Table 1.

miRNAs involved in EMT and metastasis of prostate cancer.

miRNA	Expression in PCa	Function	Targets and Signaling Pathways	References
miR-9	Up-regulated in PCa tissue	promotes invasion and migration, increases spontaneous metastasis in vivo	E-cadherin	[44]
miR-21	Up-regulated in PCa tissue [45]	promoting invasion and migration in vitro, and xenograft tumor growth	PTEN, RECK. PDCD4, BCL-2, EGFR, KLF5	[45,46,47,48,49]
	Down-regulated in PCa tissue, serum, plasma, urine [46,47]
miR-33a-5p	Down-regulated in bone metastatic PCa tissue and bone-derived cells (vs. non-metastatic PCa tissue)	inhibits EMT, migration and invasion and suppresses bone metastasis in vivo	Inactivation of TGF-β signalling via directly targeting transforming growth factor beta receptor 1 (TGFBRI)	[50]
miR-34 family	Down-regulated in PCa tissue	inhibits migration, invasion and increases metastatic potential in vivo	Repressing of CD44 and deactivation of WNT/β-catenin, JAK/STAT3, PI3K/AKT (miR34a)	[51,52,53,54]
			Targeting oncoprotein STMN1 through the CtBP1\miR-34a\STMN1\GDF15 axis (miR-34a)
			Targeting TGF-β-pathway via phosphorylation of SMAD3 (miR-34b)
miR-132 and miR-212	Down-regulated in PCa tissue	inhibits EMT, invasion and migration	Deactivation of TGF-β signaling via SOX4	[55]
miR-145	Down-regulated in PCa tissue and serum (CRPC)	inhibits invasion, migration and arrests cell cycle	Inhibition of c-Myc via targeting hEF1 and KLF4	[56,57,58,59,60]
	Up-regulated in urine (Xu et al., 2017)		Inhibition of MTDH
miR-141-3p	Down-regulated in bone metastatic PCa tissue	suppresses EMT, invasion and migration and dissemination of tumor cells	Deactivation of NF-κB signaling by targeting TRAF5 and TRAF6	[61]
miR-181a	Up-regulated in metastatic PCa vs. localized PCa tissue and serum (bone metastatic PCa)	promotes migration, invasion and EMT	SMAD2/3 activation by targeting TGIF2	[62,63]
miR-186	Up-regulated in PCa tissue, PCa xenograft, and serum(186-5p) [64,65]	enhances colony formation, 3D culture growth, vasculogenic mimicry (VM) formation capacity, invasion, and EMT	Twist1, membrane cofactor protein CD46	[64,65]
	Down-regulated in primary and metastatic PCa tissue, PCa cell lines vs. control [66,67]		YY1 and CDK6	[66,67]
miR-200 family	Down-regulated in TMPRSS2: ERG-fusion pos. PCa (miR-200c) and in bone metastatic PCa tissue (vs. localized PCa) (143-3p) [68]	inhibits migration, angiogenesis, cell adhesion and EMT	SNAI2/SLUG, ZEB and deactivation of Notch, Wnt, and TGF-β signaling	[61,69,70,71]
			Deactivation of NF-κB signaling by targeting TRAF5 and 6 (143-3p)
miR-204-5p	Down-regulated in PCa tissue	suppresses invasion, migration, and dissemination of tumor cells	Deactivation of NF-κB signaling by targeting TRAF1, TAB3, and MAP3K3	[72]
miR-210-3p	Up-regulated in bone metastatic PCa tissue (vs. non-metastatic PCa)	enhances EMT, invasion and migration and bone metastasis in vivo	activation of NF-κB signaling via targeting TNIP1 and SOCS1	[73]
miR-454	Up-regulated in in PCa tissue and cell lines	promotes PCa cell proliferation and invasion	Promoting N-myc downstream-regulated gene 2 (NDRG2) and inhibition of WNT/β-catenin signaling	[74]
miR-532-3p	Down-regulated in PCa tissue with bone metastasis	inhibits invasion, migration, and dissemination of tumor cells	Deactivation of NF-κB signaling via targeting TRAF1, TRAF2, and TRAF4	[75]
mirR-335 and -543	Down-regulated in primary PCa tissue and bone metastasis	inhibits migration and invasion	Targeting endothelial nitric oxide synthase (eNOS)	[76]
miR-505-3p and miR-19a-3p	Down-regulated in PCa cell lines down	inhibits invasion and migration	Deactivation of TGF-β signaling via targeting SMAD2, and SMAD4	[77,78]
miR-671-5p	Up-regulated in metastatic and localized PCa tissue (vs. control)	promotes proliferation, migration, and invasion in vitro and in vivo	Targeting NFIA/CRYAB axis	[79]
miR-802	Down-regulated in PCa tissue	suppresses EMT, migration and invasion (in vitro) and delays xenograft tumor formation in vivo	Flotillin-2	[80]
miR-940	Down-regulated in PCa tissue	suppresses migration and invasion	Migration and invasion enhancer 1 (MIEN1)	[81,82,83]
	Up-regulated in serum (PCa vs. control) [81]	promotes osteogenic differentiation of human mesenchymal stem cells
miR-3622a	Down-regulated in PCa tissue	inhibits EMT, progression, and dissemination of tumor cells in vitro and in vivo	ZEB1 and SNAI2	[84]

PTEN: phosphatase and tensin homolog, RECK: reversion-inducing cysteine-rich protein with Kazal motifs; PDCD4: programmed cell death protein 4, KLF: Krüppel-like factor, TRAF: tumor necrosis factor receptor-associated factor, NF-κB: nuclear factor κB, TGF-β: transforming growth factor β; TGIF2: TGF-β-induced factor homeobox 2, NFIA: nuclear factor I A, CRYAB: Alpha-B crystallin; TNIP1: TNF-α induced protein 3 interacting protein 1, SOCS1: suppressor of cytokine signaling 1.