An ex vivo study exploring the diagnostic potential of 1H magnetic resonance spectroscopy in squamous cell carcinoma of the head and neck region

Metabolomics and cellular altered pathways in cancer biology: A review

Cancer is a deadly disease that affects a cell's metabolism and surrounding tissues. Understanding the fundamental mechanisms of metabolic alterations in cancer cells would assist in developing cancer treatment targets and approaches. From this perspective, metabolomics is a great analytical tool to clarify the mechanisms of cancer therapy as well as a useful tool to investigate cancer from a distinct viewpoint. It is a powerful emerging technology that detects up to thousands of molecules in tissues and biofluids. Like other "-omics" technologies, metabolomics involves the comprehensive investigation of micromolecule metabolites and can reveal important details about the cancer state that is otherwise not apparent. Recent developments in metabolomics technologies have made it possible to investigate cancer metabolism in greater depth and comprehend how cancer cells utilize metabolic pathways to make the amino acids, nucleotides, and lipids required for tumorigenesis. These new technologies have made it possible to learn more about cancer metabolism. Here, we review the cellular and systemic effects of cancer and cancer treatments on metabolism. The current study provides an overview of metabolomics, emphasizing the current technologies and their use in clinical and translational research settings.

Plasma metabolomics of oral squamous cell carcinomas based on NMR and MS approaches provides biomarker identification and survival prediction

Metabolomics has proven to be an important omics approach to understand the molecular pathways underlying the tumour phenotype and to identify new clinically useful markers. The literature on cancer has illustrated the potential of this approach as a diagnostic and prognostic tool. The present study aimed to analyse the plasma metabolic profile of patients with oral squamous cell carcinoma (OSCC) and controls and to compare patients with metastatic and primary tumours at different stages and subsites using nuclear magnetic resonance and mass spectrometry. To our knowledge, this is the only report that compared patients at different stages and subsites and replicates collected in diverse institutions at different times using these methodologies. Our results showed a plasma metabolic OSCC profile suggestive of abnormal ketogenesis, lipogenesis and energy metabolism, which is already present in early phases but is more evident in advanced stages of the disease. Reduced levels of several metabolites were also associated with an unfavorable prognosis. The observed metabolomic alterations may contribute to inflammation, immune response inhibition and tumour growth, and may be explained by four nonexclusive views-differential synthesis, uptake, release, and degradation of metabolites. The interpretation that assimilates these views is the cross talk between neoplastic and normal cells in the tumour microenvironment or in more distant anatomical sites, connected by biofluids, signalling molecules and vesicles. Additional population samples to evaluate the details of these molecular processes may lead to the discovery of new biomarkers and novel strategies for OSCC prevention and treatment.

Evaluation of Proton MR Spectroscopy for the Study of the Tongue Tissue in Healthy Subjects and Patients With Tongue Squamous Cell Carcinoma: Preliminary Findings

Purpose

To noninvasively assess spectroscopic and metabolic profiles of healthy tongue tissue and in an exploratory objective in nontreated and treated patients with tongue squamous cell carcinoma (SCC).

Methods

Fourteen healthy subjects (HSs), one patient with nontreated tongue SCC (NT-SCC), and two patients with treated tongue SCC (T-SCC) underwent MRI and single-voxel proton magnetic resonance spectroscopy (1H-MRS) evaluations (3 and 1.5T). Multi-echo-times 1H-MRS was performed at the medial superior part (MSP) and the anterior inferior part (AIP) of the tongue in HS, while 1H-MRS voxel was placed at the most aggressive part of the tumor for patients with tongue SCC. 1H-MRS data analysis yielded spectroscopic metabolite ratios quantified to total creatine.

Results

In HS, compared to MSP and AIP, 1H-MRS spectra revealed higher levels of creatine, a more prominent and well-identified trimethylamine-choline (TMA-Cho) peak. However, larger prominent lipid peaks were better differentiated in the tongue MSP. Compared to HS, patients with NT-SCC exhibited very high levels of lipids and relatively higher values of TMA-Cho peak. Interestingly, patients with T-SCC showed almost nonproliferation activity. However, high lipids levels were measured, although they were relatively lower than lipids levels measured in patients with NT-SCC.

Conclusion

The present study demonstrated the potential use of in-vivo1H-MRS to noninvasively assess spectroscopic and metabolic profiles of the healthy tongue tissue in a spatial location-dependent manner. Preliminary results revealed differences between HS and patients with tongue NT-SCC as well as tongue T-SCC, which should be confirmed with more patients. 1H-MRS could be included, in the future, in the arsenal of tools for treatment response evaluation and noninvasive monitoring of patients with tongue SCC.

