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Patient characteristics. Tumour tissue was obtained from the Leeds Breast Research Tissue Bank at Leeds Teaching Hospital Trust. *denotes tumour size not available for one patient.
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Oxysterols can contribute to proliferation of breast cancer through activation of the Estrogen Receptors, and to metastasis through activation of the Liver X Receptors. Endogenous levels of both esterified and free sidechain-hydroxylated oxysterols were examined in breast cancer tumours from Estrogen Receptor positive and negative breast tumours, u...
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... cancer tumours were obtained from the Leeds Breast Research Tissue Bank (IRAS ID: 170113; Tissue Access Committee approval: LBTB_TAC_1/17). Tumours from ER-positive (n = 11) and ERnegative (n = 11) BCa patients were used in this study (Table 1). For more patient characteristics see Supplementary material table S1. ...Similar publications
Plant sterols (PS) are oxidized to PS oxidation products (POP). This study quantified the change in serum POP compared to cholesterol oxidation products (COP) after the intake of increasing POP doses. This was a double-blind, randomized, placebo-controlled, dose‒response pilot study with healthy individuals in four groups (15 per group). The contro...
Citations
... 27-OHC, a selective ER modulator, is considered as marker in metastasis and proliferation of ER positive breast cancer. Similarly, it can initiate the liver X receptor (LXR, a member of the nuclear receptor family of transcription factors) and play a key role in metastatic and/or chemotherapy-resistant triplenegative breast cancer [60]. MCF-7 is the most studied ER-positive breast cancer cell line in the world and has the most valuable influence to breast cancer research. ...
Breast cancer is the most common malignancy in women with high mortality. Sensitive and specific methods for the detection, characterization and quantification of endogenous steroids in body fluids or tissues are needed for the diagnosis, treatment and prognosis of breast cancer and many other diseases. At present, non-invasive diagnostic methods are gaining more and more prominence, which enable a relatively fast and painless way of detecting many diseases. Metabolomics is a promising analytical method, the principle of which is the study and analysis of metabolites in biological material. It represents a comprehensive non-invasive diagnosis, which has a high potential for use in the diagnosis and prognosis of cancers, including breast cancer. This short review focuses on the targeted metabolomics of steroid hormones, which play an important role in the development and classification of breast cancer. The most commonly used diagnostic tool is the chromatographic method with mass spectrometry detection, which can simultaneously determine several steroid hormones and metabolites in one sample. This analytical procedure has a high potential in effective diagnosis of steroidogenesis disorders. Due to the association between steroidogenesis and breast cancer progression, steroid profiling is an important tool, as well as in monitoring disease progression, improving prognosis, and minimizing recurrence.
... Indeed, it should be expected that an excessive accumulation of 27OHC within human breast cancer tissue might significantly enhance neoplastic development, but several key points should be taken into account: 1) still missing is a solid proof of a direct correlation between Table 1 In humans data supporting a favorable or unfavorable contribution of 27OHC and related metabolism to breast or prostate cancer growth and development. increased intra-tumoral 27OHC content and neoplastic progression; in addition, increased CYP27A1 and/or decreased CYPB1 activities in cancer tissue are reliable but are still indirect indices of 27OHC accumulation; 2) in human breast cancers (n = 11 ER-positive and n = 11 ERnegative carcinomas), large intra-tumoral variations in 27OHC content have been observed [22]; 3) 27OHC showed mixed agonist/antagonist effects with regard to estrogen receptors [14]; 4) estrogen receptors are not the only receptors that 27OHC binds to. This oxysterol is indeed a good ligand of liver X receptors (LXRs), retinoic acid receptor related orphan receptor (ROR), peroxisome proliferator-activated receptors (PPARs), toll like receptors (TLRs), endoplasmic reticulum proteins sterol regulatory element binding protein (SREBP) and insulin-induced gene 1 protein (INSIG) [see for a review 23]; 5) a cysteine-guanine polymorphism in the CYP7B1 has been reported [24], suggesting the opportunity to further investigate the impact of single nucleotide polymorphisms of CYP7B1 gene but also of CYP27A1 gene in cancer predisposition. ...
