Single-cell RNA sequencing reveals spatiotemporal heterogeneity and malignant progression in pancreatic neuroendocrine tumor

Abstract

Aims: Using Single-cell RNA sequencing (scRNA-seq), we explored the spatiotemporal heterogeneity of pancreatic neuroendocrine tumors (pNETs) and the underlying mechanism for malignant progression. Methods: scRNA-seq was conducted on three tumor tissues (two primary tissues from different sites, one liver metastatic lesion), one normal liver tissue, and peripheral blood mononuclear cells from one patient with a metastatic G2 pNET, followed by bioinformatics analysis and validation in a pNETs cohort. Results: The transcriptome data of 24.544 cells were obtained. We identified subpopulations of functional heterogeneity within malignant cells, immune cells, and fibroblasts. There were intra-and inter-heterogeneities of cell subpopulations for malignant cells, macrophages, T cells, and fibroblasts among all tumor sites. Cell trajectory analysis revealed several hallmarks of carcinogenesis, including the hypoxia pathway, metabolism reprogramming, and aggressive proliferation, which were activated at different stages of tumor progression. Evolutionary analysis based on mitochondrial mutations defined two dominant clones with metastatic capacity. Finally, we developed a gene signature (PCSK1 and SMOC1) defining the metastatic potential of the tumor and its prognostic value was validated in a cohort of thirty G1/G2 patients underwent surgical resection. Conclusions: Our scRNA-seq analysis revealed intra-and intertumor heterogeneities in cell populations, transcriptional states, and intercellular communications among primary and metastatic lesions of pNETs. The single-cell level characterization of the spatiotemporal dynamics of malignant cell progression provided new insights into the search for potential novel prognostic biomarkers of pNETs.

PIN1 As A Marker of Metastasis and Survival in Pancreatic Neuroendocrine Tumor Identified by Single-cell Sequencing and Proteomic Profiling

“…Pancreatic NETs have temporal heterogeneity, which refers to changes in a tumor's genetic variety over time, particularly while it is being treated (Lou, Qin, Xu, Yu, & Ji, 2022). scRNA-seq analysis revealed intra-and intertumor heterogeneities in cell populations, transcriptional states, and intercellular communications among primary and metastatic lesions of pNETs (Zhou et al, 2021). Nevertheless, the most important consideration is to nd the subgroup with high metastatic potential, screen its markers, and perform targeted treatment.…”

“…An original article published in GUT revealed the genomic intertumoral heterogeneity of PanNETs (Gill et al, 2019). Zhou Y et al described intra-and intertumor heterogeneities in PanNET cell populations by single-cell sequencing (Zhou et al, 2021). However, based on the heterogeneous characteristics of PanNETs, it is important to identify speci c subsets with high metastatic potential and to identify precise metastasis markers for guiding clinical work.…”

The Landscape and Clinical Application of the Tumor Microenvironment in Gastroenteropancreatic Neuroendocrine Neoplasms

“…It is more abundant in the metastatic foci in the liver than in primary lesions for insulinomas [ 17 ]. Single-cell sequencing of a pancreatic NET (G2) from the same patient [ 18 ] showed that macrophages could be divided into five clusters that are different from the classic M1 and M2 clusters. Among these clusters, cluster one is mainly located in the primary site, clusters two and five only exist in liver metastases, while chemokine CCL13 is only expressed in cluster one, and SPP1 is only present in clusters two and five.…”

“…The single-cell RNA sequencing of pancreatic NET (G2) from the same patient revealed that fibroblasts could be roughly divided into inflammatory, antigen-presenting, and myofibroblastic cancer-associated fibroblasts, some of which include inflammatory subtypes that can secrete cellular senescence factors [ 18 ]. It also found that the TME of primary tumors contained more heterogeneous fibroblast clusters than those of liver metastases; however, there were also fibroblasts specific to liver metastases [ 18 ]. The crosstalk between NEN cells and fibroblasts induces excessive fibrosis, and the most common example of fibrosis is mesenteric fibrosis.…”

UBE2C promotes the progression of pancreatic cancer and glycolytic activity via EGFR stabilization-mediated PI3K-Akt pathway activation

“…Despite significant advances in the understanding and treatment of many cancers, pancreatic cancer (PC) remains one of the deadliest and most difficult forms of cancer to manage. Approximately 20% of newly diagnosed PC cases worldwide arise in China (1,2). The primary approaches to treating PC include surgical resection and chemotherapy (3), but the emergence of chemoresistance represents a major barrier to effective patient treatment.…”