Development of a method for dansylation of metabolites using organic solvent-compatible buffer systems for amine/phenol submetabolome analysis

Metabolomics, which serves as a readout of biological processes and diseases monitoring, is an informative research area for disease biomarker discovery and systems biology studies. In particular, reversed-phase liquid chromatography-mass spectrometry (RPLC-MS) has become a powerful and popular tool for metabolomics analysis, enabling the detection of most metabolites. Very polar and ionic metabolites, however, are less easily detected because of their poor retention in RP columns. Dansylation of metabolites simplifies the sub-metabolome analysis by reducing its complexity and increasing both hydrophobicity and ionization ability. However, the various metabolite concentrations in clinical samples have a wide dynamic range with highly individual variation in total metabolite amount, such as in saliva. The bicarbonate buffer typically used in dansylation labeling reactions induces solvent stratification, resulting in poor reproducibility, selective sample loss and an increase in false-determined metabolite peaks. In this study, we optimized the dansylation protocol for samples with wide concentration range of metabolites, utilizing diisopropylethylamine (DIPEA) or tri-ethylamine (TEA) in place of bicarbonate buffer, and presented the results of a systemic investigation of the influences of individual processes involved on the overall performance of the protocol. In addition to achieving high reproducibility, substitution of DIPEA or TEA buffer resulted in similar labeling efficiency of most metabolites and more efficient labeling of some metabolites with a higher pK_a. With this improvement, compounds that are only present in samples in trace amounts can be detected, and more comprehensive metabolomics profiles can be acquired for biomarker discovery or pathway analysis, making it possible to analyze clinical samples with limited amounts of metabolites.

Metabolomics study of oral cancers

BACKGROUND

Oral cancer is one of the most frequently occurring cancers. Metabolic reprogramming is an important hallmark of cancer. Metabolomics characterizes all the small molecules in a biological sample, and a complete set of small molecules in such sample is referred as metabolome. Nuclear magnetic resonance spectroscopy and mass spectrometry are two widely used techniques in metabolomics studies. Increasing evidence demonstrates that metabolomics techniques can be used to explore the metabolic signatures in oral cancer. Elucidation of metabolic alterations in oral cancer is also important for the understanding of its pathological mechanisms.

AIM OF REVIEW

In this paper, we summarize the latest progress of metabolomics study in oral cancer and provide the suggestions for the future studies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The metabolomics studies in saliva, serum, and tumor tissues revealed the existence of metabolic signatures in bio-fluids and tissues of oral cancer, and several tumor-specific metabolites identified in individual study could discriminate oral cancer from healthy controls or precancerous lesions, which are potential biomarkers for the screening or early diagnosis of oral cancer. Metabolomics study of oral cancers in the future should aim to establish a routine procedure with high sensitivity, profile intracellular metabolites to find out the metabolic characteristics of tumor cells, and investigate the mechanism behind metabolomic alterations and the metabolic response of cancer cells to chemotherapy.

Quantitative NMR-Based Metabolomics on Tissue Biomarkers and Its Translation into In Vivo Magnetic Resonance Spectroscopy

Nuclear magnetic resonance (NMR) spectroscopy is an established analytical platform for analyzing metabolic profiles of cells, tissues, and body fluids. There are several advantages in introducing an NMR-based study design into metabolomics studies, including a fast and comprehensive detection, characterization, and quantification of dozens of endogenous metabolites in a single NMR spectrum. Quantitative proton ¹H-NMR is the most useful NMR-based platform for metabolomics. The frozen tissues can be analyzed noninvasively using a high-resolution magic angle spinning (HR-MAS) ¹H-NMR spectroscopy; or several extraction techniques can be applied to detect additional metabolites using a conventional liquid-based NMR technique. In this chapter, we report on tissue collection, handling, extraction methods, and ¹H-NMR acquisition protocols developed in the past decades for a precise and quantitative NMR-metabolomics approach. The NMR acquisition protocols (both HR-MAS and conventional ¹H-NMR spectroscopy) and spectral analysis steps are also presented. Since NMR can be applied "in vivo" using horizontal bore MRI scanners, several in vivo sequences for localized ¹H-MRS (magnetic resonance spectroscopy) are presented which can be directly applied for noninvasive detection of brain metabolites.

