1H MRS markers of tumour growth in intrasplenic tumours and liver metastasis induced by injection of HT-29 cells in nude mice spleen

Caudal DMN neurons innervate the spleen and release CART peptide to regulate neuroimmune function

BACKGROUND

Inflammation is a fundamental biological response to injury and infection, which if unregulated can contribute to the pathophysiology of many diseases. The vagus nerve, which primarily originates from the dorsal motor nucleus (DMN), plays an important role in rapidly dampening inflammation by regulating splenic function. However, direct vagal innervation of the spleen, which houses the majority of immune and inflammatory cells, has not been established. As an alternative to direct innervation, an anti-inflammatory reflex pathway has been proposed which involves the vagus nerve, the sympathetic celiac ganglion, and the neurotransmitter norepinephrine. Although sympathetic regulation of inflammation has been shown, the interaction of the vagus nerve and the celiac ganglia requires a unique interaction of parasympathetic and sympathetic inputs, making this putative mechanism of brain-spleen interaction controversial. BODY: As neuropeptides can be expressed at relatively high levels in neurons, we reasoned that DMN neuropeptide immunoreactivity could be used to determine their target innervation. Employing immunohistochemistry, subdiaphragmatic vagotomy, viral tract tracing, CRISPR-mediated knock-down, and functional assays, we show that cocaine and amphetamine-regulated transcript (CART) peptide-expressing projection neurons in the caudal DMN directly innervate the spleen. In response to lipopolysaccharide (LPS) stimulation, CART acts to reduce inflammation, an effect that can be augmented by intrasplenic administration of a synthetic CART peptide. These in vivo effects could be recapitulated in cultured splenocytes, suggesting that these cells express the as yet unidentified CART receptor(s).

CONCLUSION

Our results provide evidence for direct connections between the caudal DMN and spleen. In addition to acetylcholine, these neurons express the neuropeptide CART that, once released, acts to suppress inflammation by acting directly upon splenocytes.

Cancer insights from magnetic resonance spectroscopy of cells and excised tumors

Multinuclear ex vivo magnetic resonance spectroscopy (MRS) of cancer cells, xenografts, human cancer tissue, and biofluids is a rapidly expanding field that is providing unique insights into cancer. Starting from the 1970s, the field has continued to evolve as a stand-alone technology or as a complement to in vivo MRS to characterize the metabolome of cancer cells, cancer-associated stromal cells, immune cells, tumors, biofluids and, more recently, changes in the metabolome of organs induced by cancers. Here, we review some of the insights into cancer obtained with ex vivo MRS and provide a perspective of future directions. Ex vivo MRS of cells and tumors provides opportunities to understand the role of metabolism in cancer immune surveillance and immunotherapy. With advances in computational capabilities, the integration of artificial intelligence to identify differences in multinuclear spectral patterns, especially in easily accessible biofluids, is providing exciting advances in detection and monitoring response to treatment. Metabolotheranostics to target cancers and to normalize metabolic changes in organs induced by cancers to prevent cancer-induced morbidity are other areas of future development.

Anti-Metastatic Activity of an Anti-EGFR Monoclonal Antibody against Metastatic Colorectal Cancer with KRAS p.G13D Mutation

The now clinically-used anti-epidermal growth factor receptor (EGFR) monoclonal antibodies have demonstrated significant efficacy only in patients with metastatic colorectal cancer (mCRC), with wild-type Kirsten rat sarcoma viral oncogene homolog (KRAS). However, no effective treatments for patients with mCRC with KRAS mutated tumors have been approved yet. Therefore, a new strategy for targeting mCRC with KRAS mutated tumors is desired. In the present study, we examined the anti-tumor activities of a novel anti-EGFR monoclonal antibody, EMab-17 (mouse IgG_2a, kappa), in colorectal cancer (CRC) cells with the KRAS p.G13D mutation. This antibody recognized endogenous EGRF in CRC cells with or without KRAS mutations, and showed a high sensitivity for CRC cells in flow cytometry, indicating that EMab-17 possesses a high binding affinity to the endogenous EGFR. In vitro experiments showed that EMab-17 exhibited antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity activities against CRC cells. In vivo analysis revealed that EMab-17 inhibited the metastases of HCT-15 and HCT-116 cells in the livers of nude mouse metastatic models, unlike the anti-EGFR monoclonal antibody EMab-51 of subtype mouse IgG₁. In conclusion, EMab-17 may be useful in an antibody-based therapy against mCRC with the KRAS p.G13D mutation.

Foretinib Overcomes Entrectinib Resistance Associated with the NTRK1 G667C Mutation in NTRK1 Fusion-Positive Tumor Cells in a Brain Metastasis Model

