Integrative analyses of key genes and regulatory elements in fluoride-affected osteosarcoma.

Osteosarcoma is one of the most malignant tumors in adolescents with severe outcomes while fluoride is one of the most abundant elements in the environment. Epidemiological evidence has elucidated the relationship between fluoride and osteosarcoma, but the molecular mechanisms are extremely complicated. Microarray profiles were downloaded from the Gene Expression Omnibus database to identify differentially expressed genes (DEGs) in the progression of fluoride-affected osteosarcoma. The functional enrichment analysis was performed, a protein-protein interaction network, a microRNA-messenger RNA (mRNA) and a transcription factors-mRNA regulatory network were constructed and performed using Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape. A total of 171 DEGs were identified. The functions and pathways of the DEGs were enriched in nucleolus, protein ubiquitination, protein binding, RNA transport, and the spliceosome. Eighteen hub genes were identified and functional analysis revealed that these genes are mainly enriched in protein binding, nucleoplasm, and ribosomal RNA processing. Survival analysis showed that the hub genes may be involved in the invasion or recurrence of osteosarcoma. In conclusion, the DEGs and hub genes with their regulatory elements identified in this study will help us understand the molecular mechanisms underlying fluoride-affected osteosarcoma and provide candidate targets for future research.