Metabolomics reveals perturbations in endometrium and serum of minimal and mild endometriosis

Endometriosis is a common benign gynecological disease, characterized by growth and proliferation of endometrial glands and stroma outside the uterus. With studies showing metabolic changes in various biofluids of endometriosis women, we have set upon to investigate whether endometrial tissue show differences in their metabolic profiles. ¹H NMR analysis was performed on eutopic endometrial tissue of women with endometriosis and controls. Analysis was performed on spectral data and on relative concentrations of metabolites obtained from spectra using multivariate and univariate data analysis. Analysis shows that various energy, ketogenic and glucogenic metabolites have significant altered concentrations in various stages of endometriosis. In addition, altered tissue metabolites in minimal and mild stages of endometriosis were explored in serum of these patients to assess their role in disease diagnosis. For Stage I diagnosis alanine was found to have 90% sensitivity (true positives) and 58% specificity (true negatives). For Stage II diagnosis alanine, leucine, lysine, proline and phenylalanine showed significant altered levels in serum. While sensitivity of these serum metabolites varied between 69.2–100% the specificity values ranged between 58.3–91.7%. Further, a regression model generated with this panel of serum markers showed an improved sensitivity and specificity of 100% and 83%, respectively for Stage II diagnosis.

Predictive value of 1H MR spectroscopy and 18F-FDG PET/CT for local control of advanced oropharyngeal and hypopharyngeal squamous cell carcinoma receiving chemoradiotherapy: a prospective study

Purpose

To determine whether pretreatment in vivo 1H magnetic resonance (MR) spectroscopy at 3 Tesla (T) and 18F-FDG PET/CT can offer predictive power regarding the local control of oropharyngeal or hypopharyngeal squamous cell carcinoma (OHSCC) patients.

Materials and Methods

¹H MR spectroscopy was performed in addition to conventional MR imaging before definitive chemoradiotherapy in 58 patients with advanced OHSCC. The relationship of local control with the ¹H MR spectroscopy and ¹⁸F-FDG PET/CT parameters was analyzed.

Results

With a median follow-up of 17.6 months, 13 (22.4%) patients exhibited local failure; whereas the remaining 45 achieved local control. Kaplan-Meier analysis identified age > 60 years, creatine level on MRS ≦ 6.02 mM, glutamine and glutamate (Glx) level on MRS > 3.31 mM, and total lesion glycolysis (TLG) on ¹⁸F-FDG PET/CT > 217.18 g/mL × mL as significant adverse predictors for 2-year local control. Multivariate Cox regression analysis showed that age (p=0.017), Glx level on MRS (p=0.021), and TLG on ¹⁸F-FDG PET/CT (p=0.028) retained their independent prognostic significance. A scoring system was constructed based on the sum of these three factors. We found that patients with scores of 2-3 had significantly poorer local control rates than patients with scores of 0-1 (33.3% versus 86.8%, p=0.003).

Conclusion

We conclude that Glx on ¹H MR spectroscopy at 3 T was the independent prognostic factor for local control of OHSCC patients treated with chemoradiotherapy, and its combination with age and TLG may help identify a subgroup of patients at high risk for developing local failure.

"Omics" in oral cancer: New approaches for biomarker discovery

OBJECTIVES

In this review paper, we explored the application of "omics" approaches in the study of oral cancer (OC). It will provide a better understanding of how "omics" approaches may lead to novel biomarker molecules or molecular signatures with potential value in clinical practice. A future direction of "omics"-driven research in OC is also discussed.

METHODS

Studies on "omics"-based approaches [genomics/proteomics/transcriptomics/metabolomics] were investigated for differentiating oral squamous cell carcinoma,oral sub-mucous fibrosis, oral leukoplakia, oral lichen planus, oral erythroplakia from normal cases. Electronic databases viz., PubMed, Springer, and Google Scholar were searched.

RESULTS

One eighty-one studies were included in this review. The review shows that the fields of genomics, transcriptomics, proteomics, and metabolomics-based marker identification have implemented advanced tools to screen early changes in DNA, RNA, protein, and metabolite expression in OC population.

CONCLUSIONS

It may be concluded that despite advances in OC therapy, symptomatic presentation occurs at an advanced stage, where various curative treatment options become very limited. A molecular level study is essential for detecting an OC biomarker at an early stage. Modern "Omics" strategies can potentially make a major contribution to meet this need.

Head and Neck Squamous Cell Carcinoma Metabolism Draws on Glutaminolysis, and Stemness Is Specifically Regulated by Glutaminolysis via Aldehyde Dehydrogenase