Purpose: Rearrangement of the neurotrophic tropomyosin receptor kinase 1 (NTRK1) gene, which encodes tyrosine receptor kinase A (TRK-A), occurs in various cancers, including colon cancer. Although entrectinib is effective in the treatment of central nervous system (CNS) metastases that express NTRK1 fusion proteins, acquired resistance inevitably results in recurrence. The CNS is a sanctuary for targeted drugs; however, the mechanism by which CNS metastases become entrectinib-resistant remains elusive and must be clarified to develop better therapeutics.Experimental Design: The entrectinib-resistant cell line KM12SM-ER was developed by continuous treatment with entrectinib in the brain metastasis-mimicking model inoculated with the entrectinib-sensitive human colon cancer cell line KM12SM, which harbors the TPM3-NTRK1 gene fusion. The mechanism of entrectinib resistance in KM12SM-ER cells was examined by next-generation sequencing. Compounds that overcame entrectinib resistance were screened from a library of 122 kinase inhibitors.Results: KM12SM-ER cells, which showed moderate resistance to entrectinib in vitro, had acquired the G667C mutation in NTRK1 The kinase inhibitor foretinib inhibited TRK-A phosphorylation and the viability of KM12SM-ER cells bearing the NTRK1-G667C mutation in vitro Moreover, foretinib markedly inhibited the progression of entrectinib-refractory KM12SM-ER-derived liver metastases and brain tumors in animal models, predominantly through inhibition of TRK-A phosphorylation.Conclusions: These results suggest that foretinib may be effective in overcoming entrectinib resistance associated with the NTRK1-G667C mutation in NTRK1 fusion-positive tumors in various organs, including the brain, and provide a rationale for clinical trials of foretinib in cancer patients with entrectinib-resistant tumors harboring the NTRK1-G667C mutation, including patients with brain metastases. Clin Cancer Res; 24(10); 2357-69. ©2018 AACR.

Activation of Alpha 7 Cholinergic Nicotinic Receptors Reduce Blood-Brain Barrier Permeability following Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) is a major human health concern that has the greatest impact on young men and women. The breakdown of the blood-brain barrier (BBB) is an important pathological consequence of TBI that initiates secondary processes, including infiltration of inflammatory cells, which can exacerbate brain inflammation and contribute to poor outcome. While the role of inflammation within the injured brain has been examined in some detail, the contribution of peripheral/systemic inflammation to TBI pathophysiology is largely unknown. Recent studies have implicated vagus nerve regulation of splenic cholinergic nicotinic acetylcholine receptor α7 (nAChRa7) signaling in the regulation of systemic inflammation. However, it is not known whether this mechanism plays a role in TBI-triggered inflammation and BBB breakdown. Following TBI, we observed that plasma TNF-α and IL-1β levels, as well as BBB permeability, were significantly increased in nAChRa7 null mice (Chrna7(-/-)) relative to wild-type mice. The administration of exogenous IL-1β and TNF-α to brain-injured animals worsened Evans Blue dye extravasation, suggesting that systemic inflammation contributes to TBI-triggered BBB permeability. Systemic administration of the nAChRa7 agonist PNU-282987 or the positive allosteric modulator PNU-120596 significantly attenuated TBI-triggered BBB compromise. Supporting a role for splenic nAChRa7 receptors, we demonstrate that splenic injection of the nicotinic receptor blocker α-bungarotoxin increased BBB permeability in brain-injured rats, while PNU-282987 injection decreased such permeability. These effects were not seen when α-bungarotoxin or PNU-282987 were administered to splenectomized, brain-injured rats. Together, these findings support the short-term use of nAChRa7-activating agents as a strategy to reduce TBI-triggered BBB permeability.

SIGNIFICANCE STATEMENT

Breakdown of the blood-brain barrier (BBB) in response to traumatic brain injury (TBI) allows for the accumulation of circulating fluids and proinflammatory cells in the injured brain. These processes can exacerbate TBI pathology and outcome. While the role of inflammation in the injured tissue has been examined in some detail, the contribution of peripheral inflammation in BBB breakdown and ensuing pathology has not been well defined. We present experimental evidence to indicate that the stimulation of nicotinic acetylcholine α7 receptors (nAChRa7s) can reduce peripheral inflammation and BBB breakdown after TBI. These results suggest that activators of nAChRa7 may have therapeutic utility for the treatment of TBI.

Pro-Oxidant Role of Silibinin in DMBA/TPA Induced Skin Cancer: 1H NMR Metabolomic and Biochemical Study

Silibinin, a major bioactive flavonolignan in Silybum marianum, has received considerable attention in view of its anticarcinogenic activity. The present study examines its anticancer potential against 7, 12-dimethylbenz(a)anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin cancer. Male LACA mice were randomly segregated into 4 groups: Control, DMBA/TPA, Silibinin and Silibinin+DMBA/TPA. Tumors in DMBA/TPA and Silibinin+DMBA/TPA groups were histologically graded as squamous cell carcinoma. In the Silibinin+DMBA/TPA group, significant reduction in tumor incidence (23%), tumor volume (64.4%), and tumor burden (84.8%) was observed when compared to the DMBA/TPA group. The underlying protective mechanism of Silibinin action was studied at pre-initiation (2 weeks), post-initiation (10 weeks) and promotion (22 weeks) stages of the skin carcinogenesis. The antioxidant nature of Silibinin was evident at the end of 2 weeks of its treatment. However, towards the end of 10 and 22 weeks, elevated lipid peroxidation (LPO) levels indicate the pro-oxidative nature of Silibinin in the cancerous tissue. TUNEL assay revealed enhanced apoptosis in the Silibinin+DMBA/TPA group with respect to the DMBA/TPA group. Therefore, it may be suggested that raised LPO could be responsible for triggering apoptosis in the Silibinin+DMBA/TPA group. ¹H Nuclear Magnetic Resonance (NMR) spectroscopy was used to determine the metabolic profile of the skin /skin tumors. Dimethylamine (DMA), glycerophosphocholine (GPC), glucose, lactic acid, taurine and guanine were identified as the major contributors for separation between the groups from the Principal Component Analysis (PCA) of the metabolite data. Enhanced DMA levels with no alteration in GPC, glucose and lactate levels reflect altered choline metabolism with no marked Warburg effect in skin tumors. However, elevated guanine levels with potent suppression of taurine and glucose levels in the Silibinin+DMBA/TPA group are suggestive of the pro-oxidative nature of Silibinin in regressing tumors. Thus, supporting the theory of augmented LPO levels resulting in increased apoptosis in the skin tumors treated with Silibinin.

