Exploration of inhibitory mechanisms of curcumin in lung cancer metastasis using a miRNA- transcription factor-target gene network

The present study was aimed to unravel the inhibitory mechanisms of curcumin for lung cancer metastasis via constructing a miRNA-transcription factor (TF)-target gene network. Differentially expressed miRNAs between human high-metastatic non-small cell lung cancer 95D cells treated with and without curcumin were identified using a TaqMan human miRNA array followed by real-time PCR, out of which, the top 6 miRNAs (miR-302b-3p, miR-335-5p, miR-338-3p, miR-34c-5p, miR-29c-3p and miR-34a-35p) with more verified target genes and TFs than other miRNAs as confirmed by a literature review were selected for further analysis. The miRecords database was utilized to predict the target genes of these 6 miRNAs, TFs of which were identified based on the TRANSFAC database. The findings of the above procedure were used to construct a miRNA-TF-target gene network, among which miR-34a-5p, miR-34c-5p and miR-302b-3p seemed to regulate CCND1, WNT1 and MYC to be involved in Wnt signaling pathway through the LEF1 transcription factor. Therefore, we suggest miR-34a-5p/miR-34c-5p/miR-302b-3p —LEF1—CCND1/WNT1/MYC axis may be a crucial mechanism in inhibition of lung cancer metastasis by curcumin.