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Prabhu AV, Krycer JR, Brown AJ. Overexpression of a key regulator of lipid homeostasis, Scap, promotes respiration in prostate cancer cells. FEBS Lett 2013; 587:983-8. [PMID: 23454642 DOI: 10.1016/j.febslet.2013.02.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 02/19/2013] [Indexed: 01/01/2023]
Abstract
Prostate metabolism is unique, characterised by cholesterol accumulation and reduced respiration. Are these related? We modulated cholesterol levels and despite changes in mitochondrial cholesterol content, we saw no effects on lactate production or respiration. Instead, these features may be related via sterol regulatory element-binding protein 2 (SREBP-2), the master transcriptional regulator of cholesterol synthesis. SREBP-2 diverts acetyl-CoA into cholesterol synthesis and may thus reduce respiration. We examined LNCaP cells overexpressing the SREBP-2 regulator, Scap: although having higher SREBP-2 activity, these cells displayed higher respiration. This striking observation warrants further investigation. Given that SREBP-2 and Scap are regulated by factors driving prostate growth, exploring this observation further could shed light on prostate carcinogenesis.
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Affiliation(s)
- Anika Vinayak Prabhu
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia
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Cholesterol accumulation in prostate cancer: a classic observation from a modern perspective. Biochim Biophys Acta Rev Cancer 2013; 1835:219-29. [PMID: 23357067 DOI: 10.1016/j.bbcan.2013.01.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/12/2013] [Accepted: 01/15/2013] [Indexed: 12/26/2022]
Abstract
Prostate cancer (PCa) is the most common cancer in men in developed countries. Epidemiological studies have associated high blood-cholesterol levels with an increased risk of PCa, whilst cholesterol-lowering drugs (statins) reduce the risk of advanced PCa. Furthermore, normal prostate epithelial cells have an abnormally high cholesterol content, with cholesterol levels increasing further during progression to PCa. In this review, we explore why and how this occurs. Concurrent to this observation, intense efforts have been expended in cardiovascular research to better understand the regulators of cholesterol homeostasis. Here, we apply this knowledge to elucidate the molecular mechanisms driving the accumulation of cholesterol in PCa. For instance, recent evidence from our group and others shows that major signalling players in prostate growth and differentiation, such as androgens and Akt, modulate the key transcriptional regulators of cholesterol homeostasis to enhance cholesterol levels. This includes adjusting central carbon metabolism to sustain greater lipid synthesis. Perturbations in cholesterol homeostasis appear to be maintained even when PCa approaches the advanced, 'castration-resistant' state. Overall, this provides a link between cholesterol accumulation and PCa cell growth. Given there is currently no cure for castration-resistant PCa, could cholesterol metabolism be a novel target for PCa therapy? Overall, this review presents a picture that cholesterol metabolism is important for PCa development: growth-promoting factors stimulate cholesterol accumulation, which in turn presents a possible target for chemotherapy. Consequently, we recommend future investigations, both to better elucidate the mechanisms driving this accumulation and applying it in novel chemotherapeutic strategies.
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Krycer JR, Brown AJ. Does changing androgen receptor status during prostate cancer development impact upon cholesterol homeostasis? PLoS One 2013; 8:e54007. [PMID: 23320115 PMCID: PMC3540066 DOI: 10.1371/journal.pone.0054007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 12/05/2012] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Recent evidence associates prostate cancer with high cholesterol levels, with cholesterol being an important raw material for cell-growth. Within the cell, cholesterol homeostasis is maintained by two master transcription factors: sterol-regulatory element-binding protein 2 (SREBP-2) and liver X receptor (LXR). We previously showed that the androgen receptor, a major player in prostate cell physiology, toggles these transcription factors to promote cholesterol accumulation. Given that prostate cancer therapy targets the androgen receptor, selecting for cells with altered androgen receptor activity, how would this affect SREBP-2 and LXR activity? Using a novel prostate cancer progression model, we explored how this crosstalk between the androgen receptor and cholesterol homeostasis changes during prostate cancer development. METHODOLOGY/PRINCIPAL FINDINGS Firstly, we characterised our progression model, which involved 1) culturing LNCaP cells at physiological testosterone levels to generate androgen-tolerant LNCaP-305 cells, and 2) culturing LNCaP-305 with the anti-androgen casodex to generate castration-resistant LNCaP-364 cells. This progression was accompanied by upregulated androgen receptor expression, typically seen clinically, and a reduction in androgen receptor activity. Although this influenced how SREBP-2 and LXR target genes responded to androgen treatment, cellular cholesterol levels and their response to changing sterol status was similar in all LNCaP sub-lines. CONCLUSION/SIGNIFICANCE Overall cholesterol homeostasis is unaffected by changing androgen receptor activity in prostate cancer cells. This does not negate the relationship between androgens and cholesterol homeostasis, but rather suggests that other factors compensate for altered androgen receptor activity. Given that cholesterol regulation is maintained during progression, this supports the growing idea that cholesterol metabolism is a suitable target for prostate cancer.
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Affiliation(s)
- James Robert Krycer
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - Andrew John Brown
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
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A key regulator of cholesterol homoeostasis, SREBP-2, can be targeted in prostate cancer cells with natural products. Biochem J 2012; 446:191-201. [PMID: 22657538 DOI: 10.1042/bj20120545] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
There is growing evidence showing that prostate cancer cells have perturbed cholesterol homoeostasis, accumulating cholesterol to promote cell growth. Consequently, cholesterol-lowering drugs such as statins are being evaluated in prostate cancer treatment. Furthermore, natural products such as betulin (from birch tree bark) and tocotrienol (a minor form of vitamin E) have been shown to lower cholesterol levels. Using these drugs and oxysterols, we have determined which aspects of cholesterol homoeostasis should be targeted in prostate cancer, e.g. cellular cholesterol levels are increased by the transcription factor SREBP-2 (sterol-regulatory-element-binding protein isoform 2), whereas LXR (liver X receptor) promotes cholesterol efflux. Whereas betulin exerted non-specific effects on cell viability, tocotrienols produced a strong direct correlation between SREBP-2 activity and cell viability. Mechanistically, tocotrienols lowered SREBP-2 activity by degrading mature SREBP-2 independently of the proteasome. In contrast, no correlation was seen between LXR activity and cell viability, implying that SREBP-2 is a better target than LXR for prostate cancer treatment. Lastly, androgen-dependent and -independent LNCaP cells were both sensitive to tocotrienols. Overall, this suggests that tocotrienols and other drugs targeting the SREBP-2 pathway are a potential therapeutic option for prostate cancer.
