1
|
Du M, Jin J, Wu G, Jin Q, Wang X. Metabolic, structure-activity characteristics of conjugated linolenic acids and their mediated health benefits. Crit Rev Food Sci Nutr 2023; 64:8203-8217. [PMID: 37021469 DOI: 10.1080/10408398.2023.2198006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Conjugated linolenic acid (CLnA) is a mixture of octadecenoic acid with multiple positional and geometric isomers (including four 9, 11, 13-C18:3 isomers and three 8, 10, 12-C18:3 isomers) that is mainly present in plant seeds. In recent years, CLnA has shown many promising health benefits with the deepening of research, but the metabolic characteristics, physiological function differences and mechanisms of different isomers are relatively complex. In this article, the metabolic characteristics of CLnA were firstly reviewed, with focus on its conversion, catabolism and anabolism. Then the possible mechanisms of CLnA exerting biological effects were summarized and analyzed from its own chemical and physical characteristics, as well as biological receptor targeting characteristics. In addition, the differences and mechanisms of different isomers of CLnA in anticancer, lipid-lowering, anti-diabetic and anti-inflammatory physiological functions were compared and summarized. The current results show that the position and cis-trans conformation of conjugated structure endow CLnA with unique physical and chemical properties, which also makes different isomers have commonalities and particularities in the regulation of metabolism and physiological functions. Corresponding the metabolic characteristics of different isomers with precise nutrition strategy will help them to play a better role in disease prevention and treatment. CLnA has the potential to be developed into food functional components and dietary nutritional supplements. The advantages and mechanisms of different CLnA isomers in the clinical management of specific diseases need further study.
Collapse
Affiliation(s)
- Meijun Du
- State Key Lab of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, International Joint Research Laboratory for Lipid Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Jun Jin
- State Key Lab of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, International Joint Research Laboratory for Lipid Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Gangcheng Wu
- State Key Lab of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, International Joint Research Laboratory for Lipid Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Qingzhe Jin
- State Key Lab of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, International Joint Research Laboratory for Lipid Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Xingguo Wang
- State Key Lab of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, International Joint Research Laboratory for Lipid Nutrition and Safety, School of Food Science and Technology, Jiangnan University, Wuxi, China
| |
Collapse
|
2
|
Da Silva ED, Sandri EC, Fernandes LA, Carraro PC, De Oliveira DE. Conjugated linoleic acid trans-10, cis-12 increases the expression of genes from cell cycle progression and cis-9, trans-11 stimulates apoptotic genes in different mammary tumor explants of female dogs. Mol Biol Rep 2023; 50:4011-4015. [PMID: 36849857 DOI: 10.1007/s11033-023-08287-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/17/2023] [Indexed: 03/01/2023]
Abstract
BACKGROUND The conjugated linoleic acid (CLA) isomer cis-9, trans-11 is an anticarcinogen that inhibits cell proliferation and/or induces apoptosis of tumor cells. The objective of this study was to evaluate the expression of genes responsible for cell cycle regulation and apoptosis in tumor explants of mammary anaplastic carcinoma (AC) and mammary tubulopapillary carcinoma (TC) cultured in vitro with the CLA isomers cis-9, trans-11 and trans-10, cis-12. METHODS In this study we used mammary explants from two adult female dogs that revealed two types of malignant tumors: (a) anaplastic mammary carcinoma (AC) and (b) mammary tubulopapillary carcinoma (TC). The explants (n = 6 per treatment) had an average weight of 80.0 ± 2.0 mg and were cultured for 24 h in 35 mm culture plates under the following treatments: (a) Control: Culture medium + fatty acid free bovine serum albumin (BSA); (b) Culture medium + cis-9, trans-11 CLA (75 µM) diluted with fatty acid free bovine serum albumin (BSA), and; (c) Culture medium + trans-10, cis-12 CLA (75 µM) diluted with fatty acid free bovine serum albumin (BSA). After that, total RNA was extracted, complementary DNA was synthesized (cDNA), and quantitative analysis by real-time polymerase chain reaction (RT-qPCR) was conducted. Data were analyzed using the MIXED procedure of SAS. RESULTS Compared with the Control, the CLA trans-10, cis-12 treatment decreased expression of the gene encoding the p53 by 20% (P = 0.02), Caspase-3 by 25% (P = 0.06) and Bax by 51% (P = 0.001) in AC. The CLA cis-9, trans-11 increased the gene expression of proapoptotic protein Bax in TC by 68% (P = 0.01), but increased the expression of the antiapoptotic Bcl2 gene in AC by 72% (P = 0.006). CONCLUSION The CLA cis-9, trans-11 stimulates apoptotic genes in mammary tubulopapillary carcinoma, but has a contrary effect on the anaplastic carcinoma, and the CLA trans-10, cis-12 stimulates cell cycle progression genes and may have an antiapoptotic effect, mainly in mammary anaplastic carcinoma.
