Gene Expression Profiles Associated with Mφ Spatial Aggregation for HCC

To validate that the aggregation pattern identifies a pro-tumoral Mφ subset in HCC, we have employed microarray expression profiling as a discovery platform to identify the molecular and functional implications of Mφ spatial distribution in HCC. Gene ontology (GO) and gene-set enrichment analyses (GSEA) revealed that tissues rich in aggregated Mφs significantly upregulated tissue remodeling pathways and “M2” Mφ-associated genes, while pro-inflammatory “M1” gene sets were more pronounced in HCCs with predominantly scattered Mφs. These results indicate that Mφ aggregation signifies a transition to a multifaceted, pro-tumoral phenotype, highlighting the intricate relationship between spatial distribution and function of Mφs in the tumor milieu. To elucidate the molecular and functional implications of Mφ spatial distribution in HCCs, RNA samples from 19 HCC tumors, classified based on Mφ spatial distributions as determined by IHC staining, were subjected to a gene expression microarray assay (Mφ-Agg, n = 3; Mφ-Sca, n = 16).