Investigation of the roles of exosomes in colorectal cancer liver metastasis

The leading cause of death among cancer patients is tumor metastasis. Tumor-derived exosomes are emerging as mediators of metastasis. In the present study, we demonstrated that exosomes play a pivotal role in the metastatic progression of colorectal cancer. First, a nude mouse model of colorectal cancer liver metastasis was established and characterized. Then, we demonstrated that exosomes from a highly liver metastatic colorectal cancer cell line (HT-29) could significantly increase the metastatic tumor burden and distribution in the mouse liver of Caco-2 colorectal cancer cells, which ordinarily exhibit poor liver metastatic potential. We further investigated the mechanisms by which HT-29-derived-exosomes influence the liver metastasis of colorectal cancer and found that mice treated with HT-29-derived exosomes had a relatively higher level of CXCR4 in the metastatic microenvironment, indicating that exosomes may promote colorectal cancer metastasis by recruiting CXCR4-expressing stromal cells to develop a permissive metastatic microenvironment. Finally, the migration of Caco-2 cells was significantly increased following treatment with HT-29-derived exosomes in vitro, further supporting a role for exosomes in modulating colorectal tumor-derived liver metastasis. The data from the present study may facilitate further translational medicine research into the prevention and treatment of colorectal cancer liver metastasis.

Loss of HSulf-1 promotes altered lipid metabolism in ovarian cancer

Background

Loss of the endosulfatase HSulf-1 is common in ovarian cancer, upregulates heparin binding growth factor signaling and potentiates tumorigenesis and angiogenesis. However, metabolic differences between isogenic cells with and without HSulf-1 have not been characterized upon HSulf-1 suppression in vitro. Since growth factor signaling is closely tied to metabolic alterations, we determined the extent to which HSulf-1 loss affects cancer cell metabolism.

Results

Ingenuity pathway analysis of gene expression in HSulf-1 shRNA-silenced cells (Sh1 and Sh2 cells) compared to non-targeted control shRNA cells (NTC cells) and subsequent Kyoto Encyclopedia of Genes and Genomics (KEGG) database analysis showed altered metabolic pathways with changes in the lipid metabolism as one of the major pathways altered inSh1 and 2 cells. Untargeted global metabolomic profiling in these isogenic cell lines identified approximately 338 metabolites using GC/MS and LC/MS/MS platforms. Knockdown of HSulf-1 in OV202 cells induced significant changes in 156 metabolites associated with several metabolic pathways including amino acid, lipids, and nucleotides. Loss of HSulf-1 promoted overall fatty acid synthesis leading to enhance the metabolite levels of long chain, branched, and essential fatty acids along with sphingolipids. Furthermore, HSulf-1 loss induced the expression of lipogenic genes including FASN, SREBF1, PPARγ, and PLA2G3 stimulated lipid droplet accumulation. Conversely, re-expression of HSulf-1 in Sh1 cells reduced the lipid droplet formation. Additionally, HSulf-1 also enhanced CPT1A and fatty acid oxidation and augmented the protein expression of key lipolytic enzymes such as MAGL, DAGLA, HSL, and ASCL1. Overall, these findings suggest that loss of HSulf-1 by concomitantly enhancing fatty acid synthesis and oxidation confers a lipogenic phenotype leading to the metabolic alterations associated with the progression of ovarian cancer.

Conclusions

Taken together, these findings demonstrate that loss of HSulf-1 potentially contributes to the metabolic alterations associated with the progression of ovarian pathogenesis, specifically impacting the lipogenic phenotype of ovarian cancer cells that can be therapeutically targeted.

Metabolomic Dynamic Analysis of Hypoxia in MDA-MB-231 and the Comparison with Inferred Metabolites from Transcriptomics Data

Hypoxia affects the tumor microenvironment and is considered important to metastasis progression and therapy resistance. Thus far, the majority of global analyses of tumor hypoxia responses have been limited to just a single omics level. Combining multiple omics data can broaden our understanding of tumor hypoxia. Here, we investigate the temporal change of the metabolite composition with gene expression data from literature to provide a more comprehensive insight into the system level in response to hypoxia. Nuclear magnetic resonance spectroscopy was used to perform metabolomic profiling on the MDA-MB-231 breast cancer cell line under hypoxic conditions. Multivariate statistical analysis revealed that the metabolic difference between hypoxia and normoxia was similar over 24 h, but became distinct over 48 h. Time dependent microarray data from the same cell line in the literature displayed different gene expressions under hypoxic and normoxic conditions mostly at 12 h or earlier. The direct metabolomic profiles show a large overlap with theoretical metabolic profiles deduced from previous transcriptomic studies. Consistent pathways are glycolysis/gluconeogenesis, pyruvate, purine and arginine and proline metabolism. Ten metabolic pathways revealed by metabolomics were not covered by the downstream of the known transcriptomic profiles, suggesting new metabolic phenotypes. These results confirm previous transcriptomics understanding and expand the knowledge from existing models on correlation and co-regulation between transcriptomic and metabolomics profiles, which demonstrates the power of integrated omics analysis.