Collapse
Affiliation(s)
- E D Da Silva
- Department of Animal Production, Santa Catarina State University, 88520-000, Lages, Santa Catarina, Brazil
| | - E C Sandri
- Department of Animal Production, Santa Catarina State University, 88520-000, Lages, Santa Catarina, Brazil
| | - L A Fernandes
- Department of Animal Production, Santa Catarina State University, 88520-000, Lages, Santa Catarina, Brazil
| | - P C Carraro
- Department of Animal Production, Santa Catarina State University, 88520-000, Lages, Santa Catarina, Brazil
| | - D E De Oliveira
- Department of Animal Production, Santa Catarina State University, 88520-000, Lages, Santa Catarina, Brazil.
| |
Collapse
|
3
|
The Modulatory Effects of Fatty Acids on Cancer Progression. Biomedicines 2023; 11:biomedicines11020280. [PMID: 36830818 PMCID: PMC9953116 DOI: 10.3390/biomedicines11020280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Cancer is the second leading cause of death worldwide and the global cancer burden rises rapidly. The risk factors for cancer development can often be attributed to lifestyle factors, of which an unhealthy diet is a major contributor. Dietary fat is an important macronutrient and therefore a crucial part of a well-balanced and healthy diet, but it is still unclear which specific fatty acids contribute to a healthy and well-balanced diet in the context of cancer risk and prognosis. In this review, we describe epidemiological evidence on the associations between the intake of different classes of fatty acids and the risk of developing cancer, and we provide preclinical evidence on how specific fatty acids can act on tumor cells, thereby modulating tumor progression and metastasis. Moreover, the pro- and anti-inflammatory effects of each of the different groups of fatty acids will be discussed specifically in the context of inflammation-induced cancer progression and we will highlight challenges as well as opportunities for successful application of fatty acid tailored nutritional interventions in the clinic.
Collapse
|
4
|
Conjugated Linoleic Acid Effects on Cancer, Obesity, and Atherosclerosis: A Review of Pre-Clinical and Human Trials with Current Perspectives. Nutrients 2019; 11:nu11020370. [PMID: 30754681 PMCID: PMC6413010 DOI: 10.3390/nu11020370] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/03/2019] [Accepted: 02/08/2019] [Indexed: 02/07/2023] Open
Abstract
Obesity and its comorbidities, including type 2 diabetes and cardiovascular disease, are straining our healthcare system, necessitating the development of novel strategies for weight loss. Lifestyle modifications, such as exercise and caloric restriction, have proven effective against obesity in the short term, yet obesity persists because of the high predilection for weight regain. Therefore, alternative approaches to achieve long term sustainable weight loss are urgently needed. Conjugated linoleic acid (CLA), a fatty acid found naturally in ruminant animal food products, has been identified as a potential anti-obesogenic agent, with substantial efficacy in mice, and modest efficacy in obese human populations. Originally described as an anti-carcinogenic fatty acid, in addition to its anti-obesogenic effects, CLA has now been shown to possess anti-atherosclerotic properties. This review summarizes the pre-clinical and human studies conducted using CLA to date, which collectively suggest that CLA has efficacy against cancer, obesity, and atherosclerosis. In addition, the potential mechanisms for the many integrative physiological effects of CLA supplementation will be discussed in detail, including an introduction to the gut microbiota as a potential mediator of CLA effects on obesity and atherosclerosis.
