Heterogeneity characterization and therapeutic marker discovery of endometrial carcinoma using GeoMXT™ digital...

This study aimed to explore the intra- and inter-tumoral heterogeneity, gene expression profiles, tumor microenvironment (TME) alterations and the potential of therapeutic marker discovery in endometrial cancer (EC).

Digital spatial profiling (DSP) technology was used to quantify transcript abundance in distinct spatial regions of EC tissues from 4 patients. The differences among the regions were explored using bioinformatics analysis, and the mechanisms contributing to these differences were preliminarily explored using in vitro experiments.

We focused on 23 regions of interest (ROI), including 8 from normal cells, 10 from tumor cells (TC), 1 from stroma adjacent to normal cells and 4 from regions that encompassed the former three types of cells. Gene set variation analysis with 8 gene sets associated with EC revealed significant heterogeneity both within and between tumors. We estimated the abundance of immune cells in each region and found that significant disparities were observed in both the abundance and proportional representation of immune cells across all 23 ROIs. ATF5, identified as a key transcription factor, and its functionally linked target genes STMN1, CENPF, and TROAP were significantly overexpressed in TC, which was confirmed by RT-qPCR and external database analyses. Correlation analysis combined with functional assays demonstrated that ATF5 directly activates STMN1 transcription by binding to its promoter. ATF5 or STMN1 knockdown induced G2/M arrest and suppressed proliferation. Importantly, STMN1 re-expression rescued the proliferative and clonogenic defects caused by ATF5 knockdown.

Our exploratory study provides preliminary evidence of significant intra- and inter-tumoral heterogeneity in the TME and signaling pathways in EC using DSP technology. Genes such as ATF5, STMN1, CENPF, and TROAP, particularly the ATF5-STMN1 axis as a potential oncogenic pathway, may contribute to this heterogeneity and warrant further investigation as potential biomarkers and therapeutic targets in larger validation cohorts.