217/nnm.11.61] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
AIMS The aim of this work was to study if a G1-polyamidoamine dendrimer/siRNA dendriplex can remove the p42 MAPK protein in prostate cancer cells and to potentiate the anti-tumoral effect of the antidiabetic drug metformin and taxane docetaxel. MATERIAL & METHODS The dendriplex uptake was studied using flow cytometry analysis. Transfection efficiency was determined by measuring p42 MAPK mRNA and protein levels. Anti-tumoral effects were determined by measuring cellular proliferation and damage. RESULTS The dendriplex siRNA/G1-polyamidoamine dendrimer decreased both p42 MAPK mRNA and protein levels by more than 80%, which potentiates the anti-tumoral effects of metformin. CONCLUSION Blockade of the MAPK pathway using a dendrimer-vehiculized siRNA to block the MAPK signaling pathway in prostate cancer cells can potentiate the anti-tumoral activity of anticancer drugs, indicating that the combination of siRNA-mediated blockade of survival signals plus anti-tumoral therapy might be a useful approach for cancer therapy.
Collapse
|
7
|
Hsieh JT, Chen SC, Yu HJ, Chang HC. Finasteride upregulates expression of androgen receptor in hyperplastic prostate and LNCaP cells: implications for chemoprevention of prostate cancer. Prostate 2011; 71:1115-21. [PMID: 21557276 DOI: 10.1002/pros.21325] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 11/23/2010] [Indexed: 11/06/2022]
Abstract
BACKGROUND Although finasteride is recognized for its role as a chemopreventive agent for prostate cancer, higher grades of malignancy have been reported. It is questioned whether blocking of testosterone conversion to dihydrotestosterone (DHT) by finasteride in prostate tissue will change expression of androgen receptor (AR). Therefore, this study evaluated the effects of finasteride on AR expression in prostate tissue and in the LNCaP cell line. METHODS Between January and December 2006, we retrospectively selected and evaluated 47 cases of benign prostatic hyperplasia treated with variable duration of finasteride (5 mg QD) before transurethral resection of the prostate. AR expression in prostate tissue was semiquantified by immunostaining and compared with duration of finasteride treatment. An androgen-dependent prostate cancer cell line (LNCaP) was cultured in charcoal/dextran-treated FBS with DHT or testosterone, and treated with finasteride for 1-3 weeks. Samples of total RNA were collected to analyze expression of AR by real-time quantitative reverse transcription polymerase chain reaction. RESULTS Immunohistochemical study revealed significant upregulation of ARs by finasteride treatment for 30-180 days. In cell line study, quantitative real-time reverse transcription polymerase chain reaction revealed significant upregulation of ARs treated by finasteride. CONCLUSIONS In our study, finasteride influenced AR expression in benign prostate tissue and prostate cancer cell. Before we can use finasteride in chemoprevention with confidence, we still need to clarify the influence of finasteride in ARs and its regulation pathway.
Collapse
Affiliation(s)
- Ju-Ton Hsieh
- Department of Urology, National Taiwan University Hospital and National Taiwan University, College of Medicine, Taipei, Taiwan
| | | | | | | |
Collapse
|
8
|
Sekine Y, Suzuki K, Remaley AT. HDL and sphingosine-1-phosphate activate stat3 in prostate cancer DU145 cells via ERK1/2 and S1P receptors, and promote cell migration and invasion. Prostate 2011; 71:690-9. [PMID: 20979115 PMCID: PMC4159087 DOI: 10.1002/pros.21285] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 09/07/2010] [Indexed: 01/22/2023]
Abstract
BACKGROUND Androgen deprivation therapy in men with prostate cancer leads to a significant increase of high density lipoprotein (HDL), but the effect of HDL on prostate cancer is unknown. Recently, HDL, which transports sphingosine-1-phosphate (S1P), was reported to activate signal transducer and activator of transcription 3 (Stat3) in cardiomyocytes. In this study, we examined the effect of HDL and S1P on Stat3 activation in prostate cancer cells and the involvement of S1P receptors in this process in three prostate cancer cell lines (PC-3, LNCaP, and DU145). METHODS Discordial reconstituted(r) HDL containing POPC, apoA-1, and S1P were prepared by the cholate dialysis method. The phosphorylations of Stat3, ERK1/2, and Akt were detected by Western blotting. Cell migration and invasion were determined by wound-healing assay and matrigel invasion chamber assay. RESULTS HDL increased serine 727 phosphorylation of Stat3, but not tyrosine 705 only in DU145 cells. S1P and rHDL-S1P also induced the phosphorylation, but not rHDL without S1P. They also induced DU145 cells migration and invasion. PD98059, a MEK inhibitor, and pertussis toxin, a Gi inhibitor, attenuated HDL-, S1P-, and rHDL-S1P-induced Stat3 phosphorylation, whereas LY294002, a PI3K inhibitor, had no effect. Concerning S1P receptors, S1P1 expression was much lower than S1P2 and S1P3 in DU145 cells. Both JTE013, a S1P2 antagonist, and VPC23019, a S1P1/S1P3 antagonist, attenuated HDL-, S1P-, and rHDL-S1P-induced Stat3 phosphorylations and cell migrations. CONCLUSIONS These results suggest that the change in HDL plasma levels by androgen deprivation therapy may alter prostate cancer growth and metastasis.
Collapse
Affiliation(s)
- Yoshitaka Sekine
- Lipoprotein Metabolism Section, Pulmonary and Vascular Medicine Branch, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, USA.
| | | | | |
Collapse
|
9
|
Sekine Y, Demosky SJ, Stonik JA, Furuya Y, Koike H, Suzuki K, Remaley AT. High-density lipoprotein induces proliferation and migration of human prostate androgen-independent cancer cells by an ABCA1-dependent mechanism. Mol Cancer Res 2010; 8:1284-94. [PMID: 20671065 DOI: 10.1158/1541-7786.mcr-10-0008] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Androgen deprivation therapy for prostate cancer leads to a significant increase of high-density lipoprotein (HDL), which is generally viewed as beneficial, particularly for cardiovascular disease, but the effect of HDL on prostate cancer is unknown. In this study, we investigated the effect of HDL on prostate cancer cell proliferation, migration, intracellular cholesterol levels, and the role of cholesterol transporters, namely ABCA1, ABCG1, and SR-BI in these processes. HDL induced cell proliferation and migration of the androgen-independent PC-3 and DU145 cells by a mechanism involving extracellular signal-regulated kinase (ERK) 1/2 and Akt, but had no effect on the androgen-dependent LNCaP cell, which did not express ABCA1 unlike the other cell lines. Treatment with HDL did not significantly alter the cholesterol content of the cell lines. Knockdown of ABCA1 but not ABCG1 or SR-BI by small interfering RNA (siRNA) inhibited HDL-induced cell proliferation, migration, and ERK1/2 and Akt signal transduction in PC-3 cells. Moreover, after treatment of LNCaP cells with charcoal-stripped fetal bovine serum, ABCA1 was induced ∼10-fold, enabling HDL to induce ERK1/2 activation, whereas small interfering RNA knockdown of ABCA1 inhibited HDL-induced ERK1/2 activation. Simvastatin, which inhibited ABCA1 expression in PC-3 and DU145 cells, attenuated HDL-induced PC-3 and DU145 cell proliferation, migration, and ERK1/2 and Akt phosphorylation. In human prostate biopsy samples, ABCA1 mRNA expression was ∼2-fold higher in the androgen deprivation therapy group than in subjects with benign prostatic hyperplasia or pretreatment prostate cancer groups. In summary, these results suggest that HDL by an ABCA1-dependent mechanism can mediate signal transduction, leading to increased proliferation and migration of prostate cancer cells.
Collapse
Affiliation(s)
- Yoshitaka Sekine
- Lipoprotein Metabolism Section, Pulmonary and Vascular Medicine Branch, NHLBI, NIH, Building 10, Room 8N224, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | | | | | | | | | | | | |
Collapse
|
10
|
Gibbs TC, Rubio MV, Zhang Z, Xie Y, Kipp KR, Meier KE. Signal transduction responses to lysophosphatidic acid and sphingosine 1-phosphate in human prostate cancer cells. Prostate 2009; 69:1493-506. [PMID: 19536794 DOI: 10.1002/pros.20994] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are lipid mediators that bind to G-protein-coupled receptors. In this study, signaling responses to 18:1 LPA and S1P were examined in parallel in three human prostate cancer cell lines: PC-3, Du145, and LNCaP. METHODS Receptor expression was assessed by RT-PCR, Northern blotting, and immunoblotting. Cellular responses to mediators were studied by proliferation assays, phosphoprotein immunoblotting, and phospholipid metabolism assays. RESULTS All cell lines express mRNA for both LPA and S1P receptors. PC-3 and Du145, but not LNCaP, proliferate in response to LPA and S1P. Epidermal growth factor (EGF), phorbol 12-myristate 13-acetate (PMA), LPA, and S1P induce activation of Erks in PC-3 and Du145; only EGF and PMA activate Erks in LNCaP. In Du145 and PC-3, Akt is activated by EGF, LPA, and S1P. Akt is constitutively active in LNCaP; EGF but not LPA or S1P stimulates further phosphorylation. FAK is phosphorylated in response to both LPA and S1P in PC-3 and Du145, but not in LNCaP. LPA and S1P stimulate phospholipase D (PLD) activity to varying extents in the different cell lines. Notably, both lipid mediators activate PLD in LNCaP. In Du145, LPA, but not S1P, activates PLD and enhances cellular production of LPA. CONCLUSIONS Although both LPA and S1P induce signal transduction in all prostate cancer cell lines studied, a proliferation response is observed only when the Erk, Akt, and FAK pathways are activated. Other responses to the lipid mediators, such as PLD activation, likely contribute to other cellular outcomes.
