Investigating the Potential Use of Chemical Biopsy Devices to Characterize Brain Tumor Lipidomes

Abstract

The development of a fast and accurate intraoperative method that enables the differentiation and stratification of cancerous lesions is still a challenging problem in laboratory medicine. Therefore, it is important to find and optimize a simple and effective analytical method of enabling the selection of distinctive metabolites. This study aims to assess the usefulness of solid-phase microextraction (SPME) probes as a sampling method for the lipidomic analysis of brain tumors. To this end, SPME was applied to sample brain tumors immediately after excision, followed by lipidomic analysis via liquid chromatography-high resolution mass spectrometry (LC-HRMS). The results showed that long fibers were a good option for extracting analytes from an entire lesion to obtain an average lipidomic profile. Moreover, significant differences between tumors of different histological origin were observed. In-depth investigation of the glioma samples revealed that malignancy grade and isocitrate dehydrogenase (IDH) mutation status impact the lipidomic composition of the tumor, whereas 1p/19q co-deletion did not appear to alter the lipid profile. This first on-site lipidomic analysis of intact tumors proved that chemical biopsy with SPME is a promising tool for the simple and fast extraction of lipid markers in neurooncology.

Monitoring of age- and gender-related alterations of endocannabinoid levels in selected brain regions with the use of SPME probes

“…1 , a mixture of MetOH/IPA (50:50, v/v ) and also a mixture of MetOH/IPA (25/75, v/v ) with addition of ammonium acetate and acidic acid presented the best recoveries among evaluated solvents for each analyte. Ultimately, a mixture MetOH/IPA (50:50, v/v ) was selected for further analysis on ECs, which is in agreement with previous observations during the analysis of 2-AG and AEA analyzed in plasma samples (Acquaro Junior et al, 2019 ), and this mixture is also the most feasible during untargeted lipidomics studies (Bogusiewicz et al, 2021 , 2022 ). In addition, the use of MetOH/IPA (50:50, v/v) mixture provided a carryover values lower than 2% for all compounds, which indicated that majority of extracted analytes were desorbed into the selected desorption mixture.…”

Coated Blade Spray-Mass Spectrometry as a New Approach for the Rapid Characterization of Brain Tumors

“…Although the relative concentration obtained from the intact tissue corresponded to the concentration measured in the homogenate (calculated based on the standard addition method), several issues should be discussed prior to further attempts to develop the calibration strategy to determine endogenous compounds in cancer tissue with CBS-MS. First, since brain tumors are characterized by high heterogeneity, the homogenization of a small section may only result in the selection of a portion of the tumor’s phenotype [ 22 ]. Conversely, SPME probes enable the extraction of analytes along the sorbent from various parts of the tumor [ 30 ]. Second, the CBS-MS device has a bigger extraction surface than SPME fibers, which means that it can be influenced more easily by the composition of a changed region (e.g., the calcified part of the tumor where extraction is altered at a specific part of the blade).…”

Acylcarnitine Profiling in Meningiomas with Different NF2 Mutation Status

“…Then, the fibers were desorbed into 150µl of isopropanol: methanol (1:1 v/v) solution using silanized inserts. Desorption was conducted for 1 hour under agitation at 850 rpm [12]. Pooled quality control (QC) and extraction blanks were also prepared [12].…”

“…Desorption was conducted for 1 hour under agitation at 850 rpm [12]. Pooled quality control (QC) and extraction blanks were also prepared [12].…”