1H HR-MAS NMR spectroscopy of tumor-induced local metabolic "field-effects" enables colorectal cancer staging and prognostication

Colorectal cancer (CRC) is a major cause of morbidity and mortality in developed countries. Despite operative advances and the widespread adoption of combined-modality treatment, the 5-year survival rarely exceeds 60%. Improving our understanding of the biological processes involved in CRC development and progression will help generate new diagnostic and prognostic approaches. Previous studies have identified altered metabolism as a common feature in carcinogenesis, and quantitative measurement of this altered activity (metabonomics/metabolomics) has the potential to generate novel metabolite-based biomarkers for CRC diagnosis, staging and prognostication. In the present study we applied high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy to analyze metabolites in intact tumor samples (n = 83) and samples of adjacent mucosa (n = 87) obtained from 26 patients undergoing surgical resection for CRC. Orthogonal partial least-squares discriminant analysis (OPLS-DA) of metabolic profiles identified marked biochemical differences between cancer tissue and adjacent mucosa (R(2) = 0.72; Q(2) = 0.45; AUC = 0.91). Taurine, isoglutamine, choline, lactate, phenylalanine, tyrosine (increased concentrations in tumor tissue) together with lipids and triglycerides (decreased concentrations in tumor tissue) were the most discriminant metabolites between the two groups in the model. In addition, tumor tissue metabolic profiles were able to distinguish between tumors of different T- and N-stages according to TNM classification. Moreover, we found that tumor-adjacent mucosa (10 cm from the tumor margin) harbors unique metabolic field changes that distinguish tumors according to T- and N-stage with higher predictive capability than tumor tissue itself and are accurately predictive of 5-year survival (AUC = 0.88), offering a highly novel means of tumor classification and prognostication in CRC.

Liver metabolite concentrations measured with 1H MR spectroscopy

PURPOSE

To determine the feasibility of measuring choline and glycogen concentrations in normal human liver in vivo with proton (hydrogen 1 [1H]) magnetic resonance (MR) spectroscopy.

MATERIALS AND METHODS

Signed consent to participate in an institutional review board-approved and HIPAA-compliant study was obtained from 46 subjects (mean age, 46 years±17 [standard deviation]; 24 women) consecutively recruited during 285 days. Navigator-gated MR images were used to select 8-mL volumes for point-resolved spectroscopy (PRESS) with a 35-msec echo time. Line widths were minimized with fast breath-hold B0 field mapping and further manual shimming. Navigator-gated spectra were recorded with and without water suppression to determine metabolite concentrations with water signals as an internal reference. In three subjects, echo time was varied to determine the glycogen and choline T2. Linear regression analysis was used to examine relations between choline, hepatic lipid content, body mass index, glycogen content, and age.

RESULTS

Choline concentrations could be determined in 46 of 48 studies and was found to be 8.6 mmol per kilogram of wet weight±3.1 (range, 3.8-17.6; n=44). Twenty-seven spectra in 25 individuals with narrow line widths and low lipid content were adequate for quantitation of glycogen. The glycogen (glucosyl unit) concentration was 38.1 mmol/kg wet weight±14.4. The T2 of combined glycogen peaks in the liver of three subjects was 36 msec±8. Choline levels showed a weak but significant correlation with glycogen (r2=0.15; P<.05) but not with lipid content.

CONCLUSION

Navigator-gated and gradient-echo shimmed PRESS 1H MR spectroscopy may allow quantification of liver metabolites that are important for understanding and identifying disorders of glucose and lipid metabolism.

Metabolomics in the fields of oncology: a review of recent research

The study of all endogenously produced metabolites, known as metabolomics, is the youngest of the "omics" sciences. It is becoming increasingly clear that, of all of the "omics" techniques, metabolomic approaches will become increasingly useful in disease diagnosis and have potential power to improve our understanding of the underlying mechanisms of cancer. The primary aim of the review is to discuss the relationship between metabolomics and tumors are elucidated in detail. Then the review is also to introduce the technologies of metabolomics, especially emphasizing the application of metabolomics in the fields of oncology.

In vivo magnetic resonance spectroscopy of liver tumors and metastases

Primary liver cancer is the fifth most common malignancy in men and the eighth in women worldwide. The liver is also the second most common site for metastatic spread of cancer. To assist in the diagnosis of these liver lesions non-invasive advanced imaging techniques are desirable. Magnetic resonance (MR) is commonly used to identify anatomical lesions, but it is a very versatile technique and also can provide specific information on tumor pathophysiology and metabolism, in particular with the application of MR spectroscopy (MRS). This may include data on the type, grade and stage of tumors, and thus assist in further management of the disease. The purpose of this review is to summarize and discuss the available literature on proton, phosphorus and carbon-13-MRS as performed on primary liver tumors and metastases, with human applications as the main perspective. Upcoming MRS approaches with potential applications to liver tumors are also included. Since knowledge of some technical background is indispensable to understand the results, a basic introduction of MRS and some technical issues of MRS as applied to tumors and metastases in the liver are described as well. In vivo MR spectroscopy of tumors in a metabolically active organ such as the liver has been demonstrated to provide important information on tumor metabolism, but it also is challenging as compared to applications on some other tissues, in particular in humans, mostly because of its abdominal location where movement may be a disturbing factor.

