Table 1.

Impact of microRNAs on cancer-derived metastatic phenotype.

miRNA	Study Type	Samples Number	Samples Type	Samples Sources	Detection Methodology	AUC	Sensitivity	Specificity	Potential as	Reference
Let-7b-5p, miR-122-5p, miR-146b-5p, miR-210-3p and miR-215-5p	Multi-phase validation	289 BC samples and 257 normal controls	Blood samples	Hospital of Nanjing Medical University.	exiqon miRNA qPCR	0.843	81.1%	NR	Diagnosis	Li et al. [58]
miR-9 and miR-34a	Case–control	31 tumour tissues, 31 adjacent non-tumour, and 20 healthy controls	Tissues	National Tumor Bank and Isfahan Cancer Research Center of Seyed-o-Shohada Hospital.	qRT-PCR	0.71 and 0.72	83.33% and 72%.	70.37% and 76%	Diagnosis	Orange and Motovali-Bashi [59]
miR-185-5p and miR-362-5p	Case–control	68 BC patients and 13 controls	Blood samples	Qilu Hospital of Shandong University.	qRT-PCR	0.957	92.65%	92.31%	Diagnosis	Zhang et al. [61]
miR-126-5p, miR-144-5p, miR-144-3p, miR-301a-3p, miR-126-3p, miR-101-3p, and miR-664b-5p	Clinical trial	21 patients with TNBC diagnosis and 21 healthy	Blood samples	Medical Faculty of the Friedrich-Alexander University Erlangen-Nürnberg.	qRT-PCR	0.814	83.8%	74.2%	Diagnosis	Kahraman et al. [62]
miR-1246 and miR-21	In vitro and Case–control	16 BC samples and 16 healthy samples	Exosomes from plasma	USA	Small RNA sequencing and qRT-PCR	0.73	NR	NR	Diagnosis	Hannafon et al. [63]
miR-1246 and miR-21	Meta-Analysis	11 reports	Peripheral blood samples	NR	ELISA and qRT-PCR	NR	NR	NR	Diagnosis and prognosis	Wang et al. [64]
miR-21 and miR-27a	Case–control	129 BC patients and 50 patients with benign breast lesions as control group	Fasting venous blood	Jinan People’s Hospital Afliated to Shandong First Medical University.	qPCR	0.737 and 0.771,	90.62%	74.00	Diagnosis	Li et al. [65]
Let-7b-5p, miR-106a-5p, miR-19a- 3p, miR-19b-3p, miR-20a-5p, miR-223-3p, miR-25-3p, miR-425-5p, miR- 451a, miR-92a-3p, miR-93-5p, and miR-16-5p	Four-phase validation study	216 BC patient samples and 214 normal control samples	Blood samples	Jiangsu Provincial People Hospital.	exiqon miRNA qPCR validated by qRT-PCR	0.941	0.872	0.893	Diagnosis	Zou et al. [66]
Bone metastasis
miR-19a	In vitro and in vivo	NR	BC tissue from bone-metastatic lesions and primary BC tissue	NR	Taqman PCR	NR	NR	NR	Promoting metastasis	Wu et al. [68]
miR-20a-5p	In vitro	NR	MCF-7 and MDA-MB-231 cell lines	NR	qRT-PCR	NR	NR	NR	Promoting migration and invasion	Guo et al. [69]
miR-16, miR-133a, and miR-223	In vitro and in vivo	NR	MDA-MB-231 cell line, bone, and tibia samples	NR	qRT-PCR	NR	NR	NR	Promoting osteoclast activities and bone destruction	Kitayama et al. [70]
miR-143	In vitro	15 patients	BC tissue, normal adjacent tissues, MDA-MB-231, MDA-MB-436, SK-BR3, CAMA-1, and normal MB 157 cell lines	Fudan University Shanghai Cancer Center.	qRT-PCR	NR	NR	NR	Tumour suppressor	Du et al. [71]
miR-30b-5p	Cohorts	20 localized tumours and 25 advanced disease	Liquid biopsies	Breast Cancer Clinic and Laboratory Medicine Department of the Portuguese Oncology Institute of Porto.	qRT-PCR	0.831	88.9%	66.7%	Progression biomarker	Estevão-Pereira et al. [72]
Lung metastasis
miR-138-5p	In vitro and in vivo	NR	Lung tissues	Chinese PLA General Hospital.	qRT-PCR	NR	NR	NR	Promotion of lung metastasis and progression	Xun et al. [73]
miR-934	Case–control and in vitro	50 pairs of frozen BC tissue, adjacent normal tissue, and 21 lymph node metastasis BC tissue samples	Lung metastatic tissue	Huai’an Maternity and Child Health Care Hospital.	qPCR	NR	NR	NR	Prognosis biomarker	Lu et al. [74]
miR-4731	Cn vitro and in vivo	50 patients	Tumour tissue, MDA-MB-436, MDA-MB-453, MCF-7, and MDA-MB-231 cell lines	Chongqing University Central Hospital.	qRT-PCR	NR	NR	NR	Inhibition of EMT transition	Lang et al. [75]
miR-18a	In vitro and in vivo	NR	Primary tumour and lung tissues	NR	qPCR	NR	NR	NR	Promotion of metastasis	Krutilina et al. [76]
Brain metastasis
miR-4428 and miR-4480	Case–control	51 samples brain metastasis and 28 samples without brain metastasis	Serum	National Cancer Center Hospital. Japan.	Microarray	0.779 and 0.781 respectively	82.4% and 76.5%	f 64.3% and 71.4%	Prediction of brain metastasis	Sato et al. [77]
miR-10b	Retrospective Case–control	20 samples with brain metastasis and ten samples without brain metastasis	Tumour tissue block	Department of Pathology, Karmanos Cancer Institute, Wayne State University.	qRT-PCR	NR	NR	NR	Biomarker of brain metastasis and a potential therapeutic target	Ahmad et al. [78]
miR-26b-5p and miR-101-3p	Pre-Clinical	NR	Brain metastatic tumours and primary tumours	NR	qRT-PCR	NR	NR	NR	Prognostic and therapeutic	Harati et al. [79]
miR-125a	Cohort	Cohort (I) 13 pairs of BC and adjacent normal breast tissues Cohort (II) Six BC brain metastasis (BCBM) tissues Cohort (III) 20 BC and 20 BCBM patients’ plasma samples, and Cohort (IV) 53 BCBM patients’ primary tumour tissues.	Tissues and plasma	Liaocheng People’s Hospital.	qRT-PCR	NR	NR	NR	Therapeutic target	Fu et al. [80]
MN-anti-miR10b	In vitro and in vivo	NR	NR	NR	Bioluminescence and microscopy	NR	NR	NR	Treatment in brain metastasis	Yoo et al. [81]
miR-141	In vitro and in vivo	10–15 mice per group	Brain metastasis tissues	NR	RT-PCR and fluorescence methods	NR	NR	NR	Biomarker and therapeutic target of brain metastasis	Debeb et al. [82]
Liver metastasis
miR-93	In vitro and in vivo	NR	Liver tissue, MDA-MB-231, T-47D, MCF7, and HEK293 cells	NR	qRT-PCR	NR	NR	NR	Metastasis suppressor	Shibuya et al. [83]

NR = Information not reported in the article.