Abstract 7635: Orion™: 14-plex clinical sample imaging of liver cancer modalities using one-step staining and imaging

Abstract Background To better understand the complexities of the tumor microenvironment (TME), high-resolution imaging at a sub-cellular resolution and high-plex is needed. These serve as a basis for biomarker quantification and more downstream, may provide the ability to predict patient outcome. Here, we investigate three whole slide liver sections: fetal liver, hepatocellular carcinoma (HCC), and colorectal cancer (CRC) liver metastasis. Methods 5-micron sections were cut and mounted on Superfrost Plus slides prior to de-paraffinization and antigen retrieval using the BioGenex EZ-Retriever system. Autofluorescence was quenched using UV and white light and blocked with Image-iT™ FX Signal Enhancer. Whole slides were stained with the 14-plex antibody panel, coverslip mounted with ArgoFluor™ Mounting Medium and cured overnight. Whole slides were imaged at 20X using the Orion™ spatial biology platform. Coverslips were removed in aqueous solution prior to H&E staining and scanning. Results Sample specific differences were observed, likely stemming from the different tissue sources. Data revealed a distinction between hepatocytes highlighted in the autofluorescence channel, sinusoids filled with proliferating progenitor cell and macrophages, and epithelial cells lining the border of the fetal liver forming the ductal plate surrounding the portal vein. Whereas in HCC, imaging revealed autofluorescent hepatocytes obliterating the sinusoids with some hepatocytes dividing, an extensive capillary network, and red bloods cells also highlighted in the auto fluorescent channel. T cells and macrophages showed clustering within the capillary networks and as expected, hepatocytes expressed high levels of Albumin. In the CRC liver metastasis sample, hepatocytes were shown to be surrounded by T cells, neoplastic glands (PanCK), and CD163+FOLR2+ macrophages. Furthermore, the majority of the metastatic epithelial cancer cells were observed to be proliferating. Conclusions We were able to observe precise differences in the tissue architecture of liver samples from three divergent sources. Specifically, the ability to identify distinct cell subtypes and their spatial co-localization may provide mechanistic insights into the spatial immune landscape and its role in disease progression and treatment outcome. This exemplifies the need for dissecting the spatial heterogeneity of the TME using a technology that offers a high-resolution subcellular snapshot in time; exhibiting the potential for Orion to bridge the gap from bench-to-bedside. Citation Format: Selena Larkin, Jennifer Currenti, Rhea Pai, Soumi Chatterjee, Archita Mishra, Jacob George, Brady Gardner, Ankur Sharma. Orion™: 14-plex clinical sample imaging of liver cancer modalities using one-step staining and imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7635.