Collapse
Affiliation(s)
- Terra C Gibbs
- Medical University of South Carolina, Charleston, South Carolina, USA
| | | | | | | | | | | |
Collapse
|
11
|
Harashima K, Akimoto T, Nonaka T, Tsuzuki K, Mitsuhashi N, Nakano T. Heat shock protein 90 (Hsp90) chaperone complex inhibitor, Radicicol, potentiated radiation-induced cell killing in a hormone-sensitive prostate cancer cell line through degradation of the androgen receptor. Int J Radiat Biol 2009; 81:63-76. [PMID: 15962764 DOI: 10.1080/09553000400029460] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Until now, there has not been enough information on how androgens or androgen deprivation may influence the response of cancer cells to radiation. In this study, the effect of dihydrotestosterone (DHT) on cellular proliferative activity and radiosensitivity was examined in a hormone-sensitive human prostate cancer cell line, LNCaP. In addition, the study also examined how a heat shock protein 90 (Hsp90) chaperone complex inhibitor modified the effect of DHT on the radiosensitivity of the cells, because binding of the androgen receptor (AR) to Hsp90 is required to maintain the stability and functioning of AR. The hormone-sensitive human prostate cancer cell line, LNCaP, was used. Radicicol was used as one of the known Hsp90 chaperone complex inhibitors, and the cells were incubated in the presence of this compound at a concentration of 500 nM. Cellular radiosensitivity was determined by the clonogenic assay; the changes in the protein expression were examined by Western blotting or immunofluorescence. DHT at a concentration of 1 nM caused enhancement of the proliferative activity and reduction of the radiosensitivity of the cells. Radicicol at a concentration of 500 nM abolished the DHT-induced decrease in cellular radiosensitivity and potentiated the radiation-induced cell killing synergistically. Consistent with the changes in the cellular radiosensitivity, radicicol degraded AR, Raf-1 and HER2/neu via reduced binding of AR to Hsp90, although selective degradation of HER2/neu caused by Herceptin, a monoclonal antibody against HER2, did not affect the cellular radiosensitivity. The results suggest that the Hsp9O chaperone complex may be a potential molecular target for potentiation of radiation-induced cell killing in a hormone-sensitive prostate cancer cell line.
Collapse
Affiliation(s)
- K Harashima
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | | | | | | | | | | |
Collapse
|
12
|
Zeng Y, Kakehi Y, Nouh MAAM, Tsunemori H, Sugimoto M, Wu XX. Gene expression profiles of lysophosphatidic acid-related molecules in the prostate: relevance to prostate cancer and benign hyperplasia. Prostate 2009; 69:283-92. [PMID: 19025891 DOI: 10.1002/pros.20879] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To elucidate gene expression profiles of lysophosphatidic acid (LPA)-related molecules in cancer, pre-cancerous lesion, and benign hyperplasia of the prostate. MATERIALS AND METHODS Prostate tissue samples were surgically obtained from 10 patients with localized prostate cancer and seven patients with invasive bladder cancer. Cancer cells and the corresponding stromal cells from normal prostate, high grade intraepithelial neoplasia (HGPIN), benign hyperplastic glands were isolated by laser capture microdissection. mRNA levels of three LPA receptors, LPA1, LPA2, LPA3, two LPA-synthesizing enzymes, autotaxin (ATX), acylglycerol kinase (AGK), and a LPA-degradation enzyme, prostatic acid phosphatase (PAP), were quantitatively assessed. The expression levels of the same genes were also determined in three human prostate cancer cell lines LNCaP, PC-3, and DU-145. RESULTS LPA1 mRNA level was significantly decreased in HGPIN and cancer epithelia when compared to the benign glands. LPA3 mRNA level was elevated in cancer epithelia compared to benign glands. LPA3, AGK, and PAP were predominantly expressed in LNCaP cells while LPA1 and ATX gene expressions were found in PC-3 and Du-145 cells. In BPH, AGK was abundantly expressed in the stroma while PAP was predominant in epithelial cells. CONCLUSIONS By acting via LPA3, LPA may play an important role in the development of prostate cancer. Switching of LPA receptor expression from LPA3 to LPA1, may be involved in prostate cancer progression and/or androgen independence. LPA may also play a key role in the development of benign prostatic hyperplasia.
Collapse
MESH Headings
- Aged
- Aged, 80 and over
- Androgens/metabolism
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/metabolism
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Cell Line, Tumor
- Gene Expression Profiling
- Humans
- Lectins, C-Type/genetics
- Lectins, C-Type/metabolism
- Lysophospholipids/metabolism
- Male
- Microdissection
- Middle Aged
- Multienzyme Complexes/genetics
- Multienzyme Complexes/metabolism
- Pancreatitis-Associated Proteins
- Phosphodiesterase I/genetics
- Phosphodiesterase I/metabolism
- Phosphoric Diester Hydrolases
- Phosphotransferases (Alcohol Group Acceptor)/genetics
- Phosphotransferases (Alcohol Group Acceptor)/metabolism
- Prostate/physiology
- Prostatic Hyperplasia/genetics
- Prostatic Hyperplasia/metabolism
- Prostatic Hyperplasia/physiopathology
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/physiopathology
- Pyrophosphatases/genetics
- Pyrophosphatases/metabolism
- RNA, Messenger/metabolism
- Receptors, Lysophosphatidic Acid/genetics
- Receptors, Lysophosphatidic Acid/metabolism
- Urinary Bladder Neoplasms/genetics
- Urinary Bladder Neoplasms/metabolism
- Urinary Bladder Neoplasms/physiopathology
Collapse
Affiliation(s)
- Yu Zeng
- Department of Urology, Kagawa University Faculty of Medicine, Kita-gun, Kagawa, Japan
| | | | | | | | | | | |
Collapse
|
13
|
A cross-talk between the androgen receptor and the epidermal growth factor receptor leads to p38MAPK-dependent activation of mTOR and cyclinD1 expression in prostate and lung cancer cells. Int J Biochem Cell Biol 2008; 41:603-14. [PMID: 18692155 DOI: 10.1016/j.biocel.2008.07.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2008] [Revised: 07/14/2008] [Accepted: 07/16/2008] [Indexed: 11/20/2022]
Abstract
In androgen sensitive LNCaP prostate cancer cells, the proliferation induced by the epidermal growth factor (EGF) involves a cross-talk between the EGF receptor (EGFR) and the androgen receptor (AR). In lung cancer the role of the EGF-EGFR transduction pathway has been documented, whereas androgen activity has received less attention. Here we demonstrate that in LNCaP and A549 non-small cell lung cancer (NSCLC), AR and EGFR are required for either 5alpha-dihydrotestosterone (DHT) or EGF-stimulated cell growth. Only EGF activated ERK signaling and up-regulated early gene expression, while DHT triggered the expression of classical AR-responsive genes with the exception of the EGF-induced PSA transcript in A549 cells. DHT and EGF up-regulated cyclinD1 (CD1) at both mRNA and protein levels in A549 cells, while in LNCaP cells each mitogen increased only CD1 protein expression. In both cell contexts, CD1 up-regulation was prevented by selective inhibitors as well as by knock-down of either AR or EGFR and also inhibiting p38MAPK and the mammalian target of rapamycin (mTOR) pathways. Interestingly, p38MAPK and mTOR repression prevented the activation of the mTOR target ribosomal p70S6 kinase induced by DHT and EGF, indicating that p38MAPK acts as an upstream mTOR regulator. In addition, the proliferative effects promoted by both DHT and EGF in LNCaP and A549 cancer cells were no longer observed blocking either p38MAPK or mTOR activity. Hence, our data suggest that p38MAPK-dependent activation of the mTOR/CD1 pathway may represent a mechanism through which AR and EGFR cross-talk contributes to prostate and lung cancer progression.
Collapse
|
14
|
Chow L, Rezmann L, Imamura K, Wang L, Catt K, Tikellis C, Louis WJ, Frauman AG, Louis SNS. Functional angiotensin II type 2 receptors inhibit growth factor signaling in LNCaP and PC3 prostate cancer cell lines. Prostate 2008; 68:651-60. [PMID: 18288685 DOI: 10.1002/pros.20738] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND There is clear evidence of a tissue-based renin-angiotensin system in the prostate and studies to date suggest that AT(1)-receptor blocking drugs inhibit the growth of some prostate cancer cell lines and delay the development of prostate cancer. The present studies examine the action of Ang II in two prostate cancer cell lines and report the presence of functional AT(2)-receptors that regulate the actions of growth factors. METHODS Immunohistochemistry was used to identify the presence of Ang II and QPCR techniques to examine AT(1)- and AT(2)-receptor mRNA expression in androgen-dependent (LNCaP) and independent (PC3) cell lines. The effects of AT(1)- and AT(2)-receptor activation upon EGF-induced DNA synthesis and ERK2 phosphorylation in these cells were also examined. RESULTS Functional AT(2)-receptors together with Ang II were identified in both cell lines and stimulation of these receptors inhibited EGF-induced DNA synthesis and ERK2 phosphorylation. AT(1)-receptors, although present in both cell lines, were only functional in LNCaP cells where activation stimulated DNA synthesis. CONCLUSIONS Functional AT(2)-receptors are present and have the capacity to inhibit EGF-induced prostate cancer cell growth in LNCaP and fast growing androgen-independent PC3 cell lines, whereas functional AT(1)-receptors are found only in LNCaP cells where their activation stimulates DNA synthesis.
