Detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT)

The purpose of this study was to analyze the detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT). Data for a total of 492 patients who had undergone both PET/CT and colonoscopy were analyzed. After the findings of PET/CT and colonoscopy were determined independently, the results were compared in each of the six colonic sites examined in all patients. The efficacy of PET/CT was determined using colonoscopic examination as the gold standard. In all, 270 colorectal lesions 5 mm or more in size, including 70 pathologically confirmed malignant lesions, were found in 172 patients by colonoscopy. The sensitivity and specificity of PET/CT for detecting any of the colorectal lesions were 36 and 98%, respectively. For detecting lesions 11 mm or larger, the sensitivity was increased to 85%, with the specificity remaining consistent (97%). Moreover, the sensitivity for tumors 21 mm or larger was 96% (48/50). Tumors with malignant or high-grade pathology were likely to be positive with PET/CT. A size of 10 mm or smaller [odds ratio (OR) 44.14, 95% confidence interval (95% CI) 11.44-221.67] and flat morphology (OR 7.78, 95% CI 1.79-36.25) were significant factors that were associated with false-negative cases on PET/CT. The sensitivity of PET/CT for detecting colorectal lesions is acceptable, showing size- and pathology-dependence, suggesting, for the most part, that clinically relevant lesions are detectable with PET/CT. However, when considering PET/CT for screening purposes caution must be exercised because there are cases of false-negative results

The role of Nr4a1 in maternal obesity induced beta cell expansion

The academic objectives of this Mentoring Environment Grant (MEG) were to 1) train undergraduate students in the scientific process to prepare them in careers as physicians and scientists, and 2) to examine the relationship between in utero Nr4a1 beta cell specific deletion during maternal overnutrition and obesity on beta cell mass at birth and diabetic onset. We were successful in accomplishing these objectives, as evidenced by the training of four undergraduate students, presentation of research and local and national meetings, and initial preparation of a manuscript reporting our findings

Mitochondrial Protein Expression in NR4A3-knockout Mice

The expression of the orphan receptor, Nuclear Receptor Subfamily 4 Group A Member 3 (NR4A3), is upregulated in response to exercise, suggesting that it could be influential in altering gene expression for skeletal muscle adaptation to exercise. Recent research has demonstrated that when NR4A3 was knocked down in skeletal muscle cells, there was decreased expression of mitochondrial proteins, including those of the oxidative phosphorylation system (OXPHOS). The effect of deficient NR4A3 expression on mitochondrial proteins in mouse skeletal muscle is unknown. PURPOSE: We tested the hypothesis that NR4A3-knockout (KO) would suppress the expression of mitochondrial proteins in mouse skeletal muscle. METHODS: To test this hypothesis, the gastrocnemius muscles of 10 global NR4A3 knockout and 10 wild-type mice were collected, homogenized, and analyzed using western blotting. The proteins examined included OXPHOS proteins, PGC1, p-ACC, p-raptor, and cytochrome C. RESULTS: Contrary to our hypothesis, there was no significant difference in protein expression between the knockout and wild-type mice for any of the measured proteins. However, a strong trend (p=0.07 - 0.14) for decreased expression of some OXPHOS components was observed in knockout mice. CONCLUSION: Our findings suggest that contrary to findings in cultured muscle, the lack of NR4A3 in vivo does not heavily impact mitochondrial content, although it may affect components of the electron transport chain, and further testing of mitochondrial function would be beneficial. The lack of effect may be related to compensation by NR4A1, a protein related to NR4A3