Collapse
|
5
|
Berryhill GE, Trott JF, Hovey RC. Mammary gland development--It's not just about estrogen. J Dairy Sci 2015; 99:875-83. [PMID: 26506542 DOI: 10.3168/jds.2015-10105] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 09/02/2015] [Indexed: 12/22/2022]
Abstract
The mammary gland (MG) is one of a few organs that undergoes most of its growth after birth. Much of this development occurs concurrently with specific reproductive states, such that the ultimate goal of milk synthesis and secretion is coordinated with the nutritional requirements of the neonate. Central to the reproductive-MG axis is its endocrine regulation, and pivotal to this regulation is the ovarian secretion of estrogen (E). Indeed, it is widely accepted that estrogens are essential for growth of the MG to occur, both for ductal elongation during puberty and for alveolar development during gestation. As the factors regulating MG development continually come to light from the fields of developmental biology, lactation physiology, and breast cancer research, a growing body of evidence serves as a reminder that the MG are not as exclusively dependent on estrogens as might have been thought. The objective of this review is to summarize the state of information regarding our understanding of how estrogen (E) has been implicated as the key regulator of MG development, and to highlight some of the alternative E-independent mechanisms that have been discovered. In particular, we review our findings that dietary trans-10,cis-12 conjugated linoleic acid promotes ductal elongation and that the combination of progesterone (P) and prolactin (PRL) can stimulate branching morphogenesis in the absence of E. Ultimately, these examples stand as a healthy challenge to the question of just how important estrogens are for MG development. Answers to this question, in turn, increase our understanding of MG development across all mammals and the ways in which it can affect milk production.
Collapse
Affiliation(s)
- Grace E Berryhill
- Department of Animal Science, University of California-Davis, 2145 Meyer Hall, One Shields Avenue, Davis 95618
| | - Josephine F Trott
- Department of Animal Science, University of California-Davis, 2145 Meyer Hall, One Shields Avenue, Davis 95618
| | - Russell C Hovey
- Department of Animal Science, University of California-Davis, 2145 Meyer Hall, One Shields Avenue, Davis 95618.
| |
Collapse
|
6
|
Yang B, Chen H, Stanton C, Ross RP, Zhang H, Chen YQ, Chen W. Review of the roles of conjugated linoleic acid in health and disease. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.03.050] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
7
|
Louw L. Effects of conjugated linoleic acid and high oleic acid safflower oil in the treatment of children with HPV-induced laryngeal papillomatosis: a randomized, double-blinded and crossover preliminary study. Lipids Health Dis 2012; 11:136. [PMID: 23061633 PMCID: PMC3551644 DOI: 10.1186/1476-511x-11-136] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 09/05/2012] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Surgery is the mainstay therapy for HPV-induced laryngeal papillomatosis (LP) and adjuvant therapies are palliative at best. Research revealed that conjugated-linoleic acid (CLA) may improve the outcome of virally-induced diseases. The effects of Clarinol™ G-80 (CLA) and high oleic safflower oil (HOSF) on children with LP (concomitant with surgery) were evaluated. DESIGN A randomized, double-blinded, crossover and reference-oil controlled trial was conducted at a South African medical university. Study components included clinical, HPV type/load and lymphocyte/cytokine analyses, according to routine laboratory methods. PARTICIPANTS Overall: ten children enrolled; eight completed the trial; five remained randomized; seven received CLA first; all treatments remained double-blinded. INTERVENTION Children (4 to 12 years) received 2.5 ml p/d CLA (8 weeks) and 2.5 ml p/d HOSF (8 weeks) with a washout period (6 weeks) in-between. The one-year trial included a post-treatment period (30 weeks) and afterwards was a one-year follow-up period. MAIN OUTCOME MEASURES Changes in numbers of surgical procedures for improved disease outcome, total/anatomical scores (staging system) for papillomatosis prevention/viral inhibition, and lymphocyte/cytokine counts for immune responses between baselines and each treatment/end of trial were measured. FINDINGS After each treatment all the children were in remission (no surgical procedures); after the trial two had recurrence (surgical procedures in post-treatment period); after the follow-up period three had recurrence (several surgical procedures) and five recovered (four had no surgical procedures). Effects of CLA (and HOSF to a lesser extent) were restricted to mildly/moderately aggressive papillomatosis. Children with low total scores (seven/less) and reduced infections (three/less laryngeal sub-sites) recovered after the trial. No harmful effects were observed. The number of surgical procedures during the trial (n6/available records) was significantly lower [(p 0.03) (95% CI 1.1; 0)]. Changes in scores between baselines and CLA treatments (n8) were significantly lower: total scores [(p 0.02) (95% CI -30.00; 0.00)]; anatomical scores [(p 0.008) (95% CI -33.00: -2.00)]. Immune enhancement could not be demonstrated. CONCLUSIONS These preliminary case and group findings pave the way for further research on the therapeutic potential of adjuvant CLA in the treatment of HPV-induced LP.
