LINC00852 Promotes Lung Adenocarcinoma Spinal Metastasis by Targeting S100A9

Background: Lung adenocarcinoma has a strong tendency to develop into bone metastases, especially spinal metastases (SM). Long noncoding RNAs (IncRNAs) play critical roles in regulating several biological processes in cancer cells. However, the mechanisms underlying the roles of IncRNAs in the development of SM have not been elucidated to date. Methods: Clinical specimens were collected for analysis of differentially expressed IncRNAs. The Kyoto Encyclopedia of Genes and Genomes (KEGG) was used to examine the effects of these genes on pathways. RNA pull-down was utilized to identify the targeting protein of IncRNAs. The effects of IncRNA on its target were detected in A549 and SPCA-1 cells via perturbation of the IncRNA expression. Oncological behavioral changes in transfected cells and phosphorylation of kinases in the relevant pathways, with or without inhibitors, were observed. Further, tumorigenicity was found to occur in experimental nude mice. Results: LINC00852 and the mitogen-activated protein kinase (MAPK) pathway were found to be associated with SM. Moreover, the LINC00852 target S100A9 had a positive regulatory role in the progression, migration, invasion, and metastasis of lung adenocarcinoma cells, both in vitro and in vivo. Furthermore, S100A9 strongly activated the P38 and REK1/2 kinases, and slightly activated the phosphorylation of the JNK kinase in the MAPK pathway in A549 and SPCA-1 cells. Conclusion: LINC00852 targets S100A9 to promote progression and oncogenic ability in lung adenocarcinoma SM through activation of the MAPK pathway. These findings suggest a potential novel target for early intervention against SM in lung cancer.