Collapse
MESH Headings
- Cell Line, Tumor
- DNA/biosynthesis
- DNA/drug effects
- Epidermal Growth Factor/metabolism
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Expression Regulation, Neoplastic/physiology
- Humans
- Male
- Mitogen-Activated Protein Kinase 1/metabolism
- Phosphorylation
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- RNA, Messenger/metabolism
- RNA, Neoplasm/analysis
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 2/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/drug effects
- Signal Transduction/physiology
Collapse
Affiliation(s)
- L Chow
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Uysal-Onganer P, Djamgoz MB. Epidermal growth factor potentiates in vitro metastatic behaviour of human prostate cancer PC-3M cells: involvement of voltage-gated sodium channel. Mol Cancer 2007; 6:76. [PMID: 18036246 PMCID: PMC2211503 DOI: 10.1186/1476-4598-6-76] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 11/24/2007] [Indexed: 12/16/2022] Open
Abstract
Background Although a high level of functional voltage-gated sodium channel (VGSC) expression has been found in strongly metastatic human and rat prostate cancer (PCa) cells, the mechanism(s) responsible for the upregulation is unknown. The concentration of epidermal growth factor (EGF), a modulator of ion channels, in the body is highest in prostatic fluid. Thus, EGF could be involved in the VGSC upregulation in PCa. The effects of EGF on VGSC expression in the highly metastatic human PCa PC-3M cell line, which was shown previously to express both functional VGSCs and EGF receptors, were investigated. A quantitative approach, from gene level to cell behaviour, was used. mRNA levels were determined by real-time PCR. Protein expression was studied by Western blots and immunocytochemistry and digital image analysis. Functional assays involved measurements of transverse migration, endocytic membrane activity and Matrigel invasion. Results Exogenous EGF enhanced the cells' in vitro metastatic behaviours (migration, endocytosis and invasion). Endogenous EGF had a similar involvement. EGF increased VGSC Nav1.7 (predominant isoform in PCa) mRNA and protein expressions. Co-application of the highly specific VGSC blocker tetrodotoxin (TTX) suppressed the effect of EGF on all three metastatic cell behaviours studied. Conclusion 1) EGF has a major involvement in the upregulation of functional VGSC expression in human PCa PC-3M cells. (2) VGSC activity has a significant intermediary role in potentiating effect of EGF in human PCa.
Collapse
Affiliation(s)
- Pinar Uysal-Onganer
- Neuroscience Solutions to Cancer Research Group, Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
| | | |
Collapse
|
16
|
Sekine Y, Koike H, Nakano T, Nakajima K, Suzuki K. Remnant lipoproteins stimulate proliferation and activate MAPK and Akt signaling pathways via G protein-coupled receptor in PC-3 prostate cancer cells. Clin Chim Acta 2007; 383:78-84. [PMID: 17512923 DOI: 10.1016/j.cca.2007.04.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Revised: 04/10/2007] [Accepted: 04/10/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Hypertriglyceridemia was recently shown to be a risk factor for prostate cancer; however, there are only a few reports about the relationship between prostate cancer and TG (triglycerides) rich lipoproteins. Remnant lipoproteins (RLP) are TG-rich lipoproteins, which are produced by the hydrolysis of very low density lipoproteins and chylomicrons. We examined the direct effect of RLP on the proliferation and signal transduction of prostate cancer cells. METHODS RLP were isolated from human serum with an immunoaffinity mixed gel containing anti-apoA-1 and anti-apoB-100. We evaluated RLP-induced cell proliferation by using MTS assay. Moreover we examined the direct effect of RLP on the MAPK and Akt signal transductions which are reported to be correlated with prostate cancer by using Western blotting. RESULTS Incubation in the presence of RLP for 48 h induced the proliferation of prostate cancer PC-3 cells more significantly than prostate cancer LNCaP cells and human prostate stromal cells. In PC-3 cells, RLP also induced the phosphorylation of MEK/ERK via a G protein-coupled receptor-protein kinase C dependent pathway. Moreover, activation of Akt pathway was observed after RLP treatment of PC-3. CONCLUSION These findings suggested that hypertriglyceridemia, especially remnant hyperlipoproteinemia, might be one of the progressive factors for prostate cancer.
Collapse
Affiliation(s)
- Yoshitaka Sekine
- Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | | | | | | | | |
Collapse
|
17
|
Ye F, Jiang S, Volshonok H, Wu J, Zhang DY. Molecular Mechanism of Anti-Prostate Cancer Activity ofScutellaria BaicalensisExtract. Nutr Cancer 2007; 57:100-10. [PMID: 17516867 DOI: 10.1080/01635580701268352] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Scutellaria baicalensis is a widely used Chinese herbal medicine historically used in antiinflammatory and anticancer therapy. The goals of the study were to 1) determine its in vitro and in vivo anti-prostate cancer activity, 2) investigate its molecular mechanism directed at cell proliferation control including cyclooxygenase-2(COX-2) prostaglandin E2 (PGE2) and cyclins/cdks pathways, and 3) compare it with those of PC-SPES (PC stands for prostate cancer and spes is Latin for hope), a former herbal mixture for prostate cancer treatment of which S. baicalensis is a major constituent. Two human prostate cancer cell lines (LNCaP, androgen dependent, and PC-3, androgen independent) were assessed for growth inhibition. S. baicalensis exerted dose- and time-dependent increased growth inhibition in both cell lines. However, the PC-3 cells IC50 (50% growth inhibition concentration) were slightly more sensitive than LNCaP cells (IC50=0.15 mg/ml), although the former is androgen independent. S. baicalensis was more effective in inhibition of cell growth compared with PC-SPES (IC50=0.38 mg/ml for PC-3 cells). Significant reduction of PGE2 synthesis in both cells after treatment with S. baicalensis resulted from direct inhibition of COX-2 activity rather than COX-2 protein suppression. S. baicalensis also inhibited prostate-specific antigen production in LNCaP cells. Finally, S. baicalensis suppressed expression of cyclin D1 in LNCaP cells, resulting in a G1 phase arrest, while inhibiting cdk1 expression and kinase activity in PC-3 cells, ultimately leading to a G2/M cell cycle arrest. Animal studies showed a 50% reduction in tumor volume after a 7-wk treatment period. This study demonstrated that S. baicalensis may be a novel anticancer agent for the treatment of prostate cancer.
Collapse
Affiliation(s)
- Fei Ye
- Department of Pathology, Mount Sinai School of Medicine, New York University, New York, NY 10029, USA
| | | | | | | | | |
Collapse
|
18
|
Schmitz M, Grignard G, Margue C, Dippel W, Capesius C, Mossong J, Nathan M, Giacchi S, Scheiden R, Kieffer N. Complete loss of PTEN expression as a possible early prognostic marker for prostate cancer metastasis. Int J Cancer 2007; 120:1284-92. [PMID: 17163422 DOI: 10.1002/ijc.22359] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The EGF/IGF growth factors are potent mitogens that regulate cell proliferation and cell survival and are involved in prostate cancer development. Using laser microdissection technology and real-time PCR, together with immunohistochemistry, we have explored the growth factor and integrin dependent PI3-kinase/PTEN/Akt signalling pathway in prostate cell lines and tumour samples by analysing EGF-R, IGF1-R, ILK, beta3 integrin, PTEN and p-Akt protein expression. We provide evidence that loss of PTEN expression rather than upregulated EGF/IGF1 receptor expression was responsible for increased p-Akt in neoplastic prostate cells. We therefore compared PTEN expression in patient biopsies at first time diagnosis recruited prospectively (Study I, 112 patients) and patients with confirmed metastasis recruited retrospectively from the Luxembourg cancer registry (Study II, 42 patients). In Study I, loss of PTEN expression at first time diagnosis was found in 26 of 112 patients (23%). In Study II, 25 of the 42 patients (59%) with lymph node metastasis had complete loss of PTEN expression in both the neoplastic glands of the prostate and the invasive prostate cancer cells in the lymph node, and of these 13 (52%) exhibited already loss of PTEN expression at first diagnosis. These findings demonstrate that loss of PTEN expression is an important factor in progression towards metastatic disease and could potentially serve as an early prognostic marker for prostate cancer metastasis.
Collapse
Affiliation(s)
- Martine Schmitz
- Laboratoire de Biologie et Physiologie Intégrée (LBPI), Université du Luxembourg, 162A avenue de la Faïencerie, L-1511 Luxembourg
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Hao F, Tan M, Xu X, Han J, Miller DD, Tigyi G, Cui MZ. Lysophosphatidic acid induces prostate cancer PC3 cell migration via activation of LPA(1), p42 and p38alpha. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:883-92. [PMID: 17531530 PMCID: PMC3446792 DOI: 10.1016/j.bbalip.2007.04.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 03/29/2007] [Accepted: 04/16/2007] [Indexed: 11/28/2022]
Abstract
Prostate cancer cell migration is an essential event both in the progression of prostate cancer and in the steps leading to metastasis. We report here that lysophosphatidic acid (LPA), a potent bioactive phospholipid, induces prostate cancer PC3 cell migration via the activation of the LPA(1) receptor, which is linked to a PTX-sensitive activation mechanism of the mitogen-activated protein kinases (MAPK). Our results demonstrate that parallel activation of ERK1/2 and p38, but not JNK, is responsible for LPA-stimulated PC3 cell migration. Furthermore, using small interfering RNA (siRNA) technology, and overexpressing dominant-negative mutants of p38 MAPK isotypes of alpha, beta, gamma and delta, we have identified that the activation of ERK2 (p42) and p38alpha, but not of ERK1 and the other isoforms of p38 MAPK, is required for LPA-induced migration. Our study provides the first evidence for a functional role of p42 and p38alpha in LPA-induced mammalian cell migration, and also demonstrates, for the first time, that the receptor LPA(1) mediates prostate cancer cell migration. The results of the present study suggest that LPA, the receptor LPA(1), ERK2 and p38alpha are important regulators for prostate cancer cell invasion and thus could play a significant role in the development of metastasis.