Collapse
Affiliation(s)
- Louise Louw
- Department Otorhinolaryngology, Faculty of Health Sciences, University of the Free State, Box 339G42, Bloemfontein 9300, South Africa.
| |
Collapse
|
8
|
Ramirez RA, Lee A, Schedin P, Russell JS, Masso-Welch PA. Alterations in mast cell frequency and relationship to angiogenesis in the rat mammary gland during windows of physiologic tissue remodeling. Dev Dyn 2012; 241:890-900. [PMID: 22431477 DOI: 10.1002/dvdy.23778] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND The mammary epithelium undergoes proliferation and regression accompanied by remodeling of the fibrocellular and vascular stroma. Mast cells are abundant in these compartments and have been implicated in remodeling during wound healing and cancer progression. The purpose of this study was to test the hypothesis that mast cell abundance correlates with physiologic mammary tissue remodeling during estrous cycling, lactogenesis (pregnancy and lactation) and involution. RESULTS Mast cell and capillary frequency were quantified in the stroma surrounding ducts and lobules from mammary glands of rats. During estrous cycling, periductal mast cell numbers were unchanged, but lobule-associated mast cells significantly increased in the regressive phase of diestrus II. During lactogenesis, lobular stroma mast cells peaked early in pregnancy, at D2, followed by a significant decrease throughout lactation. Involution was associated with a rapid return in mast cell numbers, similar to diestrus II. Lobular vascularization peaked during the state of metestrus, when limited secretory differentiation occurs. Lobular angiogenesis peaked at D7 of pregnancy, regressed, and then returned to high levels during lactation and early involution, when secretory differentiation is high. CONCLUSIONS These results suggest mast cells are predominantly associated with regressive lobular remodeling during cycling and involution, whereas angiogenesis is predominantly associated with secretory differentiation.
Collapse
Affiliation(s)
- Robert A Ramirez
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | | | | | | | | |
Collapse
|
9
|
Belda BJ, Thompson JT, Sinha R, Prabhu KS, Vanden Heuvel JP. The dietary fatty acid 10E12Z-CLA induces epiregulin expression through COX-2 dependent PGF(2α) synthesis in adipocytes. Prostaglandins Other Lipid Mediat 2012; 99:30-7. [PMID: 22583689 DOI: 10.1016/j.prostaglandins.2012.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/01/2012] [Accepted: 05/02/2012] [Indexed: 02/06/2023]
Abstract
Conjugated linoleic acids (CLAs) are a group of dietary fatty acids that are widely marketed as weight loss supplements. The isomer responsible for this effect is the trans-10, cis-12 CLA (10E12Z-CLA) isomer. 10E12Z-CLA treatment during differentiation of 3T3-L1 adipocytes induces expression of prostaglandin-endoperoxide synthase-2 (Cyclooxygenase-2; COX-2). This work demonstrates that COX-2 is also induced in fully differentiated 3T3-L1 adipocytes after a single treatment of 10E12Z-CLA at both the mRNA (20-40 fold) and protein level (7 fold). Furthermore, prostaglandin (PG)F(2α), but not PGE(2), is significantly increased 10 fold. In female BALB/c mice fed 0.5% 10E12Z-CLA for 10 days, COX-2 was induced in uterine adipose (2 fold). In vitro, pharmacological COX-2 inhibition did not block the effect of 10E12Z-CLA on adipocyte-specific gene expression although PGF(2α) was dose-dependently decreased. These studies demonstrate that PGF(2α) was not by itself responsible for the reduction in adipocyte character due to 10E12Z-CLA treatment. However, PGF(2α), either exogenously or endogenously in response to 10E12Z-CLA, increased the expression of the potent mitogen and epidermal growth factor (EGF) receptor (EGFR) ligand epiregulin in 3T3-L1 adipocytes. Blocking PGF(2α) signaling with the PGF(2α) receptor (FP) antagonist AL-8810 returned epiregulin mRNA levels back to baseline. Although this pathway is not directly responsible for adipocyte dependent gene expression, these results suggest that this signaling pathway may still have broad effect on the adipocyte and surrounding cells.
