High expression of COL1A1 exaggerates bone metastasis in estrogen receptor-positive (ER+) breast cancer and is potential to serve as a novel therapeutic target

Bone metastasis accounts for a frequent complication in advanced estrogen receptor-positive (ER+) breast cancer, with staggeringly high percentage up to 70%. However, our understanding of molecular mechanisms underlying bone metastasis remains insufficient. In our study, 216 differentially expressed genes (DEGs) related to bone metastasis in ER + breast cancer were screened out. Enrichment analysis showed that, DEGs were enriched in construction of tumor microenvironment, including extracellular matrix, cell adhesion molecules and blood vessel development. In-depth analysis was performed on 4 dominant overlapped genes to investigate their functional feasibility in immune regulation, prognosis and pharmacological application. The expression of COL1A1, COL1A2, COL3A1 and SPARC was elevated in bone metastasis evolution and potentially associated with poor prognosis, but with no statistical significance. Halofuginone targeted on COL1A1 was pharmacologically inhibit progress of bony metastasis. Our results indicated that, high expression of COL1A1, COL1A2, COL3A1 and SPARC could be served as biomarkers for bone metastasis screening, and halofuginone could be developed for new therapeutic option after further clinical investigation.