Collapse
Affiliation(s)
- Feng Hao
- Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN 37996, USA
| | - Mingqi Tan
- Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN 37996, USA
| | - Xuemin Xu
- Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN 37996, USA
| | - Jiahuai Han
- Department of Immunology, The Scripps Research Institute, CA 92037, USA
| | - Duane D. Miller
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Gabor Tigyi
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Mei-Zhen Cui
- Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN 37996, USA
- Corresponding author. Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, 2407 River Drive, Knoxville, TN 37996, USA. Tel.: +1 865 974 8212; fax: +1 865 974 5616. (M.-Z. Cui)
| |
Collapse
|
20
|
Efferson CL, Tsuda N, Kawano K, Nistal-Villán E, Sellappan S, Yu D, Murray JL, García-Sastre A, Ioannides CG. Prostate tumor cells infected with a recombinant influenza virus expressing a truncated NS1 protein activate cytolytic CD8+ cells to recognize noninfected tumor cells. J Virol 2007; 80:383-94. [PMID: 16352563 PMCID: PMC1317509 DOI: 10.1128/jvi.80.1.383-394.2006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many viral oncolytic approaches against cancer are based on the ability of specific viruses to replicate in tumors expressing components of the constitutively activated Ras/mitogen-activated protein kinase (MAPK) pathways and/or inhibited or dysregulated alpha/beta interferon (IFN-alpha/beta) response pathways. A major issue when considering these approaches is their applicability to tumors that lack activated Ras. To identify the effector mechanisms activated by oncolytic viruses, we investigated inhibition of proliferation of the prostate cancer line LNCap by the recombinant TR-NS1 influenza A virus, a genetically attenuated influenza A/PR8/34 virus expressing a truncated nonstructural protein (NS1) of 126 amino acids. LNCap cells lack constitutively activated MAPK, extracellular signal-regulated kinase (ERK), and p38 and are resistant to death by IFN-alpha. Truncation of the NS1 protein of influenza viruses is known to result in viral attenuation due to a reduced ability of the NS1 to inhibit the IFN-alpha/beta response. Infection with TR-NS1 virus rapidly activated ERK-1 more than ERK-2 in LNCap cells. Importantly, TR-NS1 virus infection transiently inhibited cell proliferation and induced apoptosis in LNCap cells. Addition of peripheral blood mononuclear cells (PBMC) and interleukin 12 (IL-12) to TR-NS1 virus-infected LNCap cells (TR-NS1-LNCap) resulted in faster elimination of TR-NS1-LNCap cells compared with LNCap cells. Moreover, TR-NS1-LNCap cells induced IFN-gamma in PBMC. The levels of IFN-gamma were amplified by IL-12. TR-NS1-LNCap cells also induced tumor-lytic cytotoxic T lymphocytes (CTL). These CTL lysed noninfected LNCap cells in a CD8-dependent manner. Activation of cellular immunity to tumor cells by viruses is an intriguing effector pathway, which should be especially significant for elimination of human tumors that lack activated Ras.
Collapse
Affiliation(s)
- Clay L Efferson
- Department of Gynecologic Oncology, Surgical Oncology, Breast Medical Oncology and Immunology, M. D. Anderson Cancer Center, Houston, Texas 77030, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Guo R, Kasbohm EA, Arora P, Sample CJ, Baban B, Sud N, Sivashanmugam P, Moniri NH, Daaka Y. Expression and function of lysophosphatidic acid LPA1 receptor in prostate cancer cells. Endocrinology 2006; 147:4883-92. [PMID: 16809448 DOI: 10.1210/en.2005-1635] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The bioactive phospholipid lysophosphatidic acid (LPA) promotes cell proliferation, survival, and migration by acting on cognate G protein-coupled receptors named LPA(1), LPA(2), and LPA(3). We profiled gene expression of LPA receptors in androgen-dependent and androgen-insensitive prostate cancer cells and found that LPA(1) gene is differentially expressed in androgen-insensitive and LPA-responsive but not androgen-dependent and LPA-resistant cells. In human prostate specimens, expression of LPA(1) gene was significantly higher in the cancer compared with the benign tissues. The androgen-dependent LNCaP cells do not express LPA(1) and do not proliferate in response to LPA stimulation, implying LPA(1) transduces cell growth signals. Accordingly, stable expression of LPA(1) in LNCaP cells rendered them responsive to LPA-induced cell proliferation and decreased their doubling time in serum. Implantation of LNCaP-LPA(1) cells resulted in increased rate of tumor growth in animals compared with those tumors that developed from the wild-type cells. Growth of LNCaP cells depends on androgen receptor activation, and we show that LPA(1) transduces Galphai-dependent signals to promote nuclear localization of androgen receptor and cell proliferation. In addition, treatment with bicalutamide inhibited LPA-induced cell cycle progression and proliferation of LNCaP-LPA(1) cells. These results suggest the possible utility of LPA(1) as a drug target to interfere with progression of prostate cancer.
Collapse
MESH Headings
- Blotting, Northern
- Cell Cycle/physiology
- Cell Line, Tumor
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cell Nucleus/metabolism
- Cell Proliferation
- DNA, Neoplasm/biosynthesis
- DNA, Neoplasm/genetics
- Humans
- In Situ Hybridization
- Male
- Microscopy, Fluorescence
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- RNA, Neoplasm/biosynthesis
- RNA, Neoplasm/genetics
- Receptors, Androgen/genetics
- Receptors, Lysophosphatidic Acid/biosynthesis
- Receptors, Lysophosphatidic Acid/genetics
- Receptors, Lysophosphatidic Acid/metabolism
- Signal Transduction/physiology
Collapse
Affiliation(s)
- Rishu Guo
- Department of Surgery, Duke University of Medical Center, North Carolina 27710, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Calaluce R, Beck SK, Bair EL, Pandey R, Greer KA, Hoying AM, Hoying JB, Mount DW, Nagle RB. Human laminin-5 and laminin-10 mediated gene expression of prostate carcinoma cells. Prostate 2006; 66:1381-90. [PMID: 16804886 DOI: 10.1002/pros.20393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In prostate cancer progression, the basal lamina switches from predominantly laminin-5 to laminin-10. DU-145 prostate cancer cells were treated with either soluble laminin-5 (20 ng/ml) or laminin-10 (1 microg/ml) for 6, 24, and 48 hr. Total RNA was harvested for a 7,500 human cDNA microarray. Hybridizations were carried out in accordance with a 10 sample analysis of variance (ANOVA) statistical model. One thousand one hundred sixteen genes had measurable expression 2 standard deviations above background and 50% of spots for any given sample for all hybridizations were positive. Expression values of significantly varying genes were clustered and a list of 408 genes (P < 0.05) with a 1.5 or greater fold change in at least one time point were chosen for further analysis. Seventy eight changed in a time-dependent manner with laminin-10 treatment, 85 changed with laminin-5, and 13 showed changes with both treatments. The 408 genes that passed a paired t-test in at least one time-dependent category were further analyzed using Pathway Miner. One of the largest gene association networks involved signal transduction in the growth factor-MAP kinase pathways. EGFR was validated by real-time PCR and laminin-10 mediated cell adhesion activated EGFR in DU-145 cells. Both laminins appear to be important signal transducers in prostate cancer.
Collapse
Affiliation(s)
- Robert Calaluce
- Arizona Cancer Center, University of Arizona Health Sciences Center, Tucson, Arizona 85724-5024, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Ruscica M, Dozio E, Boghossian S, Bovo G, Martos Riaño V, Motta M, Magni P. Activation of the Y1 receptor by neuropeptide Y regulates the growth of prostate cancer cells. Endocrinology 2006; 147:1466-73. [PMID: 16339211 DOI: 10.1210/en.2005-0925] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study deals with the role of neuropeptide Y (NPY) in the regulation of cell proliferation. NPY is expressed in the normal and tumoral prostate, but no data on its possible role in prostate cancer (PCa) progression are available. Therefore, we evaluated the direct effect of NPY on the growth of the human PCa cell lines LNCaP (androgen dependent) and DU145 and PC3 (androgen independent). All PCa cell lines expressed Y1-R gene and protein. NPY treatment reduced the proliferation of LNCaP and DU145 cells and increased that of PC3 cells. The Y1-R antagonist BIBP3226 abolished such effects, suggesting a mandatory role of Y1-R in this process. LNCaP cells showed elevated constitutive levels of phosphorylated ERK1/2, which were not affected by NPY. In DU145 cells, NPY stimulated a long-lasting ERK1/2 activation, whereas, in PC3 cells, this effect was rapid and transient and required activation of protein kinase C. Moreover, in both cell lines, pretreatment with BIBP3226 prevented the NPY-induced ERK1/2 phosphorylation, further supporting Y1-R involvement. NPY treatment reduced forskolin-stimulated cAMP accumulation only in PC3 cells and did not change intracellular calcium concentration in any PCa cell line. These data indicate that NPY may directly regulate PCa cell growth via Y1-R. The direction of this effect appears to be related to the time kinetics of MAPK activation, i.e. long-lasting vs. transient, and to the clone-specific involvement of other intracellular signals. These findings suggest that NPY-related mechanisms might play a relevant role in the progression of PCa, at both androgen dependent and independent stages.
