Análise multielementar usando microfluorescência de raios X em culturas 3D de células de neuroblastoma humano

Abstract

Neuroblastoma (NB) is a malignancy neoplasm in the nervous system that almost exclusively occurs during infancy and early childhood. NB is responsible for 8% to 10% of cases of cancer in children. More than 50% of the diagnosed cases have generalized metastatic disease at the time of diagnosis. Trace elements elements are extremely important in the functioning of cellular processes, incluiding metabolic reactions and gene expressions. The Micro X-ray fluorescence (microXRF) technique has been widely used in biological sample analysis because it is a non-destructive technique, does not produce thermal damage and allows the analysis of several elements simultaneously. The objectives of this study were to obtain the elemental composition and elemental concentration presents in human neuroblastoma (SH-SY5Y and SK-NBE (2)). In addition, determine the limits detection of the microXRF system and analyze the spatial distributions (bidimensional maps) of the elements presents in samples comparing the NB tumor lines. Cellular spheroids were grown from 96-well plate culture cell using DMEM culture medium supplemented with 10% SFB for 5 days incubation. The microXRF spectra were obtained through the M4 Tornado spectrometer (Bruker Nano GmbH), being possible to detect the following elements: P, S, K, Cl, Ca, Fe, Cu and Zn. From a certified sample it was possible to calculate the limit detection of the system. The limit detection of the system ranged from 0.8 µg.g⁻¹ (for copper and zinc) to 7.2 µg.g⁻¹ (for phosphorus). The bidimensional maps of the chemical elements obtained showed non-uniform distributions for all elements and spheroids analyzed. In addition, the results obtained through quantification showed that the values obtained for the elementary concentrations showed great dispersion due to the heterogeneity of the cellular spheroids. The results showed through the nonparametric Mann-Whitney test with a significance level of 5% that the cell lines present significant differences.