FMNL2 is a positive regulator of cell motility and metastasis in colorectal carcinoma

FMNL2 is a member of diaphanous-related formins which act as effectors of Rho family GTPases and control the actin-dependent processes such as cell motility or invasion. We previously found that FMNL2 overexpression in metastatic cell lines and tissues of colorectal carcinoma is associated with more aggressive tumour behaviour. Here we used gain-of-function and loss-of-function approaches to investigate the effects of FMNL2 on colorectal carcinoma in vitro and in vivo. Forced expression of FMNL2 caused a significant increase in tumour cell proliferation, motility, invasion in vitro, and metastasis in vivo, whereas FMNL2 depletion showed opposite effects. We examined gene expression profiles following knockdown of FMNL2 in SW480/M5 cells. Expression of 323 genes was up-regulated by more than two-fold, whereas 222 genes were down-regulated by more than two-fold in FMNL2-depleting SW480/M5 cells. Gene ontology analysis showed that most of genes belong to functional categories such as cell cycle, cytoskeleton, transcription factor, and G-protein modulator. Pathway analysis revealed that cytoskeletal regulation by the Rho GTPase pathway, the Wnt pathway, the G-protein pathway, and the P53 pathway were affected by FMNL2. Many of these genes are in functional networks associated with cell proliferation, metastasis, Wnt or the Rho signalling pathway involved in the regulation of FMNL2. The expression of five differentially expressed genes including CXXC4, CD200, VAV1, CSF1, and EPHA2 was validated by real-time PCR and western blot analysis. Thus, FMNL2 is a positive regulator of cell motility, invasion, and metastasis of colorectal carcinoma.

Quantitative two-dimensional HRMAS 1H-NMR spectroscopy-based metabolite profiling of human cancer cell lines and response to chemotherapy

NMR spectroscopy-based metabolomics still needs development in quantification procedures. A method was designed for quantitative two-dimensional high resolution magic angle spinning (HRMAS) proton-NMR spectroscopy-based metabolite profiling of intact cells. It uses referencing of metabolite-related NMR signals to protein-related NMR signals and yields straightforward and automatable metabolite profiling. The method enables exploitation of only two-dimensionally visible metabolites and combination of one- and two-dimensional spectra, thus providing an appreciable number of screened metabolites. With this procedure, 32 intracellular metabolites were attributed and quantified in human normal fibroblasts and tumor cells. The phenotype of several tumor cell lines (MCF7, PC3, 143B, and HepG2) was characterized by high levels of glutathione in cell lines with the higher proliferation rate, high levels of creatine, low levels of free amino acids, increased levels of phospholipid derivatives (mostly phosphocholine), and lower lactate content in cell lines with the higher proliferation rate. Other metabolites such as fatty acids differed widely among tumor cell lines. The response of tumor cell lines to chemotherapy also was evaluated by differential metabolite profiling, bringing insights into drug cytotoxicity and tumor cell adaptive mechanisms. The method may prove widely applicable to tumor cell phenotyping.

Non-mammalian fat-1 gene prevents neoplasia when introduced to a mouse hepatocarcinogenesis model: Omega-3 fatty acids prevent liver neoplasia

We investigated the effect of a non-mammalian omega-3 desaturase in a mouse hepatocarcinogenesis model. Mice containing double mutations (DM) in c-myc and TGF-alpha (transforming growth factor-alpha), leading to liver neoplasia, were crossed with mice containing omega-3 desaturase. MRI analysis of triple mutant (TM) mice showed the absence of neoplasia at all time points for 92% of mice in the study. Pathological changes of TM (TGFalpha/c-myc/fat-1) mouse liver tissue was similar to control mouse liver tissue. Magnetic resonance spectroscopy (MRS) measurements of unsaturated fatty acids found a significant difference (p<0.005) between DM and TM transgenic (Tg) mice at 34 and 40 weeks of age. HPLC analysis of mouse liver tissue revealed markedly decreased levels of omega-6 fatty acids in TM mice when compared to DM (TGFalpha/c-myc) and control (CD1) mice. Mass spectrometry (MS) analysis indicated significantly decreased 16:0/20:4 and 18:1/20:4 and elevated 16:0/22:6 fatty acyl groups in both GPCho and GPEtn, and elevated 16:0/20:5, 18:0/18:2, 18:0/18:1 and 18:0/22:6 in GPCho, within TM mice compared to DM mice. Total fatty acid analysis indicated a significant decrease in 18:1n9 in TM mice compared to DM mice. Western blot analysis of liver tissue showed a significant (p<0.05) decrease in NF-kappaB (nuclear factor-kappaB) levels at 40 weeks of age in TM mice compared to DM mice. Microarray analysis of TM versus DM mice livers at 40 weeks revealed alterations in genes involved in cell cycle regulation, cell-to-cell signaling, p53 signaling, and arachidonic acid (20:4) metabolism. Endogenous omega-3 fatty acids were found to prevent HCC development in mice.

Short-term temperature effect on the HRMAS spectra of human brain tumor biopsies and their pattern recognition analysis

OBJECT

To investigate the effect of temperature (0 versus 37 degrees C) in the high-resolution magic angle spinning spectroscopy (HRMAS) pattern of human brain tumor biopsies and its influence in recognition-based tumor type prediction. This proof-of-principle study addressed the bilateral discrimination between meningioma (MM) and glioblastoma multiforme (GBM) cases.

