Methylparaben Modulates the Relationship Between Autophagy and Apoptosis in Head and Neck Squamous Cell Carcinoma Lines

In light of the increasing incidence of head and neck cancer and the widespread occurrence of methylparabens (MeP) in the human environment, which mimic the action of endogenous estrogens, we investigated the effect of this compound on head and neck squamous cell carcinoma (HNSCC) cells. We took into account autophagy and apoptosis, as well as the ability of HNSCC cell lines FaDu and Detroit 562 to proliferate, and the effect of flavonoids on the determined parameters. The obtained results revealed that MeP inhibits autophagy, indicated by downregulation of autophagy-related proteins such as beclin-1, LC3β, and APG5 expression in both cancer cell lines. Moreover, MeP, by changing the expression of mitochondrial proteins Bcl-2 and Bax, may be responsible for the reduction of apoptosis and the increased proliferation of cancer cells associated with high expression of caspase-3. The applied flavonoids restored the values of the tested parameters to the level observed in cells not exposed to MeP. In conclusion, our studies have shown for the first time that MeP, in addition to well-documented exposure factors, may facilitate the development of HNSCCs. We suggest that the adverse effects of MeP can be reduced by the use of flavonoids, which may lead to the inhibition of HNSCC cells growth.