Collapse
|
24
|
Abasolo I, Montuenga LM, Calvo A. Adrenomedullin prevents apoptosis in prostate cancer cells. ACTA ACUST UNITED AC 2006; 133:115-22. [PMID: 16297990 DOI: 10.1016/j.regpep.2005.09.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Accepted: 09/22/2005] [Indexed: 11/19/2022]
Abstract
The 52-aminoacid peptide adrenomedullin (AM) is expressed in the normal and malignant prostate. We have previously shown that prostate cancer cells produce and secrete AM, which acts as an autocrine growth inhibitory factor. We have evaluated in the present study the role of AM in prostate cancer cell apoptosis, induced either by serum deprivation or treatment with the chemotherapeutic agent etoposide (which acts as an inhibitor of topoisomerase II). For this purpose we over-expressed AM in PC-3, DU 145 and LNCaP cells, which were transfected with an expression vector carrying AM. We also treated the parental cell lines with synthetic AM in normal culture conditions and in conditions of induced-apoptosis. After serum removal, AM prevented apoptosis in DU 145 and PC-3 cells, but not in LNCaP cells. When treated with etoposide, AM prevented apoptosis in PC-3 and LNCaP cells, but not in DU 145 cells. Cell cycle analysis demonstrated a significant decrease in the percentage of AM-overexpressing PC-3 cells in the subG0/G1 phase after treatment with etoposide, as compared to the percentage of mock-transfected PC-3 treated cells. Western blot showed that protein levels of phosphorylated ERK1/2 increased in parental PC-3 cells after treatment with etoposide. In PC-3 cells overexpressing AM, phosphorylated ERK1/2 basal levels were lower than basal levels of parental PC-3 cells, and treatment with etoposide did not result in such an increase. Etoposide produced a significant increase in cleaved PARP in parental PC-3 cells. However, PC-3 clones overexpressing AM that were treated with etoposide only showed a mild increase in fragmented PARP. The ratio Bcl-2/Bax was reduced in parental or mock-transfected PC-3 cells after treatment with etoposide. On the contrary, this ratio was not reduced in PC-3 clones with AM overexpression that were treated with etoposide. All these data demonstrate that AM plays a protective role against induced apoptosis in prostate cancer cells. These results may have important implications in prostate cancer resistance to chemotherapeutic agents.
Collapse
Affiliation(s)
- Ibane Abasolo
- Division of Oncology, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | | | | |
Collapse
|
25
|
Xiao D, Chinnappan D, Pestell R, Albanese C, Weber HC. Bombesin regulates cyclin D1 expression through the early growth response protein Egr-1 in prostate cancer cells. Cancer Res 2005; 65:9934-42. [PMID: 16267018 DOI: 10.1158/0008-5472.can-05-1830] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Our previous studies indicate that the activation of mitogen-activated protein kinase (MAPK) pathway is involved in bombesin-induced cell proliferation in prostate cancer cells. Cyclin D1 is a critical regulator involved in cell cycle progression through the G1 phase into the S phase, thereby contributing to cell proliferation. Mostly, mitogen-stimulated expression of cyclin D1 is attributed to the extracellular signal-regulated kinase (ERK) activation. Here, we found that bombesin induced human cyclin D1 expression on both mRNA and protein levels in DU-145 prostate cancer cells. Mutational analyses showed that bombesin-enhanced cyclin D1 transcription required the binding of nuclear proteins to the -143 to -105 region of the human cyclin D1 promoter, which contains binding sites for transcription factors Sp-1 and early growth response protein (Egr-1). Do novo protein synthesis was requisite for bombesin-induced cyclin D1 expression. Further studies showed Egr-1 was induced upon bombesin stimulation. The induction of Egr-1 expression and its binding to the cyclin D1 promoter were essential for bombesin-enhanced cyclin D1 transcription. Inhibition of MAPK pathway with either the MEK1 inhibitor PD98059 or a dominant-negative Ras mutant, RasN17, abolished bombesin-induced cyclin D1 activation. Taken together, bombesin-induced cyclin D1 expression in prostate cancer cells is mediated by Egr-1 activation and the interaction of Egr-1 with the Egr-1/Sp1 motif of the cyclin D1 promoter through the activation of MAPK pathway. These findings represent a novel mechanism of bombesin-dependent stimulation of mitogenesis by regulating directly the cell cycle in prostate cancer.
Collapse
Affiliation(s)
- Dongmei Xiao
- Section of Gastroenterology, Boston University School of Medicine, Boston, Massachusetts 02118-2518, USA
| | | | | | | | | |
Collapse
|
26
|
Critical role of acylglycerol kinase in epidermal growth factor-induced mitogenesis of prostate cancer cells. Biochem Soc Trans 2005; 33:1362-5. [PMID: 16246119 DOI: 10.1042/bst0331362] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The bioactive phospholipids, LPA (lysophosphatidic acid) and PA (phosphatidic acid), regulate pivotal processes related to the pathogenesis of cancer. Recently, we cloned a novel type of lipid kinase that phosphorylates monoacylglycerols (such as 2-arachidonoylglycerol, an endogenous cannabinoid receptor ligand) and diacylglycerols, to form LPA and PA, respectively. This AGK (acylglycerol kinase) is highly expressed in prostate cancer cell lines and the results reviewed here suggest that AGK might be a critical player in the initiation and progression of prostate cancer. Intriguingly, down-regulation of endogenous AGK inhibited EGF (epidermal growth factor), but not LPA-induced ERK1/2 (extracellular-signal-regulated kinase 1/2) activation and progression through the S-phase of the cell cycle. In this review, we will summarize the evidence demonstrating that AGK amplifies EGF growth signalling pathways that play an important role in the pathophysiology of prostate cancer. Because LPA has long been implicated as an autocrine and paracrine growth stimulatory factor for prostate cancer cells, the identification of this novel lipid kinase that regulates its production could provide new and useful targets for preventive or therapeutic measures.
Collapse
|
27
|
Koul HK, Maroni PD, Meacham RB, Crawford D, Koul S. p42/p44 Mitogen-Activated Protein Kinase Signal Transduction Pathway: A Novel Target for the Treatment of Hormone-Resistant Prostate Cancer? Ann N Y Acad Sci 2004; 1030:243-52. [PMID: 15659803 DOI: 10.1196/annals.1329.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Prostate cancer is the second leading cause of cancer deaths in men. Conventional therapies produce a high rate of cure for patients with localized prostate cancer, but there is no cure once the disease has spread beyond the prostate. Androgen withdrawal remains the only treatment for these men with clinically advanced disease; however, most of these men, who initially respond to hormone ablation therapy, fail and the disease progresses. There is at present no effective treatment for hormone-independent prostate cancer. Several lines of evidence suggest a role of p42/p44 mitogen-activated protein kinase (p42/p44 MAP kinase) signal transduction pathways in prostate cancer. At the molecular level, a variety of genetic alterations lead to an epigenetic mechanism by which a feedback autocrine loop between membrane receptors and associated ligands serves as an essential component of the growth, proliferation, and metastasis of prostate cancer at an advanced and androgen-independent stage. Peptide growth factors are known to exert their effects by a complex array of mechanisms primarily mediated by the p42/p44 MAP kinase signal transduction pathway. Thus, we hypothesized that MAP kinase signal transduction pathways could serve as new and novel targets in prostate cancer therapy. In this article we provide an overview of the role played by MAP kinase signal transduction in the prostate.
Collapse
Affiliation(s)
- Hari K Koul
- Signal Transduction and Molecular Biology Laboratory, University of Colorado School of Medicine, Denver, CO 80262, USA.
| | | | | | | | | |
Collapse
|
28
|
Sakamoto S, Yokoyama M, Zhang X, Prakash K, Nagao K, Hatanaka T, Getzenberg RH, Kakehi Y. Increased expression of CYR61, an extracellular matrix signaling protein, in human benign prostatic hyperplasia and its regulation by lysophosphatidic acid. Endocrinology 2004; 145:2929-40. [PMID: 14988385 PMCID: PMC3477642 DOI: 10.1210/en.2003-1350] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Lysophosphatidic acid (LPA) is an endogenous lipid growth factor that is thought to play important roles in cell proliferation and antiapoptosis and therefore may have roles in the development and progression of benign prostatic hyperplasia (BPH). CYR61 (CCN1), on the other hand, is a growth factor-inducible immediate early gene that functions in cell proliferation, differentiation, and extracellular matrix synthesis. Here we show the close relationship between LPA-induced expression of CYR61 and prostate enlargement. CYR61 mRNA and protein were dramatically up-regulated by 18:1 LPA (oleoyl-LPA) within 1 and 2 h, respectively, in both stromal and epithelial prostatic cells. G protein-coupled receptors, i.e. Edg-2, Edg-4, and Edg-7, for LPA were also expressed in both stromal and epithelial prostatic cells. Furthermore, on DNA microarray analysis for normal and BPH patients, CYR61 was found to be related to the development and progression of BPH, regardless of symptoms. Although CYR61 mRNA was synthesized in hyperplastic epithelial cells, in many cases of BPH, CYR61 protein was detected in both the epithelial and stromal regions of BPH patient tissues. The functional contribution of CYR61 to prostatic cell growth was demonstrated by recombinant CYR61 protein and anti-CYR61 neutralizing antibodies, which inhibited CYR61-dependent cell spreading and significantly diminished cell proliferation, respectively. In conclusion, these data support the hypothesis that LPAs induce the expression of CYR61 by activating G proteincoupled receptors and that CYR61 acts as a secreted autocrine and/or paracrine mediator in stromal and epithelial hyperplasia, demonstrating the potential importance of this signaling mechanism in the disease.
Collapse
Affiliation(s)
- Shinji Sakamoto
- Pharmaceutical Frontier Research Laboratories, JT Inc., 13-2, Fukuura 1-chome, Kanazawa-ku, Yokohama 236-0004, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
Signal transduction research investigating mechanisms of androgen-independent prostate cancer cell proliferation has historically focused on the role of androgen and peptide growth factor receptors. More recent work has raised the idea that intracellular signaling mechanisms triggered by extracellular hormonal factors acting through heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) can also mediate and sustain this pathologic process. Prostate cancer patients with advanced disease express elevated levels of GPCRs and GPCR ligands, suggesting that the GPCR system is activated in the cancerous gland and may contribute to tumor growth. Importantly, inhibition of G protein signaling attenuates prostate cancer cell growth in animal models. The nature of intracellular signaling pathways mediating mitogenic effects of GPCRs in prostate cancer is poorly defined, although the G protein-dependent activation of the Ras-to-mitogen-activated protein kinase pathway has emerged as a critical regulatory event. Activated GPCRs may also exert their mitogenic effects in the prostate by activating the androgen receptor.