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Parada B, Reis F, Pinto Â, Sereno J, Xavier-Cunha M, Neto P, Rocha-Pereira P, Mota A, Figueiredo A, Teixeira F. Chemopreventive efficacy of Atorvastatin against nitrosamine-induced rat bladder cancer: antioxidant, anti-proliferative and anti-inflammatory properties. Int J Mol Sci 2012; 13:8482-8499. [PMID: 22942715 PMCID: PMC3430246 DOI: 10.3390/ijms13078482] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 06/14/2012] [Accepted: 07/02/2012] [Indexed: 12/19/2022] Open
Abstract
To investigate the anti-carcinogenic effects of Atorvastatin (Atorva) on a rat bladder carcinogenesis model with N-butyl-N-(4-hydroxibutil)nitrosamine (BBN), four male Wistar rat groups were studied: (1) Control: vehicle; (2) Atorva: 3 mg/kg bw/day; (3) Carcinogen: BBN (0.05%); (4) Preventive Atorva: 3 mg/kg bw/day Atorva + BBN. A two phase protocol was used, in which the drug and the carcinogen were given between week 1 and 8 and tumor development or chemoprevention were expressed between week 9 and 20, when the bladders were collected for macroscopic, histological and immunohistochemical (p53, ki67, CD31) evaluation. Serum was assessed for markers of inflammation, proliferation and redox status. The incidence of bladder carcinoma was: control 0/8 (0%); Atorva 0/8 (0%); BBN 13/20 (65%) and Atorva + BBN 1/8 (12.5%). The number and volume of tumors were significantly lower in the Atorva + BBN group, with a marked reduction in hyperplasia, dysplasia and carcinoma in situ lesions. An anti-proliferative, anti-inflammatory and antioxidant profile was also observed in the preventive Atorva group. p53 and ki67 immunostaining were significantly increased in the BBN-treated rats, which was prevented in the Atorva + BBN group. No differences were found for CD31 expression. In conclusion, Atorvastatin had a clear inhibitory effect on bladder cancer development, probably due to its antioxidant, anti-proliferative and anti-inflammatory properties.
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Affiliation(s)
- Belmiro Parada
- Laboratory of Pharmacology & Experimental Therapeutics, Institute of Biomedical Research on Light and Image, Medicine Faculty, Coimbra University, Coimbra, 3000-548, Portugal; E-Mails: (Â.P.); (J.S.)
- Department of Urology & Renal Transplantation, Coimbra University Hospital, Coimbra, 3000-075, Portugal; E-Mails: (A.M.); (A.F.)
- Authors to whom correspondence should be addressed; E-Mails: (B.P.); (F.R.); (F.T.); Tel.: +351-239-480-053 (F.R.); Fax: +351-239-480-065 (F.R.)
| | - Flávio Reis
- Laboratory of Pharmacology & Experimental Therapeutics, Institute of Biomedical Research on Light and Image, Medicine Faculty, Coimbra University, Coimbra, 3000-548, Portugal; E-Mails: (Â.P.); (J.S.)
- Authors to whom correspondence should be addressed; E-Mails: (B.P.); (F.R.); (F.T.); Tel.: +351-239-480-053 (F.R.); Fax: +351-239-480-065 (F.R.)
| | - Ângela Pinto
- Laboratory of Pharmacology & Experimental Therapeutics, Institute of Biomedical Research on Light and Image, Medicine Faculty, Coimbra University, Coimbra, 3000-548, Portugal; E-Mails: (Â.P.); (J.S.)
| | - José Sereno
- Laboratory of Pharmacology & Experimental Therapeutics, Institute of Biomedical Research on Light and Image, Medicine Faculty, Coimbra University, Coimbra, 3000-548, Portugal; E-Mails: (Â.P.); (J.S.)
| | - Maria Xavier-Cunha
- Service of Anatomic Pathology, Coimbra University Hospital, Coimbra, 3000-075, Portugal; E-Mails: (M.X.-C.); (P.N.)
| | - Paula Neto
- Service of Anatomic Pathology, Coimbra University Hospital, Coimbra, 3000-075, Portugal; E-Mails: (M.X.-C.); (P.N.)
| | - Petronila Rocha-Pereira
- Research Centre for Health Sciences, Beira Interior University, Covilhã, 6201-506, Portugal; E-Mail:
| | - Alfredo Mota
- Department of Urology & Renal Transplantation, Coimbra University Hospital, Coimbra, 3000-075, Portugal; E-Mails: (A.M.); (A.F.)
| | - Arnaldo Figueiredo
- Department of Urology & Renal Transplantation, Coimbra University Hospital, Coimbra, 3000-075, Portugal; E-Mails: (A.M.); (A.F.)
| | - Frederico Teixeira
- Laboratory of Pharmacology & Experimental Therapeutics, Institute of Biomedical Research on Light and Image, Medicine Faculty, Coimbra University, Coimbra, 3000-548, Portugal; E-Mails: (Â.P.); (J.S.)