MATERIALS AND METHODS

Forty-three tumor biopsy samples were collected (20 MM and 23 GBM), kept frozen and later analyzed at 0 degrees C and 37 degrees C by HRMAS. Post-HRMAS histopathology was used to validate the tumor type. Time-course experiments (100 min) at both temperatures were carried out to monitor HRMAS pattern changes. Principal component analysis and linear discriminant analysis were used for classifier development with a training set of 20 biopsies.

RESULTS

Temperature-dependent, spectral pattern changes mostly affected mobile lipids and choline-containing compounds resonances and were essentially reversible. Incubation of 3 MM and 3 GBM at 37 degrees C during 100 minutes produced irreversible pattern changes below 13% in a few resonances. Classification performance of an independent test set of 7 biopsies was 100% for the pulse-and-acquire, CPMG at echo times (TE) of 30 ms and 144 ms and Hahn Echo at TE 30 ms at 0 degrees C and 37 degrees C. The performance for Hahn Echo spectra at 136 ms was 83.3% at 0 degrees C and 100% at 37 degrees C.

CONCLUSION

The spectral pattern of mobile lipids changes reversibly with temperature. HRMAS demonstrated potential for automated brain tumor biopsy classification. No advantage was obtained when acquiring spectra at 37 degrees C with respect to 0 degrees C in most of the conditions used for the discrimination addressed.

Metabonomics: a useful tool for the future surgeon

BACKGROUND

In the past decade or so, a range of technologies have emerged that have shown promise in increasing our understanding of disease processes and progression. These advances are referred to as the "omics" technologies; genomics, transcriptomics, and proteomics. More recently, another "omics" approach has come to the fore: metabonomics, and this technology has the potential for significant clinical impact. Metabonomics refers to the analysis of the metabolome, that is, the metabolic profile of a system. The advantage of studying the metabolome is that the end points of biological events are elucidated.

RESULTS

Although still in its infancy, the metabonomics approach has shown immense promise in areas as diverse as toxicology studies to the discovery of biomarkers of disease. It has also been applied to studies of both renal and hepatic transplants. Metabolome analysis may be conducted on a variety of biological fluids and tissue types and may utilize a number of different technology platforms, mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy being the most popular. In this review, we cover the background to the evolution of metabonomics and its applications with particular emphasis on clinical applications.

CONCLUSIONS

We conclude with the suggestion that metabonomics offers a platform for further biomarker development, drug development, and in the field of medicine.

Noninvasive magnetic resonance spectroscopic pharmacodynamic markers of a novel histone deacetylase inhibitor, LAQ824, in human colon carcinoma cells and xenografts

The aim of this work was to use phosphorus magnetic resonance spectroscopy ((31)P MRS) to investigate the pharmacodynamic effects of LAQ824, a histone deacetylase (HDAC) inhibitor. Human HT29 colon carcinoma cells were examined by (31)P MRS after treatment with LAQ824 and another HDAC inhibitor, suberoylanilide hydroxamic acid. HT29 xenografts and tumor extracts were also examined using (31)P MRS, pre- and post-LAQ824 treatment. Histone H3 acetylation was determined using Western blot analysis, and tumor microvessel density by immunohistochemical staining of CD31. Phosphocholine showed a significant increase in HT29 cells after treatment with LAQ824 and suberoylanilide hydroxamic acid. In vivo, the ratio of phosphomonoester/total phosphorus (TotP) signal was significantly increased in LAQ824-treated HT29 xenografts, and this ratio was inversely correlated with changes in tumor volume. Statistically significant decreases in intracellular pH, beta-nucleoside triphosphate (beta-NTP)/TotP, and beta-NTP/inorganic phosphate (Pi) and an increase in Pi/TotP were also seen in LAQ824-treated tumors. Tumor extracts showed many significant metabolic changes after LAQ824 treatment, in parallel with increased histone acetylation and decreased microvessel density. Treatment with LAQ824 resulted in altered phospholipid metabolism and compromised tumor bioenergetics. The phosphocholine and phosphomonoester increases may have the potential to act as pharmacodynamic markers for noninvasively monitoring tumor response after treatment with LAQ824 or other HDAC inhibitors.

Discrimination of metabolic profiles of pancreatic cancer from chronic pancreatitis by high-resolution magic angle spinning 1H nuclear magnetic resonance and principal components analysis

The metabolic profiles of Sprague-Dawley rat pancreases were investigated by high-resolution magic angle spinning proton magnetic resonance spectroscopy ((1)H NMR) combined with principal components analysis (PCA) to discriminate pancreatic cancer from chronic pancreatitis. Intact pancreatic tissue samples were obtained from Sprague-Dawley rats with histologically proven pancreatic cancer (n = 5), chronic pancreatitis (n = 5), and two matched controls (n = 5 per group). Two (1)H NMR experiments, single-pulse and Carr-Purcell-Meiboom-Gill, were carried out separately. Increases in phosphocholine and glycerophosphocholine levels and decreases in leucine, isoleucine, valine, lactate and alanine levels were observed in chronic pancreatitis, whereas the opposite trends were observed in pancreatic cancer. Increasing taurine and decreasing betaine were found both in chronic pancreatitis and in pancreatic cancer. Additionally, the lipid content in pancreatic cancer was higher than that in chronic pancreatitis. PCA was carried out for the single-pulse and Carr-Purcell-Meiboom-Gill (1)H NMR spectra, respectively, to visualize separation among the samples and to extract characteristic metabolites of pancreatic cancer and chronic pancreatitis. Decreased phosphocholine and glycerophosphocholine were suggested as unique metabolite indicators of pancreatic cancer. Furthermore, even with the disturbance of various quantities of lipid contents pancreatic cancer and chronic pancreatitis could be differentiated well by the combination of high-resolution magic angle spinning (1)H NMR and PCA. Thus this combination was demonstrated to have the potential to improve magnetic resonance spectroscopy for positive early diagnosis of pancreatic cancer in clinical settings.

