17 research outputs found
BET inhibitors (BETi) influence oxidative phosphorylation metabolism by affecting mitochondrial dynamics leading to alterations in apoptotic pathways in triple-negative breast cancer (TNBC) cells
MALAT1 as a Regulator of the Androgen-Dependent Choline Kinase A Gene in the Metabolic Rewiring of Prostate Cancer
Simple Summary Despite the rapid advance in cancer therapies, treatment-resistant relapse remains a significant challenge in cancer treatment. Acquired resistance arises during or after treatment administration, and is usually the main contributor to relapse. For example, prostate cancer, the most frequent type of cancer in the elderly male population, frequently develops into aggressive forms resistant to chemical and hormonal therapies. In this condition, the so-called "cholinic phenotype" that is characterized by the overexpression of choline kinase alpha (CHKA) and increased phosphocholine levels leads to aberrant lipid metabolism. Our work demonstrates that CHKA, which is necessary for membrane phospholipid synthesis, is a target of the long non-coding RNA MALAT1. This study helps to further decipher how MALAT1 affects the regulation of crucial phospholipid/sphingolipid metabolic enzymes, as well as how the androgen receptor pathway is involved in MALAT1-dependent transcriptional regulation. Background. Choline kinase alpha (CHKA), an essential gene in phospholipid metabolism, is among the modulated MALAT1-targeted transcripts in advanced and metastatic prostate cancer (PCa). Methods. We analyzed CHKA mRNA by qPCR upon MALAT1 targeting in PCa cells, which is characterized by high dose-responsiveness to the androgen receptor (AR) and its variants. Metabolome analysis of MALAT1-depleted cells was performed by quantitative High-resolution 1 H-Nuclear Magnetic Resonance (NMR) spectroscopy. In addition, CHKA genomic regions were evaluated by chromatin immunoprecipitation (ChIP) in order to assess MALAT1-dependent histone-tail modifications and AR recruitment. Results. In MALAT1-depleted cells, the decrease of CHKA gene expression was associated with reduced total choline-containing metabolites compared to controls, particularly phosphocholine (PCho). Upon MALAT1 targeting a significant increase in repressive histone modifications was observed at the CHKA intron-2, encompassing relevant AR binding sites. Combining of MALAT1 targeting with androgen treatment prevented MALAT1-dependent CHKA silencing in androgen-responsive (LNCaP) cells, while it did not in hormone-refractory cells (22RV1 cells). Moreover, AR nuclear translocation and its activation were detected by confocal microscopy analysis and ChIP upon MALAT1 targeting or androgen treatment. Conclusions. These findings support the role of MALAT1 as a CHKA activator through putative association with the liganded or unliganded AR, unveiling its targeting as a therapeutic option from a metabolic rewiring perspective
Young transgenic hMTH1 mice are protected against dietary fat-induced metabolic stressâimplications for enhanced longevity
hMTH1 protects against mutation during oxidative stress. It degrades 8-oxodGTP to exclude potentially mutagenic oxidized guanine from DNA. hMTH1 expression is linked to ageing. Its downregulation in cultured cells accelerates RAS-induced senescence, and its overexpression in hMTH1-Tg mice extends lifespan. In this study, we analysed the effects of a brief (5Â weeks) high-fat diet challenge (HFD) in young (2Â months old) and adult (7Â months old) wild-type (WT) and hMTH1-Tg mice. We report that at 2Â months, hMTH1 overexpression ameliorated HFD-induced weight gain, changes in liver metabolism related to mitochondrial dysfunction and oxidative stress. It prevented DNA damage as quantified by a comet assay. At 7Â months old, these HFD-induced effects were less severe and hMTH1-Tg and WT mice responded similarly. hMTH1 overexpression conferred lifelong protection against micronucleus induction, however. Since the canonical activity of hMTH1 is mutation prevention, we conclude that hMTH1 protects young mice against HFD by reducing genome instability during the early period of rapid growth and maximal gene expression. hMTH1 protection is redundant in the largely non-growing, differentiated tissues of adult mice. In hMTH1-Tg mice, expression of a less heavily mutated genome throughout life provides a plausible explanation for their extended longevity
Recommended from our members
Metabolomic Reprogramming Detected by 1H-NMR Spectroscopy in Human Thyroid Cancer Tissues.