Collapse
Affiliation(s)
- Benjamin J Belda
- The Center for Molecular Toxicology and Carcinogenesis and The Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, United States
| | | | | | | | | |
Collapse
|
10
|
Krishnan S, Russell J, Bodziak M, Koury S, Masso-Welch P. Direct effects of conjugated linoleic acid isomers on P815 mast cells in vitro. Immunol Invest 2012; 41:399-411. [PMID: 22268590 DOI: 10.3109/08820139.2011.647187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Conjugated linoleic acid (CLA) is a dietary fatty acid which causes extensive remodeling and mast cell recruitment in the mouse mammary gland. Two CLA isomers, 9,11- and 10,12-CLA, have differing effects in vivo, with only 10,12-CLA increasing mast cell number. The purpose of this project is to test the hypothesis that CLA acts directly on the mast cell. The P815 mastocytoma cell line was assayed for the effects of CLA on mast cell number, proliferation, apoptosis, and differentiation. Both CLA isomers decreased viable mast cell number, with no effect on membrane integrity, or cell cycle distribution. 10,12-CLA induced an increase in apoptosis, assessed by Annexin-FITC binding. Both isomers increased mast cell granularity, and secretion of MMP-9. The complex effects of CLA isomers on mast cells in the mammary gland are distinct from direct effects on mast cells in vitro, and may require interactions between multiple cell types present in vivo.
Collapse
Affiliation(s)
- Siddharth Krishnan
- Department of Biotechnical and Clinical Laboratory Sciences, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA.
| | | | | | | | | |
Collapse
|
11
|
The molecular mechanism of leptin secretion and expression induced by aristolochic acid in kidney fibroblast. PLoS One 2011; 6:e16654. [PMID: 21304902 PMCID: PMC3033396 DOI: 10.1371/journal.pone.0016654] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 01/05/2011] [Indexed: 12/17/2022] Open
Abstract
Background Leptin is a peptide hormone playing pivotal role in regulating food intake and energy expenditure. Growing evidence has suggested the pro-inflammatory and fibrogenic properties of leptin. In addition, patients with renal fibrosis have higher level of plasma leptin, which was due to the increased leptin production. Aristolochic acid (AA) is a botanical toxin characterized to associate with the development of renal fibrosis including tubulointerstitial fibrosis. However, whether leptin is upregulated to participate in AA-induced kidney fibrosis remain completely unknown. Methodology/Principal Findings In this study, leptin expression was increased by sublethal dose of AA in kidney fibroblast NRK49f determined by enzyme-linked immunosorbent assay and Western blot. Data from real-time reverse transcriptase-polymerase chain reaction revealed that leptin was upregulated by AA at transcriptional level. DNA binding activity of CCAAT enhancer binding protein α (C/EBP α), one of the transcription factors for leptin gene, was enhanced in DNA affinity precipitation assay and chromatin immunoprecipitation experiments. Knockdown of C/EBP α expression by small interfering RNA markedly reduced AA-induced leptin expression. Moreover, AA promoted Akt interaction with p-PDK1, and increased phosphorylated activation of Akt. Akt knockdown, and inhibition of Akt signaling by LY294002 and mTOR inhibitor rapamycin reduced leptin expression. Furthermore, treatment of LY294002 or rapamycin significantly suppressed AA-induced C/EBP α DNA-binding activity. These results suggest that Akt and C/EBP α activation were involved in AA-regulated leptin expression. Conclusions/Significance Our findings demonstrate the first that AA could induce secretion and expression of fibrogenic leptin in kidney fibroblasts, which reveal potential involvement of leptin in the progression of kidney fibrosis in aristolochic acid nephropathy.
