Table 4.

Prognostic non-coding RNA biomarkers for BCBM

Biomarker	Increased or decreased	Clinical samples	Potential molecular mechanism	Refs.
miRNA-19a (combined with IBSP)	Increased	23 serum samples from patients with ER-positive breast cancer and 22 samples from healthy individuals	IBSP recruits osteoclast precursor cells and enhances their uptake of exosomes containing miRNA-19a miRNA-19a promotes osteoclast differentiation	[98]
miRNA-30b-5p	Increased	82 samples of primary breast cancer tissue and 93 samples of metastatic breast cancer tissue 20 peripheral blood samples from patients with localized breast cancer and 25 samples from patients with advanced breast cancer	miRNA-30b-5p may be associated with EMT	[99]
miRNA-16,miRNA-378	Increased	21 serum samples from healthy women and 38 serum samples from breast cancer patients with bone metastasis	miRNA-16 and miRNA-378 enhance osteoclast function	[100–102]
miRNA-124	Decreased	79 paired samples of primary breast cancer lesions and non-tumor breast tissue adjacent to the cancer, as well as 34 samples of BCBM	miRNA-124 inhibits the survival and differentiation of osteoclast precursor cells and regulates the RANKL pathway. It also inhibits the proliferation and migration of breast cancer cells	[103–105]
miRNA-429	Decreased	21 bone metastasis samples, including 7 paired samples of bone metastasis and primary breast cancer	miRNA-429 promotes osteoblast differentiation and downregulates the expression of CrkL and MMP-9	[106]
LncRNA FGF14-AS2	Decreased	39 paired samples of breast cancer and non-tumor tissue adjacent to the cancer	LncRNA FGF14-AS2 inhibits breast cancer metastasis and suppresses the expression of RUNX2, thereby inhibiting osteoclast differentiation	[107, 108]

Multiple signatures are not included