Thyroid cancer cells demonstrate an increase in oxidative stress and decreased antioxidant action, but the effects of this increased oxidative stress on cell function remain unknown. We aimed to identify changes in the metabolism of thyroid cancer cells caused by oxidative stress, using proton nuclear magnetic resonance (1H-NMR) spectroscopy. Samples of thyroid cancer and healthy thyroid tissue were collected from patients undergoing thyroidectomy and analyzed with 1H-NMR spectroscopy for a wide array of metabolites. We found a significant increase in lactate content in thyroid cancer tissue compared to healthy tissue. Metabolomic analysis demonstrated significant differences between cancer tissue and healthy tissue, including an increase in aromatic amino acids, and an average decrease in citrate in thyroid cancer tissue. We hypothesize that these changes in metabolism may be due to an oxidative stress-related decrease in activity of the Krebs cycle, and a shift towards glycolysis in cancer tissue. Thus, thyroid cancer cells are able to reprogram their metabolic activity to survive in conditions of high oxidative stress and with a compromised antioxidant system. Our findings, for the first time, suggested a connection between oxidative stress and the alteration of the metabolic profile in thyroid tumors
Recommended from our members
Metabolomic Reprogramming Detected by 1H-NMR Spectroscopy in Human Thyroid Cancer Tissues.
Thyroid cancer cells demonstrate an increase in oxidative stress and decreased antioxidant action, but the effects of this increased oxidative stress on cell function remain unknown. We aimed to identify changes in the metabolism of thyroid cancer cells caused by oxidative stress, using proton nuclear magnetic resonance (1H-NMR) spectroscopy. Samples of thyroid cancer and healthy thyroid tissue were collected from patients undergoing thyroidectomy and analyzed with 1H-NMR spectroscopy for a wide array of metabolites. We found a significant increase in lactate content in thyroid cancer tissue compared to healthy tissue. Metabolomic analysis demonstrated significant differences between cancer tissue and healthy tissue, including an increase in aromatic amino acids, and an average decrease in citrate in thyroid cancer tissue. We hypothesize that these changes in metabolism may be due to an oxidative stress-related decrease in activity of the Krebs cycle, and a shift towards glycolysis in cancer tissue. Thus, thyroid cancer cells are able to reprogram their metabolic activity to survive in conditions of high oxidative stress and with a compromised antioxidant system. Our findings, for the first time, suggested a connection between oxidative stress and the alteration of the metabolic profile in thyroid tumors
The over-expression of human hydrolase hMTH1 modulates metabolism and fat composition in mice exposed to high fat diet: a MRI and MRS study
The over-expression of human hydrolase hMTH1 modulates metabolism and fatcomposition in mice exposed to high fat
diet: a MRI and MRS study
Synopsis
Oxidative stress is implicated in cancer, neurodegeneration and aging. hMTH1 is a hydrolase able to remove oxidized precursors from nucleotideâspool, thus avoiding oxidative nucleic acids damage. Overexpression of hMTH1 in mice is protective against oxidative damage, neurodegenerationand prolongs life span. Our study showed that the overexpression of hMTH1 in mice fed with high fat diet (HFD), a dietary regimen linked toinflammation, is associated with increased brown interscapular fat (linked to protection from obesity) and with reduced perivesical fat volume(indicator of poor cardiovascular outcomes) up to four weeks. These effects seem to be reversed by prolonging HFD.
Introduction
The role of the oxidative stress in the pathogenesis of
cancer, neurodegeneration and aging is well established. The human MutT
homologue(hMTH1) is a hydrolase
able to protect nucleic acids from oxidative damage, by avoiding the
incorporation of oxidized precursors in both DNA andRNA. Transgenic mice, which overexpress the human MTH1 gene (hMTH1âTg) are protected from neurodegeneration and motor impairment
andare characterized by a decreased oxidative DNA damage, a prolonged
life-span and an enhanced exploratory behavior.
It has been shown
thathigh fat diet is one of the most frequent environmental
trigger, able to cause chronic inflammation which characterizes obesity and
metabolicsyndrome.
Aims
Aims of this study were to understand if the
the oxidative DNA damage protection mediated by the over-expression of hMTH1 is able to counteractthe metabolic alterations and
the inflammation induced by the exposure to a high-fat diet (HFD, 45% of fat)
for 33 weeks.
Methods
Male C57bl6 mice 10 wk
old, wild-type (wt) and hMTH1-Tg, were fed with HFD for 33 weeks (two groups of
5 mice each). Body weight, oxidative DNAdamage/repair (by Single Cell Gel
Electrophoresis assay) and other clinic parameters were measured. At 4, 11 (or 16), 22 and 33 weeks of HFDfeeding and two months after
the end the HFD exposure (recovery time), animals underwent to MRI and MRS. Brain metabolism, interscapularbrown fat and liver fat were assessed by
MRS. The volume of perivesical fat was assessed by MRI. Experiments were
performed on a VARIAN Inovasystem operating at 4.7T with a transmitter volume
RF coil actively decoupled from the receiver surface coil (RAPID Biomedical,
Rimpar, Germany).1H localised MR spectra were collected from the
hippocampus (HIP) and prefrontal cortex (PFC) using a PRESS sequence, according
to a quantitativeprotocol.
