Long non-coding RNA (lncRNA) is a new type of non-coding RNA that has an important regulatory influence on several human diseases, including cancer metastasis. HOX antisense intergenic RNA (HOTAIR), a newly discovered lncRNA, has an important effect on tumour proliferation, migration and metastasis. HOTAIR regulates cell proliferation, changes gene expression, and promotes tumour cell invasion and migration. However, its molecular mechanism of action remains unknown. The present review summarizes the molecular mechanism and role of HOTAIR in tumour invasion and metastasis, discusses the association between HOTAIR and tumour metastasis through different pathways, such as the transforming growth factor β, Wnt/β-catenin, PI3K/AKT/MAPK and vascular endothelial growth factor pathways, emphasizes the function of HOTAIR in human malignant tumour metastasis and provides a foundation for its application in the diagnosis, prognosis and medical treatment of various tumours.

Bone metastasis of lung cancer and detailed mechanisms are still elusive, and the roles of exosomes derived from lung adenocarcinoma cells in this process have attracted much attention. In this study, we found that lung adenocarcinoma cell-derived exosomes (LCC-Exos) promoted osteogenesis and bone resorption in vitro. Furthermore, LCC-Exos target bone in vivo and promoted bone resorption in vivo. Mechanistically, LCC-Exosomal miR-328 promoted bone resorption by targeting Nrp2 and LCC-ExosmiR-328 Inhibitors inhibited bone resorption in vivo. Thus, LCC-Exosomal miR-328 promote osteoclastogenesis by targeting Nrp2 and LCC-ExosmiR-328 Inhibitors may serve as a potential nanomedicine for the treatment of bone metastasis.