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Erngren, Ida
Publications (3 of 3) Show all publications
Erngren, I., Haglöf, J., Engskog, M. K., Nestor, M., Hedeland, M., Arvidsson, T. & Pettersson, C. (2019). Adduct formation in electrospray ionisation-mass spectrometry with hydrophilic interaction liquid chromatography is strongly affected by the inorganic ion concentration of the samples. Journal of Chromatography A, 1600, 174-182
Open this publication in new window or tab >>Adduct formation in electrospray ionisation-mass spectrometry with hydrophilic interaction liquid chromatography is strongly affected by the inorganic ion concentration of the samples
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2019 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1600, p. 174-182Article in journal (Refereed) Published
Abstract [en]

Hydrophilic interaction liquid chromatography (HILIC)/electrospray ionisation-mass spectrometry (ESI-MS) has gained interest for the analysis of polar analytes in bioanalytical applications in recent years. However, ESI-MS is prone to adduct formation of analytes. In contrast to reversed phase chromatography, small inorganic ions have retention in HILIC, i.e. analytes and inorganic ions may co-elute, which could influence the adduct formation. In the present paper, it was demonstrated that the co-elution of sodium ions or potassium ions and analytes in HILIC/ESI-MS affect the adduct formation and that different concentrations of sodium ions and potassium ions in biological samples could have an impact on the quantitative response of the respective adducts as well as the quantitative response of the protonated adduct. The co-elution also lead to cluster formation of analytes and sodium formate or potassium formate, causing extremely complicated spectra. In analytical applications using HILIC/ESI-MS where internal standards are rarely used or not properly matched, great care needs to be taken to ensure minimal variation of inorganic ion concentration between samples. Moreover, the use of alkali metal ion adducts as quantitative target ions in relative quantitative applications should be made with caution if proper internal standards are not used.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2019
Keywords
Adduct formation, Hydrophilic interaction liquid chromatography, Mass spectrometry, Screening, Metabolomics, Cluster formation
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-390383 (URN)10.1016/j.chroma.2019.04.049 (DOI)000472687800021 ()31047661 (PubMedID)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-12Bibliographically approved
Elmsjö, A., Haglöf, J., Engskog, M. K., Erngren, I., Nestor, M., Arvidsson, T. & Pettersson, C. (2018). Method selectivity evaluation using the co-feature ratio in LC/MS metabolomics: Comparison of HILIC stationary phase performance for the analysis of plasma, urine and cell extracts.. Journal of Chromatography A, 1568, 49-56
Open this publication in new window or tab >>Method selectivity evaluation using the co-feature ratio in LC/MS metabolomics: Comparison of HILIC stationary phase performance for the analysis of plasma, urine and cell extracts.
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2018 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1568, p. 49-56Article in journal (Refereed) Published
Abstract [en]

Evaluation of the chromatographic separation in metabolomics studies has primarily been done using preselected sets of standards or by counting the number of detected features. An alternative approach is to calculate each feature's co-feature ratio, which is a combined selectivity measurement for the separation (i.e. extent of co-elution) and the MS-signal (i.e. adduct formation and in-source fragmentation). The aim of this study was to demonstrate how the selectivity of different HILIC stationary phases can be evaluated using the co-feature ratio approach. The study was based on three sample types; plasma, urine and cell extracts. Samples were analyzed on an UHPLC-ESI-Q-ToF system using an amide, a bare silica and a sulfobetaine stationary phase. For each feature, a co-feature ratio was calculated and used for multivariate analysis of the selectivity differences between the three stationary phases. Unsupervised PCA models indicated that the co-feature ratios were highly dependent on type of stationary phase. For several metabolites a 15-30 fold difference in the co-feature ratio were observed between the stationary phases. Observed selectivity differences related primarily to the retention patterns of unwanted matrix components such as inorganic salts (detected as salt clusters), glycerophospholipids, and polyethylene glycols. These matrix components affected the signal intensity of co-eluting metabolites by interfering with the ionization efficiency and/or their adduct formation. Furthermore, the retention pattern of these matrix components had huge influence on the number of detected features. The co-feature ratio approach has successfully been applied for evaluation of the selectivity performance of three HILIC stationary phases. The co-feature ratio could therefore be used in metabolomics for developing selective methods fit for their purpose, thereby avoiding generic analytical approaches, which are often biased, as type and amount of interfering matrix components are metabolome dependent.

Keywords
Co-feature ratio (CFR), Hydrophilic interaction chromatography, Mass spectrometry, Metabolomics, Salt clusters
National Category
Analytical Chemistry Pharmaceutical Sciences
Identifiers
urn:nbn:se:uu:diva-364208 (URN)10.1016/j.chroma.2018.05.007 (DOI)000443669600006 ()29789170 (PubMedID)
Available from: 2018-10-24 Created: 2018-10-24 Last updated: 2018-10-29Bibliographically approved
Niklison-Chirou, M. V., Erngren, I., Engskog, M. K., Haglöf, J., Picard, D., Remke, M., . . . Marino, S. (2017). TAp73 is a marker of glutamine addiction in medulloblastoma. Genes & Development, 31(17), 1738-1753
Open this publication in new window or tab >>TAp73 is a marker of glutamine addiction in medulloblastoma
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2017 (English)In: Genes & Development, ISSN 0890-9369, E-ISSN 1549-5477, Vol. 31, no 17, p. 1738-1753Article in journal (Refereed) Published
Abstract [en]

Medulloblastoma is the most common solid primary brain tumor in children. Remarkable advancements in the understanding of the genetic and epigenetic basis of these tumors have informed their recent molecular classification. However, the genotype/phenotype correlation of the subgroups remains largely uncharacterized. In particular, the metabolic phenotype is of great interest because of its druggability, which could lead to the development of novel and more tailored therapies for a subset of medulloblastoma. p73 plays a critical role in a range of cellular metabolic processes. We show overexpression of p73 in a proportion of non-WNT medulloblastoma. In these tumors, p73 sustains cell growth and proliferation via regulation of glutamine metabolism. We validated our results in a xenograft model in which we observed an increase in survival time in mice on a glutamine restriction diet. Notably, glutamine starvation has a synergistic effect with cisplatin, a component of the current medulloblastoma chemotherapy. These findings raise the possibility that glutamine depletion can be used as an adjuvant treatment for p73-expressing medulloblastoma.

Place, publisher, year, edition, pages
COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT, 2017
Keywords
medulloblastoma, p73, glutamine, metabolomics
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-336829 (URN)10.1101/gad.302349.117 (DOI)000412275500004 ()28971956 (PubMedID)
Available from: 2017-12-20 Created: 2017-12-20 Last updated: 2017-12-20Bibliographically approved
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