Cancer cells use alternate energetic pathways; however, cancer stem cell (CSC) metabolic energetic pathways are unknown. The purpose of this study was to define the metabolic characteristics of head and neck cancer at different points of its pathogenesis with a focus on its CSC compartment. UPLC-MS/MS-profiling and GC-MS-validation studies of human head and neck cancer tissue, saliva, and plasma were used in conjunction with in vitro and in vivo models to carry out this investigation. We identified metabolite biomarker panels that distinguish head and neck cancer from healthy controls, and confirmed involvement of glutamate and glutaminolysis. Glutaminase, which catalyzes glutamate formation from glutamine, and aldehyde dehydrogenase (ALDH), a stemness marker, were highly expressed in primary and metastatic head and neck cancer tissues, tumorspheres, and CSC versus controls. Exogenous glutamine induced stemness via glutaminase, whereas inhibiting glutaminase suppressed stemness in vitro and tumorigenesis in vivo. Head and neck CSC (CD44hi/ALDHhi) exhibited higher glutaminase, glutamate, and sphere levels than CD44lo/ALDHlo cells. Glutaminase drove transcriptional and translational ALDH expression, and glutamine directed even CD44lo/ALDHlo cells toward stemness. Glutaminolysis regulates tumorigenesis and CSC metabolism via ALDH. These findings indicate that glutamate is an important marker of cancer metabolism whose regulation via glutaminase works in concert with ALDH to mediate cancer stemness. Future analyses of glutaminolytic-ALDH driven mechanisms underlying tumorigenic transitions may help in the development of targeted therapies for head and neck cancer and its CSC compartment.

Renal cell carcinoma: a critical analysis of metabolomic biomarkers emerging from current model systems

Metabolomics, an emerging field of "omics" sciences, has caught wide scientific attention in the area of biomarker research for cancers in which early diagnostic biomarkers have the potential to greatly improve patient outcome, such as renal cell carcinoma (RCC). Metabolomic approaches have been successfully applied to various human RCC model systems, mostly ex vivo neoplastic renal tissues and biofluids (urine and serum) from patients with RCC. Importantly, in contrast to other cancers, only a few studies have addressed the RCC metabolome using cancer cell culture-based in vitro models. Herein, we first carried out a comprehensive review of current metabolomic data in RCC, with emphasis on metabolite disturbances and dysregulated metabolic pathways identified in each of these experimental models. We then critically analyzed the consistency of evidence in this field and whether metabolites found altered in tumor cell and tissue microenvironment are reflected in biofluids, which constitute the rationale underlying the translation of discovered metabolic biomarkers into noninvasive diagnostic tools. Finally, dominant metabolic pathways and promising metabolites as biomarkers for diagnosis and prognosis of RCC are outlined.

Metabolomics of Head and Neck Cancer: A Mini-Review

Metabolomics is used in systems biology to enhance the understanding of complex disease processes, such as cancer. Head and neck cancer (HNC) is an epithelial malignancy that arises in the upper aerodigestive tract and affects more than half a million people worldwide each year. Recently, significant effort has focused on integrating multiple “omics” technologies for oncological research. In particular, research has been focused on identifying tumor-specific metabolite profiles using different sample types (biological fluids, cells and tissues) and a variety of metabolomic platforms and technologies. With our current understanding of molecular abnormalities of HNC, the addition of metabolomic studies will enhance our knowledge of the pathogenesis of this disease and potentially aid in the development of novel strategies to prevent and treat HNC. In this review, we summarize the proposed hypotheses and conclusions from publications that reported findings on the metabolomics of HNC. In addition, we address the potential influence of host-microbe metabolomics in cancer. From a systems biology perspective, the integrative use of genomics, transcriptomics and proteomics will be extremely important for future translational metabolomic-based research discoveries.

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.

Correlation of Choline/Creatine and Apparent Diffusion Coefficient values with the prognostic parameters of Head and Neck Squamous Cell Carcinoma

The aim of this study was to measure choline/creatine (Ch/Cr) levels through (1)H-MRS and apparent diffusion coefficient (ADC) values through diffusion-weighted MRI, and to correlate these values with the prognostic parameters of head and neck squamous cell carcinoma (HNSCC). The institutional review board approved this study and informed written consent was obtained from all study participants. A prospective study of 43 patients (31 men and 12 women; mean age, 65 years) with HNSCC was conducted. Single-voxel (1)H-MRS was performed at the tumor or metastatic cervical lymph node with point-resolved spectroscopy (PRESS) at TE = 135 ms. Diffusion-weighted MR images with b values of 0, 500 and 1000 s/mm(2) and contrast MRI of the head and neck were performed. The Ch/Cr levels and ADC values of HNSCC were calculated. The gross tumor volume (GTV) was also calculated. The degree of tumor differentiation was determined through pathological examination. The HNSCC Ch/Cr level was negatively correlated with the ADC value (r = -0.662, p = 0.001). There was a significant difference in the Ch/Cr and ADC values at different degrees of tumor differentiation (p = 0.003 and p = 0.001) and with different GTVs (p = 0.122 and p = 0.001). The following prognostic parameter categories were used: (i) poorly differentiated and undifferentiated versus well differentiated to moderately differentiated; and (ii) HNSCC with GTV < 30 cm(3) versus GTV > 30 cm(3). The cut-off values for Cho/Cr and ADC for each category were 1.83, 0.95 and 1.94, 0.99, respectively, and the areas under the curve were 0.771, 0.967 and 0.726, 0.795, respectively, for each category. We conclude that the Ch/Cr levels determined using (1)H-MRS and the ADC values are well correlated with several prognostic parameters of HNSCC.