Direct translation of findings achieved in experimental cell or animal models to humans is quite a difficult task. We focused here only on the epidemiological and ex vivo human studies so far available about the role of 27-hydroxycholesterol (27OHC) and related metabolism in cancer development. Some studies point to an adverse effect of 27OHC in breast cancer, based on the oxysterol's recognized ability to bind to and modulate estrogen receptors. The detrimental role of this side chain oxysterol would be evident in cancer progression, mainly in post-menopausal women and in an advanced stage of the disease. Other human researches, however, would rather correlate 27OHC intra-tumoral levels to a better prognosis. The analyses on human prostate cancer specimens performed to date are all against a detrimental contribution of 27OHC, rather suggesting interesting anti-prostate cancer effects exerted by this oxysterol. Finally, an increased 27OHC synthesis on the contrary seems to favour progression of late stage cancers in colon, brain and thyroid tissues, as found for breast cancer, possibly due to pro-inflammatory and pro-survival signalling triggered by disproportionate amounts of this oxysterol.
... Likewise, in the characterization of 22 BC specimens for oxysterol content to evaluate intra-and inter-tumor variation, authors reported significant differences of 27-HC concentrations among ER+ versus ER- [102]. Evidence suggests the heterogeneity in 27-HC content in the cancer tissues, authors propose a possible association due to differential invasion of macrophages, fibroblast and/or adipocytes, capable of synthesizing oxysterols [102]. ...
... Likewise, in the characterization of 22 BC specimens for oxysterol content to evaluate intra-and inter-tumor variation, authors reported significant differences of 27-HC concentrations among ER+ versus ER- [102]. Evidence suggests the heterogeneity in 27-HC content in the cancer tissues, authors propose a possible association due to differential invasion of macrophages, fibroblast and/or adipocytes, capable of synthesizing oxysterols [102]. In a recent report, serum oxysterols were determined in 58 patients with primary breast carcinoma in different tumor stages before treatment, reporting lower 27-HC levels in small tumors, in contrast with higher tumor burden [103]. ...
ApoB-lipoproteins and their components modulate intracellular metabolism and have been associated with the development of neoplastic phenomena, such as proliferation, anchorage-independent growth, epithelial-mesenchymal transition, and cancer invasion. In cancer cells, the modulation of targets that regulate cholesterol metabolism, such as synthesis de novo, endocytosis, and oxidation, are contributing factors to cancer development. While mechanisms associated with sterol regulatory element-binding protein 2 (SREBP-2)/mevalonate, the low-density lipoprotein receptor (LDL-R) and liver X receptor (LXR) have been linked with tumor growth; metabolites derived from cholesterol-oxidation, such as oxysterols and epoxy-cholesterols, also have been described as tumor processes-inducers. From this notion, we perform an analysis of the role of lipoproteins, their association with intracellular cholesterol metabolism, and the impact of these conditions on breast cancer development, mechanisms that can be shared during atherogenesis promoted mainly by LDL. Pathways connecting plasma dyslipidemias in conjunction with the effect of cholesterol-derived metabolites on intracellular mechanisms and cellular plasticity phenomena could provide new approaches to elucidate the triggering factors of carcinogenesis, conditions that could be considered in the development of new therapeutic approaches.
... 22 Alternatively, derivatization strategies can be utilized to enhance sterol ionization. For in-solution studies, we and others have exploited enzyme-assisted derivatization for sterol analysis (EADSA) 23,24 where the sterol molecule is reacted first with the cholesterol oxidase enzyme to oxidize the 3β-hydroxy group to 3-oxo and then with Girard-P (GP) hydrazine to give a charge-tagged sterol hydrazone ( Figure 1). This strategy enhances the MS signal and provides unique structural information upon multistage fragmentation (MS n ) which, together with the retention time and accurate mass measurements, can provide unambiguous identification, even of isomeric species. ...
