Fig. 3.

The Rab22a-NeoF1 fusion protein in exosomes facilitates M2 polarization and induces lung metastasis. a Macrophages were incubated with exosomes, and the heatmap showed the differential expression profiles of the M2-like macrophage markers. b–d Mice were pre-treated with exosomes for 3 weeks and subsequently injected with sarcoma cells. The lung metastases were evaluated 3 weeks later. b n = 5 biologically independent mice. Data are mean ± s.d with P values. c Representative IVIS imaging. d H&E-stained lung sections. e The hypothesis of the function and mechanism of Rab22a-NeoF1 fusion protein in osteosarcoma. Rab22a-NeoF1 fusion protein activates the cellular RhoA by binding to SmgGDS607. The exosomal Rab22a-NeoF1 promotes RhoA activation by the exosomal PYK2 and facilitates the pulmonary pre-metastatic niche formation by promoting macrophage recruitment and by increasing M2 macrophages

(Reprinted with permission from Ref [14] Copyright © 2021, Li Zhong et al.)