A STEAM sequence was used in the interscapular
brown fat and liver for water to lipid ratio determination. T1-weighted MRI wasperformed to quantify the volume of visceral fat depot (a risk factor for
metabolic dysfunction) in the four different mice groups. Repeatedmeasurements ANOVA was used for statistical comparisons
(significance at p<0.05).
Serum Metabolomics was carried out on
Bruker Avanceoperating at 9.4 T spectrometer, by using standard presaturation
pulse sequence and spin echo Carr-Purcell-Meiboom-Gill 1D sequence (CPMG)according to Beckonert
protocol on intact serum.
Results
During HFD regimen, a significant increase
in the accumulation of oxidative DNA damage has been observed in wt mice
(repeated measurementsANOVA: genotype effect, p=0.02), as shown in Figure 1a).
Notably, hMTH1-Tg mice resulted to be protected both in basal and HFD
conditions, albeita comparable weight gain has been observed (Figure 1b). Alterations in brain metabolite
concentrations have been detected in both PFC and HIP atbasal level and during
the HFD regimen. Quantitative results are shown in Figure 2.
In the interscapular fat we observed an increase in thewater/lipid
signals ratio (which corresponds to increased brown adipose tissue, BAT) in the
hMTH1-tg mice group which is maintained up to 4
weeksof HFD regimen (figure 3a and b). 1H
MRS of the liver revealed a reduced amount of fat for the hMTH1-tg mice after 4 weeks of HFD stimulus(p<0.05) which is no longer
observed at late times, as shown in Figure 3c and d. T1-weighted MRI of the abdomen revealed a slightly reducedamount of visceral fat for
the hMTH1-tg mice at basal level but an increase in the hMTH1-tg animals at late stages after the beginning of
the HFDstimulus, as shown in Figure 4a and b. Analyses at the end of HFD (33 weeks) and during the recovery time are
in progress.
Metabolomics analyseson
serum samples showed that the overexpression of hMHT1 induced a tight control
of glucose and lipid homeostasis metabolism as compared towt-mice in HFD
(figure 5a and b). In particular, we found significant changes in glucose, and
low-density lipoprotein/very low density lipoprotein(LDL/VLDL) signals following
HFD in wt mice. Despite the stimulation of a high-fat diet, MTH1 mice are not able to alter blood glucose levels, nor toincrease the levels of VLDL / LDL in
circulation.
Discussion and conclusions
Differences have been
detected between wt and hMTH1-Tg mice before the beginning of
HFD, suggesting a crosstalk between genomic instabilityand metabolic dysfunction. Brain metabolism alteration highlights a direct effect
on brain functionality. In spite of similar
body weight increase,nuclear oxidative DNA damage is lower in hMTH1-Tg than in
wt at all time points, while adipose organ extension and composition maintain
thebasal differences between wt and
hMTH1-Tg mice only up to 4 weeks of oxidative stimulus. The protective
role of hMTH1 against oxidative damageis associated with an increase in BAT (which
may provide protection from obesity
) and with a reduced abdominal
perivesical fat volume (which isconsidered an independent indicator of poor
cardiovascular outcomes
). The protective effect observed in the
hMTH1 mice up to 4 weeks seems tobe reversed by a prolonged HFD exposition,
suggesting a not-obvious link between HFD and oxidative damage modulation by
hMTH1.
Acknowledgements
We thank the Italian National Institute of Health for financial support
References
1. De
Luca G et al PLoS Genet 2008;4:e1000266.
2. De Luca G et al Aging Cell
2013;12:695-705.
3. Canese R et al NMR Biomed 2012;25:632-642.
4. Beckonert O et al.
Nat Protoc 2007; 2:2692â2703
5. Matsuita M et al, International Journal of Obesity 2014; 38,812â817.
6. Powell-Wiley et al, Circulation
2021;43:e984
Metabolic reprogramming during spontaneus mammary tumor development and progression in HER2/neu transgenic mice: a role for endogenus type I Interferon
Metabolic reprogramming during spontaneous mammary tumor development and progression in HER2/neu transgenic mice: a role for endogenous type I Interferon
Metabolic reprogramming was linked to the major hallmarks of cancer, including tumor development, progression and therapy resistance.
Our study aims to identify, by non invasive in vivo MRS and ex vivo high resolution (HR)-MRS, the metabolic changes involved in spontaneous, oncogene-driven carcinogenesis occurring in Her2/neu transgenic mice, with particular focus on the role of endogenous type I IFN (IFN-I).