Despite being a critical molecule in the brain, mass spectrometry imaging (MSI) of cholesterol has been under-reported compared to other lipids due to the difficulty in ionizing the sterol molecule. In the present work, we have employed an on-tissue enzyme-assisted derivatization strategy to improve detection of cholesterol in brain tissue sections. We report distribution and levels of cholesterol across specific structures of the mouse brain, in a model of Niemann-Pick type C1 disease, and during brain development. MSI revealed that in the adult mouse, cholesterol is the highest in the pons and medulla and how its distribution changes during development. Cholesterol was significantly reduced in the corpus callosum and other brain regions in the Npc1 null mouse, confirming hypomyelination at the molecular level. Our study demonstrates the potential of MSI to the study of sterols in neuroscience.
... Oxysterols (oxygenated metabolites of cholesterol) have been linked to BCa through activation of the ER and Liver X Receptors [37]. While LC-MS analysis of oxysterols in BCa tumours has revealed large intratumour variations and no significant differences in oxysterol levels between ERþ and ER-breast cancers [37], circulating levels of oxysterols such as cholestane-3b,5a,6b-triol, have shown promise as prognostic markers in patients with luminal subtype breast cancer [38]. ...
... Oxysterols (oxygenated metabolites of cholesterol) have been linked to BCa through activation of the ER and Liver X Receptors [37]. While LC-MS analysis of oxysterols in BCa tumours has revealed large intratumour variations and no significant differences in oxysterol levels between ERþ and ER-breast cancers [37], circulating levels of oxysterols such as cholestane-3b,5a,6b-triol, have shown promise as prognostic markers in patients with luminal subtype breast cancer [38]. Previously, Voisin et al. reported that the cholesterol metabolite, 6-oxo-cholestan-3b,5a-diol, promotes BCa progression by activation of the GR. ...
The accurate quantification of steroid hormones and their metabolites is essential for research into hormone dependent breast cancer. Although widely employed, steroid quantification by immunoassays are subject to limitations such as cross-reactivity with endogenous steroids and exogenous drugs, including the aromatase inhibitor fulvestrant. Mass spectrometry based methodologies overcome these limitations and also allow for the quantification of large panels of steroids thereby enabling the comprehensive quantification of the circulating and intratumoural steroid metabolomes. This review provides a brief overview of recent studies that have employed mass spectrometry for the quantification of estrogens and other steroid hormones in breast cancer research, highlighting the necessity and power of this technique as well as the need for its wide spread implementation.
... Alternatively, derivatisation strategies can be utilised to enhance sterol ionisation. For in-solution studies we and others have exploited enzymeassisted derivatisation for sterol analysis (EADSA) (Griffiths et al., 2013, Griffiths et al., 2016, Crick et al., 2015, Solheim et al., 2019 where the sterol molecule is reacted first with cholesterol oxidase enzyme in order to oxidise the 3β-hydroxyl group to a 3-oxo and then with Girard-P (GP) hydrazine to give a charge-tagged sterol hydrazone (Figure 1). This strategy enhances MS signal and provides unique structural information upon multistage fragmentation (MS n ) which, together with retention time and accurate mass measurements, can provide unambiguous identification, even of isomeric species. ...
Despite being a critical molecule for neurobiology and brain health, mass spectrometry imaging (MSI) of cholesterol has been under reported compared to other lipids, due to the difficulty in ionising the sterol molecule. In the present work we have employed an on-tissue enzyme-assisted derivatisation strategy to improve detection of cholesterol in brain tissue sections. We report distribution and levels of cholesterol across specific brain structures of the mouse brain, in a model of Niemann-Pick type C1 (NPC1) disease, and during brain development. MSI revealed how cholesterol changes during development and that in the adult is highest in pons and medulla of the brain stem. Cholesterol was significantly reduced in the corpus callosum and other brain regions in the Npc1 null mouse, confirming hypomyelination at the molecular level. Our study demonstrates the potential of MSI to the study of sterols in neuroscience.