Collapse
Affiliation(s)
- Yehia Daaka
- Department of Surgery and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
| |
Collapse
|
30
|
Siddiqui IA, Adhami VM, Afaq F, Ahmad N, Mukhtar H. Modulation of phosphatidylinositol-3-kinase/protein kinase B- and mitogen-activated protein kinase-pathways by tea polyphenols in human prostate cancer cells. J Cell Biochem 2004; 91:232-42. [PMID: 14743383 DOI: 10.1002/jcb.10737] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have earlier shown that oral infusion of a polyphenolic fraction isolated from green tea, at a human achievable dose (equivalent to six cups of green tea per day), significantly inhibits prostate cancer (PCA) development and metastasis in transgenic adenocarcinoma of mouse prostate (TRAMP) model that closely mimics progressive form of human prostatic disease (Gupta et al. [2001]: Proc. Natl. Acad. Sci. U.S.A. 98:10350-10355.). A complete understanding of the mechanism(s) and molecular targets of PCA chemopreventive effects of tea polyphenols may be useful in developing novel approaches for its prevention. In this study, we employed two distinct human PCA cell lines viz. DU145 (androgen-unresponsive prostate carcinoma cells) and LNCaP (androgen-responsive prostate carcinoma cells) and, employing immunoblot analysis, we evaluated the effect of epigallocatechin-3-gallate (EGCG), the major polyphenol present in green tea and theaflavins (TF), the major polyphenol present in black tea on phosphatidylinositol-3-kinase (PI3K)/protein kinase B (PKB) and mitogen-activated protein kinase (MAPK) pathways. Both EGCG and TF treatment were found to (i) decrease the levels of PI3K and phospho-Akt and (ii) increase Erk1/2 in both DU145 and LNCaP cells. Our data showing the inhibition of the constitutive levels of PI3K and the phosphorylation of Akt could be important because the treatment approaches should be aimed at the inhibition of the constitutive levels of PI3K and Akt. Our data also suggest that Erk1/2 could be involved in the anti-cancer effects of EGCG and TF. Taken together, our study, for the first time demonstrated the modulation of the constitutive activation of PI3K/Akt and Erk1/2 pathways by EGCG as well as TF. We suggest that detailed studies in appropriate tumor model system are needed to establish the relevance of the cell culture work to in vivo models.
Collapse
|
31
|
Sgambato A, Camerini A, Faraglia B, Ardito R, Bianchino G, Spada D, Boninsegna A, Valentini V, Cittadini A. Targeted inhibition of the epidermal growth factor receptor-tyrosine kinase by ZD1839 (?Iressa?) induces cell-cycle arrest and inhibits proliferation in prostate cancer cells. J Cell Physiol 2004; 201:97-105. [PMID: 15281092 DOI: 10.1002/jcp.20045] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The epidermal growth factor (EGF) plays a role in the development of prostate cancer, which becomes essential after androgen resistance has emerged. The EGF receptor (EGFR) is therefore a potential target for anticancer therapy. We evaluated the effects of ZD1839 ('Iressa'), an orally active EGFR-tyrosine kinase inhibitor, on prostate cancer cell lines. The effects of ZD1839 were evaluated on the anchorage dependent and independent growth of androgen-responsive (LNCaP) and androgen-independent (DU145 and PC3) cells by a cell proliferation assay, cell counting, and soft agar analysis. Flow cytometric analysis and Western blotting were used to assess the effects on the cell-cycle and on protein expression levels, respectively. ZD1839 caused a dose- and time-dependent growth inhibition in all three cell lines. A dose-dependent supra-additive increase in growth inhibition was observed when ZD1839 was combined with the antiandrogen flutamide or ionizing radiation (IR). The antiproliferative effect of ZD1839 was mainly cytostatic and associated with a block in the G(0)/G(1) phase of the cell-cycle, evident after about 12 h of treatment. In the DU145 cells this block was associated with an increase in expression of the CDK inhibitor p27(Kip1), both in the cytoplasmic and nuclear fractions. The increase in p27(Kip1) was not evident in the LNCaP and PC3 cells. No changes were observed in the expression of cyclin D1 protein. These results demonstrate the antiproliferative effects of ZD1839 on the growth of prostate cancer cells and suggest that inhibition of EGFR-associated signal transduction pathway might represent a promising novel therapeutic strategy for the treatment of prostate cancer.
Collapse
Affiliation(s)
- Alessandro Sgambato
- Centro di Ricerche Oncologiche "Giovanni XXIII"-Istituto di Patologia Generale, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Pelaia G, Cuda G, Vatrella A, Fratto D, Grembiale RD, Tagliaferri P, Maselli R, Costanzo FS, Marsico SA. Effects of transforming growth factor-[beta] and budesonide on mitogen-activated protein kinase activation and apoptosis in airway epithelial cells. Am J Respir Cell Mol Biol 2003; 29:12-8. [PMID: 12600835 DOI: 10.1165/rcmb.2002-0074oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Airway epithelial cells play a central role in the inflammatory, apoptotic, and remodeling processes associated with asthma. Within this context, a key function is exerted by transforming growth factor-beta (TGF-beta), whose biological effects are mediated at least in part by mitogen-activated protein kinases (MAPKs). The aim of our study was to investigate, in primary cultures of human bronchial epithelial cells (HBEC), the effects of TGF-beta (10 ng/ml) on both MAPK activation and apoptosis, in the presence or absence of a pretreatment with budesonide (10-8 M). MAPK activation was detected by Western blotting, using anti-phospho-MAPK monoclonal antibodies, which specifically recognize the phosphorylated, active forms of these enzymes. Apoptosis was assayed by caspase-3 activation and fluorescence microscopy, using annexin-V (An-V) and propidium iodide (PI) as markers of cell death. Our results show that TGF-beta induced a marked ( reverse similar 9-fold) increase in p38 MAPK phosphorylation, and also dramatically enhanced cell death, which was completely prevented by specific MAPK inhibitors. Both MAPK activation and apoptosis were effectively inhibited by budesonide (BUD), thereby suggesting that the powerful antiapoptotic action of inhaled glucocorticoids may be very important for their protective role against epithelial injury, which represents a key pathogenic event in asthma.
Collapse
Affiliation(s)
- Girolamo Pelaia
- Department of Experimental and Clinical Medicine, University of "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Farini D, Puglianiello A, Mammi C, Siracusa G, Moretti C. Dual effect of pituitary adenylate cyclase activating polypeptide on prostate tumor LNCaP cells: short- and long-term exposure affect proliferation and neuroendocrine differentiation. Endocrinology 2003; 144:1631-43. [PMID: 12639948 DOI: 10.1210/en.2002-221009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide that elicits the increase of intracellular cAMP levels and protein kinase A activity in various cell systems. Here we show that the pattern of cAMP elevation triggered by PACAP is critical for the fate of LNCaP prostate cancer cells. We demonstrate that these cells express PACAP and its type 1 receptor. A short-term stimulation with PACAP, which generates a transient cAMP rise, induces proliferation of LNCaP cells through a protein kinase A-dependent activation of the MAPK cascade. On the contrary, we observed that chronic PACAP stimulation, giving rise to a sustained cAMP accumulation, leads to proliferation arrest and neuroendocrine differentiation. Moreover, PACAP stimulates phosphory-lation and activation of the cAMP response element binding transcription factor (CREB), and MAPK activation is necessary for its full transcriptional activity, indicating a direct involvement of cAMP response element in PACAP action. These findings demonstrate that a crucial event determining the outcome of prostatic cancer cells progression is the sustained vs. transient intracellular cAMP increase.
Collapse
Affiliation(s)
- Donatella Farini
- Department of Public Health and Cellular Biology, Unit of Histology, University of Rome Tor Vergata, 00133 Rome, Italy
| | | | | | | | | |
Collapse
|
34
|
Steiner H, Godoy-Tundidor S, Rogatsch H, Berger AP, Fuchs D, Comuzzi B, Bartsch G, Hobisch A, Culig Z. Accelerated in vivo growth of prostate tumors that up-regulate interleukin-6 is associated with reduced retinoblastoma protein expression and activation of the mitogen-activated protein kinase pathway. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 162:655-63. [PMID: 12547723 PMCID: PMC1851151 DOI: 10.1016/s0002-9440(10)63859-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Interleukin-6 (IL-6) is a multifunctional cytokine that activates the signaling pathways of Janus kinases-signal transducers and activators of transcription (STAT) and/or mitogen-activated protein kinases (MAPK) in various tumors. Thus, it modulates cell growth and apoptosis. IL-6 levels are elevated in tissues and sera from prostate cancer patients and IL-6 receptor expression has been detected in prostate cancer cell lines and clinical specimens. Continuous exposure of prostate cancer cells to IL-6 might alter their responsiveness to this cytokine. To gain more insight into the function of IL-6 in prostate carcinoma, we have inoculated LNCaP-IL-6+ cells, generated after prolonged treatment with IL-6, into nude mice (total n = 16, two independent experiments). Controls included animals bearing LNCaP-IL-6- cells, passaged at the same time as LNCaP-IL-6+ cells without supplementation of IL-6. LNCaP-IL-6+ tumor volumes were larger than those of their counterparts at all time points. There were no signs of cachexia in any of the experimental animals and all mice were free of metastases. To better understand the mechanisms responsible for accelerated growth of LNCaP-IL-6+ tumors, we have investigated the expression of cell-cycle regulatory molecules by Western blot analysis. The levels of cyclin-dependent kinase 2 were elevated in LNCaP-IL-6+ cells. There was a strong down-regulation of cyclins D1 and E in the LNCaP-IL-6+ subline. The cell-cycle inhibitor p27 was expressed at a low level in LNCaP-IL-6+ cells and could not be up-regulated by addition of IL-6. Most notably, LNCaP-IL-6+ cells exhibited a reduced expression of the hypophosphorylated form of the retinoblastoma protein (pRb). Accelerated tumor growth in our model system was also associated with alterations in IL-6-signaling pathways. The ability of IL-6 to induce tyrosine phosphorylation of STAT3 was abolished in the LNCaP-IL-6+ subline. In contrast, the levels of the MAPK extracellular signal-regulated kinases 1/2 increased in cells generated after long-term IL-6 treatment. The inhibitor of MAPK kinase PD 98059 retarded the proliferation of LNCaP-IL-6+ but not that of control cells. In summary, we show in the present study that chronic exposure of prostate cancer cells to IL-6 facilitates tumor growth in vivo by abolishment of the growth control by pRb and activation of the MAPK signaling pathway. These findings could be relevant to understand the role of IL-6 in prostate cancer progression.
