title: A micro-Raman spectroscopic investigation of leukemic U-937 cells in aged cultures.
abstract: Recently it has been shown that micro-Raman spectroscopy combined with multivariate analysis is able to discriminate among different types of tissues and tumoral cells by the detection of significant alterations and/or reorganizations of complex biological molecules, such as nucleic acids, lipids and proteins. Moreover, its use, being in principle a non-invasive technique, appears an interesting clinical tool for the evaluation of the therapeutical effects and of the disease progression. In this work we analyzed molecular changes in aged cultures of leukemia model U937 cells with respect to fresh cultures of the same cell line. In fact, structural variations of individual neoplastic cells on aging may lead to a heterogeneous data set, therefore falsifying confidence intervals, increasing error levels of analysis and consequently limiting the use of Raman spectroscopy analysis. We found that the observed morphological changes of U937 cells corresponded to well defined modifications of the Raman contributions in selected spectral regions, where markers of specific functional groups, useful to characterize the cell state, are present. A detailed subcellular analysis showed a change in cellular organization as a function of time, and correlated to a significant increase of apoptosis levels. Besides the aforementioned study, Raman spectra were used as input for principal component analysis (PCA) in order to detect and classify spectral changes among U937 cells.
authors.affiliation: Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.
authors.forename: Enza
authors.initials: E
authors.lastname: Fazio
authors.affiliation: CNR-IPCF Istituto per i Processi Chimico-Fisici, Viale F. Stagno d'Alcontres 37, 98158 Messina, Italy.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Trusso
authors.affiliation: Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy. Electronic address: dfranco@unime.it.
authors.forename: Domenico
authors.initials: D
authors.lastname: Franco
authors.affiliation: Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.
authors.forename: Marco Sebastiano
authors.initials: MS
authors.lastname: Nicolò
authors.affiliation: Dipartimento di Patologia Umana dell'adulto e dell'età Evolutiva "Gaetano Barresi", University of Messina, Via Consolare Valeria, 1, 98125 Messina, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Allegra
authors.affiliation: Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.
authors.forename: Fortunato
authors.initials: F
authors.lastname: Neri
authors.affiliation: Dipartimento di Patologia Umana dell'adulto e dell'età Evolutiva "Gaetano Barresi", University of Messina, Via Consolare Valeria, 1, 98125 Messina, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Musolino
authors.affiliation: Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.
authors.forename: Salvatore P P
authors.initials: SP
authors.lastname: Guglielmino
mesh_terms: D017209:Apoptosis; D006801:Humans; D007938:Leukemia / Q000378:metabolism / Q000473:pathology*; D015999:Multivariate Analysis; D025341:Principal Component Analysis; D013059:Spectrum Analysis, Raman / Q000379:methods*; D020298:U937 Cells
keywords: Micro-Raman technique; Multivariate data analysis; Single cells identification; U397 neoplastic cells