Objective: Surgery and radioactive iodine therapy are the main treatments for papillary thyroid carcinoma (PTC), and effective drugs are lacking. As a promising natural product, nobiletin (NOB) has a wealth of pharmacological activities like anti-tumor, antivirus, and other effects. In this research, bioinformatics methods and cellular assays were combined to explore how NOB inhibited PTC.
Materials and methods: Our NOB targets were derived from three databases, including the SwissTargetPrediction database, Traditional Chinese Medicine System Pharmacology Database, and the TargetNet server. Four databases were used to identify disease-related targets: GeneCards, PharmGkb, Online Mendelian Inheritance in Man, and DisGeNET. Finally, cross-targets of disease and drug were deemed as pharmacological targets, and they were used for GO and KEGG enrichment analysis. STRING and Cytoscape were applied for PPI Network and core Targets Ranking. Molecular docking analysis validated binding affinity values for NOB and core targets. By using cell proliferation and migration assays, NOB was assessed for its effects on PTC proliferation and migration phenotype. Western blot validated the downregulation of the PI3K/Akt pathway.
Results: (1) Preliminarily, 85 NOB targets were predicted for NOB intervention in PTC. (2) Our core target screening identified TNF, TP53, and EGFR, and our molecular docking results confirmed good binding between NOB and protein receptors. (3) NOB inhibited proliferation and migration of PTC cells. PI3K/AKT pathway target proteins were downregulated.
Conclusions: (1) Bioinformatics analyses revealed that NOB may inhibit PTC by regulating TNF, TP53, EGFR and PI3K/AKT signalling pathway. (2) As evidenced by cell experiments, there was an inhibition of proliferating and migrating PTCs by NOB via the PI3K/AKT signalling pathway.