Our group reported that the lack of endogenous IFN-I system significantly affects Her2/neu carcinogenesis (Castiello et al, 2018). Since this phenomenon was not related to the known immunomodulatory properties of these cytokines, we investigated whether the possible reshaping of metabolic pathways was involved.
Both in vivo MRS and ex vivo high resolution (HR)-MRS revealed that normal (non-tumoral) mammary glands of mice lacking a functional endogenous IFN-I (IFNARI-/-) had increased fatty acids concentration with respect to the wild type counterpart. This result paralleled the observation of specific trascriptomic profiles in IFNARI-/- normal mammary glands, that exhibited decreased expression of genes involved in OXPHOS and mitochondrial activity and increased expression of Sterol regulatory element-binding proteins, a known regulator of fatty acids biosynthesis and an independent prognostic marker in breast cancer. Interestingly, a trend in fatty acids increase could be also observed in Her2+ early tumor lesions, but not in l bigger tumor masses (>500 um3) spontaneously developed in IFNARI-/- mice.
HR-MRS analyses of aqueous metabolites revealed that, as expected, the metabolic fingerprint of Her2+ tumors lesions of all sizes was significantly different from normal mammary glands in both IFNARI+/+ and IFNARI-/- mice. Nevertheless, the impact of the lack of endogenous IFN-I could be more clearly observed in early stage Her2+ tumors. The alterations in myo-inositol and gluthathione concentrations observed in IFNARI-/- tumors suggest that endogenous IFN-I may exert its antitumor activity by affecting key metabolic regulators of tumor cells proliferation.
Our study provide the first evidence that endogenous IFN-I is involved in metabolic pathways in both normal mammary glands and early phase breast cancer. Further research is needed to unravel the link between these IFN-related metabolic changes and the proliferation advantage of IFNARI-/- breast cancer cells
Changes in metabolic patterns during tumor development and progression in HER2/neu spontaneous breast cancer: a role for endogenous type I Interferon
Changes in metabolic patterns during tumor development and progression in HER2/neu spontaneous breast cancer: a role for endogenous type I Interferon
In the last decades, cell metabolism emerged as a key factor involved in tumor development, progression and therapy resistance. Our group reported that the disruption of endogenous type I Interferon (IFN-I) system affects spontaneous Her2/neu-driven carcinogenesis through intrinsic control of cancer stem cells (Castiello et al, 2018). In order to investigate whether the possible remodeling of metabolic pathways was involved in this phenomenon, we applied non invasive in vivo MRS and ex vivo high resolution (HR)-MRS to analyze the changes in metabolic profiles occurring in healthy mammary glands and spontaneous tumors developed in Her2/ neu transgenic mice, with particular focus on IFN-I. Both in vivo MRS and ex vivo high resolution (HR)-MRS revealed that, in the absence of a functional endogenous IFN-I (IFNARI-/-), normal (non-tumoral) mammary glands had increased fatty acids concentration with respect to the wild type counterpart. This result paralleled the observation that IFNARI-/- normal mammary glands exhibited decreased expression of genes involved in OXPHOS and mitochondrial activity and increased expression of Sterol regulatory element-binding proteins, a known regulator of fatty acids biosynthesis. Interestingly, Her2+ early tumor lesions developed in IFNARI-/- mice also exhibited increased fatty acids content versus wild type mice. In contrast, bigger tumor masses (>500 um3) presented a more dysregulated and less consistent metabolic profile in both groups. As expected, the metabolic fingerprint of Her2+ tumors lesions of all sizes, assessed by HR-MRS analyses of aqueous metabolites, was significantly different from normal mammary glands in IFNARI+/+ and IFNARI-/- mice. Nevertheless, the impact of the lack of endogenous IFN-I could be observed in early stage Her2+ tumors. The alterations in myo-inositol and gluthathione concentrations observed in IFNARI-/- tumors suggest that endogenous IFN-I may exert its antitumor activity also by affecting key metabolic regulators of tumor cells proliferation. Our study provide the first evidence that endogenous IFN-I takes part in the regulation of some metabolic pathways occurring in normal mammary glands and affecting early phase of spontaneous breast cancer development. How these metabolic changes eventually provide a proliferation advantage to breast cancer cells is a matter of further investigation
AKT-driven epithelial-mesenchymal transition in triple negative breast cancer cells is affected by copper bioavailability via a Her2/LOXL2-independent pathway
AKT-driven epithelial-mesenchymal transition is affected by copper bioavailability in HER2 negative breast cancer cells via a LOXL2-independent mechanism
The main mechanism underlying cancer dissemination is the epithelial to mesenchymal transition (EMT). This process is orchestrated by cytokines like TGFÎČ, involving "non-canonical" AKT- or STAT3-driven pathways. Recently, the alteration of copper homeostasis seems involved in the onset and progression of cancer