- Authors to whom correspondence should be addressed; E-Mails: (B.P.); (F.R.); (F.T.); Tel.: +351-239-480-053 (F.R.); Fax: +351-239-480-065 (F.R.)
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Murtola TJ, Syvälä H, Pennanen P, Bläuer M, Solakivi T, Ylikomi T, Tammela TLJ. The importance of LDL and cholesterol metabolism for prostate epithelial cell growth. PLoS One 2012; 7:e39445. [PMID: 22761797 PMCID: PMC3384647 DOI: 10.1371/journal.pone.0039445] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Accepted: 05/21/2012] [Indexed: 01/02/2023] Open
Abstract
Cholesterol-lowering treatment has been suggested to delay progression of prostate cancer by decreasing serum LDL. We studied in vitro the effect of extracellular LDL-cholesterol on the number of prostate epithelial cells and on the expression of key regulators of cholesterol metabolism. Two normal prostatic epithelial cell lines (P96E, P97E), two in vitro immortalized epithelial cell lines (PWR-1E, RWPE-1) and two cancer cell lines (LNCaP and VCaP) were grown in cholesterol-deficient conditions. Cells were treated with 1-50 µg/ml LDL-cholesterol and/or 100 nM simvastatin for seven days. Cell number relative to control was measured with crystal violet staining. Changes in mRNA and protein expression of key effectors in cholesterol metabolism (HMGCR, LDLR, SREBP2 and ABCA1) were measured with RT-PCR and immunoblotting, respectively. LDL increased the relative cell number of prostate cancer cell lines, but reduced the number of normal epithelial cells at high concentrations. Treatment with cholesterol-lowering simvastatin induced up to 90% reduction in relative cell number of normal cell lines but a 15-20% reduction in relative number of cancer cells, an effect accompanied by sharp upregulation of HMGCR and LDLR. These effects were prevented by LDL. Compared to the normal cells, prostate cancer cells showed high expression of cholesterol-producing HMGCR but failed to express the major cholesterol exporter ABCA1. LDL increased relative cell number of cancer cell lines, and these cells were less vulnerable than normal cells to cholesterol-lowering simvastatin treatment. Our study supports the importance of LDL for prostate cancer cells, and suggests that cholesterol metabolism in prostate cancer has been reprogrammed to increased production in order to support rapid cell growth.
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Affiliation(s)
- Teemu J Murtola
- School of Medicine, University of Tampere, Tampere, Finland.
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Ivanov VN, Hei TK. Regulation of apoptosis in human melanoma and neuroblastoma cells by statins, sodium arsenite and TRAIL: a role of combined treatment versus monotherapy. Apoptosis 2012; 16:1268-84. [PMID: 21910007 DOI: 10.1007/s10495-011-0649-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Treatment of melanoma cells by sodium arsenite or statins (simvastatin and lovastatin) dramatically modified activities of the main cell signaling pathways resulting in the induction of heme oxygenase-1 (HO-1) and in a downregulation of cyclooxygenase-2 (COX-2) protein levels. Through heme degradation and the production of carbon monoxide and biliverdin, HO-1 plays a protective role in different scenario of oxidative stress followed by mitochondrial apoptosis. Both sodium arsenite and statins could be efficient inducers of apoptosis in some melanoma cell lines, but often exhibited only modest proapoptotic activity in others, due to numerous protective mechanisms. We demonstrated in the present study that treatment by sodium arsenite or statins with an additional inhibition of HO-1 expression (or activation) caused a substantial upregulation of apoptosis in melanoma cells. Sodium arsenite- or statin-induced apoptosis was independent of BRAF status (wild type versus V600E) in melanoma lines. Monotreatment required high doses of statins (20-40 μM) for effective induction of apoptosis. As an alternative approach, pretreatment of melanoma cells with statin at decreased doses (5-20 μM) dramatically enhanced TRAIL-induced apoptosis, due to suppression of the NF-κB and STAT3-transcriptional targets (including COX-2) and downregulation of cFLIP-L (a caspase-8 inhibitor) protein levels. Furthermore, combined treatment with sodium arsenite and TRAIL or simvastatin and TRAIL efficiently induced apoptotic commitment in human neuroblastoma cells. In summary, our findings on enhancing effects of combined treatment of cancer cells using statin and TRAIL provide the rationale for further preclinical evaluation.
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Affiliation(s)
- Vladimir N Ivanov
- Department of Radiation Oncology, Center for Radiological Research, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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Abstract
Cellular metabolism influences life and death decisions. An emerging theme in cancer biology is that metabolic regulation is intricately linked to cancer progression. In part, this is due to the fact that proliferation is tightly regulated by availability of nutrients. Mitogenic signals promote nutrient uptake and synthesis of DNA, RNA, proteins and lipids. Therefore, it seems straight-forward that oncogenes, that often promote proliferation, also promote metabolic changes. In this review we summarize our current understanding of how 'metabolic transformation' is linked to oncogenic transformation, and why inhibition of metabolism may prove a cancer's 'Achilles' heel'. On one hand, mutation of metabolic enzymes and metabolic stress sensors confers synthetic lethality with inhibitors of metabolism. On the other hand, hyperactivation of oncogenic pathways makes tumors more susceptible to metabolic inhibition. Conversely, an adequate nutrient supply and active metabolism regulates Bcl-2 family proteins and inhibits susceptibility to apoptosis. Here, we provide an overview of the metabolic pathways that represent anti-cancer targets and the cell death pathways engaged by metabolic inhibitors. Additionally, we will detail the similarities between metabolism of cancer cells and metabolism of proliferating cells.