Integrative metabonomics as potential method for diagnosis of thyroid malignancy

Thyroid nodules can be classified into benign and malignant tumors. However, distinguishing between these two types of tumors can be challenging in clinics. Since malignant nodules require surgical intervention whereas asymptomatic benign tumors do not, there is an urgent need for new techniques that enable accurate diagnosis of malignant thyroid nodules. Here, we used ¹H NMR spectroscopy coupled with pattern recognition techniques to analyze the metabonomes of thyroid tissues and their extracts from thyroid lesion patients (n = 53) and their adjacent healthy thyroid tissues (n = 46). We also measured fatty acid compositions using GC−FID/MS techniques as complementary information. We demonstrate that thyroid lesion tissues can be clearly distinguishable from healthy tissues, and malignant tumors can also be distinguished from the benign tumors based on the metabolic profiles, both with high sensitivity and specificity. In addition, we show that thyroid lesions are accompanied with disturbances of multiple metabolic pathways, including alterations in energy metabolism (glycolysis, lipid and TCA cycle), promotions in protein turnover, nucleotide biosynthesis as well as phosphatidylcholine biosynthesis. These findings provide essential information on the metabolic features of thyroid lesions and demonstrate that metabonomics technology can be potentially useful in the rapid and accurate preoperative diagnosis of malignant thyroid nodules.

Nuclear magnetic resonance metabolomic profiling of urine provides a noninvasive alternative to the identification of biomarkers associated with endometriosis

OBJECTIVE

To investigate whether urine metabolomic profile can be used to identify biomarkers associated to endometriosis.

DESIGN

Prospective study. For each subject, a urine sample was collected after overnight fasting and before surgery.

SETTING

University medical center.

PATIENT(S)

The clinical cohort included 45 endometriosis patients, diagnosed at early (n = 6) and advanced (n = 39) stages of the disease, and 36 healthy women. All women underwent diagnostic laparoscopy to visually confirm the presence or absence of endometriotic lesions.

INTERVENTION(S)

Metabolomic profiling of urine samples based on (1)H-nuclear magnetic resonance (NMR) spectroscopy in combination with statistical approaches.

MAIN OUTCOME MEASURE(S)

Comparative identification of metabolites present in urine from endometriosis patients and healthy women.

RESULT(S)

The urine metabolomic profile of endometriosis patients exhibited higher concentrations of N(1)-methyl-4-pyridone-5-carboxamide, guanidinosuccinate, creatinine, taurine, valine, and 2-hydroxyisovalerate and decreased concentrations of lysine compared with healthy women. Most of these metabolites are involved in inflammation and oxidative stress processes. These pathophysiologic events had been previously described to be present in ectopic endometrial proliferation foci.

CONCLUSION(S)

Overall, the results demonstrate the potential of (1)H-NMR-based metabolomics, a rapid and noninvasive approach, to identify metabolic changes associated to endometriosis in urine samples. This information could be useful to get a better understanding of the pathogenesis of endometriosis, thus providing support to the noninvasive diagnosis of this pathology.

Future Imaging Alternatives: The Clinical Non-invasive Modalities in Diagnosis of Oral Squamous Cell Carcinoma (OSCC)

Background : Oral squamous cell carcinoma (OSCC) has a remarkably high incidence worldwide, and a fairly serious prognosis. This is encouraging further research into advanced technologies for non-invasive methods of making early diagnoses, ideally in primary care settings. Method : In this article, the available objective Non-imaging methods for diagnosing OSCC have been reviewed. MEDLINE, EMBASE, the Cochrane Library, and CINAHL have been searched for advanced technologies of non-invasive methods in diagnosis of OSCC, including oral brush biopsy, optical biopsy, saliva-based oral cancer diagnosis and others. Results : Toluidine blue, one of the oldest non-invasive methods for diagnosing OSCC, is unreliable because of its subjectivity, as it is dependent on the experience of the examiner. The diagnosis of Oral carcinoma by Oral brush biopsy with exfoliative cytology based on nano-bio-chip sensor platform shows 97–100% sensitivity and 86% specificity. Another promising non-invasive technique for OSCC diagnosis is saliva-based oral cancer diagnosis, which is an alternative to serum testing. Optical biopsy, which uses the technology of spectroscopy, can be used to detect changes at a sub-cellular level; thus, it provides information that may not be available with conventional histology with reliable sensitivity and specificity. Conclusion : It is clearly evident that screening and early effective detection of cancer and pre-cancerous lesions have the potential to reduce the morbidity and mortality of this disease. The imaging technologies are subjective procedures since all of them require interpretation and significantly affected by the examiner experience. These make further research for advanced objective procedures. Saliva-based oral cancer diagnosis and optical biopsy are promising objective non-invasive methods for diagnosing OSCC. They are easy to perform clinically at primary care set. They show promising pathways for future development of more effective method for the diagnosis of OSCC.