Collapse
Affiliation(s)
- Hannes Steiner
- Departments of Urology, Pathology, and Medical Chemistry and Biochemistry, University of Innsbruck, Innsbruck, Austria
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Bell WC, Myers RB, Hosein TO, Oelschlager DK, Grizzle WE. The response of extracellular signal-regulated kinase (ERK) to androgen-induced proliferation in the androgen-sensitive prostate cancer cell line, LNCaP. Biotech Histochem 2003; 78:11-6. [PMID: 12713136 DOI: 10.1080/10520290312120003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
The mechanisms by which androgens stimulate proliferation of prostate cancer cells are poorly understood. It has been proposed that androgen stimulation may induce the mitogen-activated protein (MAP) kinase system in prostate cancer cells and lead to cellular proliferation. We attempted to evaluate the role of the extracellular signal-regulated kinase (ERK) pathway in the stimulation by androgens of prostate cancer cell proliferation. Androgen-sensitive prostate cancer cell line (LNCaP) cells plated on sterile glass coverslips were treated with 10(-8) M dihydrotestosterone (DHT) or epidermal growth factor (EGF) (10 ng/ml) for periods ranging from 1 min to 96 h. The proliferative index of the cells, evaluated by immunoperoxidase staining of cells with an antibody to Ki-67, was increased at least two-fold at all time points from 5 min to 48 h following exposure to either DHT or EGF. Immunohistochemical evaluation of ERK1/2 and pERK (activated ERK) demonstrated high levels of ERK1/2 in untreated LNCaP cells, while pERK was expressed at much lower levels. Following treatment with DHT, no change in staining intensity for either ERK1/2 or pERK was observed, while treatment with EGF resulted in no change in ERK1/2, but significantly increased cytoplasmic staining for pERK at all time points beyond 2 min. These results were confirmed by Western blot analysis of ERK1/2 and pERK expression in these cell lines following treatment with DHT or EGF. Our findings suggest that the proliferative response of prostate cancer cells to androgens, unlike the proliferative response to EGF, is not mediated by the activation of ERK1/2, and that currently undefined pathways other than those involving ERK1/2 are involved.
Collapse
Affiliation(s)
- W C Bell
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | | | | | | | | |
Collapse
|
36
|
Kue PF, Taub JS, Harrington LB, Polakiewicz RD, Ullrich A, Daaka Y. Lysophosphatidic acid-regulated mitogenic ERK signaling in androgen-insensitive prostate cancer PC-3 cells. Int J Cancer 2002; 102:572-9. [PMID: 12447997 DOI: 10.1002/ijc.10734] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Advanced and recurrent prostate tumors contain elevated levels of activated extracellular signal-regulated kinases 1 and 2 (ERK) in comparison to early-stage or benign specimens, and inhibition of ERK activation attenuates growth factor-dependent proliferation of prostate cells, suggesting a potential regulatory role for ERK in prostate tumorigenesis. Factors responsible for ERK activation in prostate cells are not well defined. Here, we show positive cooperative interaction between the G protein-coupled lysophosphatidic acid (LPA) and tyrosine kinase epidermal growth factor (EGF) receptors in androgen-insensitive prostate cancer PC-3 cells. Pre-treatment of the PC-3 cells with LPA decreases the dose of EGF required to elicit maximal activation of EGFR. Furthermore, treatment with LPA alone induces the rapid (maximal signal within 2 min) tyrosine phosphorylation of EGFR, and subsequent (maximal signal after 5 min) activation of ERK, suggesting that EGFR activation precedes ERK phosphorylation and may constitute a required component for signal relay from the LPA receptor to ERK. Accordingly, we show that inhibition of EGFR kinase activity attenuates the LPA-regulated ERK activation. In addition, we find that the LPA-regulated tyrosine phosphorylation of EGFR and activation of ERK are attenuated by batimastat, a generic inhibitor of matrix metalloproteinases (MMP). However, unlike the situation in fibroblasts, we find that the LPA-induced transactivation of EGFR in PC-3 cells is not mediated by shedding of heparin-binding EGF. Together, our data show that LPA and EGF cooperate to induce mitogenic signaling in prostate cancer cells in an MMP-regulated activation of the ERK pathway.
Collapse
Affiliation(s)
- Pao F Kue
- Department of Surgery (Urology), Duke University Medical Center, Durham, NC 27710, USA
| | | | | | | | | | | |
Collapse
|
37
|
Xie Y, Gibbs TC, Mukhin YV, Meier KE. Role for 18:1 Lysophosphatidic Acid as an Autocrine Mediator in Prostate Cancer Cells. J Biol Chem 2002; 277:32516-26. [PMID: 12084719 DOI: 10.1074/jbc.m203864200] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lysophosphatidic acid (LPA) is a lipid mediator that may play an important role in growth and survival of carcinomas. In this study, LPA production and response were characterized in two human prostate cancer (CaP) cell lines: PC-3 and Du145. Bombesin, a neuroendocrine peptide that is mitogenic for CaP cells, stimulated focal adhesion kinase phosphorylation and activated the extracellular signal-regulated kinase/mitogen-activated protein kinase pathway. Similar responses were elicited by 18:1 LPA (oleoyl-LPA). Studies using radioisotopic labeling revealed that both PC-3 and Du145 generate LPA and that LPA production is increased by bombesin. The kinetics of bombesin-induced phospholipase D activation and LPA production were similar. Using electrospray ionization mass spectrometry, 18:1 LPA was found to be an abundant LPA species in CaP cell medium. Structure activity studies of acyl-LPAs revealed that 18:1 LPA is most efficacious for activation of extracellular signal-regulated kinase and phospholipase D in CaP cells. Incubation with 18:1 LPA caused homologous desensitization of LPA response, whereas bombesin caused heterologous desensitization. LPA was present at nanomolar levels in medium from bombesin-treated cells. LPA extracted from the medium induced calcium mobilization in CaP cells. These results demonstrate that bioactive LPA is generated by CaP cells in response to a mitogen and suggest that 18:1 LPA can act as an autocrine mediator.
Collapse
Affiliation(s)
- Yuhuan Xie
- Department of Pharmacology and Medicine and the Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425, USA
| | | | | | | |
Collapse
|
38
|
Adolfsson PI, Ahlstrand C, Varenhorst E, Svensson SPS. Lysophosphatidic acid stimulates proliferation of cultured smooth muscle cells from human BPH tissue: sildenafil and papaverin generate inhibition. Prostate 2002; 51:50-8. [PMID: 11920958 DOI: 10.1002/pros.10077] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The endogenous substance lysophosphatidic acid (LPA) has been found to generate proliferation of cultured smooth muscle cells (SMC). Therefore, the effect of LPA on human benign prostate hyperplasia (BPH) could be of interest. METHODS The proliferative effect of LPA on cultured human prostatic SMC from specimens obtained at trans-urethral resection of the prostate (TURP) because of BPH, was analyzed by [3H]-thymidine and [35S]-methionine incorporation. In addition, LPA stimulated BPH SMC were treated with papaverin, forskolin, sildenafil or zaprinast, well known to increase the intracellular level of cAMP or cGMP. RESULTS LPA produced a dose-dependent increase in BPH SMC, both regarding DNA- and protein-synthesis with EC50 values of 3 and 10 microM, respectively. Furthermore, both papaverin, a general phosphodiesterase inhibitor regarding cAMP hydrolyzes, and forskolin, an adenylyl cyclase stimulating agent, inhibited the LPA-stimulated DNA replication in a dose dependent manner with IC50 = 2.5, and 0.35 microM, respectively. cGMP increasing agents, such as the NO-donors SIN-1 and SNAP, produced a weak anti-proliferative response. However, both phosphodiesterase 5 inhibitors sildenafil (Viagra) and zaprinast efficiently blocked DNA replication. In addition, when the protein synthesis was examined, we found that the LPA response was significantly inhibited by forskolin and papaverin. CONCLUSIONS The major conclusion of this investigation is that the endogenous serum component LPA, is able to promote human BPH SMC growth. In addition, our study indicates that cyclic nucleotides can inhibit this effect. Future clinical studies will be needed to determine if different specific phosphodiesterase inhibitors per se or in combination could represent a new therapeutic possibility for the treatment of BPH.
Collapse
Affiliation(s)
- Per I Adolfsson
- Department of Medicine and Care, Division of Pharmacology, Faculty of Health Science, Linköping University, Linköping, Sweden.
| | | | | | | |
Collapse
|
39
|
Abstract
Lysophosphatidic acid (LPA) belongs to a new family of lipid mediators that are endogenous growth factors and that elicit diverse biological effects, usually via the activation of G protein-coupled receptors. LPA can be generated after cell activation through the hydrolysis of preexisting phospholipids in the membranes of stimulated cells. A dramatic elevation of LPA levels was found in serum of patients suffering from ovarian carcinoma. Because these high LPA amounts can be detected as early as stage I of the disease, LPA has been introduced as a new marker for ovarian cancer. Progression of the malignancy is correlated with a differential expression of various LPA receptor subtypes. The presence of LPA in the follicular fluid of healthy individuals implicates that this biological mediator may be relevant to normal ovarian physiology. LPA induces proliferation and mitogenic signaling of prostate cancer cells, and a novel LPA receptor isoform has been recognized in healthy prostate tissues. This evidence indicates multiple roles for LPA in both male and female reproductive physiology and pathology. In this review, we summarize the literature on LPA generation, the way it is degraded, and the mechanisms by which signals are transduced by various LPA receptors in reproductive tissues, and we discuss possible future research directions in these areas.