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Oxysterols are allosteric activators of the oncoprotein Smoothened. Nat Chem Biol 2012; 8:211-20. [PMID: 22231273 PMCID: PMC3262054 DOI: 10.1038/nchembio.765] [Citation(s) in RCA: 211] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 11/03/2011] [Indexed: 12/13/2022]
Abstract
Oxysterols are a class of endogenous signaling molecules that can activate the Hedgehog pathway, which has critical roles in development, regeneration and cancer. However, it has been unclear how oxysterols influence Hedgehog signaling, including whether their effects are mediated through a protein target or indirectly through effects on membrane properties. To answer this question, we synthesized the enantiomer and an epimer of the most potent oxysterol, 20(S)-hydroxycholesterol. Using these molecules, we show that the effects of oxysterols on Hedgehog signaling are exquisitely stereoselective, consistent with the hypothesis that they function through a specific protein target. We present several lines of evidence that this protein target is the seven-pass transmembrane protein Smoothened, a major drug target in oncology. Our work suggests that these enigmatic sterols, which have multiple effects on cell physiology, may act as ligands for signaling receptors and provides a generally applicable framework for probing sterol signaling mechanisms.
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Krycer JR, Brown AJ. Cross-talk between the androgen receptor and the liver X receptor: implications for cholesterol homeostasis. J Biol Chem 2011; 286:20637-47. [PMID: 21489984 PMCID: PMC3121513 DOI: 10.1074/jbc.m111.227082] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 04/01/2011] [Indexed: 01/16/2023] Open
Abstract
High cholesterol levels are associated with prostate cancer development. Androgens promote cholesterol accumulation by activating the sterol-regulatory element-binding protein isoform 2 (SREBP-2) transcription factor. However, SREBP-2 is in balance with the liver X receptor (LXR; NR1H2/NR1H3), a transcription factor that prevents cholesterol accumulation. Here, we show that LXR activity is down-regulated by the androgen receptor (AR; NR3C4). In turn, this reduces LXR target gene expression. This antagonism on LXR is also exerted by other steroid hormone receptors, including the estrogen, glucocorticoid, and progesterone receptors. This suggests a generalizable mechanism, but the AR does not affect LXR mRNA levels, protein degradation, or DNA binding. We also found that the AR does not require protein synthesis to influence LXR, suggesting a direct antagonism. However, the AR does not directly bind LXR. The AR N-terminal domain (involved in transactivation), but not its DNA-binding domain, is required to suppress LXR activity, suggesting coactivator competition. Overall, this androgen-mediated antagonism of LXR complements SREBP-2 activation, providing a more complete picture as to how androgens increase cellular cholesterol levels in a prostate cancer setting. Given the cross-talk between other steroid hormone receptors and LXR, hormonal regulation of cholesterol via LXR may occur in a variety of cellular contexts.
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Affiliation(s)
- James Robert Krycer
- From the School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrew John Brown
- From the School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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Miller T, Yang F, Wise CE, Meng F, Priester S, Munshi MK, Guerrier, Dostal DE, Glaser SS. Simvastatin stimulates apoptosis in cholangiocarcinoma by inhibition of Rac1 activity. Dig Liver Dis 2011; 43:395-403. [PMID: 21334995 PMCID: PMC3071437 DOI: 10.1016/j.dld.2011.01.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/03/2011] [Accepted: 01/10/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND Simvastatin is a cholesterol-lowering drug that is widely used to prevent and treat atherosclerotic cardiovascular disease. Simvastatin exhibits numerous pleiotropic effects including anti-cancer activity. However, the effect of simvastatin on cholangiocarcinoma has not been evaluated. AIM The aim of our study was to determine the effect of simvastatin on cholangiocarcinoma proliferation. METHODS The effect of simvastatin was evaluated in five human cholangiocarcinoma cell lines (Mz-ChA-1, HuH-28, TFK-1, SG231, and HuCCT1) and normal cholangiocyte cell line (HiBEpiC). RESULTS We found that simvastatin stimulates a reduction in cell viability and apoptosis of cholangiocarcinoma cell lines, whilst in normal human cholangiocytes, HiBEpiC, simvastatin inhibits proliferation with no effect on apoptosis. Simvastatin-induced reduction of cell viability was partially blocked by pre-treatment with metabolites of the mevalonate pathway. In Mz-ChA-1 cells, pre-treatment with cholesterol alone stimulated an increase in the number of viable cells and fully restored cell viability following simvastatin treatment. Treatment with simvastatin triggered the loss of lipid raft localised Rac1 and reduction of Rac1 activity in Mz-ChA-1 cells. This effect was prevented by pre-treatment with cholesterol. CONCLUSION Collectively, our results demonstrate that simvastatin induces cholangiocarcinoma cancer cell death by disrupting Rac1/lipid raft colocalisation and depression of Rac1 activity.
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Affiliation(s)
- Timothy Miller
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
| | - Fuquan Yang
- Shengjing Hospital, China Medical University, Shenyang City, Liaoning Province, China, 100004
| | - Candace E. Wise
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
| | - Fanyin Meng
- Scott & White Digestive Disease Research Center, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504,Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
| | - Sally Priester
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
| | - Md Kamruzzaman Munshi
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
| | - Guerrier
- Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
| | - David E. Dostal
- Molecular Cardiology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
| | - Shannon S. Glaser
- Scott & White Digestive Disease Research Center, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504,Department of Medicine, Division of Gastroenterology, Scott & White and Texas A&M Health Science Center, College of Medicine, 702 Southwest HK Dodgen Loop, Temple, Texas USA 76504
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Jahn KA, Su Y, Braet F. Multifaceted nature of membrane microdomains in colorectal cancer. World J Gastroenterol 2011; 17:681-90. [PMID: 21390137 PMCID: PMC3042645 DOI: 10.3748/wjg.v17.i6.681] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 11/23/2010] [Accepted: 11/30/2010] [Indexed: 02/06/2023] Open
Abstract
Membrane microdomains or lipid rafts are known to be highly dynamic and to act as selective signal transduction mediators that facilitate interactions between the cell’s external and internal environments. Lipid rafts play an important mediating role in the biology of cancer: they have been found in almost all existing experimental cancer models, including colorectal cancer (CRC), and play key regulatory roles in cell migration, metastasis, cell survival and tumor progression. This paper explores the current state of knowledge in this field by highlighting some of the pioneering and recent lipid raft studies performed on different CRC cell lines and human tissue samples. From this literature review, it becomes clear that membrane microdomains appear to be implicated in all key intracellular signaling pathways for lipid metabolism, drug resistance, cell adhesion, cell death, cell proliferation and many other processes in CRC. All signal transduction pathways seem to originate directly from those peculiar lipid islands, thereby orchestrating the colon cancer cells’ state and fate. As confirmed by recent animal and preclinical studies in different CRC models, continuing to unravel the structure and function of lipid rafts - including their associated complex signaling pathways - will likely bring us one step closer to better monitoring and treating of colon cancer patients.
