Chemoprevention of 4-NQO-Induced Oral Cancer by the Combination of Resveratrol and EGCG: In Vivo, In Silico and In Vitro Studies

Background: Squamous cell carcinoma of head and neck (SCCHN) is a devastating disease with high morbidity and mortality and the 6th most common cancer worldwide. The 5-year relative survival for advanced-stage disease is below 50%, stressing the need for chemoprevention. In the current study, we investigated the chemopreventive efficacy of the combination of resveratrol and epigallocatechin gallate (EGCG). Methods: We used the 4-Nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis model. C57BL/6 mice were exposed to drinking water containing 4-NQO for 10 weeks. From week 11, mice were treated with vehicle, resveratrol, EGCG and their combination until week 22. RNASeq, qPCR and in silico analysis were performed identifying differentially expressed genes and enriched pathways. Results: Resveratrol alone and in combination with EGCG significantly inhibited the number of visible lesions, whereas the number of microscopic lesions and lesion areas were significantly inhibited only by the combination. The expression of Ki-67 was also significantly inhibited in resveratrol and combination groups. Growth differentiation factor 15 (GDF15), Activation transcription factor 3 (ATF3) and several other genes associated with xenobiotic metabolism as significantly upregulated genes, with GDF15 being the most upregulated one. Furthermore, hallmarks of xenobiotic metabolism and several other anticancer pathways were enriched after treatment with resveratrol and the combination. Conclusions: Our data strongly demonstrate the chemopreventive potential of the combination of resveratrol and EGCG and pave the way for further clinical developments.