Metabolomics by proton nuclear magnetic resonance spectroscopy of the response to chloroethylnitrosourea reveals drug efficacy and tumor adaptive metabolic pathways

Metabolomics of tumors may allow discovery of tumor biomarkers and metabolic therapeutic targets. Metabolomics by two-dimensional proton high-resolution magic angle spinning nuclear magnetic resonance spectroscopy was applied to investigate metabolite disorders following treatment by chloroethylnitrosourea of murine B16 melanoma (n = 33) and 3LL pulmonary carcinoma (n = 31) in vivo. Treated tumors of both types resumed growth after a delay. Nitrosoureas provoke DNA damage but the metabolic consequences of genotoxic stress are little known yet. Although some differences were observed in the metabolite profile of untreated tumor types, the prominent metabolic features of the response to nitrosourea were common to both. During the growth inhibition phase, there was an accumulation of glucose (more than x10; P < 0.05), glutamine (x3 to 4; P < 0.01), and aspartate (x2 to 5; P < 0.01). This response testified to nucleoside de novo synthesis down-regulation and drug efficacy. However, this phase also involved the increase in alanine (P < 0.001 in B16 melanoma), the decrease in succinate (P < 0.001), and the accumulation of serine-derived metabolites (glycine, phosphoethanolamine, and formate; P < 0.01). This response witnessed the activation of pathways implicated in energy production and resumption of nucleotide de novo synthesis, thus metabolic pathways of DNA repair and adaptation to treatment. During the growth recovery phase, it remained polyunsaturated fatty acid accumulation (x1.5 to 2; P < 0.05) and reduced utilization of glucose compared with glutamine (P < 0.05), a metabolic fingerprint of adaptation. Thus, this study provides the proof of principle that metabolomics of tumor response to an anticancer agent may help discover metabolic pathways of drug efficacy and adaptation to treatment.

Tumour metabolomics in animal models of human cancer

Multinuclear Nuclear Magnetic Resonance Spectroscopy (MRS) and mass spectrometry (MS) are the key analytical techniques used in an increasing manner to explore tumor metabolite profiles. Recent work has revealed that metabolite profiles in various tumor preparations (i.e., cultured cells, tissue specimens, and tumors in vivo) show strong correlations with tumor type, proliferation, metabolic activity, and cell death. These data are regarded as highly promising for tumor diagnosis as well as assessment of prognosis and treatment response in a clinical setting. In this pursuit, animal models of human cancer have played a central role. In this short account, we review the potentials of MRS and MS techniques for animal tumor metabolomic work, as well as highlight some interesting applications of these techniques for various animal tumor types.

Analysis of the changes in the 1H NMR spectral pattern of perchloric acid extracts of C6 cells with growth

The aim of this work was to identify spectral markers of cell proliferation that could be of use in clinical MRS. Cultured C6 ATCC rat glioma cells were used as models for this purpose and metabolites were extracted with perchloric acid at three different growth curve stages: log, confluence and post-confluence. 1D and 2D in vitro(1)H NMR spectra were recorded at 9.4 T. Statistically significant changes in myo-inositol and glutamine concentrations between log phase and post-confluence were found when normalized to the creatine ratio. The myo-inositol/creatine ratio was 2.76 +/- 0.82 at log phase increasing to 7.43 +/- 1.34 at post-confluence, while the glutamine/creatine ratio decreased from 0.22 +/- 0.03 to 0.10 +/- 0.02. No significant differences were recorded for other metabolites investigated. The fact that both myo-inositol and glutamine are detectable by in vivo MRS at clinical fields makes their changes relevant as potential astrocytic tumour proliferation rate markers in clinical MRS.

Comparison of HR MAS MR spectroscopic profiles of breast cancer tissue with clinical parameters

Breast cancer is the most frequent form of cancer in women and improved diagnostic methods are desirable. Malignant cells have altered metabolism and metabolic mapping might become a tool in cancer diagnostics. High-resolution magic angle spinning (HR MAS) MR spectroscopy of tissue biopsies provides detailed information on metabolic composition. The 600 MHz 1H HR MAS spectra were acquired of breast cancer tissue from 85 patients and adjacent non-involved tissue from 18 of these patients. Tissue specimens were investigated by microscopy after MR analysis. The resulting spectra were examined by three different approaches. Relative intensities of glycerophosphocholine (GPC), phosphocholine (PC) and choline were compared for cancerous and non-involved specimens. Eight metabolites, choline, creatine, beta-glucose, GPC, glycine, myo-inositol, PC and taurine, were quantified from the recorded spectra and compared with tumor histological type and size, patient's lymph node status and tissue composition of sample. The spectra were also compared with tumor histological type and size, lymph node status and tissue composition of samples using principal component analysis (PCA). Tumor samples could be distinguished from non-involved samples (82% sensitivity, 100% specificity) based on relative intensities of signals from GPC, PC and choline in 1H HR MAS spectra. Tissue concentrations of metabolites showed few differences between groups of samples, which can be caused by limitations in the quantification procedure. Choline and glycine concentrations were found to be significantly higher in tumors larger than 2 cm compared with smaller tumors. PCA of MAS spectra from patients with invasive ductal carcinomas indicated a possible prediction of spread to axillary lymph nodes. Metabolite estimates and PCA of MAS spectra were influenced by the percentage of tumor cells in the investigated specimens.

