Supplementary Materialsoncotarget-11-2702-s001. impressive depletion of lysophosphatidylcholine species LPC[16:0], LPC[18:2] and, in parallel, accumulation of major glycerophospholipid species PE-P[36:4], PC[32:1], PC[34:1] in neoplastic areas. This was confirmed by shotgun lipidomics of dissected healthy and tumor tissue sections. A combination of the negative (LPC[16:0]) and positive (PC[32:1], PC[34:1]) markers was also applicable to uncover tumorous character of a pre-operative biopsy. Furthermore, marker potential of lysophospholipids was supported by elevated expression levels of the lysophospholipid degrading enzyme lysophospholipase A1 (LYPLA1) in the tumor regions of paraffin-embedded HNSCC samples. Finally, experimental evidence of 3D cell spheroid tests showed that LPC[16:0] facilitates HNSCC invasion, implying that HNSCC progression may be dependent on lysophospholipid supply. Altogether, a series of novel proteins and lipid species were identified by IMS and IHC screening, which may serve as potential molecular markers for tumor diagnosis, prognosis, and may pave the way to better understand HNSCC pathophyisiology. mutations, chemokine receptors, methylation markers, interleukins, which are mostly related to a subgroup of cases and also fail to provide a basis for specific and sensitive tumor identification . Therefore, seeking molecular markers for early and precise diagnosis, reliable prediction of treatment results and recurrence rate remains a major goal in fighting HNSCC. In light of inter- and intratumor heterogeneity that often causes treatment resistance and tumor relapse, application of multiregion sequencing and imaging approaches should become a regular practice . For the same reasons, selection of marker signatures rather than single molecular targets has been suggested essential for precise diagnosis and prognosis . A large dataset of omics results is now available for different tumor types, where serum, saliva, blood or solid samples have been fingerprinted for disease-associated molecular changes . GSK2838232 Tumors are characterized with a set of molecular changes of the proteome as well as the lipidome and metabolome . GSK2838232 Receptor mutations or changes in protein expression levels and localization have long been in the focus of tumor marker discovery, and recently lipidomic and metabolomic patterns have been outlining a molecular signature that may be of diagnostic and prognostic value [7C9]. Rabbit polyclonal to RAB4A However, ensemble analytical approaches are not capable of providing accurate localization-dependent information, hence it is still little known about the intratumoral and stromal localization of molecules. This is a major obstacle for understanding the molecular function and marker potential of critical proteins, lipids and metabolites in cancer. Imaging mass spectrometry (IMS) enables a label-free and sensitive detection and visualization of individual proteins and lipids in their fresh-frozen native tissue context. MALDI IMS specifically, provides images of 50C100 m resolution for low molecular weight (LMW) proteins and lipids, where identity of each visualized molecule can be determined with the aid of omics or LC-MS techniques. Screening for tumor-associated LMW protein and lipid changes in HNSCC cells, here we determine S100A8, S100A9 and particular phospholipids to build up and lysophosphatidylcholine to become depleted in the tumor. Further we display how the lysophospholipid digesting LYPLA1 can be gathered in the tumor area of HNSCC tumors. Visualization of intratumoral heterogeneity factors to the need of multiregion evaluation and usage of multiple molecular markers for dependable decisions. Outcomes S100A8 and S100A9 build up in the tumor cells A tumor mass leading to destruction of the proper side from the larynx have been detected inside a 73-year-old individual, laryngoscopic biopsy exposed intrusive keratinizing squamous cell carcinoma. Radiology demonstrated GSK2838232 localized tumor without lymph node participation. Large plenty of to explore potential intratumoral heterogeneity, this HNSCC specimen was selected for in-depth testing (Shape 1). 15 m cryosections had been ready for pathological hematoxylin-eosin (H/E) staining and MALDI IMS (Shape 1), and the rest of the tissue was held frozen for even more analysis. Tumor portion of the specimen was designated predicated on morphological characterization from the H/E stained test (Shape 1A). Within an 80 m quality MALDI MS picture group of the 4C17 kDa selection of LMW proteins, S100A8 and S100A9 had been essentially undetectable in the healthful stromal regions of the specimen, while these were within the tumor and tumor.