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63
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Puttananjaiah MKH, Dhale MA, Gaonkar V, Keni S. Statins: 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors demonstrate anti-atherosclerotic character due to their antioxidant capacity. Appl Biochem Biotechnol 2010; 163:215-22. [PMID: 20640529 DOI: 10.1007/s12010-010-9031-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 07/01/2010] [Indexed: 12/24/2022]
Abstract
Atherosclerosis is a chronic inflammatory disease of multiple etiologies. It is associated with the accumulation of oxidized lipids in arterial lesions leading to coronary heart disease. 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (commonly known as statins) are widely used in cardiovascular disease prevention to lower the cholesterol. The antioxidant activity of HMG-CoA reductase inhibitors was studied by lipid peroxidation inhibition assay, DPPH, and hydroxyl radical scavenging-activity methods. The lovastatin (93%) and simvastatin (96%) showed significant action of lipid peroxidation inhibition compared to other HMG-CoA reductase inhibitors. The DPPH radical and hydroxyl radical scavenging activity of simvastatin was 38% and 33%, respectively. The oxidative modification of serum lipid due to reactive oxygen species causes atherosclerosis. This study revealed the importance of lovastatin and simvastatin to prevent oxidative stress-related cardiovascular diseases.
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Affiliation(s)
- Mohan-Kumari H Puttananjaiah
- Department of Food Microbiology, Central Food Technological Research Institute, Council of Scientific and Industrial Research, Mysore, India
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Krycer JR, Sharpe LJ, Luu W, Brown AJ. The Akt-SREBP nexus: cell signaling meets lipid metabolism. Trends Endocrinol Metab 2010; 21:268-76. [PMID: 20117946 DOI: 10.1016/j.tem.2010.01.001] [Citation(s) in RCA: 269] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2009] [Revised: 12/22/2009] [Accepted: 01/06/2010] [Indexed: 01/09/2023]
Abstract
Phosphatidylinositol 3'-kinase (PI3K) and Akt are signaling kinases involved in cell survival and proliferation. Recent evidence suggests that PI3K/Akt activates the sterol-regulatory element-binding proteins (SREBPs), master transcriptional regulators of lipid metabolism. The precise molecular mechanisms are controversial and differ between SREBP isoforms; proposed mechanisms include increased trafficking and processing of SREBP, reduced degradation, and involvement of the downstream signaling hub, mammalian target of rapamycin complex 1 (mTORC1). In this report, we explore the various mechanistic links between Akt and SREBP. We consider this relationship in diseases where Akt and lipids play crucial roles, including diabetes, viral infections and cancer, suggesting that this Akt-SREBP link provides fresh insights into human health and disease.
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Affiliation(s)
- James R Krycer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia
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Abstract
Although often considered in a negative light, cholesterol is an essential molecule with unusually diverse functions. Cholesterol and related sterols (ergosterol in yeast, phytosterols in plants) is considered a hallmark of eukaryotes, and may even have triggered the evolution of multicellular organisms. Synthesis of cholesterol is an extremely oxygen-intensive process and requires sufficient terrestrial oxygen to proceed. In turn, several lines of evidence support the argument that cholesterol evolved at least in part as an adaptation to the hazards of oxygen. This evolutionary perspective usefully informs medical research on cholesterol to address health-related issues, as illustrated by examples drawn from three prominent human diseases: cataracts, heart disease, and cancer.
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Affiliation(s)
- Andrew J Brown
- BABS, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney NSW 2052, Australia.
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66
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Krycer JR, Kristiana I, Brown AJ. Cholesterol homeostasis in two commonly used human prostate cancer cell-lines, LNCaP and PC-3. PLoS One 2009; 4:e8496. [PMID: 20041144 PMCID: PMC2794383 DOI: 10.1371/journal.pone.0008496] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 12/03/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Recently, there has been renewed interest in the link between cholesterol and prostate cancer. It has been previously reported that in vitro, prostate cancer cells lack sterol-mediated feedback regulation of the major transcription factor in cholesterol homeostasis, sterol-regulatory element binding protein 2 (SREBP-2). This could explain the accumulation of cholesterol observed in clinical prostate cancers. Consequently, perturbed feedback regulation to increased sterol levels has become a pervasive concept in the prostate cancer setting. Here, we aimed to explore this in greater depth. METHODOLOGY/PRINCIPAL FINDINGS After altering the cellular cholesterol status in LNCaP and PC-3 prostate cancer cells, we examined SREBP-2 processing, downstream effects on promoter activity and expression of SREBP-2 target genes, and functional activity (low-density lipoprotein uptake, cholesterol synthesis). In doing so, we observed that LNCaP and PC-3 cells were sensitive to increased sterol levels. In contrast, lowering cholesterol levels via statin treatment generated a greater response in LNCaP cells than PC-3 cells. This highlighted an important difference between these cell-lines: basal SREBP-2 activity appeared to be higher in PC-3 cells, reducing sensitivity to decreased cholesterol levels. CONCLUSION/SIGNIFICANCE Thus, prostate cancer cells are sensitive to changing sterol levels in vitro, but the extent of this regulation differs between prostate cancer cell-lines. These results shed new light on the regulation of cholesterol metabolism in two commonly used prostate cancer cell-lines, and emphasize the importance of establishing whether or not cholesterol homeostasis is perturbed in prostate cancer in vivo.