Quantification of phosphocholine and glycerophosphocholine with 31P edited 1H NMR spectroscopy

Choline and the related compounds phosphocholine (PC) and glycerophosphocholine (GPC) are considered to be important metabolites in oncology. Past studies have demonstrated correlations linking the relative ratios and concentrations of these metabolites with the development and progression of cancer. Currently, in vivo and tissue ex vivo magnetic resonance spectroscopy methods have mostly centered on measuring the total concentration of these metabolites and have difficulty in differentiating between them. Here, a new scheme that uses (31)P edited (1)H spectroscopy to quantify the concentrations of choline, PC and GPC in biological samples is reported and its applicability is demonstrated using samples of human brain tumor extracts. This method is particularly well-suited for analytical situations where the PC and GPC resonances are not sufficiently resolved and/or are obscured by other metabolites. Consequently, this scheme has the potential to be used for the analysis of choline compounds in ex vivo tissue samples.

Taurine Detection by Proton Magnetic Resonance Spectroscopy in Medulloblastoma: Contribution to Noninvasive Differential Diagnosis with Cerebellar Astrocytoma

OBJECTIVE:

We sought to evaluate whether taurine detection in short-echo (20 ms) proton magnetic resonance spectroscopy contributes to the noninvasive differential diagnosis between medulloblastoma and cerebellar astrocytoma in children and young adults. These two types of tumor have very different prognoses and may be difficult to differentiate by neuroradiological or clinical means.

METHODS:

Single-voxel proton magnetic resonance spectra of tumors were acquired at 1.5 T in 14 patients with biopsy-proven primary cerebellar tumors (six medulloblastomas, seven astrocytomas, and one mixed astroependymoma) using short-echo time (20 ms) and long-echo time (135 ms). For taurine assignment, qualitative analysis was performed on short-echo time spectra and results were compared in vitro with spectra of model solutions. Perchloric acid extracts of postsurgical tumor biopsies were performed in two medulloblastoma cases.

RESULTS:

Taurine detection was demonstrated in all patients with medulloblastoma and in none of those with astrocytoma. We were unable to ascertain any relationship between taurine and metastatic spread within the medulloblastoma group.

CONCLUSION:

Medulloblastomas characteristically seem to show taurine detectable in vivo by short-echo proton magnetic resonance spectroscopy, which may help to discriminate medulloblastoma from cerebellar astrocytoma.

Quantitative HRMAS proton total correlation spectroscopy applied to cultured melanoma cells treated by chloroethyl nitrosourea: demonstration of phospholipid metabolism alterations

Recent NMR spectroscopy developments, such as high-resolution magic angle spinning (HRMAS) probes and correlation-enhanced 2D sequences, now allow improved investigations of phospholipid (Plp) metabolism. Using these modalities we previously demonstrated that a mouse-bearing melanoma tumor responded to chloroethyl nitrosourea (CENU) treatment in vivo by altering its Plp metabolism. The aims of the present study were to investigate whether HRMAS proton total correlation spectroscopy (TOCSY) could be used as a quantitative technique to probe Plp metabolism, and to determine the Plp metabolism response of cultured B16 melanoma cells to CENU treatment in vitro. The exploited TOCSY signals of Plp derivatives arose from scalar coupling among the protons of neighbor methylene groups within base headgroups (choline and ethanolamine). For strongly expressed Plp derivatives, TOCSY signals were compared to saturation recovery signals and demonstrated a linear relationship. HRMAS proton TOCSY was thus used to provide concentrations of Plp derivatives during long-term follow-up of CENU-treated cell cultures. Strong Plp metabolism alteration was observed in treated cultured cells in vitro involving a down-regulation of phosphocholine, and a dramatic and irreversible increase of phosphoethanolamine. These findings are discussed in relation to previous in vivo data, and to Plp metabolism enzymatic involvement.

Motion correction and lipid suppression for 1H magnetic resonance spectroscopy

Spectral/spatial spin-echo pulses with asymmetric excitation profiles were incorporated into a PRESS-based localization sequence to provide lipid suppression while retaining a sufficient amount of water to allow for correction of motion-induced shot-to-shot phase variations. 1H magnetic resonance spectroscopy data were acquired at 1.5 Tesla from a motion phantom and in vivo from the human liver, kidney, and breast. The results demonstrated that lipids in the chemical shift stopband were completely suppressed and that full metabolite signal intensity was maintained after implementation of a regularization algorithm based on phasing the residual water signal. Liver and kidney spectra contained a large resonance at 3.2 ppm that was ascribed to trimethylammonium moieties (betaine plus choline) and a weaker signal at 3.7 ppm that may result from glycogen. A breast spectrum from a histologically proven invasive ductal carcinoma displayed a highly elevated choline signal (3.2 ppm) relative to that from a normal volunteer.