Using the Synergy between HPLC-MS and MALDI-MS Imaging to Explore the Lipidomics of Clear Cell Renal Cell Carcinoma

Abstract

Lipid imaging mass spectrometry (LIMS) has been tested in several pathological contexts, demonstrating its ability to segregate and isolate lipid signatures in complex tissues, thanks to the technique's spatial resolution. However, it cannot yet compete with the superior identification power of high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS), and therefore, very often, the latter is used to refine the assignment of the species detected by LIMS. Also, it is not clear if the differences in sensitivity and spatial resolution between the two techniques lead to a similar panel of biomarkers for a given disease. Here, we explore the capabilities of LIMS and HPLC-MS to produce a panel of lipid biomarkers to screen nephrectomy samples from 40 clear cell renal cell carcinoma patients. The same set of samples was explored by both techniques, and despite the important differences between them in terms of the number of detected and identified species (148 by LIMS and 344 by HPLC-MS in negative-ion mode) and the presence/absence of image capabilities, similar conclusions were reached: using the lipid fingerprint, it is possible to set up classifiers that correctly identify the samples as either healthy or tumor samples. The spatial resolution of LIMS enables extraction of additional information, such as the existence of necrotic areas or the existence of different tumor cell populations, but such information does not seem determinant for the correct classification of the samples, or it may be somehow compensated by the higher analytical power of HPLC-MS. Similar conclusions were reached with two very different techniques, validating their use for the discovery of lipid biomarkers.

Enhancing lipid production in plant cells through high-throughput genome editing and phenotyping via a scalable automated pipeline

“…This finding indicates that single protoplast MALDI-FTICR-MS facilitates accurate and efficient high-throughput lipid measurement on single plant cells, positioning it as a valuable alternative to the LC-MS/MS approach. Similar results on the comparability and concordance between LC-MS and MALDI have also been recently reported in human cells (Martín-Saiz et al 2023). Moreover, our single cell measurements and data processing have the capacity to segregate the engineered and unengineered cell types within the 43-OWD group, demonstrating that based on single-cell heterogeneity, we can estimate which protoplasts have been genetically engineered (Supplementary Figure S5E).…”

Quantitative mass spectrometry imaging: therapeutics & biomolecules

“…[155][156][157][158] A recent study by Martı ´n-Siaz and colleagues elegantly demonstrated the blending of MALDI-MSI and HPLC-MS to distinguish how well the two techniques correlate with one another in lipid biomarker discovery in clear cell renal cell carcinoma. 159 This study found that both MALDI-MSI and HPLC-MS experiments could spatially classify the lipid signature to distinct regions in the kidney, such as the cortex and medulla. A direct comparison of healthy vs. renal cell carcinoma was made using MALDI-MSI and quantification was conducted using internal standards with HPLC-MS analysis.…”

Recent Analytical Methodologies in Lipid Analysis

“…Thanks to the years of improvement in instrumentation and bioinformatics, MALDI-MSI was developed to a method capable of lipid classes and species identification and semi-quantification with no need to use chromatographic separation [76,85]; it is therefore considered as a universal tool for the study of lipids [76]. Evidence of the versatility of MALDI-MSI was recently proven by Martín-Saiz et al [86]. The authors used a combination of two independent methods, MALDI-MSI and HPLC-MS, for lipids screening in clear cell renal cell carcinoma patients.…”