Collapse
|
12
|
Foote MR, Giesy SL, Bernal-Santos G, Bauman DE, Boisclair YR. t10,c12-CLA decreases adiposity in peripubertal mice without dose-related detrimental effects on mammary development, inflammation status, and metabolism. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1521-8. [PMID: 20844263 DOI: 10.1152/ajpregu.00445.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The trans 10, cis 12-conjugated linoleic acid (10,12-CLA) isomer reduces adiposity in several animal models. In the mouse, however, this effect is associated with adipose tissue inflammation, hyperinsulinemia and hepatic lipid accumulation. Moreover, 10,12-CLA was recently shown to promote mammary ductal hyperplasia and ErbB2/Her2-driven mammary cancer in the mouse. Reasons for detrimental effects of 10,12-CLA on the mouse mammary gland could relate to its effect on the mammary fat pad (MFP), which is essential for normal development. Accordingly, we hypothesized that mammary effects of 10,12-CLA were mediated through the MFP in a dose-dependent manner. Female FVB mice were fed 10,12-CLA at doses of 0%, 0.1%, 0.2%, or 0.5% of the diet from day 24 of age, and effects on mammary development and metabolism were measured on day 49. The 0.5% dose reduced ductal elongation and caused premature alveolar budding. These effects were associated with increased expression of inflammatory markers and genes shown to alter epithelial growth (IGF binding protein-5) and alveolar budding (TNF-α and receptor of activated NF-κB ligand). The 0.5% dose also caused hyperinsulinemia and hepatic lipid accumulation. In contrast, the 0.1% 10,12-CLA dose had no adverse effects on mammary development, metabolic events, and inflammatory responses, but remained effective in decreasing adipose weights and lipogenic gene expression. These results show that a low dose of 10,12-CLA reduces adiposity in the mouse without negative effects on mammary development, inflammation, and metabolism, and suggest that previously reported detrimental effects relate to the use of excessive doses.
Collapse
Affiliation(s)
- M R Foote
- Dept. of Animal Science, Cornell Univ., 259 Morrison Hall, Ithaca, NY 14853, USA
| | | | | | | | | |
Collapse
|
13
|
Flowers M, Schroeder JA, Borowsky AD, Besselsen DG, Thomson CA, Pandey R, Thompson PA. Pilot study on the effects of dietary conjugated linoleic acid on tumorigenesis and gene expression in PyMT transgenic mice. Carcinogenesis 2010; 31:1642-9. [PMID: 20624750 DOI: 10.1093/carcin/bgq148] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Conjugated linoleic acid (CLA) is a class of commercially available fatty acids that have been associated with anticancer properties in rodent models of chemical carcinogenesis. We conducted a pilot study to examine the antitumor effect of dietary CLA in a polyoma virus-middle T antigen (PyMT) mouse model of invasive breast cancer. Virgin 4-week-old PyMT mice were administered a mixed-isomer CLA diet (1% wt/wt) or control AIN-93G diet for 4 weeks (N = 6 and 5, respectively) and tumor burden was assessed at 8 weeks of age. Thoracic mammary glands were prepared as whole mounts with other glands being formalin fixed and paraffin embedded for histology and immunohistochemistry (IHC). Total RNA was prepared for microarray and real-time reverse transcription-polymerase chain reaction analysis. Western blots were performed for protein expression analysis. Tumor incidence was significantly increased in CLA-treated animals compared with controls (P = 0.009) and occurred with extensive lobular-alveolar expansion and loss of mammary adipose tissue. More than 100 genes were downregulated > or = 2-fold in the CLA-treated group compared with controls, including adipose-specific markers, as wells as cytoskeletal and adhesion-related genes. This was supported by dramatic decreases in the epithelial adherens E-cadherin and beta-catenin as demonstrated by IHC. Taken together, these results suggest that dietary CLA affects the mammary stromal environment, leading to tumor progression and cellular expansion in the PyMT mouse model. Further studies of the potential for cancer promotion are needed, especially because mixed-isomer CLA formulations are sold commercially as a nutritional supplement.
