Spatial transcriptomics reveals molecular cues underlying the site specificity of the adult mouse oral mucosa and its stem cell niches.

The oral cavity is a multifunctional organ composed of structurally heterogeneous mucosal tissues that remain poorly characterized. Oral mucosal tissues are highly stratified and segmented along an epithelial-lamina propria axis. Here, we performed spatial transcriptomics (tomo-seq) on the tongue, cheeks, and palate of the adult mouse to understand the cues that maintain the oral mucosal sites.

Spatial transcriptomics reveals profound subclonal heterogeneity and T-cell dysfunction in extramedullary myeloma.

Extramedullary disease (EMD) is a high-risk feature of multiple myeloma (MM) and remains a poor prognostic factor, even in the era of novel immunotherapies. Here, we applied spatial transcriptomics (RNA tomography for spatially resolved transcriptomics [tomo-seq] [n = 2] and 10x Visium [n = 12]) and single-cell RNA sequencing (n = 3) to a set of 14 EMD biopsies to dissect the 3-dimensional architecture of tumor cells and their microenvironment. Overall, infiltrating immune and stromal cells showed both intrapatient and interpatient variations, with no uniform distribution over the lesion.

Tumor-Derived Lactic Acid Modulates Activation and Metabolic Status of Draining Lymph Node Stroma.

Communication between tumors and the stroma of tumor-draining lymph nodes (TDLN) exists before metastasis arises, altering the structure and function of the TDLN niche. Transcriptional profiling of fibroblastic reticular cells (FRC), the dominant stromal population of lymph nodes, has revealed that FRCs in TDLNs are reprogrammed. However, the tumor-derived factors driving the changes in FRCs remain to be identified.