PO-463 Multiparametric analysis of lung cancer tissue sections using imaging mass cytometry

Abstract

IntroductionA novel tool for multiparametric molecular pathology analysis of tissue sections is described. Imaging Mass Cytometry (IMC), a new mass spectrometer-based technology, provides visualisation and spatial distribution of up to 40 markers in a single tissue section with 1 µm resolution. IMC uses metal-tagged antibodies (mtAbs), a pulsed UV laser for ablating regions of interest, and a stream of inert gas to transfer material generated by the laser to the mass cytometer.1Material and methodsTissue microarray (TMA) of human lung cancer was stained according to IMC protocol2 using a mix of 23 mtAbs.The samples were inserted into the ablation chamber of the Hyperion Imaging System. CyTOF® Software v6.7 and MCD Viewer 1.0 were used for data acquisition and rendering of pseudo three-colour images. Quantification of selected markers was done with Definiens Tissue Studio® (DTS) software. Standard HPA protocol was used for immunohistochemical (IHC) staining.Results and discussionsIMC analysis of human lung cancer TMA stained with a panel of 23 mtAbs revealed that core morphology was consistent with anatomopathological tumour classification. Immune cell phenotype and spatial distribution assessed by IHC and IMC were equivalent.IMC generated data was used to quantitate PD-L1 marker expression. Percentages of cells expressing different levels of PD-L1 and average intensity of PD-L1 related signal were calculated for tumour and stroma regions of each core. In addition, PD-L1 corresponding signal intensity was calculated in cytoplasm and membrane compartments of marker-positive cells.ConclusionIMC technology is a powerful tool for multiparametric histopathological analysis. It allows researchers to simultaneously detect up to 40 markers with single-cell detection resolution equivalent to conventional IHC. Using DTS software we demonstrate quantitation of multiple markers in lung tumour sections probed with a panel of 23 mtAbs.ReferencesChang Q, Ornatsky OI, Siddiqui I, Loboda A, Baranov VI, Hedley DW. Imaging Mass Cytometry. Cytometry A 2017;91:160–169.Chang Q, Ornatsky O, Hedley D. Staining of frozen and formalin-fixed, paraffin-embedded tissues with metal-labeled antibodies for Imaging Mass Cytometry analysis. Curr Protoc Cytom, 2017;82(October):12.47.1–12.47.8.