... They observed a correlation between esterified and free 27-hydroxycholesterol in both tumors. However, no significant differences in levels of other endogenous oxysterols were observed between ER+ and ER− tumors [54]. ...
Breast cancer is the most frequent cancer among women. In 2018, it is estimated that 627,000 women died from breast cancer. This is approximately 15% of all cancer deaths among women (WHO 2018). Breast cancer is a multifactorial chronic disease. While important progress has been made to treat patients, many questions regarding aspects of this disease relating to carcinogenesis are still open. During carcinogenesis, cells exhibit cholesterol homeostasis deregulation. This results in an accumulation of intracellular cholesterol, which is required to sustain their high growth rate. Cholesterol efflux and influx are two metabolic pathways that are necessary to prevent cholesterol accumulation in the cells. Liver X receptors (LXRs) are nuclear receptors that, upon activation, induce the expression of ABC transporters, responsible for promoting cholesterol efflux, and the expression of IDOL (inducible degrader of low-density lipoprotein receptor), in charge of reducing cholesterol influx. Oxysterols, oxygenated derivatives of cholesterol formed through different pathways, have been discovered as LXR-specific ligands. Some oxysterols are involved in tumor formation while others are considered anti-tumor agents. In the present review, we discuss the involvement of cholesterol, oxysterols and LXRs in breast cancer pathophysiology, with an emphasis on the biological effects of LXR ligands.
... The foregoing discussion has highlighted that oxidised lipids generated from PUFA, In recent years, much effort has been invested to accurately quantify lipid oxidation products from minimum sample volumes (4,5,192). The development of ultra-high performance liquid chromatography methods with short runtimes using targeted and sensitive quantification using quadrapole ion trap mass spectrometers has been successfully applied to different types of biological samples (6,163,221) and is likely to revolutionise our understanding of the spatial and temporal distribution of these modified lipids. ...
Significance:
Inflammation increases during the ageing process. It is linked to mitochondrial dysfunction and increased ROS production. Mitochondrial macromolecules are critical targets of oxidative damage; they contribute to respiratory uncoupling with increased ROS production, redox stress, and a cycle of senescence, cytokine production and impaired oxidative phosphorylation. Targeting the formation or accumulation of oxidised biomolecules, particularly oxidised lipids, in immune cells and mitochondria could be beneficial for age-related inflammation and comorbidities. Recent Advances: Inflammation is central to age-related decline in health and exhibits a complex relationship with mitochondrial redox state and metabolic function. Improvements in mass spectrometric methods have led to the identification of families of oxidised phospholipids, cholesterols and fatty acids that increase during inflammation and which modulate Nrf2, PPARγ, AP1 and NFkB redox sensitive transcription factor activity. The kinetic and spatial resolution of the modified lipidome has profound and sometimes opposing effects on inflammation, promoting initiation at high concentration and resolution at low concentration of oxidised phospholipid.
Future directions:
There is an emerging opportunity to prevent or delay age-related inflammation and vascular co-morbidity through a resolving (oxy)lipidome that is dependent on improving mitochondrial quality control and restoring redox homeostasis.
... 26-OHC (commonly referred to as 27-OHC [5]) for example is the most abundant scOHC, but is a relatively weak LXR agonist [1,6]. Moreover, there is little difference in scOHC concentrations between breast cancer subtypes [7]. ...
... We recently evaluated LXR ligand bio-availability in a small BCa cohort [7] and found large inter tumoural heterogeneity in oxysterol content, but no difference in ligand concentrations between tumour subtypes. Systematic evaluation of scOHC bioavailability and activation potential, coupled with analysis of NR cofactor expression between BCa subtypes has not been performed previously. ...