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Affiliation(s)
- James Robert Krycer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Ika Kristiana
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Andrew John Brown
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
- * E-mail:
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Wiklund ED, Catts VS, Catts SV, Ng TF, Whitaker NJ, Brown AJ, Lutze-Mann LH. Cytotoxic effects of antipsychotic drugs implicate cholesterol homeostasis as a novel chemotherapeutic target. Int J Cancer 2009; 126:28-40. [PMID: 19662652 DOI: 10.1002/ijc.24813] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The reported reduction in cancer risk in those suffering from schizophrenia may be because antipsychotic medications have antineoplastic effects. In this study, 6 antipsychotic agents with a range of structural and pharmacological properties (reserpine, chlorpromazine, haloperidol, pimozide, risperidone and olanzapine), were screened for their effect on the viability of cell lines derived from lymphoblastoma, neuroblastoma, non-small cell lung cancer and breast adenocarcinoma. We aimed to determine if antipsychotic drugs in general possess cancer-specific cytotoxic potential, and whether it can be attributed to a common mode of action. With the exception of risperidone, all drugs tested displayed selective inhibition of the viability of cancer cell lines compared with normal cells. Using Affymetrix expression microarrays and quantitative real-time polymerase chain reaction, we found that for the antipsychotic drugs, olanzapine and pimozide, cytotoxicity appeared to be mediated via effects on cholesterol homeostasis. The role of cholesterol metabolism in the selective cytotoxicity of these drugs was supported by demonstration of their increased lethality when coadministered with a cholesterol synthesis inhibitor, mevastatin. Also, pimozide and olanzapine showed accelerating cytotoxic effects from 12 to 48 hr in time course studies, mirroring the time-dependent onset of cytotoxicity induced by the amphiphile, U18666A. On the basis of these results, we concluded that the Class II cationic amphiphilic properties of antipsychotic drugs contribute to their cytotoxic effects by acting on cholesterol homeostasis and altering the biophysical properties of cellular membranes, and that drugs affecting membrane-related cholesterol pathways warrant further investigation as potential augmentors of standard cancer chemotherapy.
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Affiliation(s)
- Erik D Wiklund
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
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68
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Mimeault M, Batra SK. Recent advances on skin-resident stem/progenitor cell functions in skin regeneration, aging and cancers and novel anti-aging and cancer therapies. J Cell Mol Med 2009; 14:116-34. [PMID: 19725922 PMCID: PMC2916233 DOI: 10.1111/j.1582-4934.2009.00885.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Recent advances in skin-resident adult stem/progenitor cell research have revealed that these immature and regenerative cells with a high longevity provide critical functions in maintaining skin homeostasis and repair after severe injuries along the lifespan of individuals. The establishment of the functional properties of distinct adult stem/progenitor cells found in skin epidermis and hair follicles and extrinsic signals from their niches, which are deregulated during their aging and malignant transformation, has significantly improved our understanding on the etiopathogenesis of diverse human skin disorders and cancers. Particularly, enhanced ultraviolet radiation exposure, inflammation and oxidative stress and telomere attrition during chronological aging may induce severe DNA damages and genomic instability in the skin-resident stem/progenitor cells and their progenies. These molecular events may result in the alterations in key signalling components controlling their self-renewal and/or regenerative capacities as well as the activation of tumour suppressor gene products that trigger their growth arrest and senescence or apoptotic death. The progressive decline in the regenerative functions and/or number of skin-resident adult stem/progenitor cells may cause diverse skin diseases with advancing age. Moreover, the photoaging, telomerase re-activation and occurrence of different oncogenic events in skin-resident adult stem/progenitor cells may also culminate in their malignant transformation into cancer stem/progenitor cells and skin cancer initiation and progression. Therefore, the anti-inflammatory and anti-oxidant treatments and stem cell-replacement and gene therapies as well as the molecular targeting of their malignant counterpart, skin cancer-initiating cells offer great promise to treat diverse skin disorders and cancers.
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Affiliation(s)
- Murielle Mimeault
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA.
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69
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Molecular mechanisms involved in farnesol-induced apoptosis. Cancer Lett 2009; 287:123-35. [PMID: 19520495 DOI: 10.1016/j.canlet.2009.05.015] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 05/14/2009] [Accepted: 05/15/2009] [Indexed: 12/11/2022]
Abstract
The isoprenoid alcohol farnesol is an effective inducer of cell cycle arrest and apoptosis in a variety of carcinoma cell types. In addition, farnesol has been reported to inhibit tumorigenesis in several animal models suggesting that it functions as a chemopreventative and anti-tumor agent in vivo. A number of different biochemical and cellular processes have been implicated in the growth-inhibitory and apoptosis-inducing effects of farnesol. These include regulation of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and CTP:phosphocholine cytidylyltransferase alpha (CCTalpha), rate-limiting enzymes in the mevalonate pathway and phosphatidylcholine biosynthesis, respectively, and the generation of reactive oxygen species. In some cell types the action of farnesol is mediated through nuclear receptors, including activation of farnesoid X receptor (FXR) and peroxisome proliferator-activated receptors (PPARs). Recent studies have revealed that induction of endoplasmic reticulum (ER) stress and the subsequent activation of the unfolded protein response (UPR) play a critical role in the induction of apoptosis by farnesol in lung carcinoma cells. This induction was found to be dependent on the activation of the MEK1/2-ERK1/2 pathway. In addition, farnesol induces activation of the NF-kappaB signaling pathway and a number of NF-kappaB target genes. Optimal activation of NF-kappaB was reported to depend on the phosphorylation of p65/RelA by the MEK1/2-MSK1 signaling pathway. In a number of cells farnesol-induced apoptosis was found to be linked to activation of the apoptosome. This review provides an overview of the biochemical and cellular processes regulated by farnesol in relationship to its growth-inhibitory, apoptosis-promoting, and anti-tumor effects.