Collapse
Affiliation(s)
- Lygia T Budnik
- Institute for Hormone and Fertility Research, University of Hamburg, Grandweg 64, D-22529 Hamburg, Germany.
| | | |
Collapse
|
40
|
|
41
|
GUANOSINE PHOSPHATE BINDING PROTEIN COUPLED RECEPTORS IN PROSTATE CANCER:. J Urol 2002. [DOI: 10.1097/00005392-200203000-00080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
42
|
Pelaia G, Cuda G, Vatrella A, Grembiale RD, De Sarro G, Maselli R, Costanzo FS, Avvedimento VE, Rotiroti D, Marsico SA. Effects of glucocorticoids on activation of c-jun N-terminal, extracellular signal-regulated, and p38 MAP kinases in human pulmonary endothelial cells. Biochem Pharmacol 2001; 62:1719-24. [PMID: 11755126 DOI: 10.1016/s0006-2952(01)00791-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mitogen-activated protein kinases (MAPK) play a central role in signal transduction by regulating many nuclear transcription factors involved in inflammatory, immune, and proliferative responses. The aim of this study was to investigate, in human pulmonary endothelial cells, the effects of synthetic glucocorticosteroids on activation of c-jun N-terminal kinases, extracellular signal-regulated kinases, and p38 subgroups of the MAPK family. Human microvascular endothelial cells from lung were stimulated for 2 h with either H(2)O(2) (2 mM), IL-1beta (10 ng/mL), or tumour necrosis factor-alpha (10 ng/mL). Under these conditions, a remarkable increase in the phosphorylation pattern of c-jun N-terminal kinases, extracellular signal-regulated kinases 1/2, and p38 was detected. Pretreatment for 12 h with dexamethasone (100 nM) was able to prevent phosphorylation-dependent MAPK activation in stimulated cells, without substantially affecting the expression levels of these enzymes. Our results suggest that inhibition of MAPK signaling pathways in human pulmonary endothelial cells may significantly contribute, by interfering with activation of several different transcription factors, to the antiinflammatory and immunosuppressive effects of glucocorticosteroids.
Collapse
Affiliation(s)
- G Pelaia
- Department of Pharmacobiological Sciences, "Magna Graecia" University of Catanzaro, Catanzaro, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Jones HE, Barrow D, Dutkowski CM, Goddard L, Smith C, Harper ME, Nicholson RI. Effect of an EGF-R selective tyrosine kinase inhibitor and an anti-androgen on LNCaP cells: identification of divergent growth regulatory pathways. Prostate 2001; 49:38-47. [PMID: 11550209 DOI: 10.1002/pros.1116] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The effect of an EGF-R selective tyrosine kinase (EGF-RTK) quinazoline inhibitor ZM252868 was determined on the androgen-sensitive human prostatic tumour cell line LNCaP, which can also respond via the EGF-R-regulated growth pathway for cell proliferation. Potential interaction or 'cross-talk' between steroid and the growth factor mitogen-activated protein kinase (MAPK) signalling pathway was also investigated. METHODS The responses of LNCaP cells to various growth factors in the absence and presence of the EGF-RTK inhibitor and/or steroid and anti-androgen Casodex, was determined using cell population analysis. The effect of the inhibitor on the expression of androgen receptor, EGF-R and activated MAPK was assessed immunocytochemically and changes in the MAPK signalling cascade were also determined using Western blotting techniques. RESULTS The ZM252868 inhibitor had no effect on LNCaP basal growth. At 100 nM and 1 microM concentrations, the inhibitor reduced the marked EGF- and TGF-alpha-stimulated LNCaP cell growth by 60% and to basal levels, respectively. Both bFGF- and 5alpha-DHT-stimulated growth were unaffected in this concentration range. The inhibitor (1 microM) decreased the expression of immunoreactive EGF-R but had no effect on androgen receptor levels. Activation of MAPK by EGF was noted, being down-regulated by the inhibitor at a concentration of 1 microM. MAPK was not activated by 5alpha-DHT. The anti-androgen Casodex reduced 5alpha-DHT-stimulated cell growth but had no effect on EGF-R mediated LNCaP growth or EGF-stimulated activated MAPK activity. Treatment with EGF and 5alpha-DHT in combination produced an additive effect on cell proliferation, with the anti-androgen and the EGF-RTK inhibitor only reducing the 5alpha-DHT- or EGF-stimulated portion of growth, respectively. CONCLUSIONS The study demonstrated the efficacy and selectivity of the ZM252868 inhibitor in inhibiting EGF-R mediated LNCaP cell growth. Additionally, no interaction between androgen and EGF-R mediated growth pathways was determined.
Collapse
Affiliation(s)
- H E Jones
- Tenovus Centre for Cancer Research, Welsh School of Pharmacy, Cardiff University, UK.
| | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
PURPOSE We investigated the mitogenic role of bradykinin (BK) in the regulation of the extracellular signal regulated kinase 1 and 2 (ERK), and the growth of androgen insensitive prostate cancer cells. MATERIALS AND METHODS Androgen insensitive PC3 cells were used in these studies. BK and epidermal growth factor were used as mitogens. The chemical inhibitors tyrphostin AG1478 (epidermal growth factor receptor inhibitor), bisindolylmaliemide (protein kinase C inhibitor) and PD98059 (MEK inhibitor) were applied 30 minutes before stimulation with agonist. Down-regulation of protein kinase C was accomplished by incubating cells overnight with phorbol ester. Cell proliferation was measured using WST-1 reagent and the trypan blue exclusion assay. ERK expression and activation were assayed by immunoblotting for total and phosphorylated ERK. RESULTS Bradykinin induced the proliferation of PC3 cells in a pathway that requires the activation of ERK. The BK regulated activation of ERK was time and dose dependent, yielding a maximal response at the same concentration range that elicits cellular growth. BK exerted its effect on ERK activation via a protein kinase C and epidermal growth factor receptor dependent pathway. Inhibition of the kinase activity of protein kinase C or epidermal growth factor receptor eliminated BK induced ERK activation. Furthermore, the inhibition of epidermal growth factor receptor transactivation abolished BK induced cell proliferation. CONCLUSIONS Our results show that BK induces the proliferation of androgen insensitive prostate cancer cells and suggest a possible pathophysiological role for BK in prostate cancer.
Collapse
Affiliation(s)
- L Barki-Harrington
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | |
Collapse
|
45
|
BARKI-HARRINGTON LIZA, DAAKA YEHIA. BRADYKININ INDUCED MITOGENESIS OF ANDROGEN INDEPENDENT PROSTATE CANCER CELLS. J Urol 2001. [DOI: 10.1016/s0022-5347(05)66305-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- LIZA BARKI-HARRINGTON
- From the Departments of Surgery and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina
| | - YEHIA DAAKA
- From the Departments of Surgery and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina
| |
Collapse
|
46
|
Tigyi G. Physiological responses to lysophosphatidic acid and related glycero-phospholipids. Prostaglandins Other Lipid Mediat 2001; 64:47-62. [PMID: 11324707 DOI: 10.1016/s0090-6980(01)00107-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
1-Acyl-2-hydroxy(lyso)-sn-glycero-3-phosphate (lysophosphatidic acid, LPA) has attracted a lot of attention in recent years due to the wide range of its biological effects that span the phylogenetic tree from slime mold to human. LPA can be viewed as a pleiotropic phospholipid growth factor that utilizes the same signal transduction mechanisms as traditional polypeptide growth factors; however, LPA activates these mechanism via specific G protein-coupled receptors. The concentration of LPA in serum is in the high micromolar range, making it the most abundant mitogen/survival factor present in serum, one that is often unknowingly utilized in tissue culture. The present review gives a historical perspective and a critical analysis of the LPA literature with a special emphasis on the physiological implications of its effects.
Collapse
Affiliation(s)
- G Tigyi
- Department of Physiology, University of Tennessee Health Sciences Center Memphis, 38163, USA.
| |
Collapse
|
47
|
Tessier DM, Matsumura F. Increased ErbB-2 tyrosine kinase activity, MAPK phosphorylation, and cell proliferation in the prostate cancer cell line LNCaP following treatment by select pesticides. Toxicol Sci 2001; 60:38-43. [PMID: 11222871 DOI: 10.1093/toxsci/60.1.38] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The oncogene erbB-2 codes for a receptor tyrosine kinase that functions as a key mitotic signal in a variety of cell types. Amplification or overexpression of erbB-2 occurs in many forms of cancer, such as of the breast, colon, and prostate, and is an indicator of poor prognosis in those diseases. In the human prostate cancer cell lines LNCaP and PC-3, erbB-2 kinase was activated by pesticides of different chemical classes: (1) the organochlorine insecticides beta-hexa-chlorocyclohexane (beta-HCH), o,p'-dichlorodiphenyltrichloroethane (o,p'-DDT), and heptachlor epoxide; (2) the pyrethroid insecticide trans-permethrin, and (3) the fungicide chlorothalonil. o,p'-DDT also causes phosphorylation of mitogen-activated protein kinase (MAPK) and cellular proliferation of the androgen-dependent LNCaP line. However, no proliferative effect was observed in the androgen-independent PC-3 line. The proliferative effect of o,p'-DDT in LNCaP could not be blocked by the androgen receptor antagonist p,p'-dichlorodiphenyldichloroethene (p,p'-DDE), indicating that this effect of o,p'-DDT does not occur through direct interaction with the androgen receptor. Together these data demonstrate a putative mechanism for the action of certain pesticides in hormonal carcinogenesis.
Collapse
Affiliation(s)
- D M Tessier
- Department of Environmental Toxicology and the Center for Environmental Health Sciences, University of California, Davis, California 95616, USA.
| | | |
Collapse
|