Tumor-derived miR-378a-3p-containing extracellular vesicles promote osteolysis by activating the Dyrk1a/Nfatc1/Angptl2 axis for bone metastasis

Yu-Xiang Fang,Wei-Qiang Gao,Wei Xue,Nan Jing,Baijun Dong,Xiao Wang,Huixiang Xiao,Xinxing Du,Jialin Wang

doi:10.1016/j.canlet.2021.11.017

Abstract

Most prostate cancer (PCa)-related deaths are caused by progression to bone metastasis. Recently, the importance of extracellular vesicles (EVs) in pre-metastatic niche formation has been reported. However, whether and how tumor-derived EVs interact with bone marrow macrophages (BMMs) to release EV-delivered microRNAs to promote osteolysis and induce pre-metastatic niche formation for PCa bone metastasis remain unclear. Our in vitro and in vivo functional and mechanistic assays revealed that EV-mediated release of miR-378a-3p from tumor cells was upregulated in bone-metastatic PCa, maintaining low intracellular miR-378a-3p concentration to promote proliferation and MAOA-mediated epithelial-to-mesenchymal transition. Moreover, miR-378a-3p enrichment in tumor-derived EVs was induced by hnRNPA2B1 (a transfer chaperone) overexpression. After tumor-derived EVs were taken in by BMMs, enriched miR-378a-3p promoted osteolytic progression by inhibiting Dyrk1a to improve Nfatc1 (an osteolysis-related transcription factor) nuclear translocation, to activate the expression of downstream target gene Angptl2. As a feedback, increased Angptl2 secretion into the tumor environment promoted PCa progression. In conclusion, tumor-derived miR-378a-3p-containing EVs play a significant role in PCa bone metastasis by activating the Dyrk1a/Nfatc1/Angptl2 axis in BMMs to induce osteolytic progression, making miR-378a-3p a potential predictor of metastatic PCa. Reducing the release of miR-378a-3p-containing EVs or inhibiting the recruitment of miR-378a-3p into EVs can be a therapeutic strategy against PCa metastasis.

Highlights

The majority of the deaths of prostate cancer (PCa) are caused by progression to bone metastatic PCa
We found that extracellular vesicles (EVs)-mediated release of miR-378a-3p from tumor cells was upregulated in bone-metastatic PCa which keeps a low intracellular concentration of miR-378a-3p, to promote proliferation and the MAOA-mediated epithelial-to-mesenchymal transition (EMT) in PCa cells
Our findings indicate that tumor-derived miR-378a-3p-containing EVs play a significant role in promoting prostate cancer bone metastasis by activating a Dyrk1a/Nfatc1/Angptl2 axis in bone marrow macrophages (BMMs) to induce osteolytic progression, which implicates that miR-378a-3p may be a potential predictor of metastatic PCa

Summary

Methods

Bioinformatics and qRT-PCR analyses were used to screen microRNAs and to identify the elevated expression of miR-378a-3p in both serum-derived EVs from PCa patients and in culture medium-derived EVs from PCa cell lines. The human PCa cell lines PC3, DU145, C4-2B, LNCAP and the murine leukemic monocyte macrophage cell line RAW264.7 cells were purchased from the American Type Culture Collection (ATCC, Manassas, USA). PC3, DU145, C42-B, LNCAP and BPH1 cells were cultured in DMEM or RPMI-1640 medium (Thermo Fisher Scientific, MD, USA) containing 10% fetal bovine serum (FBS; Gibco). Wide type (WT) and mutant (MUT) sequences of putative microRNA-378a-3p target site(s) on 3’UTR of MAOA and Dyrk1a (named as MAOA-WT,MAOA-MUT, Dyrk1a-T1WT, Dyrk1a-T1MUT, Dyrk1aT2WT, Dyrk1a-T2MUT, Dyrk1a-T3WT, Dyrk1a-T3MUT, DYRK1A-T1WT, DYRK1A-T1MUT, DYRK1A-T2WT, DYRK1A -T2MUT, DYRK1A -T3WT, DYRK1A -T3MUT, DYRK1A-T4WT, DYRK1A-T4MUT, DYRK1A-T5WT, DYRK1A -T5MUT, DYRK1A -T6WT ,DYRK1A -T6MUT, DYRK1A -T7WT and DYRK1A -T7MUT, respectively) were synthesized (Sangon Biotech Comp, Shanghai, China) and inserted with the backbone respectively. Above-described gene sequences were listed in Additional file: Table S1

Results

Discussion

Conclusion