Ribosomal Protein S6 Phosphorylation is Elevated in NR4A3 Knockout Muscle

Exercise training produces many muscle and body adaptations that improve health and function. Many of these adaptations are driven by altered gene expression. Nuclear Receptor Subfamily 4 Group A Member 3 (NR4A3; AKA NOR-1) is an orphan nuclear receptor and transcription factor whose expression is among the most upregulated genes after exercise, suggesting that it plays a critical role in the adaptation to training. Recently, a knockdown study in cultured skeletal muscle cells showed that the silencing of NR4A3 led to impaired signaling through the mechanistic target of rapamycin (mTOR), a key molecular driver of muscle mass maintenance. PURPOSE: Determine whether NR4A3 knockout in mice suppresses anabolic signaling through mTOR in muscle tissue. METHODS: Resting gastrocnemius muscles were collected from 10 global NR4A3 knockout (KO) and 9 wild-type (WT) mice and analyzed via western blotting for phosphorylated and total mTOR, p70 ribosomal protein S6 kinase (S6k), eukaryotic initiation factor 4E-binding protein 1 (4EBP1), and ribosomal protein S6 (rpS6). RESULTS: Gastrocnemius size was not different between WT vs. KO mice. No significant differences were noted in signaling protein phosphorylation between WT and KO except for rpS6 phosphorylation, which was elevated in KO muscles by 120%, contrary to our hypothesis. RpS6 is phosphorylated by both S6k (whose phosphorylation was not affected basally) and another kinase, p90 ribosomal protein S6 kinase (p90RSK). p90RSK is regulated by mitogen-activated protein kinase (MAPK) signaling. Therefore, we also measured Erk, p38, and Jnk phosphorylation, which were not significantly affected in KO muscles. CONCLUSION: Our findings indicate that NR4A3 knockout may enhance muscle anabolic potential (via elevated rpS6 action) but not through upstream mTOR or MAPK signaling. Furthermore, this suggests that the inhibition of NR4A3 could enhance muscle growth but not in unstimulated, resting muscle

Targeting cancer metabolism: a therapeutic window opens

Genetic events in cancer activate signalling pathways that alter cell metabolism. Clinical evidence has linked cell metabolism with cancer outcomes. Together, these observations have raised interest in targeting metabolic enzymes for cancer therapy, but they have also raised concerns that these therapies would have unacceptable effects on normal cells. However, some of the first cancer therapies that were developed target the specific metabolic needs of cancer cells and remain effective agents in the clinic today. Research into how changes in cell metabolism promote tumour growth has accelerated in recent years. This has refocused efforts to target metabolic dependencies of cancer cells as a selective anticancer strategy.Burroughs Wellcome FundSmith Family FoundationStarr Cancer ConsortiumDamon Runyon Cancer Research FoundationNational Institutes of Health (U.S.

Cdk5r1 Overexpression Induces Primary β

Decreased β-cell mass is a hallmark of type 1 and type 2 diabetes. Islet transplantation as a method of diabetes therapy is hampered by the paucity of transplant ready islets. Understanding the pathways controlling islet proliferation may be used to increase functional β-cell mass through transplantation or by enhanced growth of endogenous β-cells. We have shown that the transcription factor Nkx6.1 induces β-cell proliferation by upregulating the orphan nuclear hormone receptors Nr4a1 and Nr4a3. Using expression analysis to define Nkx6.1-independent mechanisms by which Nr4a1 and Nr4a3 induce β-cell proliferation, we demonstrated that cyclin-dependent kinase 5 regulatory subunit 1 (Cdk5r1) is upregulated by Nr4a1 and Nr4a3 but not by Nkx6.1. Overexpression of Cdk5r1 is sufficient to induce primary rat β-cell proliferation while maintaining glucose stimulated insulin secretion. Overexpression of Cdk5r1 in β-cells confers protection against apoptosis induced by etoposide and thapsigargin, but not camptothecin. The Cdk5 kinase complex inhibitor roscovitine blocks islet proliferation, suggesting that Cdk5r1 mediated β-cell proliferation is a kinase dependent event. Overexpression of Cdk5r1 results in pRb phosphorylation, which is inhibited by roscovitine treatment. These data demonstrate that activation of the Cdk5 kinase complex is sufficient to induce β-cell proliferation while maintaining glucose stimulated insulin secretion

Metabolomic analysis of human disease and its application to the eye

Metabolomics, the analysis of the metabolite profile in body fluids or tissues, is being applied to the analysis of a number of different diseases as well as being used in following responses to therapy. While genomics involves the study of gene expression and proteomics the expression of proteins, metabolomics investigates the consequences of the activity of these genes and proteins. There is good reason to think that metabolomics will find particular utility in the investigation of inflammation, given the multi-layered responses to infection and damage that are seen. This may be particularly relevant to eye disease, which may have tissue specific and systemic components. Metabolomic analysis can inform us about ocular or other body fluids and can therefore provide new information on pathways and processes involved in these responses. In this review, we explore the metabolic consequences of disease, in particular ocular conditions, and why the data may be usefully and uniquely assessed using the multiplexed analysis inherent in the metabolomic approach

