Fig. 1

New subtypes of PCP cells and their spatial distributions were identified in calcified PCP tumor tissue via spatial transcriptome sequencing. A: Imaging features of calcified PCPs used for spatial transcriptome sequencing. The red arrow indicates calcification in the tumor on CT imaging. The yellow dotted box indicates the PCP tumor with its solid component and cystic cavity on MRI. The procedures of spatial transcriptome sequencing are shown in steps 1 to 3 (created in Biorender). www.biorender.com). B: HE staining of spatial transcriptomic regions of the PCP sample; the area within the dashed box is the gene capture region. The map of spatial location indicates the distribution of each cluster on the tissue. The locations of the seven clusters were determined according to the spatial distribution of marker genes for each cluster. Each spot in the figure is a single gene capture unit, and each spot in the tissue includes 1–10 cells. The number of spots in the tissue was 2957, the mean number of reads per spot was 97833, and the median number of genes per spot was 2496. The number of genes with at least one UMI count in any tissue-covered spot is 22000, which is the total number of detected genes. C: All the spots captured in the tumor specimen were divided into 7 clusters according to the expression of specific marker genes in each cluster. Cluster 0, Cluster 1, Cluster 3, and Cluster 4 specifically expressed CTNNB1, one of the classical marker genes for PCP, as well as the marker genes CDH1 and CDH3 for epithelial cells; therefore, these clusters were defined as PCP cells and named PCP-1, PCP-2, PCP-3, and PCP-4. Cluster 2 specifically expressed the T-cell marker genes NFAT5, NPIPB5 and FAM83B. Cluster 5 specifically expressed the fibroblast markers MGP and VIM. Cluster 6 specifically expressed the B-cell marker genes IGHG1 and IGKC. D: Spatial map for the cell clustering heatmap showing the marker gene expression level and specificity; a deeper red color indicates a higher expression level of the marker gene for that cluster. The spatial location of each cluster’s markergene is highly consistent with the spatial distribution of the clusters in a given tissue