A Transcriptome Atlas of a Cross Section of a Multifocal Prostate Cancer

Understanding the heterogeneous molecular landscape of prostate cancer is fundamental to improve treatment of the disease. Here, we aim to provide a broad molecular view of a cross- section of a prostate organ. This study manifests several unique tumor gene expression subtypes, with adjacent stroma, occupying distinct and different anatomical regions. The interplay between multiple molecularly defined tumor gene expression factors and/or Gleason scoring and the corresponding tumor microenvironment was hereby studied in detail. We perform a molecular sub-categorization of the tumor microenvironment throughout the whole prostate, using three different molecular principles; (i) AR staining, since loss of stromal AR is directly proportional to the degree of differentiation (Gleason score), (ii) Masson staining for its role in marking reactive stroma, and (iii) spatial transcriptomics analysis. In particular, we performed a detailed analysis of spatial distribution in histologic sections at the invasive border of a tumor foci contrasting it to the tumor core. Here, we show spatially confined DEPDC1, CHN1 and CRISP3 upregulation at the invasive border with implications of signal transduction pathways such as; PTEN, TGF-beta Receptor Complex, NOTCH4, ERBB2, and VEGF signaling, some of which are druggable. Overall, our results show an unprecedented view of the molecular heterogeneity of a prostate cancer not evident by other means. Here, we reveal patient-specific gene expression hallmarks from low to aggressive cancer within the same cross section of a prostate.