Current concepts and future of noninvasive procedures for diagnosing oral squamous cell carcinoma--a systematic review

Background

Oral squamous cell carcinoma (OSCC) has a remarkably high incidence worldwide, and a fairly serious prognosis, encouraging further research into advanced technologies for noninvasive methods of making early diagnoses, ideally in primary care settings.

Objectives

Our purpose was to examine the validity of using advanced noninvasive technologies in diagnosis of OSCC by identifying and evaluating relevant published reports.

Data source

MEDLINE, EMBASE, and CINAHL were searched to identify clinical trials and other information published between 1990 and 10 June 2014; the searches of MEDLINE and EMBASE were updated to November 2014. Study selection: Studies of noninvasive methods of diagnosing OSCC, including oral brush biopsy, optical biopsy, saliva-based oral cancer diagnosis, and others were included.

Data extraction

Data were abstracted and evaluated in duplicate for possible relevance on two occasions at an interval of 2 months before being included or excluded.

Data synthesis

This study identified 163 studies of noninvasive methods for diagnosing OSCC that met the inclusion criteria. These included six studies of oral brush biopsy, 42 of saliva-based oral diagnosis, and 115 of optical biopsy. Sixty nine of these studies were assessed by the modified version of the QUADAS instrument. Saliva-based oral cancer diagnosis and optical biopsy were found to be promising noninvasive methods for diagnosing OSCC.

Limitation

The strength of evidence was rated low for accuracy outcomes because the studies did not report important details required to assess the risk for bias.

Conclusions

It is clear that screening for and early detection of cancer and pre-cancerous lesions have the potential to reduce the morbidity and mortality of this disease. Advances in technologies for saliva-based oral diagnosis and optical biopsy are promising pathways for the future development of more effective noninvasive methods for diagnosing OSCC that are easy to perform clinically in primary care settings.

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.

MR spectroscopy of head and neck cancer

The aim of this review is to discuss the technique and potential applications of magnetic resonance spectroscopy (MRS) in head and neck cancer. We illustrate the technical issues related to data acquisition, post processing and interpretation of MRS of head and neck lesions. MRS has been used for differentiation of squamous cell carcinoma from normal tissue. The main potential clinical application of proton MRS ((1)H-MRS) is monitoring patients with head and neck cancer undergoing therapy. Pretreatment prediction of response to therapy can be done with phosphorus MRS ((31)P-MRS). Although performance of MRS of head and neck is challenging, technological advances in both software and hardware has the potential to impact on the clinical management of patients with head and neck cancer.

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.

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.

Correlation of biomarkers in head and neck squamous cell carcinoma

OBJECTIVE: To evaluate the relationship of functional magnetic resonance imaging (MRI) parameters, including choline/creatine ratio (Cho/Cr) and apparent diffusion coefficient (ADC) with protein expression of 10 common tumor and prognostic markers in head and neck squamous cell carcinoma.

STUDY DESIGN: Cross-sectional study.

SETTING: University hospital.

SUBJECTS AND METHODS: The Cho/Cr and ADC obtained from 74 patients with head and neck squamous cell carcinoma were correlated with the expression level of the 10 protein markers as determined by immunohistochemistry.

RESULTS: Cho/Cr showed significant positive correlations with cyclooxygenase 2 in primary tumors ( r = 0.714), and epidermal growth factor receptor in metastatic cervical lymph nodes ( r = 0.522). ADC showed significant ( r = −0.591) negative correlation with human epidermal growth factor receptor 2 in metastatic cervical lymph nodes.

CONCLUSION: There are relationships between protein and functional MRI markers. Future research in this direction may improve our understanding of the cancer micro-environment.

Proton and phosphorous MR spectroscopy in squamous cell carcinomas of the head and neck

RATIONALE AND OBJECTIVES

Phosphorous magnetic resonance spectroscopy ((31)P MRS) has been used to evaluate and predict treatment response in squamous cell carcinoma of the head and neck (HNSCC). Several studies have also shown the potential of proton MRS ((1)H MRS) in assessing response in HNSCC. In view of the inherent limitations associated with performing (31)P MRS in clinical settings, the current study was performed to explore whether (1)H MRS could provide similar or complementary metabolic information in HNSCC.

