RNA isolation form MG63 cells in the control and experimental groups . Control cells were cultured under normal condition . Experimental cells were pretreated with { BIW8 } for 24 h. According to the manufacturer 's instructions , the total RNA of MG63 cells was extracted by using TRIzol ( Invitrogen , USA ) . RNA concentration and quality were determined with a NanoDrop Spectrophotometer . Microarray data were converted into recognizable format and annotated with software Genome Studio . The probes detected with p - value lower than 0.01 in at least one sample were accepted as significant and used for further analysis . The raw data were normalized using the quantile algorithm from the package limma of R. 1.13.1 Identification of differentially expressed genes ( DEGs ) . |Fold change| > 1.5 and adj . P < 0.05 were set as the cut - offs to screen out differentially expressed genes ( DEGs ) . 1.13.2 Heatmaps and volcano plots analysis . Clustered heatmaps and volcano plots of the control and experimental groups were generated using the package ggplot2 of R. 1.13.3 Enrichment analysis of DEGs . Functional enrichment analysis of DEGs was performed by DAVID ( The Database for Annotation , Visualization and Integrated Discovery ) to identify GO categories in by their biological processes ( BP ) , molecular functions ( MF ) , or cellular components ( CC ) . The DAVID database was also used to perform pathway enrichment analysis with reference from KEGG ( Kyoto Encyclopedia of Genes and Genomes ) pathways . False discovery rate ( FDR ) < 0.05 was used as the cut - off .