Single-Cell RNA Sequencing Reveals the Migration of Osteoclasts in Giant Cell Tumor of Bone.

Wenyu Feng,Zhaojie Qin,Yun Liu,Shijie Liao,Qingjun Wei,Jiake Xu,Tianyu Xie,Juliang He,Chengsen Lin,Xiaohong Jiang,Qian Huang,Jie Ma,Huijiang Liu,Mingwei He

doi:10.3389/fonc.2021.715552

Abstract

Giant cell tumor of bone (GCTB) is benign tumor that can cause significant osteolysis and bone destruction at the epiphysis of long bones. Osteoclasts are thought to be highly associated with osteolysis in GCTB. However, the migration of osteoclasts in GCTB remains unclear. A deeper understanding of the complex tumor microenvironment is required in order to delineate the migration of osteoclasts in GCTB. In this study, samples were isolated from one patient diagnosed with GCTB. Single-cell RNA sequencing (scRNA-seq) was used to detect the heterogeneity of GCTB. Multiplex immunofluorescence staining was used to evaluate the cell subtypes identified by scRNA-seq. A total of 8,033 cells were obtained from one patient diagnosed with GCTB, which were divided into eight major cell types as depicted by a single-cell transcriptional map. The osteoclasts were divided into three subsets, and their differentiation trajectory and migration status were further analyzed. Osteoclast migration may be regulated via a series of genes associated with cell migration. Furthermore, four signaling pathways (RANKL, PARs, CD137 and SMEA3 signaling pathway) were found to be highly associated with osteoclast migration. This comprehensive single-cell transcriptome analysis of GCTB identified a series of genes associated with cell migration as well as four major signaling pathways that were highly related to the migration of osteoclasts in GCTB. Our findings broaden the understanding of GCTB bionetworks and provides a theoretical basis for anti-osteolysis therapy against GCTB in the future.

Highlights

Giant cell tumor of bone (GCTB) is destructive osteolytic benign tumor that often affect the epiphysis of long bones and can lead to severe motor dysfunction [1]
The dissociated cells were stained with trypan blue (0.4%; cat. no. 420301; Thermo Fisher) to calculate cell viability and diluted with Dulbecco’s phosphate-buffered saline (DPBS) containing 1% fetal bovine serum (FBS; cat. no. 10091148; Thermo Fisher) into appropriate concentrations for the step
GCTB Cellular Contribution scRNA-seq analysis was performed on samples obtained from a patient diagnosed with GCTB during tumor resection (Figure 1A)

Summary

Introduction

Giant cell tumor of bone (GCTB) is destructive osteolytic benign tumor that often affect the epiphysis of long bones and can lead to severe motor dysfunction [1]. GCTB usually occurs in young adults between the ages of 30 and 40 years [2]. The main pathologic feature of GCTB is severe osteolysis that is thought to be caused by osteoclasts, which are multinucleated cells derived from the monocyte/macrophage lineage [3]. Surgical resection is the main treatment for GCTB. The use of drugs designed to inhibit the function of osteoclasts, such as denosumab or zoledronic acid, can contribute to symptomatic relief but do not inhibit the development of GCTB [5]. An in-depth understanding of the mechanism behind osteoclast-mediated osteolysis by GCTB is of critical importance

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Results

Conclusion