Collapse
Affiliation(s)
- Margaret Flowers
- Department of Experimental Therapeutics, John Wayne Cancer Institute, 2200 Santa Monica Boulevard, Santa Monica, CA 90404, USA.
| | | | | | | | | | | | | |
Collapse
|
14
|
Islam MA, Kim YS, Oh TW, Kim GS, Won CK, Kim HG, Choi MS, Kim JO, Ha YL. Superior anticarcinogenic activity of trans,trans-conjugated linoleic acid in N-methyl-N-nitrosourea-induced rat mammary tumorigenesis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:5670-5678. [PMID: 20373764 DOI: 10.1021/jf100117a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The anticarcinogenic activity of a mixture of trans,trans-conjugated linoleic acid (trans,trans-CLA) was investigated in rat mammary tumorigenesis induced by N-methyl-N-nitrosourea (MNU), with references to cis-9,trans-11-CLA and trans-10,cis-12-CLA isomers. Female, 7-week-old Sprague-Dawley rats were intraperitoneally injected with MNU (50 mg/kg of body weight) and then subjected to one of five diets (control, 1% trans,trans-CLA, 1% cis-9,trans-11-CLA, 1% trans-10,cis-12-CLA, and 1% linoleic acid; 8 rats/group) for 16 weeks. Food and water were made available ad libitum. trans,trans-CLA significantly (p < 0.05) reduced tumor incidence, number, multiplicity, and size and significantly (p < 0.05) increased apoptosis, relative to cis-9,trans-11-CLA and trans-10,cis-12-CLA. The molecular mechanism of trans,trans-CLA was elucidated by measuring apoptosis-related gene products and fatty acid composition in tumors. trans,trans-CLA led to increases in the p53 protein and Bax protein levels but suppressed the expression of Bcl-2 protein. The activation of caspase-3 led to the cleavage of poly(ADP-ribose) polymerase, which resulted in the execution of apoptosis. In addition, trans,trans-CLA reduced cytosolic phospholipase A2, cyclooxygenease-2, and peroxisome proliferator-activated receptor gamma protein levels. These results suggest that the trans,trans-CLA inhibits MNU-induced rat mammary tumorigenesis through the induction of apoptosis in conjunction with the reduction of arachidonic acid metabolites and that the efficacy of trans,trans-CLA is superior to cis-9,trans-11-CLA and trans-10,cis-12-CLA.
