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Assessment of the Molecular Expression and Structure of Gangliosides in Brain Metastasis of Lung Adenocarcinoma by an Advanced Approach Based on Fully Automated Chip-Nanoelectrospray Mass Spectrometry

Domenii publicaţii > Chimie + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: A.D. Zamfir, A.Serb, Z.VukeliC, C.Flangea, C.Schiopu,D.Marincic, S.Kalanj-Bognar, F.Capitan, E.Sisu

Editorial: JASMS, 22, p.2145-2159, 2011.

Rezumat:

Gangliosides (GGs), sialic acid-containing glycosphingolipids, are known to be involved in the
invasive/metastatic behavior of brain tumor cells. Development of modern methods for
determination of the variations in GG expression and structure during neoplastic cell transformation
is a priority in the field of biomedical analysis. In this context, we report here on the first
optimization and application of chip-based nanoelectrospray (NanoMate robot) mass spectrometry
(MS) for the investigation of gangliosides in a secondary brain tumor. In our work a native
GG mixture extracted and purified from brain metastasis of lung adenocarcinoma was screened
by NanoMate robot coupled to a quadrupole time-of-flight MS. A native GG mixture from an agematched
healthy brain tissue, sampled and analyzed under identical conditions, served as a
control. Comparative MS analysis demonstrated an evident dissimilarity in GG expression in the
two tissue types. Brain metastasis is characterized by many species having a reduced Nacetylneuraminic
acid (Neu5Ac) content, however, modified by fucosylation or O-acetylation
such as Fuc-GM4, Fuc-GM3, di-O-Ac-GM1, O-Ac-GM3. In contrast, healthy brain tissue is
dominated by longer structures exhibiting from mono- to hexasialylated sugar chains. Also,
significant differences in ceramide composition were discovered. By tandem MS using collisioninduced
dissociation at low energies, brain metastasis-associated GD3 (d18:1/18:0) species as
well as an uncommon Fuc-GM1 (d18:1/18:0) detected in the normal brain tissue could be
structurally characterized. The novel protocol was able to provide a reliable compositional and
structural characterization with high analysis pace and at a sensitivity situated in the fmol range.

Cuvinte cheie: Quadrupole time-of-flight tandem mass spectrometry, Chip-nanoelectrospray, Gangliosides, Lung adenocarcinoma, Brain metastasis