NMR-Based Prostate Cancer Metabolomics

Author's accepted version (postprint).This is an Accepted Manuscript of an article published by Springer in Methods in Molecular Biology on 22 May 2018.Available online: https://doi.org/10.1007/978-1-4939-7845-8_14acceptedVersio

Prognostic value of metabolic response in breast cancer patients receiving neoadjuvant chemotherapy

<p>Abstract</p> <p>Background</p> <p>Today's clinical diagnostic tools are insufficient for giving accurate prognosis to breast cancer patients. The aim of our study was to examine the tumor metabolic changes in patients with locally advanced breast cancer caused by neoadjuvant chemotherapy (NAC), relating these changes to clinical treatment response and long-term survival.</p> <p>Methods</p> <p>Patients (n = 89) participating in a randomized open-label multicenter study were allocated to receive either NAC as epirubicin or paclitaxel monotherapy. Biopsies were excised pre- and post-treatment, and analyzed by high resolution magic angle spinning magnetic resonance spectroscopy (HR MAS MRS). The metabolite profiles were examined by paired and unpaired multivariate methods and findings of important metabolites were confirmed by spectral integration of the metabolite peaks.</p> <p>Results</p> <p>All patients had a significant metabolic response to NAC, and pre- and post-treatment spectra could be discriminated with 87.9%/68.9% classification accuracy by paired/unpaired partial least squares discriminant analysis (PLS-DA) (<it>p </it>< 0.001). Similar metabolic responses were observed for the two chemotherapeutic agents. The metabolic responses were related to patient outcome. Non-survivors (< 5 years) had increased tumor levels of lactate (<it>p </it>= 0.004) after treatment, while survivors (≥ 5 years) experienced a decrease in the levels of glycine (<it>p </it>= 0.047) and choline-containing compounds (<it>p </it>≤ 0.013) and an increase in glucose (<it>p </it>= 0.002) levels. The metabolic responses were not related to clinical treatment response.</p> <p>Conclusions</p> <p>The differences in tumor metabolic response to NAC were associated with breast cancer survival, but not to clinical response. Monitoring metabolic responses to NAC by HR MAS MRS may provide information about tumor biology related to individual prognosis.</p

Molecular preservation by extraction and fixation, mPREF: a method for small molecule biomarker analysis and histology on exactly the same tissue

<p>Abstract</p> <p>Background</p> <p>Histopathology is the standard method for cancer diagnosis and grading to assess aggressiveness in clinical biopsies. Molecular biomarkers have also been described that are associated with cancer aggressiveness, however, the portion of tissue analyzed is often processed in a manner that is destructive to the tissue. We present here a new method for performing analysis of small molecule biomarkers and histology in exactly the same biopsy tissue.</p> <p>Methods</p> <p>Prostate needle biopsies were taken from surgical prostatectomy specimens and first fixed, each in a separate vial, in 2.5 ml of 80% methanol:water. The biopsies were fixed for 24 hrs at room temperature and then removed and post-processed using a non-formalin-based fixative (UMFIX), embedded, and analyzed by hematoxylin and eosin (H&E) and by immunohistochemical (IHC) staining. The retained alcohol pre-fixative was analyzed for small molecule biomarkers by mass spectrometry.</p> <p>Results</p> <p>H&E analysis was successful following the pre-fixation in 80% methanol. The presence or absence of tumor could be readily determined for all 96 biopsies analyzed. A subset of biopsy sections was analyzed by IHC, and cancerous and non-cancerous regions could be readily visualized by PIN4 staining. To demonstrate the suitability for analysis of small molecule biomarkers, 28 of the alcohol extracts were analyzed using a mass spectrometry-based metabolomics platform. All extracts tested yielded successful metabolite profiles. 260 named biochemical compounds were detected in the alcohol extracts. A comparison of the relative levels of compounds in cancer containing <it>vs</it>. non-cancer containing biopsies showed differences for 83 of the compounds. A comparison of the results with prior published reports showed good agreement between the current method and prior reported biomarker discovery methods that involve tissue destructive methods.</p> <p>Conclusions</p> <p>The Molecular Preservation by Extraction and Fixation (mPREF) method allows for the analysis of small molecule biomarkers from exactly the same tissue that is processed for histopathology.</p