Investigation of Inter- and Intratumoral Heterogeneity of Glioblastoma Using TOF-SIMS

Abstract

Glioblastoma (GBM) is one of the most aggressive human cancers with a median survival of less than two years. A distinguishing pathological feature of GBM is a high degree of inter- and intratumoral heterogeneity. Intertumoral heterogeneity of GBM has been extensively investigated on genomic, methylomic, transcriptomic, proteomic and metabolomics levels, however only a few studies describe intratumoral heterogeneity because of the lack of methods allowing to analyze GBM samples with high spatial resolution. Here, we applied TOF-SIMS (Time-of-flight secondary ion mass spectrometry) for the analysis of single cells and clinical samples such as paraffin and frozen tumor sections obtained from 57 patients. We developed a technique that allows us to simultaneously detect the distribution of proteins and metabolites in glioma tissue with 800 nm spatial resolution. Our results demonstrate that according to TOF-SIMS data glioma samples can be subdivided into clinically relevant groups and distinguished from the normal brain tissue. In addition, TOF-SIMS was able to elucidate differences between morphologically distinct regions of GBM within the same tumor. By staining GBM sections with gold-conjugated antibodies against Caveolin-1 we could visualize border between zones of necrotic and cellular tumor and subdivide glioma samples into groups characterized by different survival of the patients. Finally, we demonstrated that GBM contains cells that are characterized by high levels of Caveolin-1 protein and cholesterol. This population may partly represent a glioma stem cells. Collectively, our results show that the technique described here allows to analyze glioma tissues with a spatial resolution beyond reach of most of other omics approaches and the obtained data may be used to predict clinical behavior of the tumor.

Mapping cisplatin-induced viscosity alterations in cancer cells using molecular rotor and fluorescence lifetime imaging microscopy

“…The method has demonstrated applicability for lipidomic analysis for various cancer cells. [35][36][37] The aim of this work was to study cisplatin-induced changes in plasma membrane viscosity using FLIM with BODIPY-based molecular rotor in cancer cells in cell monolayer and multicellular spheroids and correlate them lipid profile, measured with ToF-SIMS, and responsiveness of cells to the treatment. The specific questions we addressed here are: (1) does cisplatin cause any changes in viscosity of cellular plasma membranes when used at therapeutically relevant concentrations; (2) how common are these effects for different cancer cell lines cultured as a monolayer and in multicellular structures; (3) are these changes associated with cell survival and/or cell death; and (4) if membrane lipid composition is the underlying reason for the observed changes in viscosity.…”

WITHDRAWN: Glioblastoma cell-derived extracellular vesicle miR-27a-3p facilitates M2 macrophage polarization

“…Glioblastoma is the most lethal type of glioma with aggressive brain tumors and often occurred in individuals older than 65 years [1,2]. Moreover, the median survival of glioblastoma is less than two years [3], which is in urgent need of novel treatment modalities.…”

Obtaining molecular imagings of pesticide residues on strawberry surfaces with probe sampling followed by ambient ionization mass spectrometric analysis

“…MSI's two most commonly used ionization methods are matrix-assisted laser desorption/ionization (MALDI) and secondary ionization mass spectrometry (SIMS). [6][7][8] SIMS can detect organic and inorganic compounds under a very high spatial resolution (sub-micrometer), but the masses of the detectable molecules or elements are relatively low, 9 whereas MALDI can detect large biological molecules and is the most commonly used ionization method for MSI but has a low spatial resolution (10-50 μm). MALDI-MSI is performed in microprobe mode in a vacuum, and thus, the signals of the molecules in each laser desorption spot are recorded individually.…”

“…Several AIMS methods have been used for MSI analysis, such as desorption electrospray ionization (DESI), [10][11][12][13] electrospray laser desorption ionization (ELDI), 1,2 probe electrospray ionization (PESI), 3 laser ablation electrospray ionization (LAESI), 4,5 and low-temperature plasma probe (LTP). 14 The differences in MSI analysis between AIMS and MALDI include (1) minimal or no sample pretreatment required for AIMS-MSI, with homogenous matrix deposition on tissue samples being necessary for MALDI-MSI, and…”