... To confirm the luciferase LXRA reporter was representative of regulation within a normal chromosomal context, we next examined expression at two endogenous canonical LXR target loci, ABCA1 [35] and APOE [36]. Vehicle control, GW3965, 26-OHC (the most abundant scOHC in breast tumour tissue [7]) or 24,25-EC (the scOHC that elicited the greatest fold induction in reporter cells Figure 2d), and by 24,25-EC at 4 h (multiple t-tests with FDR < 1% and Holm-Sidak correction: p = 0.003). We repeated GW3965 treatment in second ER-positive (T47D) and ER-negative (MDA-MB-231) lines confirming our observations that ABCA1 (two-way ANOVA: p < 0.05 ( Figure S3a)) and APOE (two-way ANOVA: p < 0.001 ( Figure S3b)), were significantly more induced in ER-negative cells compared to the ER-positive ones. ...
Interventions that alter cholesterol have differential impacts on hormone receptor positive- and negative-breast cancer risk and prognosis. This implies differential regulation or response to cholesterol within different breast cancer subtypes. We evaluated differences in side-chain hydroxycholesterol and liver X nuclear receptor signalling between Oestrogen Receptor (ER)-positive and ER-negative breast cancers and cell lines. Cell line models of ER-positive and ER-negative disease were treated with Liver X Receptor (LXR) ligands and transcriptional activity assessed using luciferase reporters, qPCR and MTT. Publicly available datasets were mined to identify differences between ER-negative and ER-positive tumours and siRNA was used to suppress candidate regulators. Compared to ER-positive breast cancer, ER-negative breast cancer cells were highly responsive to LXR agonists. In primary disease and cell lines LXRA expression was strongly correlated with its target genes in ER-negative but not ER-positive disease. Expression of LXR’s corepressors (NCOR1, NCOR2 and LCOR) was significantly higher in ER-positive disease relative to ER-negative, and their knock-down equalized sensitivity to ligand between subtypes in reporter, gene expression and viability assays. Our data support further evaluation of dietary and pharmacological targeting of cholesterol metabolism as an adjunct to existing therapies for ER-negative and ER-positive breast cancer patients.
... The stringent activation of LXR by oxysterols is inhibited by PSS, but whether this translates into a possible dietary suppression of human LXR-oxysterol signalling in tumour prone tissues such as the breast, or metastatic sites such as the bone, remains to be determined. This is a clinically important question as ER-negative disease remains more challenging to successfully treat than ER-positive disease and a role for oxysterol signalling in breast cancer progression is now apparent, despite no clear difference in oxysterol concentrations between subtypes [42]. Our data provide a potential molecular explanation as to why diets, lifestyles, and chronic pharmacological treatments, which are associated with cholesterol suppression, are also associated with improved outcomes. ...
Low fruit and vegetable consumption and high saturated fat consumption causes elevated circulating cholesterol and are breast cancer risk factors. During cholesterol metabolism, oxysterols form that bind and activate the liver X receptors (LXRs). Oxysterols halt breast cancer cell proliferation but enhance metastatic colonization, indicating tumour suppressing and promoting roles. Phytosterols and phytostanols in plants, like cholesterol in mammals, are essential components of the plasma membrane and biochemical precursors, and in human cells can alter LXR transcriptional activity. Here, a panel of breast cancer cell lines were treated with four dietary plant sterols and a stanol, alone or in combination with oxysterols. LXR activation and repression were measured by gene expression and LXR-luciferase reporter assays. Oxysterols activated LXR in all cell lines, but surprisingly phytosterols failed to modulate LXR activity. However, phytosterols significantly inhibited the ability of oxysterols to drive LXR transcription. These data support a role for phytosterols in modulating cancer cell behaviour via LXR, and therefore suggest merit in accurate dietary recordings of these molecules in cancer patients during treatment and perhaps supplementation to benefit recovery.
