MicroRNAs in pathogenesis of breast cancer: Implications in diagnosis and treatment

Table 1 List of major oncogenic microRNAs in breast cancer

MiRNA	Known target mRNA	Function	Ref.
MiR-10b	HOXD10	Promotes cell proliferation, metastasis and angiogenesis	[108]
MiR-126	IGFBP2, MERTK, PITPNC1	Promotes angiogenesis	[18]
MiR-155	SOCS1, TP53INP1, FOXO3, RhoA	Promotes cell proliferation	[12,20,21,62]
MiR-21	PTEN, TPM1, PDCD4, Maspin	Promotes cell proliferation	[22-24,109]
MiR-375	RASD1	Epigenetic modification of tumor suppressor genes	[110,111]
MiR-221/222	TRPS1	Induce metastasis	[28,29,65]
MiR-373	CD-44	Induce metastasis	[14,26]
MiR-520c	CD-44	Induce metastasis	[14,26]
MiR-9	SOCS5, E-cadherin	Induce metastasis	[27,112,113]
MiR-632	DNAJB6	Induce metastasis	[30]
MiR-196b	HOXD10 (indirect)	Promotes angiogenesis	[15]
MiR-7	HOXB3	Epigenetic modification of tumor suppressor genes	[16]
MiR-218	HOXB3	Epigenetic modification of tumor suppressor genes	[16]
MiR-203	SOCS3	Promotes cell proliferation	[25]

HOXD10: Homeobox D10; IGFBP2: Insulin-like growth factor binding protein 2; MERTK: C-mer proto-oncogene tyrosine kinase; PITPNC1: Phosphatidylinositol transfer protein, cytoplasmic 1; SOCS1: Suppressor of cytokine signaling 1; TP53INP1: Tumor protein p53 inducible nuclear protein 1; FOXO3: Forkhead box O3; RhoA: Ras homolog family member A; PTEN: Phosphatase and tensin homolog; TPM1: Tropomyosin 1 (alpha); PDCD4: Programmed cell death 4; RASD1: Rat Sarcoma dexamethasone-induced 1; TRPS1: Trichorhinophalangeal syndrome 1; DNAJB6: DnaJ (Hsp40) homolog, subfamily B, member 6; HOXB3: Homeobox B3; MiRNA: MicroRNA.

Table 2 List of major tumor suppressor microRNAs in breast cancer

MiRNA	Known target mRNA	Function	Ref.
Let-7 family	RAS, HMGA2	Inhibit cell proliferation and mammosphere formation	[11,114]
MiR-125	HuR, HER2, ETS1, Cyclin J, MEGF9	Inhibit cell proliferation and invasion	[38,39,115,116]
MiR-205	ZEB1 and ZEB2	Reduces EMT and metastasis	[1,40]
MiR-200 family	ZEB1/2	Reduces EMT and metastasis	[117]
MiR-206	Cyclin D2	Inhibits Cyclin D2 in MCF-7 cells	[118]
MiR-34a	Bcl2, SIRT1	Inhibits migration, invasion and metastasis	[69]
MiR-335	SOX-4, TNC	Inhibits metastasis	[41,42]
MiR-342	HER2	Increases cell proliferation	[119]
MiR-15a/16	HER2	Increases cell proliferation	[68]
MiR-302	RAD52 and AKT1	Affects DNA repair	[78]
MiR-31	RhoA, ITGA5, RDX	Reduces invasion and metastasis	[44]
MiR-519c	HIF-1α	Inhibits angiogenesis	[45]

MiRNA: MicroRNAs; Let-7: Lethal-7; RAS: Rat Sarcoma; HMGA2: High mobility group AT-hook 2; HuR: ELAV like RNA binding protein 1; ETS1: V-ets avian erythroblastosis virus E26 oncogene homolog 1; MEGF9: Multiple EGF-like-domains 9; ZEB1/2: Zinc finger E-box binding homeobox 1/2; Bcl2: B-cell CLL/lymphoma 2; SIRT1: Sirtuin 1; SOX-4: SRY (sex determining region Y)-box 4; TNC: Tenascin C; HER2: Human epidermal growth factor receptor 2; RAD52: RAD52 homolog (S. cerevisiae); AKT1: V-akt murine thymoma viral oncogene homolog 1; RhoA: Ras homolog family member A; ITGA5: Integrin, alpha 5 (fibronectin receptor, alpha polypeptide); RDX: Radixin; HIF-1α: Hypoxia inducible factor 1, alpha subunit; EMT: Epithelial to mesenchymal transition.