Dataset Information

Single-cell RNA-seq reveals the genesis and heterogeneity of tumor microenvironment in pancreatic undifferentiated carcinoma with osteoclast-like giant-cells

ABSTRACT:

Background

Undifferentiated carcinoma with osteoclast-like giant cells (OGCs) of pancreas (UCOGCP) is a rare subtype of pancreatic ductal adenocarcinoma (PDAC), which had poorly described histopathological and clinical features.

Methods

In this study, single-cell RNA sequencing (scRNA-seq) was used to profile the distinct tumor microenvironment of UCOGCP using samples obtained from one UCOGCP patient and three PDAC patients. Bioinformatic analysis was carried out and immunohistochemical (IHC) staining was used to support the findings of bioinformatic analysis. After quality control of the raw data, a total of 18,376 cells were obtained from these four samples for subsequent analysis. These cells were divided into ten main cell types following the Seurat analysis pipeline. Among them, the UCOGCP sample displayed distinct distribution patterns from the rest samples in the epithelial cell, myeloid cell, fibroblast, and endothelial cell clusters. Further analysis supported that the OGCs were generated from stem-cell-like mesenchymal epithelial cells (SMECs).

Results

Functional analysis showed that the OGCs cluster was enriched in antigen presentation, immune response, and stem cell differentiation. Gene markers such as LOX, SPERINE1, CD44, and TGFBI were highly expressed in this SMECs cluster which signified poor prognosis. Interestingly, in myeloid cell, fibroblasts, and endothelial cell clusters, UCOGCP contained higher percentage of these cells and unique subclusters, compared with the rest of PDAC samples.

Conclusions

Analysis of cell communication depicted that CD74 plays important roles in the formation of the microenvironment of UCOGCP. Our findings illustrated the genesis and function of OGCs, and the tumor microenvironment (TME) of UCOGCP, providing insights for prognosis and treatment strategy for this rare type of pancreatic cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01596-8.

SUBMITTER: Wang X

PROVIDER: S-EPMC9214989 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature

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Project description:Background and objectiveUndifferentiated carcinoma of the pancreas with osteoclast-like giant cells (UCOGC) is a rare variant of malignant pancreatic tumor. There is still no standardized treatment for this uncommon subtype, as surgical resection with lymphadenectomy is the only potentially curative treatment so far. In this paper, we describe the current knowledge of this very rare specific subtype of pancreatic cancer (PC) as a narrative review.MethodsFor this review, we did not specify the time range of studies referred to due to limited data availability. Our inclusion criteria comprised previous studies, which specifically focused on the rare UCOGC subtype of PC as a confirmed histopathology, either pure or present together with other subtypes. We disregarded the studies involving any other PC subtype but not UCOGC, including undifferentiated and anaplastic carcinomas without osteoclast-like giant cell components.Key content and findingsThe limited available data precludes a definitive assessment of the efficacy of both neoadjuvant and adjuvant chemotherapy in the treatment of UCOGC. Monoclonal antibody pembrolizumab has been proven to be effective in metastatic cases. Multiple cases demonstrate a better overall survival rate for patients with UCOGC only versus those having UCOGC as a component with a pancreatic ductal adenocarcinoma (PDAC) histopathological subtype. The same conclusion can be also drawn comparing the survival rate of patients having pure UCOGC versus UCOGC with associated PDAC. Programmed cell death ligand-1 expression has been shown to be an important determinant, which shortens the survival period of patients diagnosed with UCOGC.ConclusionsThe rarity of UCOGC limits data for clinical courses and treatment plans. We need more data to better understand the relationship between pathogenic mutations, histological subtypes, and prognosis in PC, including UCOGC. Understanding UCOGC's molecular, clinical, radiological, and pathological characteristics can lead to earlier, more accurate diagnoses and better management.

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