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Fildes JE, Shaw SM, Williams SG, Yonan N. Potential immunologic effects of statins in cancer following transplantation. Cancer Immunol Immunother 2009; 58:461-7. [PMID: 18523769 PMCID: PMC11030733 DOI: 10.1007/s00262-008-0541-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 05/22/2008] [Indexed: 11/29/2022]
Abstract
3-hydroxy-3-methyglutaryl CoA reductase inhibitors (statins) are frequently used following organ transplantation and have well reported pleiotropic effects, including immunomodulation, which may be of benefit in preventing graft rejection. However, the immunomodulatory effects of statins on cell transformation and malignancy, combined with the immunologic processes and administration of immunosuppression are almost completely unknown. The administration of immunosuppression is well recognised as the main cause of cancer following transplantation, so the addition of an immunomodulatory agent should be associated with an increased incidence of cancer, as immune surveillance and response may be suppressed, allowing cellular transformation and proliferation combined with lack of recognition to occur. This hypothetical review attempts to delineate the mode of action of statins in terms of pro/anti-carcinogenic mechanisms, while considering graft rejection and the presence of immunosuppression.
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Affiliation(s)
- J E Fildes
- The Transplant Centre, University Hospital of South Manchester NHS Foundation Trust, Wythenshawe Hospital, Manchester, UK.
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Migita T, Narita T, Nomura K, Miyagi E, Inazuka F, Matsuura M, Ushijima M, Mashima T, Seimiya H, Satoh Y, Okumura S, Nakagawa K, Ishikawa Y. ATP citrate lyase: activation and therapeutic implications in non-small cell lung cancer. Cancer Res 2008; 68:8547-54. [PMID: 18922930 DOI: 10.1158/0008-5472.can-08-1235] [Citation(s) in RCA: 277] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Enhanced glucose and lipid metabolism is one of the most common properties of malignant cells. ATP citrate lyase (ACLY) is a key enzyme of de novo fatty acid synthesis responsible for generating cytosolic acetyl-CoA and oxaloacetate. To evaluate its role in lung cancer progression, we here analyzed ACLY expression in a subset of human lung adenocarcinoma cell lines and showed a relationship with the phosphatidyl-inositol-3 kinase-Akt pathway. The introduction of constitutively active Akt into cells enhanced the phosphorylation of ACLY, whereas dominant-negative Akt caused attenuation. In human lung adenocarcinoma samples, ACLY activity was found to be significantly higher than in normal lung tissue. Immunohistochemical analysis further showed phosphorylated ACLY overexpression in 162 tumors, well-correlating with stage, differentiation grade, and a poorer prognosis. Finally, to show the therapeutic potential and mechanism of ACLY inhibition for lung cancer treatment, we assessed the effect of RNA interference targeting ACLY on lipogenesis and cell proliferation in A549 cells. ACLY inhibition resulted in growth arrest in vitro and in vivo. Interestingly, increased intracellular lipids were found in ACLY knockdown cells, whereas de novo lipogenesis was inhibited. Supplementation of insulin could rescue the proliferative arrest elicited by ACLY inhibition; however, in contrast, fatty acid palmitate induced cell death. Taken together, these findings suggest that ACLY is involved in lung cancer pathogenesis associated with metabolic abnormality and might offer a novel therapeutic target.
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Affiliation(s)
- Toshiro Migita
- Divisions of Pathology, The Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.
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Caldieri G, Giacchetti G, Beznoussenko G, Attanasio F, Ayala I, Buccione R. Invadopodia biogenesis is regulated by caveolin-mediated modulation of membrane cholesterol levels. J Cell Mol Med 2008; 13:1728-1740. [PMID: 19175685 DOI: 10.1111/j.1582-4934.2008.00568.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Invadopodia are proteolytically active protrusions formed by invasive tumoural cells when grown on an extracellular matrix (ECM) substratum. Clearly, invadopodia are specialized membrane domains acting as sites of signal transduction and polarized delivery of components required for focalized ECM degradation. For these reasons, invadopodia are a model to study focal ECM degradation by tumour cells. We investigated the features of invadopodia membrane domains and how altering their composition would affect invadopodia biogenesis and function. This was achieved through multiple approaches including manipulation of the levels of cholesterol and other lipids at the plasma membrane, alteration of cholesterol trafficking by acting on caveolin 1 expression and phosphorylation. We show that cholesterol depletion impairs invadopodia formation and persistence, and that invadopodia themselves are cholesterol-rich membranes. Furthermore, the inhibition of invadopodia formation and ECM degradation after caveolin 1 knock-down was efficiently reverted by simple provision of cholesterol. In addition, the inhibitory effect of caveolin 3(DGV) expression, a mutant known to block cholesterol transport to the plasma membrane, was similarly reverted by provision of cholesterol. We suggest that invadopodia biogenesis, function and structural integrity rely on appropriate levels of plasma membrane cholesterol, and that invadopodia display the properties of cholesterol-rich membranes. Also, caveolin 1 exerts its function in invadopodia formation by regulating cholesterol balance at the plasma membrane. These findings support the connection between cholesterol, cancer and caveolin 1, provide further understanding of the role of cholesterol in cancer progression and suggest a mechanistic framework for the proposed anti-cancer activity of statins, tightly related to their blood cholesterol-lowering properties.