Collapse
Affiliation(s)
- Mohammad A Islam
- Division of Applied Life Science (BK21 Program), Graduate School, Gyeongsang National University, Jinju, Republic of Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Hsu YC, Meng X, Ou L, Ip MM. Activation of the AMP-activated protein kinase-p38 MAP kinase pathway mediates apoptosis induced by conjugated linoleic acid in p53-mutant mouse mammary tumor cells. Cell Signal 2010; 22:590-9. [PMID: 19932174 PMCID: PMC2838459 DOI: 10.1016/j.cellsig.2009.11.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 11/13/2009] [Indexed: 12/20/2022]
Abstract
Conjugated linoleic acid (CLA) inhibits tumorigenesis and tumor growth in most model systems, an effect mediated in part by its pro-apoptotic activity. We previously showed that trans-10,cis-12 CLA induced apoptosis of p53-mutant TM4t mouse mammary tumor cells through both mitochondrial and endoplasmic reticulum stress pathways. In the current study, we investigated the role of AMP-activated protein kinase (AMPK), a key player in fatty acid metabolism, in CLA-induced apoptosis in TM4t cells. We found that t10,c12-CLA increased phosphorylation of AMPK, and that CLA-induced apoptosis was enhanced by the AMPK agonist 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) and inhibited by the AMPK inhibitor compound C. The increased AMPK activity was not due to nutrient/energy depletion since ATP levels did not change in CLA-treated cells, and knockdown of the upstream kinase LKB1 did not affect its activity. Furthermore, our data do not demonstrate a role for the AMPK-modulated mTOR pathway in CLA-induced apoptosis. Although CLA decreased mTOR levels, activity was only modestly decreased. Moreover, rapamycin, which completely blocked the activity of mTORC1 and mTORC2, did not induce apoptosis, and attenuated rather than enhanced CLA-induced apoptosis. Instead, the data suggest that CLA-induced apoptosis is mediated by the AMPK-p38 MAPK-Bim pathway: CLA-induced phosphorylation of AMPK and p38 MAPK, and increased expression of Bim, occurred with a similar time course as apoptosis; phosphorylation of p38 MAPK was blocked by compound C; the increased Bim expression was blocked by p38 MAPK siRNA; CLA-induced apoptosis was attenuated by the p38 inhibitor SB-203580 and by siRNAs directed against p38 MAPK or Bim.
Collapse
Affiliation(s)
- Yung-Chung Hsu
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | | | | | | |
Collapse
|
16
|
Flowers M, Thompson PA. t10c12 conjugated linoleic acid suppresses HER2 protein and enhances apoptosis in SKBr3 breast cancer cells: possible role of COX2. PLoS One 2009; 4:e5342. [PMID: 19399184 PMCID: PMC2671134 DOI: 10.1371/journal.pone.0005342] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 03/31/2009] [Indexed: 12/29/2022] Open
Abstract
Background HER2-targeted therapy with the monoclonal antibody trastuzumab (Herceptin®) has improved disease-free survival for women diagnosed with HER2-positive breast cancers; however, treatment resistance and disease progression are not uncommon. Current data suggest that resistance to treatment in HER2 cancers may be a consequence of NF-κB overexpression and increased COX2-derived prostaglandin E2 (PGE2). Conjugated linoleic acid (CLA) has been shown to have anti-tumor properties and to inhibit NF-κB activity and COX2. Methods In this study, HER2-overexpressing SKBr3 breast cancer cells were treated with t10c12 CLA. Protein expression of the HER2 receptor, nuclear NF-κB p65, and total and phosphorylated IκB were examined by western blot and immunofluorescence. PGE2 levels were determined by ELISA. Proliferation was measured by metabolism of 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), and apoptosis was measured by FITC-conjugated Annexin V staining and flow cytometry. Results/Conclusions We observed a significant decrease in HER2 protein expression on western blot following treatment with 40 and 80 µM t10c12 CLA (p<0.01 and 0.001, respectively) and loss of HER2 protein in cells using immunoflourescence that was most pronounced at 80 µM. Protein levels of nuclear NF-κB p65 were also significantly reduced at the 80 µM dose. This was accompanied by a significant decrease in PGE2 levels (p = 0.05). Pretreatment with t10c12 CLA significantly enhanced TNFα-induced apoptosis and the anti-proliferative action of trastuzumab (p = 0.05 and 0.001, respectively). These data add to previous reports of an anti-tumor effect of t10c12 CLA and suggest an effect on the HER2 oncogene that may be through CLA mediated downregulation of COX2-derived PGE2.
Collapse
Affiliation(s)
- Margaret Flowers
- Department of Nutritional Sciences, University of Arizona, Tucson, AZ, USA.
| | | |
Collapse
|
17
|
Serini S, Piccioni E, Merendino N, Calviello G. Dietary polyunsaturated fatty acids as inducers of apoptosis: implications for cancer. Apoptosis 2009; 14:135-52. [DOI: 10.1007/s10495-008-0298-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|