Background
To better understand the complexities of the tumor microenvironment (TME), high-resolution imaging at subcellular 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-plexantibody panel, coverslip mounted with ArgoFluor™ Mounting Medium and cured overnight. Whole slides were imaged at 20Xusing the Orion™ spatial biology platform.
Results
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 revealedautofluorescent hepatocytes obliterating the sinusoids with some hepatocytes dividing, an extensivecapillary network, and red bloods cells highlighted in the autofluorescent channel. In CRC liver metastasis sample, hepatocytes were surrounded by T cells, neoplastic glands (PanCK), andCD163+FOLR2+macrophages.The majority of metastatic epithelial cancer cells were observed to be proliferating.
Conclusions
We were able to observe precise differences in tissue architecture of liver samples from three divergent sources. Specifically, 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.