MATERIALS AND METHODS

Fifteen patients with HNSCC underwent pretreatment magnetic resonance imaging. Both (1)H MRS and (31)P MRS were performed on viable solid parts of the metastatic lymph nodes of these patients. Peak areas of total choline (tCho) and unsuppressed water as observed on (1)H MRS and phosphomonoester (PME) and beta-nucleotide triphosphate (beta-NTP) on (31)P MRS were computed. Pearson's correlation coefficient was used to correlate the tCho/water and PME/beta-NTP ratios.

RESULTS

In all patients, the metastatic nodes appeared hyperintense on T2-weighted images and hypointense on T1-weighted images with variable signal intensity. A prominent resonance of tCho on (1)H MRS and a resonance of PME on (31)P MRS from the metastatic nodes of all patients were observed. A moderate correlation of 0.31 was observed between tCho/water and PME/beta-NTP (P > .05).

CONCLUSIONS

The biochemical pathways involved in (1)H MRS of tCho may be different from the phospholipid metabolites seen on (31)P MRS of head and neck cancers, and thus the two MRS techniques may be complementary to each other.

Detecting colorectal cancer by 1H magnetic resonance spectroscopy of fecal extracts

Colorectal cancer is one of the most common cancers in the western world. Its early detection has been found to improve the prognosis of the patient, providing a wide window of opportunity for successful therapeutic interventions. However, current diagnostic techniques all have some limitations; there is a need to develop a better technique for routine screening purposes. We present a new methodology based on magnetic resonance spectroscopy of fecal extracts for the non-invasive detection of colorectal cancer. Five hundred twenty-three human subjects (412 with no colonic neoplasia and 111 with colorectal cancer, who were scheduled for colonoscopy or surgery) were recruited to donate a single sample of stool. One-dimensional (1)H magnetic resonance spectroscopy (MRS) experiments were performed on the supernatant of aqueous dispersions of the stool samples. Using a statistical classification strategy, several multivariate classifiers were developed. Applying the preprocessing, feature selection and classifier development stages of the Statistical Classification Strategy led to approximately 87% average balanced sensitivity and specificity for both training and monitoring sets, improving to approximately 92% when only crisp results, i.e. class assignment probabilities > or =75%, are considered. These results indicate that (1)H magnetic resonance spectroscopy of human fecal extracts, combined with appropriate data analysis methodology, has the potential to detect colorectal neoplasia accurately and reliably, and could be a useful addition to the current screening tools.

Early stage diagnosis of oral cancer using 1H NMR-based metabolomics

Oral cancer is the eighth most common cancer worldwide and represents a significant disease burden. If detected at an early stage, survival from oral cancer is better than 90% at 5 years, whereas late stage disease survival is only 30%. Therefore, there is an obvious clinical utility for novel metabolic markers that help to diagnose oral cancer at an early stage and to monitor treatment response. In the current study, blood samples of oral cancer patients were analyzed using nuclear magnetic resonance spectroscopy to derive a metabolic signature for oral cancer. Using multivariate chemometric analysis, we obtained an excellent discrimination between serum samples from cancer patients and from a control group and could also discriminate between different stages of disease. The metabolic profile obtained for oral cancer is significant, even for early stage disease and relatively small tumors. This suggests a systemic metabolic response to cancer, which bears great potential for early diagnosis.

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.

Characterization of synovial tissue from arthritis patients: a proton magnetic resonance spectroscopic investigation

Hypoxia may contribute to the pathogenesis of synovitis in rheumatoid arthritis (RA). Magnetic resonance spectroscopy (MRS) is a technique that uses radiofrequency waves to generate a signal which allows a qualitative and quantitative assessment of the biochemical composition of tissue. MRS was used to evaluate RA synovial tissue for evidence of hypoxia and anaerobic metabolism. Synovial tissue samples obtained from eighteen RA patients and four osteoarthritis control patients undergoing total knee replacement were analyzed using proton MRS, processed for histopathology and scored for inflammation and vascularity. Spectra from severely and mildly inflamed tissue differed in peak intensity at regions 1.3 ppm (representing lactic acid and lipid), 3.0 ppm (representing creatine), 3.2 ppm (representing choline containing metabolites), and 3.8 ppm (representing carbohydrates, possibly glucose). With increasing inflammation, the intensities of the peak resonance at 1.3 ppm increased and that at 3.8 ppm decreased. The intensities of the 3.8 and 3.0 ppm peaks were reduced in highly vascular tissue. Specific MR spectral features reflect the anaerobic metabolism that is evident with progressively increasing degrees of RA synovial inflammation and vascularity. These features correlate partially with synovial histopathology.

