Characterization of GM-CSF and G-CSF expressing cell subtypes in the tumor microenvironment using the Paletrra™ multiplex immunofluorescence assay integrated with RNAscope™

Modulators of GM-CSF and G-CSF are being explored for cancer therapy, but deciding where to intervene means knowing which cells inside a tumor actually produce them; this AACR 2025 poster from NeoGenomics places both cytokines in their cell of origin across colon, lung, melanoma and prostate tumor microarrays by reading RNA and protein together in one FFPE section.

Presented by NeoGenomics.

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• Both cytokines were traced to their cell of origin across four tumor types in a single section. Tissue microarrays of untreated colon adenocarcinoma (64 cases), lung adenocarcinoma (64 cases), malignant melanoma (73 cases) and prostate adenocarcinoma (52 cases) were run through an integrated workflow pairing RNAscope in-situ hybridization for GM-CSF and G-CSF RNA with Paletrra multiplex immunofluorescence for immune, stromal and tumor protein markers on the same FFPE section.
• Prevalence was low across all 4 indications, and G-CSF was generally more prevalent than GM-CSF. Both cytokines were detected at fairly low overall prevalence in every tumor microarray evaluated, with colon and lung adenocarcinoma showing the highest prevalence of the two and melanoma and prostate lower, so neither cytokine behaves as uniformly abundant across indications.
• The two cytokines came from different cells, and GM-CSF’s T cell signal was predominantly CD4+ helper. G-CSF was expressed mostly by tumor cells and FAP+ fibroblasts, while GM-CSF came from T cells, fibroblasts and tumor; within the T cell compartment GM-CSF was predominantly in CD4+ T helper rather than CD8+ cytotoxic cells, and nearest-neighbour analysis of a single lung core and a single colon core placed T and dendritic cells beside GM-CSF+ T cells, and T cells and macrophages beside G-CSF+ tumor.