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Affiliation(s)
- Giusi Caldieri
- Tumor Cell Invasion Laboratory, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Giada Giacchetti
- Tumor Cell Invasion Laboratory, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Galina Beznoussenko
- Tumor Cell Invasion Laboratory, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Francesca Attanasio
- Tumor Cell Invasion Laboratory, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Inmaculada Ayala
- Tumor Cell Invasion Laboratory, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Roberto Buccione
- Tumor Cell Invasion Laboratory, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
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McCarthy FRK, Brown AJ. Autonomous Hedgehog signalling is undetectable in PC-3 prostate cancer cells. Biochem Biophys Res Commun 2008; 373:109-12. [PMID: 18544338 DOI: 10.1016/j.bbrc.2008.05.169] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 05/30/2008] [Indexed: 11/26/2022]
Abstract
The Hedgehog signalling pathway has been implicated in the development of prostate cancer, although this area remains controversial. Some but not all studies have noted relatively high Hedgehog pathway activity in commonly used prostate cancer cell lines. We aimed to evaluate the widely used PC-3 cell line as a model to investigate Hedgehog signalling in a prostate cancer setting. Using a sensitive Hedgehog inducible luciferase reporter assay, we found no evidence of autonomous Hedgehog signalling in PC-3 cells, irrespective of passage number. In addition, manipulations that should either increase (an oxysterol) or decrease (cyclopamine) Hedgehog pathway activity had no effect on reporter activity, and cyclopamine treatment did not affect PC-3 cell viability. Therefore, our findings contradict some earlier reports and caution against the use of PC-3 cells to investigate the Hedgehog pathway in a prostate cancer setting.
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Affiliation(s)
- Frank R K McCarthy
- BABS, School of Biotechnology and Biomolecular Sciences, Biosciences Building D26, University of New South Wales, Sydney, NSW 2052, Australia
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Hu Z, Zhang F, Yang Z, Yang N, Zhang D, Zhang J, Cao K. Combination of simvastatin administration and EPC transplantation enhances angiogenesis and protects against apoptosis for hindlimb ischemia. J Biomed Sci 2008; 15:509-17. [DOI: 10.1007/s11373-008-9243-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2007] [Accepted: 02/22/2008] [Indexed: 02/02/2023] Open
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Glynn SA, O'Sullivan D, Eustace AJ, Clynes M, O'Donovan N. The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, simvastatin, lovastatin and mevastatin inhibit proliferation and invasion of melanoma cells. BMC Cancer 2008; 8:9. [PMID: 18199328 PMCID: PMC2253545 DOI: 10.1186/1471-2407-8-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Accepted: 01/16/2008] [Indexed: 11/25/2022] Open
Abstract
Background A number of recent studies have suggested that cancer incidence rates may be lower in patients receiving statin treatment for hypercholesterolemia. We examined the effects of statin drugs on in vitro proliferation, migration and invasion of melanoma cells. Methods The ability of lovastatin, mevastatin and simvastatin to inhibit the melanoma cell proliferation was examined using cytotoxicity and apoptosis assays. Effects on cell migration and invasion were assessed using transwell invasion and migration chambers. Hypothesis testing was performed using 1-way ANOVA, and Student's t-test. Results Lovastatin, mevastatin and simvastatin inhibited the growth, cell migration and invasion of HT144, M14 and SK-MEL-28 melanoma cells. The concentrations required to inhibit proliferation of melanoma cells (0.8–2.1 μM) have previously been achieved in a phase I clinical trial of lovastatin in patients with solid tumours, (45 mg/kg/day resulted in peak plasma concentrations of approximately 3.9 μM). Conclusion Our results suggest that statin treatment is unlikely to prevent melanoma development at standard doses. However, higher doses of statins may have a role to play in adjuvant therapy by inhibiting growth and invasion of melanoma cells.
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Affiliation(s)
- Sharon A Glynn
- National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland.
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Platz EA. Epidemiologic musing on statin drugs in the prevention of advanced prostate cancer. Cancer Epidemiol Biomarkers Prev 2007; 16:2175-80. [PMID: 17982117 DOI: 10.1158/1055-9965.epi-07-0777] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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van Alphen RJ, Verweij J, Eskens FALM. Trial design for cancer (cell)-specific anticancer therapies. Expert Opin Ther Targets 2007; 11:1137-41. [PMID: 17845141 DOI: 10.1517/14728222.11.9.1137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The last decade has brought a totally new class of systemic anticancer treatment options, the so-called cancer (cell)-specific (CCS) anticancer agents. Until recently, this treatment modality has been referred to as 'targeted therapy' but as all existing systemic anticancer therapies have a clearly defined target, this seems to be a misnomer. Despite impressive results of several CCS drugs, the present set up of drug development is ill suited for CCSs due to the nature of the majority of these compounds. The authors focus on specific aspects of how to design early clinical trials with this new class of anticancer agents with focus on pharmacodynamic behaviour in relation to response, optimal dose and treatment duration.
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Abstract
The sonic hedgehog (SHH) pathway was first defined genetically in fruit flies. Subsequently, the SHH network has been shown to be critical for normal mammalian development, by mediating interactions between stromal and epithelial cells. Recent evidence suggests that, deregulation of SHH signaling is important in the pathogenesis of cancer. Further, some observations suggest that a SHH paracrine mechanism mediating tumor-mesenchymal interactions may contribute to the metastatic capacity of cancer. Preclinical studies demonstrate that tumor cells in which SHH is deregulated are dependent on signaling through this pathway for the maintenance of proliferation and viability. SHH antagonists have been identified and show promise in inhibiting tumor growth in preclinical studies. The utility of these agents in the management of cancer patients awaits the outcome of ongoing and future clinical trials.
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Affiliation(s)
- Nikhil S Chari
- Department of Hematopathology, The University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
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