Metabonomics and its application in oncobiology research

The primary aim of this review is to introduce the research status of metabonomics/metabolomics and the application of metabonomics in oncobiology research. At first, the concept of metabonomics and the relationship between metabonomics and tumors are elucidated in detail. Then the research technologies of metabonomics in oncobiology are introduced. Finally, the latest advances in the application of metabonomics in early diagnosis, treatment and prognosis of tumors are summarized.

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.

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.

In vivo 1H MR spectroscopy of thyroid carcinoma

To determine if proton magnetic resonance spectroscopy (1H MRS) of thyroid carcinoma is feasible and to determine if 1H MRS spectra of malignant tumors differ from that of normal thyroid tissue. We performed 1H MRS at 1.5 T at echo-times (TE) 136 and 272 ms to examine eight patients with thyroid cancer (primary tumour or nodal metastasis) larger than 1 cm3 in size and five volunteers with normal thyroids. Spectra acquired from six primary tumors (three anaplastic carcinomas, two papillary carcinomas and one follicular carcinoma) and two nodes (two papillary carcinoma metastases) were analyzed in the time-domain using a non-linear least squares fitting algorithm with incorporation of prior knowledge. Choline (3.2 ppm) was identified in all solid carcinomas with a mean choline/creatine of 4.3 at TE 136 ms and 5.4 at TE 272 ms. Ratios for malignant tumors at TE 136 ms ranged from 1.6 in well differentiated follicular carcinoma to 9.4 in anaplastic carcinoma. No choline was detected in normal thyroid tissues. Our results showed that 1H MRS is a feasible technique for the evaluation of malignant thyroid tumors larger than 1 cm3 and that proton spectra of malignant tumors differ from that of normal thyroid tissue.

Advances in Head and Neck Imaging

This article discusses new techniques in head and neck imaging.

In vivo and ex vivo proton MR spectroscopy of primary and secondary melanoma

In vivo magnetic resonance (MR) spectroscopy at 1.5T was performed on a large polypoid cutaneous melanoma, and two enlarged lymph nodes containing metastatic melanoma, from three patients. Spectra were acquired in vivo from voxels wholly within the primary tumour or secondary lymph node and were thus uncontaminated by signals from adjacent tissue. Tissue biopsies taken after resection of primary tumours and secondary lymph nodes were examined by 8.5T magnetic resonance spectroscopy (MRS) and the results compared with the in vivo spectra, and with spectra from normal skin and a benign skin lesion. There was good agreement between the dominant features of 1.5T spectra acquired in vivo and 8.5T spectra acquired from resected tissue. However, less intense resonances observed at 8.5T in malignant biopsy tissue were not consistently observed at 1.5T in vivo. In vivo spectra from primary and metastatic melanoma showed high levels of choline metabolites. An intense lactate resonance was also present in the in vivo spectrum of primary melanoma. All 8.5T spectra of biopsies from primary and secondary melanoma showed high levels of choline metabolites and lactate, and additional resonances consistent with elevated levels of taurine, alanine, lysine, and glutamate/glutamine relative to normal and benign tissue. Elevated levels of choline, lactate, taurine, and amino acids appear to be clinically useful markers for identifying the pathology of primary and metastatic melanoma.

Magnetic resonance spectroscopy of head and neck neoplasms

Magnetic resonance spectroscopy (MRS) is a validated noninvasive method for evaluation of possible malignant tumor and lymph nodes of the head and neck. From its roots as a budding research application, it has made the critical transition to a widespread clinical tool. MRS analyzes the tissue at a molecular level and searches for the presence of specific metabolites, which are markers for malignancy. Differentiation of benign from malignant neoplasm, detection of recurrence of malignant tumor and noninvasive treatment monitoring of treated or untreated tumor are some of the important utilities of MRS. One dimensional 1H-MRS is the most popular and promising technique for spectroscopic analysis while P-31 MRA and two-dimensional correlated spectroscopy (2D COSY) have also showed some promise. This article describes the application of magnetic resonance spectroscopy for evaluation of malignant tumors of the neck.

Newer MR imaging techniques for head and neck

Dynamic and functional imaging techniques are being developed to improve the evaluation of various pathologic processes of the head and neck region. These techniques include dynamic contrast-enhanced MR imaging for evaluating soft tissue masses and cervical lymph nodes, the use of ultrasmall superparamagnetic iron oxide contrast agent, and functional techniques such as in vivo and in vitro MR spectroscopy of head and neck cancer and lymph nodes and apparent diffusion coefficient mapping of parotid glands. These techniques can help to differentiate nonmalignant tissue from malignant tumors and lymph nodes and can aid in differentiating residual malignancies from postradiation changes. From methodological development, they are making the critical transition to preclinical and clinical validating methods and eventually to widespread clinical tools.